The left and right ventricles of the four-chambered heart have distinct developmental origins and functions. Chamber-specific developmental programming underlies the differential gene expression of ion channel subunits regulating cardiac electrophysiology that persists into adulthood. Here, we discuss regional specific electrical responses to genetic mutations and cardiac stressors, their clinical correlations, and describe many of the multi-scale techniques commonly used to analyze electrophysiological regional heterogeneity. The evolution of species from the sea onto land required the ability to oxygenate blood in the lungs. Coincident with the need for a pulmonic circulation, the embryo developed a way of recruiting additional cells into the heart to form the second ventricle. While the left ventricle (LV) is derived from cells within the first heart field, the cells that ultimately form the mature right ventricle (RV) derive from a distinct progenitor population defined as the second heart field. It is well known that LV and RV cardiomyocytes have distinct transcriptional profiles during development, and that their transcriptional profiles become more similar in the adult heart . HoweverFirst and second heart field patterning is controlled by distinct transcriptional networks, with pathways, such as Hand1, predominantly active in the first heart field, while Hand2 and Wnt signaling play important functions during second heart field development ,4,5. Cha+ current density was observed in the RV [Hairy-related transcription factor 2  in the LV as expected, given that Hey2 is a direct Notch target. In contrast, unexpectedly, Notch activation in the RV downregulates Hey2 expression [Hey2 expression due to discordant chamber effects, and it was only after separating LV from RV that these chamber-specific effects were observed. This example underscores the idea that separately interrogating distinctly programmed regions, such as the LV and RV, may result in different insights. Interestingly, genome-wide association studies have implicated variants near several ion channels, as well as the 6q22.31 locus near HEY2 with Brugada syndrome (BrS) [Hey2 regulate chamber-specific ion channel gene expression may yield important translational insights.In addition to the importance of timing, regional developmental programming may result in distinct chamber-specific electrophysiological responses. To highlight one example, we performed single cell voltage clamp experiments on dissected left versus right ventricular tissue in Notch activated hearts and observed different electrical responses. While activation of Notch signaling prolongs the action potential duration (APD) and downregulates voltage-gated potassium currents in the LV, no change in APD or Kn the RV . These epression . Our inime (BrS) . BrS is It is well known that the LV and RV have distinct geometries and mechanical properties suited for either pumping blood against high systemic pressures to the body versus against lower pressures to the lungs. This concept is highlighted in a rare congenital cardiac malformation, congenitally corrected transposition of the great arteries (ccTGA), where both the atrioventricular and ventriculoarterial connections are discordant . In thisIn addition to properties that confer mechanical differences, unique transcriptional signatures of ion channel subunits confer distinct electrical functions to the LV and RV. This concept has emerged clinically with respect to genetic mutations specifically affecting one ventricle of the heart, despite all ventricular myocytes possessing the same genome. One disease that highlights differences between LV and RV cardiomyocytes is arrhythmogenic cardiomyopathy (ACM), a heritable condition predisposing to ventricular arrhythmias and sudden cardiac death. ACM was predominantly considered an RV-dominant disease, otherwise known as Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC), until about a decade ago. Two more subtypes of ACM, biventricular ACM and LV-dominant ACM, have been identified and studied in the last few years, however, ARVC is still considered the most dominant subtype . ARVC isCardiomyocytes are excitable cells due to the movement of ions across the cell membrane. This ionic movement causes changes in membrane voltage, resulting in the cardiac action potential (AP). Cardiomyocytes are electrically coupled to each other through gap junctions, which allow the AP of a single cell to electrically stimulate a neighboring cell and ultimately to propagate throughout the cardiac tissue. Distinct regional expression of ion channels leads to the LV AP waveform morphology being distinguishable from that of the RV, and even the AP morphologies within the same chamber differ depending on location within the chamber wall . These baseline differences in regional cardiac EP confer a unique susceptibility to arrhythmia predisposition in diseased states when ion channel function is affected.Arrhythmias develop when electrical impulse activation and/or propagation are disrupted. For instance, atrial fibrillation is an arrhythmia in which ectopic electrical foci or “triggers” originate near the pulmonary veins. Due to impairments in the left atrial electrical substrate, reentrant circuits continuously activate the atrial myocardium much faster than what occurs during sinus rhythm. The vulnerability of the atrium to fibrillate in response to ectopic foci is influenced by factors including tissue architecture, such as size of the left atrium and presence of fibrosis, as well as intrinsic properties of the cardiomyocytes affecting impulse propagation (sodium current and gap junction expression) and action potential duration . There am/dtmaxdV , AP amplitude, and APD at multiple stages of repolarization, can provide insight into which ionic currents may be altered in an experimental model. There are several types of single cell patch clamp configurations one can use  depending on the experimental question. In-depth descriptions of EP principles and an overview of the single cell patch clamp methods are available, and are outside the scope of this review [Regional EP heterogeneity can be measured by isolating cardiomyocytes from different chambers through tissue digestion with enzymes to break down the extracellular matrix and connective tissues, followed by micro-dissection. Using this technique, one can perform expression studies along with isolated patch clamp recording to characterize EP parameters, such as individual ionic currents and APs. Alterations to AP characteristics such as resting membrane potential, s review .HEY2, which affects the expression of subunits comprising the outward K+ current, Ito [Hey2+/− heterozygous knockout mice, Veerman et al. determined that loss of Hey2 differentially affects subepicardial cardiomyocytes, resulting in their EP properties becoming more like subendocardial cardiomyocytes [+ current, Ito,fast, which is normally differentially regulated across the chamber wall in non-failing human LV, is remodeled specifically in failing LV subepicardial cardiomyocytes leading to attenuation of the normal transmural gradient [Recent studies have further probed EP heterogeneity by isolating cardiomyocytes from different layers of the chamber walls, therefore allowing characterization of EP properties of subepicardial, midmyocardial, and subendocardial myocytes separately ,21. It hent, Ito . Using imyocytes . WithoutThe advantages of using isolated cardiomyocytes include the ability to analyze cells from all layers of the cardiac wall within the same animal. Furthermore, one can isolate cells from regions of the heart anatomically difficult to access using tissue preparations, such as pacemaker cells from the sinoatrial node (SAN) or Purkinje cells within the ventricle. Single-cell isolation is the primary technique used to study specific ionic currents in the heart, however, the enzymatic digestion is harsh on cell viability and can alter the cellular expression profile and/or partially digest transmembrane proteins altering ionic currents. Another disadvantage is loss of endogenous physical and electrical coupling with nearby cells, which ultimately influences cellular EP properties. To overcome this disadvantage, a novel technique, known as loose patch photolysis, was recently developed by the Escobar laboratory that enables ionic currents and kinetics to be measured in intact tissues . Sharp mRecently, there has been increasing interest in the use of organotypic slices as a model system for studying cardiac physiology. Unlike isolated cardiomyocytes, tissue architecture and electrical coupling with surrounding cells is maintained in cardiac slices, thereby allowing measurements of impulse propagation. Cardiac slices are typically between 100–400 μm, and given the diffusion limits of oxygen through tissue, slice viability can be maintained via superfusion, eliminating the need for vascular perfusion. Organotypic cardiac slices have been studied from small and large animals including mice, rats, guinea pigs, rabbits, dogs, and pigs, as well as from human heart biopsies and human hearts not suitable for transplantation ,24,25. MSimilar to the cardiac slice preparation, wedge preparations preserve the native tissue architecture with the advantage of traversing the entire thickness of the chamber, thereby accommodating studies which include arrhythmia inducibility. Major drawbacks include the need for a coronary artery for cannulation and perfusion of oxygenated physiologic solution, thereby limiting its use on atrial preparations and its use on small animals. In addition, while cardiac slices can be cultured for multiple days, a cardiac wedge is viable for hours, thus imposing time limitations on experiments.Langendorff-perfused whole hearts can be used to study cardiac physiology and arrhythmia susceptibility, and in some instances, provide the most relevant ex vivo model. Sick Sinus Syndrome (SSS), otherwise known as SAN dysfunction, is characterized by a slow heart rate, sinus pauses, and susceptibility to supraventricular tachycardia . Severalm/dtmaxdV of atrial cardiomyocytes is significantly slower after transient induction of Notch signaling, suggesting a functional impairment in Na+ current [Scn5a expression in the right atrial myocardium, and since mutations within Scn5a have been linked to familial SSS, this is a plausible mechanism for heart rate slowing after transient Notch activation [Like isolated cardiomyocyte recordings, sharp microelectrode intracellular recordings are used to probe the electrical activity at a single-cell level. However, sharp microelectrode recordings can be performed on intact tissue. The microelectrodes used are called “sharp” because they penetrate the cell membrane without significant damage to cellular function as the membrane quickly seals itself around the microelectrode. Sharp microelectrodes allow one to assess the EP characteristics of tissue slices, wedges, or intact hearts by impaling a single cell and measuring APs of that particular cell without subjecting the tissue to a digestion protocol. The AP characteristics mentioned previously that can be obtained when doing single cell patch clamping can also be measured using sharp microelectrodes on intact tissue. For example, as mentioned above, Qiao and Lipovsky et al. utilized sharp microelectrode intracellular recordings on Langendorff-perfused intact mouse hearts to demonstrate that the  current . Notch itivation . Additiotivation ,32. WhilWhile recording EP parameters from single cells provides key insights, optical mapping is a technique that can be used to assay EP parameters in cardiac slices, wedge preparations, and whole-organ level physiology. Using voltage-sensitive dyes and high-speed cameras, optical APs can be measured with high spatial and temporal resolution without the need for recording electrodes . In addiOptical mapping of genetically mutant mouse hearts has been used extensively to study regional-specific conduction abnormalities . For exaIn summary, optical mapping is a versatile technique that can be applied to the study of cardiac electrical activity at both the tissue and whole-organ level. The relative simplicity of the setup combined with the availability of open-source analysis software has increased the availability and favorability of this technique to laboratories outside of the traditional EP field. A main disadvantage of this technique is the inability to measure at multiple depths. Multi-photon microscopy has been recently used to measure electrical activity and calcium transients simultaneously at varying tissue depths in intact Langendorff-perfused hearts, allowing transmural EP differences to be studied with high spatial and temporal resolution ,37. Alth2+ transients and study conduction abnormalities in mice in vivo [Optical mapping utilizes cardiotoxic voltage-sensitive dyes which limits the ability to perform sequential experiments on a single sample ex vivo. Optogenetics combines the utility of optical electrophysiology with genetics and circumvents the use of cardiotoxic dyes, enabling electrophysiologic measurements in vivo through the use of genetically-encoded voltage indicators (GEVIs). GEVIs are proteins that can sense voltage changes and have been genetically engineered to express an indicator, such as fluorescence, in response to voltage changes. In addition to GEVIs, genetically encoded calcium indicators (GECIs), such as GCaMP2, have been developed and utilized to visualize Ca in vivo ,39. Opto in vivo ,41. This in vivo . Recentl in vivo ,44,45. HElectrocardiographic imaging (ECGI) is a non-invasive imaging procedure that can map electrical activity on the cardiac epicardial surface in humans. A multi-electrode vest records 250 body-surface electrocardiograms (ECGs), which can be combined with computed tomography (CT) or magnetic resonance imaging (MRI) to provide cardiac geometry. This technology can provide patient-specific activation maps and repolarization patterns of the epicardial surface and has been used to study hereditary arrhythmias such as Long QT syndrome (LQTS) and BrS, as well as acquired arrhythmias such as post-myocardial infarction ventricular tachycardia ,47,48,49Zhang et al. used ECGI to delineate the cardiac electrophysiological substrate underlying the BrS phenotype . BrS patIn summary, the evolution of technology and experimentation has revealed a greater appreciation of regional heterogeneity in the heart during health and disease. To fully understand the basis for regulation of cardiac electrophysiology, it is imperative to integrate concepts and techniques from diverse disciplines, including clinical cardiology, biomedical engineering, physiology, genomics, and developmental biology. Filling these gaps in our knowledge is challenging and requires us to understand several languages, but is nonetheless crucial to maximizing our collective understanding and to prevent potential new insights from being “lost in translation”.


Metagenomic approaches are now commonly used in microbial ecology to study microbial communities in more detail, including many strains that cannot be cultivated in the laboratory. Bioinformatic analyses make it possible to mine huge metagenomic datasets and discover general patterns that govern microbial ecosystems. However, the findings of typical metagenomic and bioinformatic analyses still do not completely describe the ecology and evolution of microbes in their environments. Most analyses still depend on straightforward sequence similarity searches against reference databases. We herein review the current state of metagenomics and bioinformatics in microbial ecology and discuss future directions for the field. New techniques will allow us to go beyond routine analyses and broaden our knowledge of microbial ecosystems. We need to enrich reference databases, promote platforms that enable meta- or comprehensive analyses of diverse metagenomic datasets, devise methods that utilize long-read sequence information, and develop more powerful bioinformatic methods to analyze data from diverse perspectives. Observations are key to science; for example, optical and electron microscopies are important methods of observation combined with various staining methods. Among recent observational technologies, high-throughput DNA sequencing technologies have rapidly produced vast amounts of genetic information at low cost, making available thousands of microbial genomes. These genome sequences provide a comprehensive catalog of the microbial genetic elements underlying diverse microbial physiology, and also assist in weaving a massive tapestry of microbial evolutionary histories , DNA cloning, and PCR have been used to detect specific members and/or functional genes in microbial communities . Since Several bioinformatic tools have been developed and popularized to analyze metagenomic and amplicon sequence data. Web servers, such as MG-RAST , IMG/M , EBI Mete.g., RefSeq  [Another information source that may improve the performance of metagenomic assembly is long-range contiguity. The recent development of methods to investigate long-range chromatin interactions (ure [5C]  and Hi-Cure [5C] ) may alsMicrobial genomes are affected by the environment during their evolution. Metabolic processes encoded in the genome, from biosynthesis to biodegradation, directly link microbial communities to the environment. Since most microbes are uncultivable, the direct estimation of community-scale metabolic pathways is also targeted by a metagenomic analysis. The most straightforward approach is to conduct sequence-similarity searches against pathway databases, such as KEGG , MetaCycOperon structures, which are unique to prokaryotic genomes, reflect the function of their encoded genes and need to be associated with microbial ecological strategies. Thus, if we observe systematic variations in the gene order (or gene cluster structures) due to gene losses, fusions, duplications, inversions, translocations, and HGTs from an analysis of metagenome data, these variations may provide important clues for linking microbial communities to the environment . Althougplasmidome analysis, is now being conducted to directly investigate environmental plasmids without culturing or cloning , there is no such gene for viral studies. An analysis of clustered regularly interspaced short palindromic repeats (CRISPRs) is a related emerging field because these repeats represent previous exposures to (or attacks from) viruses  of many datasets is expected to reveal general patterns or laws that determine how microbes interact with their environments and how their genomes have been shaped. It is important to note that different datasets have been constructed with different experimental methods and conditions.Abundant metagenomic datasets containing dozens of terabytes of sequence data are currently found in the Short Read Archive database at NCBI, and its content is increasing daily . WhereasRegarding global correlations between environments and microbial genomes, correlations involving genomic GC contents  and genode novo assembly of bacterial and viral genomes  and nanopore-based sequencers . Long reads are already contributing to many types of bioinformatic analyses, including the high-quality  genomes , 67 and  genomes . Long rei.e., less than 1 Gb in each SMART cell). This throughput is markedly smaller than that of the so-called massively parallel sequencers  and may be insufficient for describing taxonomically diverse microbial communities. In addition, the low accuracy of PacBio RS II reads (approximately 85%) may hinder a bioinformatic analysis, unless highly redundant sequencing  is performed to reach high accuracy in the ensemble. Along with the development of new bioinformatic methods, protocols also need to be optimized to avoid DNA fragmentation during extraction (Long-read metagenomics will be an emerging field, but there are still limitations to be considered. Although PacBio RS II with P6-C4 chemistry may generate reads with an average length of approximately 15 kb, less than 50,000 reads are generated per SMART cell (traction , 111.Metagenomic and bioinformatic approaches are already common in microbial ecology and have been used to investigate whole communities containing many types of uncultivable microbes . However


Human chorionic gonadotropin (hCG) is no longer a single, omnipotent ovulation triggering option. Gonadotropin releasing hormone (GnRH) agonist, initially presented as a substitute for hCG, has led to a new era of administering GnRH agonist followed by hCG triggering. According to this new concept, GnRH agonist enables successful ovum maturation, while hCG supports the luteal phase and pregnancy until placental shift. The physiological luteinizing hormone (LH) surge, well-known as the crucial step in ovum meiosis and maturation, as well as in maturation of its supporting cells, has been traditionally replaced by human chorionic gonadotropin (hCG) in artificial reproductive technologies (ART) cycles. The actual event of ovulation is far from simple and involves multiple cascades and processes ,2,3,4, mWe thoroughly understand that both LH and hCG bind to the same LH/hCG receptor (LHCGR), but this does not imply an identical response. The major structural difference between the two hormones is the sequence of the b-subunit and the critical difference is their pharmacokinetics; hence, clearance . hCG hasThe equivalence of human recombinant LH and human recombinant hCG has been studied thoroughly in terms of potency, kinetics and response . In vitrWe should also keep in mind that medicated cycles change the biological pattern, not only in terms of gonadotropins, but also in terms of the LHCGR. This receptor has a dynamic expression pattern throughout the cycle. It reaches maximum expression and effect in the mid-luteal phase and decreases with corpus luteum regression . In contFrom a clinical perspective, the most troubling issue arising from the use of hCG for final follicular maturation is ovarian hyperstimulation syndrome (OHSS), because of its prolonged clearance. hCG is considered fundamental in triggering OHSS due to its ability to up-regulate VEGF expression in luteinized granulosa cells . VEGF isIs hCG alone, without previous ovarian stimulation, sufficient to explain the pathophysiology of OHSS? This interesting concept was tested in unstimulated pregnancies with hCG concentrations above 150,000 IU/L. None of the patients developed spontaneous OHSS . The litIf indeed such distinctive intracellular events follow LHCGR activation by hCG compared to LH, and if hCG is closely related to the occurrence of OHSS, why is recombinant LH (rLH) not commonly used for final ovarian maturation? In a multicenter study, patients received either rhLH or u-hCG to achieve final follicular maturation . The rhLART medicine has entered a new era of zero tolerance to OHSS, otherwise termed an “OHSS free clinic” ,25. In tCan we explain why pregnancy rates are compromised after the use of GnRH agonist triggering? This is a surprising observation, since one would not expect endogenous LH and FSH surges to be so inferior to hCG triggering. It is even more puzzling when we consider that in non-suppressed in vivo cycles, circulating estrogen and progesterone levels were found sufficient  and almoThe use of GnRH agonist triggering has raised interest in a new concept: dual triggering, which combines both hCG and endogenous LH/FSH surges. The idea of combining hCG with GnRH agonist triggering was introduced in 2008 in an effort to reduce the increased pregnancy loss rate associated with GnRH agonist triggering . It was Does hCG have a role in triggering ovulation of small follicles that were traditionally considered “immature”? The concept of in vitro maturation (IVM) has provided surprisingly interesting and challenging information: hCG priming of follicles smaller than 10 mm in diameter resulted in similar MII oocyte yields compared to follicles larger than 10 mm . Some arUntil the last decade, hCG was an essential component of ART cycles. In the last few years, “the post-long protocol dominance era” has yielded a fascinating evolution of ovulation triggering modes. GnRH-ag triggering replaced hCG as a means of avoiding OHSS, and has further led the ART community into new horizons of egg maturation. In the current era, GnRH-ag triggering is being tested in combination with hCG as an option to achieve better results in special circumstances and/or populations. Combining hCG and GnRH-ag increases their advantages and is a promising area for future research. The new concept is dichotomous: GnRH-ag is the better option for egg maturation and hCG is superior for luteal phase support. Hopefully, future research will teach us the best combination and the ideal timing for this treatment method.


Wound matrix materials are used to improve the regeneration of dermal and epidermal layers in both acute and chronic wounds. Contemporary wound matrices are primarily composed of biologic materials such as processed xenogeneic and allogeneic tissues. Unfortunately, existing biologic wound matrices possess multiple limitations including poor longevity, durability, strength, and enzymatic resistance required for persistent support for new tissue formation. A fully-synthetic, resorbable electrospun material  that exhibits structural similarities to the native extracellular matrix offers a new approach to the treatment of acute and chronic wounds. This novel matrix is the first product to combine the advantages of synthetic construction  with the positive attributes of biologic materials (e.g. biomimetic architecture similar to human extracellular matrix (ECM), fibrous architecture optimized to support cellular migration and proliferation, engineered porosity to encourage tissue ingrowth and vascularization). These features allow RWM to achieve rapid and complete healing of full-thickness wounds that, in preclinical studies, is comparable to Integra Bilayer Wound Matrix , a gold standard biologic material with diverse clinical indications in the wound care. Together, this review suggests that the RWM offers a unique fully-synthetic alternative to existing biologic matrices that is effective, widely available, easy to store, simple to apply and low cost. The wound healing is a complex process involving the participation of multiple cell types in the reconstruction of functional tissue. Normal wound healing proceeds in four stages: hemostasis, inflammation, proliferation, and remodeling -3. AcuteCommon materials for healing chronic woundsThe engineered wound matrices have been developed to play an active role in healing chronic wounds -7. ConteFully synthetic materials as a solution to common material limitationsFully synthetic wound matrix materials can offer increased control of material and mechanical properties and avoid the risk of disease transmission, yet they commonly lack native tissue architecture and suitable biocompatibility profiles compared to biologic matrices. Synthetic materials include simple impervious dressings, such as Tegaderm  and Opsite  which serve as a temporary physical barrier to protect the wound from trauma, infection, and dehydration. Alternatively, Bio-A Wound Matrix  is a fibrous resorbable material composed of polyglycolic acid and trimethylene carbonate whose porous structure supports cellular infiltration, tissue ingrowth, and vascularization . Bio-A hComposite biologic and synthetic materials have also been used to create wound matrices that simultaneously support tissue ingrowth and act as a temporary epidermis for mechanical protection and exudate control. Transcyte , for example, incorporates neonatal fibroblasts in a nylon mesh, where the mesh provides support for tissue ingrowth while the fibroblasts produce new ECM as well as regenerative factors such as cytokines . NeonataOptimal specifications for wound matrix materialsExisting wound matrix materials do not offer a solution capable of meeting all demands for clinical use. As such, there is a continued need for new wound matrix materials that can further improve outcomes for wound healing. An ideal wound matrix should avoid dehydration, prevent infection, and elicit minimal inflammation . AdditioA novel synthetic nanofabricated scaffold: An introduction and reviewComposition and Characteristics OverviewA novel synthetic nanofabricated scaffold (Restrata Wound Matrix (RWM), Acera Surgical, St. Louis, Missouri) has been developed which is a sterile, single-use device intended for use in the local management of wounds. The RWM is a soft, white, conformable, non-friable, absorbable matrix that acts as a protective covering for wound defects, providing a moist environment for the body’s natural healing process to occur Figure . The RWMThe RWM is composed of two synthetic polymers, polyglactin 910 poly (lactic-co-glycolic acid) (PLGA) (10:90) and polydioxanone, which are approved by the Food and Drug Administration (FDA) and currently utilized in biomedical applications such as resorbable sutures. These polymers are co-spun into non-woven sheets that are roughly 0.5 mm thick. This wound matrix is fully resorbable, as polyglactin 910 and polydioxanone are naturally degraded by hydrolysis.Electrospinning creates a material that is soft and compliant, providing high conformability to wound surfaces, while being capable of withstanding clinician handling. Electrospun PLGA, for example, can obtain a tensile modulus of approximately 40-80 MPa, which mimics the tensile modulus of native skin . The RWMRestrata Wound Matrix Method of ActionThe architecture, surface topography, and structural scale of wound matrices have a significant effect on the biological activity of regenerative cell populations . The RWMRestrata Wound Matrix Exhibits Structural Attributes Similar to Native Extracellular Matrix ArchitectureThe RWM is constructed of a blend of electrospun synthetic nanofibers that are similar to the structure of native ECM Figure . In natiElectrospun Fibers Support Cellular Ingrowth, Differentiation and RetentionElectrospun fibers have been shown to support cellular ingrowth and migration critical to successful wound healing. Fibroblasts have been shown to proliferate and spread more rapidly and upregulate collagen expression on PLGA fibers 350-1100 nm in diameter, as compared to fibers of smaller or larger dimensions ,22. The Cell spreading and migration have also been influenced by the diameter of electrospun fibers. Synthetic fibers 350-1100 nm in diameter have been shown to affect the spreading, migration, and phenotype of adherent fibroblasts and mesenchymal stem cells (MSCs) ,22. The The Porosity of Electrospun Matrix Supports Cellular Infiltration and NeovascularizationThe RWM is comprised of an electrospun fiber matrix with engineered porosity suitable for both cellular ingrowth and neovascularization. Electrospun fibrous materials are capable of attaining an interconnected pore structure that is similar to natural tissue and permits cellular migration and tissue ingrowth as well as transport of oxygen, nutrients, and waste . The higFully-Synthetic Construction Offers Excellent BiocompatibilityThe synthetic composition of RWM offers a suitable scaffold for cellular ingrowth and tissue formation without the need or use of biologic xenogeneic or allogeneic materials or substrates. The RWM, therefore, offers a wound matrix material devoid of any risk of allergic response to animal products, zoonotic disease transmission, or ethical/religious concerns. The RWM’s use of well-characterized medical grade synthetic polymers that exhibit excellent biocompatibility can also significantly reduce the inflammatory response at the site of application. Compared to the inevitable host response elicited by biological materials from foreign human  or animal (xenograft) sources, electrospun wound matrix materials may offer reduced levels of inflammation within the wound bed both at acute and sub-acute timepoints. The RWM is also fully resorbable, similar to leading biologic xenograft and allograft products. The resorbable nature of RWM ensures that no permanent implant or material will remain at the site of application and that no chronic inflammatory reaction against the material will exist to limit wound healing or resolution.Fully-Synthetic Construction Offers Resistance to Enzymatic Degradation Resorption of RWM’s electrospun polymer matrix occurs in controlled stages that are governed by progressive hydrolysis rather than rapid enzymatic proteolysis. The RWM is composed of multiple electrospun polyglactin 910 and polydioxanone fiber populations. The RWM’s synthetic electrospun fiber matrix is therefore resistant to key enzymes released by inflammatory cells (e.g. MMPs) within the wound bed. The RWM thereby resists rapid enzymatic degradation at the wound site, avoiding premature degradation by proteases that directly contribute to and are overexpressed in chronic non-healing wounds. Wound matrices such as RWM that can resist protease degradation can provide a more stable and a more persistent scaffold capable of supporting wound healing over a longer time course .Increased Persistence in Wound Bed May Lead to Fewer Re-ApplicationsThe RWM has been engineered to resorb at a rate that matches the time course of tissue ingrowth. Due to its polymeric composition, RWM gradually resorbs via hydrolysis within the wound bed over the course of roughly 30 days. This prolonged presence within the wound site is anticipated to provide continued support of cellular infiltration, vascularization, and re-epithelialization, which occurs over a course of three weeks in normal wound healing . The timDegradation Products Elicit Antimicrobial EffectWhile RWM does not contain any active agents or drugs, the RWM is well suited for use in colonized wounds. Previous studies have demonstrated that the monomers and degradation products of RWM have antimicrobial effects . For exaIntended Use of Restrata Wound MatrixThe RWM is intended for use in the management of wounds, including: partial and full thickness wounds, pressure sores/ulcers, venous ulcers, diabetic ulcers, chronic vascular ulcers, tunneled/undermined wounds, surgical wounds , trauma wounds , and draining wounds. The RWM is not indicated for use in third-degree burns and should not be used in the patients with known sensitivity to resorbable suture materials.The RWM is supplied in the form of terminally sterile, in a single use double peel package in a variety of sizes. The contents of the package are guaranteed sterile and non-pyrogenic unless the package has been opened or damaged. The RWM is available in sizes ranging from 2.5cm x 2.5cm up to 12.5cm x 17.5cm.Preclinical Demonstration of Restrata Wound Matrix in a Porcine Wound Healing ModelThe RWM was compared to the Integra Bilayer Wound Matrix in the treatment of full-thickness cutaneous wounds in Yucatan miniature swine. Full thickness wounds (3 cm in diameter) were created along the dorsum of the swine and the Integra Bilayer Wound Matrix or the RWM was applied directly to the wounds Figure .2). Under the conditions of this study, RWM sped wound closure compared to Integra Bilayer Wound Matrix.Both RWM and the Integra Bilayer Wound Matrix supported wound healing, however, wound area decreased more rapidly with RWM Figure . CompareThe wounds treated with RWM also had an average Bates-Jensen wound score that was 46% and 19% lower than for wounds treated with the Integra Bilayer Wound Matrix by day 15 and day 30, respectively Figure . The wouHistological analysis of wound tissue sections revealed significant differences in inflammation, granulation tissue, collagen maturation, vascularization, and epithelialization of wounds treated with either material Figure . The RWMNo existing clinical materials meet all the expectations of an ideal regenerative wound matrix. Current options for wound care range from graft materials, including autografts, allografts, and xenografts, to engineered materials, are derived from biologic or synthetic components. Traditionally, synthetic wound matrix materials have offered excellent control over material and mechanical properties, but have lacked the architecture and regenerative properties of biologic matrices.Restrata wound matrix (RWM), a fully-synthetic, resorbable electrospun material that possesses structural elements similar to natural ECM, offers a new approach to the treatment of acute and chronic wounds by combining the advantages of synthetic construction with the positive attributes of biologic materials. Further characterization of the novel RWM material in the pre-clinical and clinical settings will be showing the breadth of application.


In low-resource settings, malaria and macronutrient undernutrition are major health problems in pregnancy, contributing significantly to adverse pregnancy outcomes such as preterm birth and fetal growth restriction. Affected pregnancies may result in stillbirth and neonatal death, and surviving children are at risk of poor growth and infection in infancy, and of non-communicable diseases in adulthood. Populations exposed to macronutrient undernutrition frequently reside in malaria-endemic areas, and seasonal peaks of low food supply and malaria transmission tend to coincide. Despite these geographic and temporal overlaps, integrated approaches to these twin challenges are infrequent.This opinion article examines the current evidence for malaria-macronutrition interactions and discusses possible mechanisms whereby macronutrient undernutrition and malaria may interact to worsen pregnancy outcomes. Macronutrient undernutrition dysregulates the immune response. In pregnant women, undernutrition may worsen the already increased susceptibility to malarial infection and could impair development of protective immunity to malaria, and is likely to exacerbate the impact of placental malaria on fetal growth. Malarial infection, in turn, can drive nutritional depletion; poor gestational weight gain and weight loss in pregnancy increases the risk of adverse pregnancy outcomes. Despite a commendable number of studies and trials that, in isolation, attempt to address the challenges of malaria and undernutrition in pregnancy, few dare to venture beyond the ‘single disease – single solution’ paradigm. We believe that this may be a lost opportunity: researching malaria–nutrition interactions, and designing and implementing integrated interventions to prevent and treat these commonly co-existing and intertwining conditions, may markedly reduce the high burden of preterm birth and fetal growth restriction in affected areas.We call for more collaboration between researchers studying malaria and nutrition in pregnancy, and propose a research agenda to address this important twin health problem. Pregnancy and early childhood (the first 1000 days of life) are critical periods that determine short- and long-term health outcomes , and malThe World Health Organization’s (WHO) Sustainable Development Goals include ending hunger and malnutrition; reducing maternal, newborn and child mortality; and ending infections such as malaria . In LMIC. In this call for increased collaboration between malaria and nutrition experts, we discuss the evidence for malaria–nutrition interactions in pregnancy, with a focus on macronutrient undernutrition, as this remains relatively understudied, notwithstanding the importance of micronutrient deficiencies. Macronutrient undernutrition refers to insufficient consumption of carbohydrates, fats and proteins, and is typically assessed using anthropometric measures in resource-limited settings. We summarise currently available tools to prevent and treat macronutrient undernutrition and malaria in pregnancy and outline key research questions that may advance our understanding of gestational malaria–nutrition interactions with a view to developing novel approaches to improve pregnancy outcomes in LMICs.A growing body of evidence suggests that malaria and maternal undernutrition interact to worsen pregnancy outcomes. However, interventions to protect pregnant women and their fetuses from macronutrient undernutrition and gestational malaria remain poorly integrated. Our belief is that maternal nutrient deficiency remains a neglected public health problem, and that few successful interventions in this area have adequately dealt with malaria as a cofactor2, with prevalence being highest, again, in LMICs in Africa and Asia [Each year, 125 million pregnant women, mostly in sub-Saharan Africa and Asia, are at risk of malaria infection . Worldwiand Asia , 12.There is evidence for geographical, socio-economic, temporal and mechanistic links between malaria and macronutrient undernutrition Fig. . Global Malaria and macronutrient undernutrition in pregnancy are also linked temporally. In pregnant Gambian women, the incidence of FGR, preterm birth (PTB) and malaria were all highest late in the hunger season , the parMacronutrient undernutrition is associated with increased malaria morbidity and mortality in children and non-pregnant adults, suggesting important immunological interactions , 16. MalPlasmodium falciparum infection on fetal growth and birthweight is more pronounced amongst women with macronutrient undernutrition compared to well-nourished women [P. falciparum parasitaemia on uteroplacental flow and fetal growth were most pronounced amongst undernourished women (low MUAC or BMI) [P. falciparum infection and reduced birthweight was only reported amongst women with a low BMI [Studies suggest that the effect of ed women , 20, 21. or BMI) , 20. SimWhile poor nutrition and malaria have important adverse consequences for maternal health, the developing fetus is most affected. This can have severe immediate as well as long-term consequences – the foundations for an effective immune system, adequate growth, and short- and long-term health are laid in utero . MacronuMalaria and macronutrient undernutrition in pregnancy have each been associated with increased infant morbidity and mortality. Many of the 900,000 LBW deliveries attributed to malaria take place in areas where maternal nutrition is poor, but the extent to which undernutrition contributes to this burden is unknown . In uterIn undernourished children, research indicates that antibody responses to various infections remain adequate, yet most such studies involve a small number of subjects and rarely assess antibody functionality . By contP. falciparum antibody responses. In pregnancy, the most important antibody target is PfVAR2CSA, a parasite protein inserted in the surface of infected erythrocytes that mediates placental parasite sequestration [PfVAR2CSA protein [Limited studies have assessed the effect of maternal macronutrient undernutrition on acquisition or maintenance of stration . Suscept protein , and thi protein .PfVAR2CSA-expressing infected erythrocytes but maternal weight was inversely correlated with antibody levels to P. falciparum merozoite surface protein 2 and to PfVAR2CSA [2 at first antenatal visit had higher antibody levels to PfVAR2CSA at 36 gestational weeks than those with a normal or raised BMI [In Papua New Guinea and Malawi, maternal MUAC was not associated with levels of antibody to fVAR2CSA . In a diEven if antibody levels or functionality are not affected, maternal macronutrient undernutrition might affect the ability of phagocytic cells to clear infection . UndernuPregnancy is characterised by a switch from a pro-inflammatory T-helper 1 (Th1) to a Th2 cytokine response, which protects the fetal allograft from rejection by the maternal immune system . AlthougPlacental malaria affects transplacental transport of nutrients, including amino acids and glucose ; this isA growing body of evidence suggests that malaria infection in early pregnancy increases the risk of adverse pregnancy outcomes independently of infections following organogenesis and placentation . While tThe adipokine leptin increases Th1 cell numbers and cytokine secretion . Low levBoth protein-energy undernutrition and malaria infection are associated with elevated serum cortisol levels , 57, whiThe IGF axis is a principal driver of fetal growth . InflammPlasmodium infection [Pregnant women with macronutrient undernutrition are prone to concurrent micronutrient deficiencies, with iron deficiency probably being the most common. Attempts should be made to take these into account when studying malaria–nutrition relationships , 60. In nfection –65.Furthermore, both malaria infection and macronutrient malnutrition, particularly protein deficiency, are causes of maternal anaemia, itself associated with LBW , 22. Oth2) should receive support. Many pregnant women still seek antenatal care late, and BMI tends to increase as a result of gestational weight gain [Assessment of maternal nutrition forms part of the WHO’s focused antenatal care strategy , which sght gain ; therefoght gain , but cutght gain . Maternaght gain . These mTo protect pregnant women from malaria, the WHO currently recommends the use of insecticide-treated bed nets, monthly intermittent preventive treatment with sulphadoxine-pyrimethamine from second trimester onwards, and malaria case detection and management . By contBalanced energy-protein supplementation was shown to improve pregnancy outcomes and increase birthweight by an average of 100 g in undernourished women . In The Other approaches to improve maternal nutritional status whilst reducing malaria risk could be of use. Intermittent preventive treatment with sulphadoxine-pyrimethamine and azithromycin reduced the risk of LBW, improved birthweight and gestational length, and prevented growth faltering in early infancy in two of three clinical trials , 83. In Many pregnant women are at risk of both undernutrition and malaria, yet few studies have investigated gestational malaria–nutrition interactions. Given their potential consequences for fetal growth and development, an expanded evidence base on malaria–nutrition interactions in pregnancy is urgently needed, with closer collaboration between malariologists, nutritionists and reproductive health specialists. Table Better mapping the overlapping burdens of undernutrition and malaria infection in pregnancy could be complemented by pooled analysis of data from pregnancy cohort studies that measured both nutritional and malariometric indices to confirm effect measure modification of the malaria–birthweight relationship by nutritional status. Studies are needed in early pregnancy and periconceptionally , when imChlamydia trachomatis) whilst providing antimalarial protection, also deserve further evaluation [There is mounting evidence that antenatal identification and tailored management of high-risk mothers may prevent adverse pregnancy outcomes due to malaria and undernutrition, and further research, such as pooled analysis, may provide additional evidence for this approach. Potential target groups include adolescent, primigravid, undernourished, HIV-infected or anaemic women. These women in particular may benefit from enhanced malaria prevention strategies combined with effective nutritional supplementation, which can be delivered conjointly through antenatal care systems. Drugs that improve gestational weight gain in undernourished women, or that clear other deleterious infections , and long-term health. To meet the World Health Assembly’s targets for improving nutrition status, including decreases in maternal anaemia and LBW, improvement of malaria prevention will also be necessary given the major contributions of malaria to both LBW and anaemia.Joint efforts by nutritionists and malaria experts are needed to determine the burden and significance of malaria-nutrition interactions in pregnancy, and to develop interventions that protect pregnant women and their children from this dangerous dyad.


The normal wound healing process involves a well-organized cascade of biological pathways and any failure in this process leads to wounds becoming chronic. Non-healing wounds are a burden on healthcare systems and set to increase with aging population and growing incidences of obesity and diabetes. Stem cell-based therapies have the potential to heal chronic wounds but have so far seen little success in the clinic. Current research has been focused on using polymeric biomaterial systems that can act as a niche for these stem cells to improve their survival and paracrine activity that would eventually promote wound healing. Furthermore, different modification strategies have been developed to improve stem cell survival and differentiation, ultimately promoting regenerative wound healing. This review focuses on advanced polymeric scaffolds that have been used to deliver stem cells and have been tested for their efficiency in preclinical animal models of wounds. Wounds result from a disruption of the normal architecture of the skin . Wound hBlood vessels are damaged during wound formation, initiating the clotting cascade. The resulting fibrin matrix serves as a site for cellular attachment, as well as a reservoir for cytokines and growth factors needed during latter phases of healing ,4. PlateFibroblasts migrate to the wound matrix and release collagen, fibronectin, and proteoglycans, replacing the initial fibrin matrix with new ECM. In response to the hypoxic wound environment, they too release cytokines, including fibroblast growth factor (FGF), hepatocyte growth factor (HGF), TGFβ, EGF, and VEGF. In conjunction with signaling factors released during earlier stages, these promote the formation of new blood vessels, a critical component of acute wound healing . Re-epitProgression from an acute to chronic wound results from various local or systemic factors that alter the wound microenvironment. Local factors , as well as systemic factors  impair wound healing through prolonged inflammation, reduced angiogenesis, and a decrease in growth factor signaling. Additionally, chronic wounds have been found to have increased expression of MMPs causing excessive wound matrix degradation and prolonged healing, as is the case in diabetic patients . Treating wounds and their associated complications places a large financial burden on the healthcare system, which exceeded $25 billion annually in the US by 2009 . TraditiAmong cell-based therapy, the use of stem cells for their regenerative wound healing potential is gaining widespread recognition. Many types of adult stem cells have been used in clinical trials for wound healing, but none has been approved yet ,13,14,15This review focuses primarily on various polymeric biomaterial-based delivery vehicles that have been developed to date for stem cell delivery to wounds. Our goal is to discuss stem cell delivery systems that have been specifically tested in animal models of wounds. Here, we first describe various stem cells that have been utilized for wound healing applications and discuss their delivery by natural and synthetic polymer-based scaffolds to acute and chronic wounds. Furthermore, we have a section on surface modification describing different modification strategies of these scaffolds to promote stem cell survival and wound healing. Stem cells have self-renewal and multipotency abilities that may help in creating advanced tissue engineered skin substitutes. Among the main sources of cells that may be used to engineer such substitutes are adult stem cells, embryonic stem cells (ESCs), and induced pluripotent stem cells (iPSCs). These cells have the potential to secret paracrine factors, making them an attractive option for the treatment of acute and chronic wounds . So far,ESCs, derived from the inner cell mass of the blastocyst, have the ability to differentiate into any cell type, including skin cells ,24,25, aiPSCs are the newest class of pluripotent stem cells first developed in 2006 by Takahashi and Yamanaka . Like ESco-glycolic) acid, polyanhydrides, polyethylene glycol, and others. These different polymers have specific physio-chemical characteristics and functional groups that allow for precise control of the creation of biomaterials with desired properties for a wide range of cell therapy applications. However, it is to be noted that the most important features critical to the success of any polymer are bioactivity, biodegradability, and biocompatibility [Over the last few decades, stem cell delivery using polymer based biomaterials has been the subject of intense investigation ,34. Thestibility .Natural polymers such as collagen, fibrinogen, tropoelastin, hyaluronic acid, glycosaminoglycans, etc., are found in the extracellular matrix. Scaffolds fabricated using these polymers are biocompatible, bioactive, assist in cell attachment to cell surface receptors, and provide a niche to control cell function . Some otCollagen, one of the major ECM-based proteins, has been used widely to fabricate scaffolds for stem cell delivery. Bone marrow derived MSCs (BM-MSCs), adipose derived MSCs (ADSCs), and other adult stem cells have been delivered using collagen scaffolds. O’Loughlin et al. fabricated a collagen scaffold to deliver BM-MSCs to a diabetic rabbit ear ulcer wound model. Topical application of the MSC-collagen treatment in a dose-dependent fashion significantly increased wound closure rates compared to that of untreated groups. Higher cell doses yielded better wound closure and faster rates of wound healing. The wound closure was associated with increased angiogenesis in the MSC-collagen groups . A similFibrin, another ECM-based protein, has been shown to form gels by reacting with thrombin. Although not investigated as extensively as collagen, fibrin has also been studied as a potential scaffold material for the delivery of stem cells. Ozpur et al., described a method of creating artificial skin tissue by using fibrin gels seeded with keratinocytes and ADSCs. This skin substitute promoted healing by complete re-epithelialization of the wound with no contraction and increased vessel density and collage deposition . AnotherAnother important ECM bio-macromolecule is elastin, which has been used for various tissue engineering applications, including in the form of tropoelastin ,69. In tSilk protein is a natural fibrous protein that has been used for various tissue engineering applications. In a study by Navone et al., AD-MSCs were obtained from human lipoaspirates and tested for the ability to differentiate both before and after seeding on silk fibroin (SF) scaffolds. Sheets of the silk fibroin scaffold were prepared through electrospinning and were loaded with MSCs to generate cellularized scaffolds (AD-MSCs-SF). The SF scaffolds allowed for growth of AD-MSCs as well as retention of differentiation capacity. Evaluation of both the cellularized and decellularized scaffolds in diabetic mice revealed improved tissue regeneration and enhanced expression of angiogenesis-related genes, corroborated by in vitro analysis. The ability of the scaffolds to affect migration of human umbilical vein endothelial cells (HUVEC), keratinocytes, and dermal fibroblasts was also observed, with enhanced HUVEC migration and release of angiogenic factors. Interestingly, the decellularized scaffold demonstrated comparable efficacy to the cellularized scaffold, showing potential for future application in wound care . Hyaluronic acid (HA) or hyaluronan is another major component of ECM. It contains sites for cell adhesion and has been widely used for surface modification of scaffolds and/or hydrogels to enhance cell survival and proliferation. Recently Gerecht et al. used acrylated HA (AHA) to form a smart hydrogel containing cell adhesive peptide and MMP-sensitive peptide cross-linker. The AHA hydrogel was used to deliver early vascular cells derived from human iPSC (hiPSC). The vascularized scaffold showed enhanced angiogenesis and wound closure in diabetic immunodeficient mice . Chitosan, xanthan, and carboxymethylcellulose are polysaccharides that have been used to culture stem cells. More information regarding other polysaccharide-based polymers can be found in Synthetic polymers are an alternative to natural materials and have well-defined and tunable chemical and mechanical properties. They present some advantages over natural polymer based biomaterials including their ability to be fabricated to have specific degradation rates. Thus a wide array of synthetic polymers has been explored for almost all tissue engineering applications . Refer tN-isopropylacrylamide (PNIPAM) and poly(amidoamine) (PAA). The PNIPAM-PAA hydrogel was used to deliver BM-MSCs to ulcers in a diabetic mice. The hydrogel alone and with BM-MSCs showed reduction of M1 inflammatory macrophages. BM-MSC-laden hydrogels induced rapid healing of diabetic ulcer by increasing angiogenesis, granulation tissue formation, ECM secretion, wound contraction, and re-epithelialization [Chen et al., reported a hydrogel of poly lization . Poly (PVA) is a synthetic polymer that has been widely used for drug delivery and tissue engineering application . In one l-lactic acid (PLLA) and poly lactic-co-glycolic acid (PLGA) are biodegradable synthetic polymers that have been used to deliver stem cells to wounds [g-PLLA scaffold was shown to successfully support the growth and endothelial functions of these CB-EPCs in vitro. In murine dermal wound models, the CB-EPC-seeded scaffold promoted vascular regeneration and was superior to conventional intradermal CB-EPC injection treatments in terms of localization and survival/retention of EPCs, as well as neovascularization at the wound bed. Similarly, another work by Yang et al. studied the effect of scaffolds seeded with VEGF-enhanced stem cells on wound healing in mice. Scaffolds made using PLGA and PLLA were used to deliver VEGF enhanced human MSCs. Subcutaneous implantation of the scaffold plus enhanced human MSCs demonstrated increased blood vessel migration into the constructs compared to implantation of stem cells transfected by a control plasmid and those transfected with VEGF using a commercial reagent [Poly-o wounds ,76. Kim Some other biodegradable synthetic polymers that have been used for regenerative applications are polycaprolactone (PCL) and polyethyleneglycol (PEG). Bahrami et al., fabricated an electrospun nanofibrous scaffold using PCL to deliver USSCs. The scaffold, which was modified with laminin, showed good cell viability, and in vivo study showed increased wound closure and a thin epidermis with recovered skin appendages in the dermal layer . Similarco-2-(2-methoxyethoxy) ethyl methacrylate-co-poly(ethylene glycol) diacrylate (PEGMEMA-MEO2MA-PEGDA). The hydrogel supported cell viability and proliferation of rat ADSCs. In vivo testing in a rat dorsal full-thickness wound model revealed that the hydrogel system improved angiogenesis [2MA–PEGDA hydrogel with HA showed a marked increase in secretion of growth factors over a 7-day period [, wounds of diabetic mice treated with MDSCs in the PEG-PLGA-PEG hydrogel showed increased epithelium migration, collagen deposition, engraftment of MDSCs, and enhanced wound closure rates within the first ten days after treatment [Geesala et al. produced a semi-inter penetrating network porous 3D scaffold using PEG-polyurethane (PEG-PU) and PEG-dimethylether (PEGDME). The scaffold was also shown to be thermostable, biodegradable, cytocompatible, and protective against oxidative stress. The scaffold loaded with BM-MSCs promoted healing with an increase in fibroblast proliferation, collagen deposition, and anti-oxidant enzyme activities. Furthermore, it reduced proinflammatory cytokines IL-1b, 6, 8, and TNF-α and upregulated anti-inflammatory cytokines IL-10 and 13. Increased engraftment was seen by expression of Sca-1+Lin-CD90+CD133+. Improved neovascularization was also evident, with increased expression of PECAM, VEGFR3, neuropilin 2, and Tie2 . In the ogenesis . A modify period . Lee et reatment .Though these synthetic polymers allow for engineering of biomaterials with tunable properties , disadvantages for choosing such materials include poor bioactivity due to a lack of cell attachment sites and acidic byproducts that can trigger an immune response ,40,41,83The interaction between cells and the biomaterial surface dictates the survival and function of stem cells within scaffolds. Surface modification of a biomaterial by incorporating suitable biological and chemical cues can ultimately control stem cell activity by manipulating the signal transduction pathways in stem cells after its attachment on the surface ,40. SurfModifications to collagen scaffolds have been made to replicate the ECM environment of wounds by addition of biomacromolecules such as glycosaminoglycans (GAGs) or laminin. Liu et al. (2008) created collagen–GAG scaffolds to study wound healing in porcine models. In in vivo partial thickness burn wounds, treatment with MSC-seeded scaffolds showed improved healing and keratinization, less wound contraction, and more vascularization compared to scaffold alone or no treatment. Labeled MSCs were also detected in the epidermal and dermal components of the wound bed, indicating that they had migrated from the scaffold and were integrated into the neoepidermis and neodermis . In anotCatanzano et al., used an alginate (ALG)-HA hydrogel for dermal regeneration . HA of 1Silk protein sericin has widely been used for various biomedical application . RecentlIn another work, Fibrin fragment E (FbnE) was used for the modification of an alginate scaffold and used for culturing cord blood epidermal progenitor cells (CB-EPCs). FbnE was shown to promote adhesion and endothelial differentiation of CB-EPCs in vitro. In vivo, co-administration of the FbnE-enriched scaffold with CB-EPCs accelerated wound closure and vascularization compared to administration of the FbnE scaffold alone . In a work by Natesan et al., PEGylated fibrin was used along with collagen to fabricate a bilayer hydrogel to deliver ADSCs. The authors found that the ADSCs successfully proliferated and differentiated in the bilayer hydrogel in vitro. They formed dense tubular microvascular networks in the PEGylated fibrin-based hydrogel. The bilayer hydrogel decreased wound contraction and increased wound closure time compared to the saline-treated control. In addition, rats treated with the ADSCs–bilayer hydrogel showed a significant increase in granulation tissue formation, re-epithelialization of wound margins, and better progression of the epithelial margin toward the center of the wound . SimilarAdvancements in the field of stem cell biology and biomaterials have created exciting opportunities for wound healing therapy. Polymeric biomaterials can now be rationally designed to provide a niche for the stem cells to survive and function. The purpose of this review was to detail some of the most commonly used biomaterial scaffolds for transplantation of stem cells for wound healing applications. It sought to detail the types of materials available and highlight their unique properties with respect to stem cell delivery with an emphasis on how they perform in vivo in preclinical models of wounds. We believe this will help readers choose a material that would best suit their specific wound healing needs. This review also touched on how modifications to biomaterials can play a large role in further promoting stem cell function and regenerative wound healing. Other considerations when designing such scaffolds including the method of fabrication and composite scaffolds  are beyond the scope of this review. Ultimately there are a number of significant challenges researchers must overcome before a stem cell and biomaterial-based option for wound healing therapy can be used in the clinical setting. In addition to overcoming the difficulty of obtaining a renewable source of stem cells in large quantities, major advances in both the understanding of the local cues necessary for stem cell survival and function and development of biomaterials necessary to promote these functions is key. These polymer-based biomaterials should be tested in a variety of in vivo and in vitro studies prior to their application with the stem cells on a clinical level. The future lies in utilizing high throughput arrays to test the functionality of new biomaterials for their usage in stem cell delivery in short periods of time while wasting few materials, ultimately allowing for a more rapidly developed end product. Further progress in this field involves utilizing a hybrid approach to produce personalized tissue engineered constructs by using patient specific cells, biomimetic matrices  and bioactive stimuli  to promote a regenerative healing . Further


Seven hundred and forty-three independent feeding events were observed with ROVs from near-surface waters down to depths approaching 4000 m, involving an assemblage of 84 different predators and 82 different prey types, for a total of 242 unique feeding relationships. The greatest diversity of prey was consumed by narcomedusae, followed by physonect siphonophores, ctenophores and cephalopods. We highlight key interactions within the poorly understood ‘jelly web’, showing the importance of medusae, ctenophores and siphonophores as key predators, whose ecological significance is comparable to large fish and squid species within the central California deep pelagic food web. Gelatinous predators are often thought to comprise relatively inefficient trophic pathways within marine communities, but we build upon previous findings to document their substantial and integral roles in deep pelagic food webs.Food web linkages, or the feeding relationships between species inhabiting a shared ecosystem, are an ecological lens through which ecosystem structure and function can be assessed, and thus are fundamental to informing sustainable resource management. Empirical feeding datasets have traditionally been painstakingly generated from stomach content analysis, direct observations and from biochemical trophic markers . Each approach carries inherent biases and limitations, as well as advantages. Here, using 27 years (1991–2016) of  These interlocking food chains are an established, central foundation of modern ecological investigations ,2. The bWithin the deep sea, Earth's largest ecosystem, the challenge of gathering empirical feeding data for food webs is particularly formidable due to logistical access and sampling constraints . AnalysiEmpirical data on trophic links have recently been generated from biochemical tracers like stable isotopes and fatty acids –13, whicin situ observations of feeding . Gen. Genin sWaters offshore of central California are characterized by marked spring and summer coastal upwelling events, followed by intrusion of oceanic California Current water and then, the northward movement of warm surface water along the coast during winter . The pelin situ deep pelagic feeding observations from within the oceanic ecosystem spanning up to 250 km offshore of the greater Monterey Bay region, collected by the Monterey Bay Aquarium Research Institute (MBARI) using scientifically optimized ROVs across the full water column (0–4000 m). We identify the most commonly observed predator–prey interactions based on quantified observations over the 27-year time series, looking across depth zones and seasons, where possible. We assemble ecosystem-level schematics of overall energy flow and synthesize ecologically distinct primary food web pathways. Some ROV-based observations of trophic links between midwater species in Monterey Bay have been published (e.g. )Alepisaurus ferox) and opah (Lampris guttatus) have documented regular consumption of salps and pyrosomes, and cephalopods that are known gelativores )ativores ,56. Pengativores . The useativores ). Additiativores , stromatativores  are know(c)in situ observations, are potentially subject to avoidance by at least some taxa that are sensitive to noise and light, and are mobile enough to escape [Dosidicus gigas and Gonatus are presented as key consumers of midwater fishes such as myctophids and bathylagids [Each method of observation or ecological tool used to gather trophic data in the midwater must be interpreted within the context of inherent limitations and biases. Commonly used midwater trawls are known to significantly underestimate the biomass of key pelagic groups depending on trawl type . Additioo escape . Thus, ahylagids ,62,63. ANo single trophic assessment method should be presented as a stand-alone approach to characterizing food web structure. ROV observations are ideal for documenting the jelly web, which is difficult to assess by other methods. With mostly transparent gelatinous predators, we can see prey long after they have been captured and eaten, and ROV observations eliminate the risk of prey extrusion following sample collection. ROVs are less optimal for observation of predation by fishes and crustaceans, where already ingested prey cannot usually be visually documented without capture and dissection. While our findings are more focused on the food web roles of soft-bodied animals less sensitive to the presence of a ROV, this perspective is not generally captured by other more commonly used methods.A second limitation of our study is the inability to separate diel feeding across depth zones, as the large majority of the observations occurred during daylight hours. Diel vertical migration is a widespread phenomenon among midwater animals, and future studies should focus on key differences between day- and night-time feeding by both migrators and non-migrators. These results do, however, demonstrate that many food web linkages are active at depth during the day, and not just in near-surface waters at night. Lastly, because the feeding observations presented were collated from over 25 years of midwater ROV programmes at MBARI, we were unable to robustly evaluate the influence of inter-annual, seasonal and depth-related variability on overall food web structure.in situ feeding observations can be synthesized to provide both fine-scale and big-picture understanding of pelagic food webs. Integrating this quantitative feeding data into ecosystem models will support strategic resource management from a whole-ecosystem perspective [This study highlights the importance of a persistent and continued presence in the deep sea, demonstrating for the first time how the resultant collection of spective . Such kn


EVs have been found to play a critical role in cell-to-cell communication by transferring non-coding RNAs (ncRNAs) including microRNAs (miRNAs), long ncRNAs (lncRNAs) and so on. Emerging evidence shows that transferring biological information through EVs to neighboring cells in intercellular communication not only keep physiological functions, but also participate in the pathogenesis of liver diseases. Liver diseases often promote release of EVs and/or in different cargo sorting into these EVs. Either of these modifications can promote disease pathogenesis. Given this fact, EV-associated ncRNAs, such as miR-192, miR-122 and lncRNA-ROR and so on, can serve as new diagnostic biomarkers and new therapeutic targets for liver disease, because altered EV-associated ncRNAs may reflect the underlying liver disease condition. In this review, we focus on understanding the emerging role of EV-associated ncRNAs in viral hepatitis, liver fibrosis, alcoholic hepatitis (AH), non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC) and discuss their utility in biomarker discovery and therapeutics. A better understanding of this multifaceted pattern of communication between different type cells in liver may contribute to developing novel approaches for personalized diagnostics and therapeutics.Extracellular vesicles (EVs) are small membranous vesicles secreted from normal, diseased, and transformed cells  Table 1)  . EVs areTable 1) . HoweverTable 1) . FollowiTable 2).As is well-known, ncRNAs are usually divided into two main classes according to their size: (1) short ncRNAs (<200 nt), such as miRNAs, endogenous small interfering RNA (siRNA) and piwi-interacting RNA (piRNA); (2) long ncRNAs  . AlthougC. elegans, was described in 1993  lines LX-2 cells after treatment with TGF-β1 . In the last years, the discovery of EVs has represented a revolution and a paradigm shift . EVs are heterogeneous in size and are released from nearly all cells under both physiological and pathological conditions . Manifestation of a role for EVs-associated ncRNAs in liver disease pathogenesis will support their potential use as disease biomarkers. The ability to selectively manipulate ncRNAs in EVs through either exogenous or endogenous approaches offers further opportunities for their use in disease therapeutics.In 2007, EVs was first supposed to be an important mediator of many biological events through transferring genetic information to target cell . Nowadayune cell . MultiplViral hepatitis is caused by a variety of hepatitis viruses, which can arise as a consequence of liver disease. Many studies showed that the EVs derived from a variety of cells play multiple roles in the development of viral hepatitis, including virus transmission, host immune regulation and micro-environment manipulation . HepatitLiver fibrosis is characterized by extensive deposition of extracellular matrix (ECM) and an activation of HSCs resulting from a protracted wound-healing response . HSCs, pIn addition, studies found that EVs derived from platelets or granulocytes in patients with sepsis have function of promote coagulation and suggested thrombin generation, in proportion to the severity of the disseminated intravascular coagulopathy . HoweverAlcoholic hepatitis (AH) is an acute hepatic inflammation accompanied with intrinsical morbidity and mortality and increasing health problems across the world. AH is a result of the complex interactions between ethanol metabolism, inflammation, and innate immunity on the liver . CurrentSeveral reports have confirmed that the miRNAs cargo within EVs derived from sera of alcohol-fed mice are potential novel biomarkers in AH. MiR-192 and miR-30a were considered as EV cargos that were significantly increased in the circulation of subjects with AH . AdditioNon-alcoholic fatty liver disease (NAFLD) is a dominant cause of chronic liver disease around the world. NAFLD has become a severe health issue and it can progress toward a more severe form of the disease, the non-alcoholic steatohepatitis (NASH) . NASH isHepatocellular carcinoma (HCC) is the most common malignancy and the third leading cause of cancer-related death worldwide. HCC has been certificated to be highly refractory to treatment . The croOn the other hand, growing studies showed that EV-mediated lncRNAs can regulate gene expression via various mechanisms. EV–mediated transfer of lncRNA as a mechanism by which tumor cells can modulate their local cellular environment . These rFigure 3). Our knowledge about EVs has been rapidly growing in recent years, along with the analyses of protein, mRNA, ncRNAs and lipid in EVs. We search recently published articles about EV-associated ncRNAs by using PubMed tool. We found that EV-associated ncRNAs are increasingly recognized as essential regulators of biological processes in normal and pathological conditions thus having a high potential to targeted delivery and therapeutic intervention in liver and other diseases. There are evidences that ncRNAs in EVs may sever as or transfer damage-related molecular patterns to recipient cells of the liver micro-environment and coordinate many of the main pathological events occurring concurrently during the liver disease progression. Therefore, the ncRNAs in EVs may become specific biomarkers for liver disease if research will reveal that ncRNAs are indeed differ in different pathologies, and technologies will be advanced to allow the routine detection of the ncRNAs in individual samples. Nevertheless, the information that can be acquired by the detailed detection of EVs-associated ncRNAs is already contributing to understand the pathogenesis of liver diseases, and will do so even more in the future. Our previous researches showed that ncRNAs play regulatory roles in liver fibrosis and tumor. We found that miR-145 inhibits HSCs activation and proliferation by targeting ZEB2 through Wnt/β-catenin pathway. EVs are being developed also as highly multifunctional drug delivery tools with new features. Thus EVs-associated ncRNAs are one of the more promising fields of investigation in liver diseases, with the potential to shed light on pathogenic mechanisms, to reveal long needed biomarkers. It is hoped that these efforts will be soon translated into clinical practice. To achieve this goal, a combination of clinically driven, genetically defined, morphologically classified, and molecular-based study will have to be performed. Multidisciplinary research group with differential background should cooperate to successfully address these issues.In conclusion, we have highlighted several of the most recent and original studies reporting the role of ncRNAs in EVs as link between liver fibrosis, viral hepatitis, NASH, AH and HCC. The association of specific EV constituents with disease offers potential for the use of EVs as biomarkers to diagnose and predict behavior or treatment response in many different types of liver diseases (LZ and XW designed review idea and took part in the critical revision of manuscript. JY participated in drafting of manuscript; CL participated in the cited articles search.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Uterine leiomyomata are the most common benign tumors of the gynecologic tract impacting up to 80% of women by 50 years of age. It is well established that these tumors are the leading cause for hysterectomy with an estimated total financial burden greater than $30 billion per year in the United States. However, for the woman who desires future fertility or is a poor surgical candidate, definitive management with hysterectomy is not an optimal management plan. Typical gynecologic symptoms of leiomyoma include infertility, abnormal uterine bleeding (AUB)/heavy menstrual bleeding (HMB) and/or intermenstrual bleeding (IMB) with resulting iron-deficiency anemia, pelvic pressure and pain, urinary incontinence, and dysmenorrhea. The morbidity caused by these tumors is directly attributable to increases in tumor burden. Interestingly, leiomyoma cells within a tumor do not rapidly proliferate, but rather the increase in tumor size is secondary to production of an excessive, stable, and aberrant extracellular matrix (ECM) made of disorganized collagens and proteoglycans. As a result, medical management should induce leiomyoma cells toward dissolution of the extracellular matrix, as well as halting or inhibiting cellular proliferation. Herein, we review the current literature regarding the medical management of uterine leiomyoma. Epidemiologic data report that leiomyomata are virtually nonexistent prior to menarche and typically have an indolent course following menopause, strongly implicating gonadal hormones in the induction and maintenance of this disease process [Uterine leiomyomata, also referred to as myomas and fibroids, are the most common solid tumors of the gynecologic tract. These benign tumors are postulated to arise from a single, genetically altered, mesenchymal cell under the influence of gonadal hormones, namely, progesterone and 17 process –7. Despi process , 9. Risk process , 11. Of  process .Increasing tumor burden results in characteristic symptoms depending on the location of the tumor within the uterine corpus, that is, whether the tumor is submucosal, intramural, or subserosal. For example, leiomyomata distorting the uterine cavity  often produce abnormal uterine bleeding (AUB), heavy menstrual bleeding (HMB), and/or intermenstrual bleeding (IMB) in the presence or absence of dysmenorrhea. These cavity-distorting tumors are often implicated in iron-deficiency anemia (secondary to AUB) and infertility. If a given patient is able to achieve pregnancy with a leiomyoma impacting the uterine cavity, they also are more likely to experience adverse pregnancy outcomes to include recurrent pregnancy loss (RPL), abnormal placentation , fetal malpresentation, preterm delivery, cesarean section, and postpartum hemorrhage –14. TumoHysterectomy is one of the most common surgeries performed on women and remains the only definitive treatment for leiomyomata. Myomectomy provides temporary reduction in uterine volume but is associated with a risk of recurrence estimated to be 11% with removal of a solitary fibroid and 26% or greater when multiple fibroids are removed over a 10–30-month time period , 15. TheMultiple less invasive techniques including hysteroscopic myomectomy , magnetic resonance imaging-guided focused ultrasound surgery, cryomyolysis, uterine artery embolization, and temporary occlusion of the uterine arteries have been employed to offer uterus-sparing options . HoweverBecause gonadal hormones induce, and maintain, leiomyoma growth via the production of an aberrant extracellular matrix (ECM), much research has focused on the development of medical agents to circumvent steroidal influence in an effort to reduce the burden of disease. These medications include centrally acting gonadotropin-releasing hormone analogs  and peripherally acting agents to include aromatase inhibitors, antiprogestins, and selective progesterone receptor modulators (SPRMs).Taken together, the management of leiomyoma depends on given patient's symptoms, age, and desire for future fertility. In the case of women suffering from abnormal uterine bleeding, heavy menstrual bleeding, medical management with NSAIDs, progestin, combination of oral contraceptives, a levonorgestrel releasing intrauterine device, or tranexamic acid has been shown to be beneficial . On the For those women either not interested in definitive management with hysterectomy or considered to be poor surgical candidates, options for management of their disease should include agents aimed at reducing tumor burden by dissolution of the aberrant ECM. Herein, this manuscript will review the medical management of symptomatic uterine leiomyomata with particular emphasis placed on those medications that favor dissolution of the aberrant ECM.Nonsteroidal anti-inflammatory drugs  have been employed in an effort to ameliorate abnormal uterine bleeding/heavy menstrual bleeding for a number of years. These agents inhibit the enzyme cyclooxygenase, which diminishes the production of prostaglandins. A Cochrane review evaluating the effectiveness of NSAIDs in the management of abnormal uterine bleeding/heavy menstrual bleeding included 18 studies . The autTranexamic acid is a synthetic lysine derivative that prevents fibrin degradation by competitively blocking lysine-binding sites on plasminogen, thereby preventing fibrin degradation. This action favors clotting, which reduces menstrual blood flow. Several randomized control trials have demonstrated a reduction in menstrual blood flow as compared to placebo –31. TranSeveral studies have specifically evaluated the impact of tranexamic acid on women with symptomatic uterine leiomyomata –31. In tβ-estradiol and progesterone, in combination or progesterone only formulations, are commonly utilized to regulate heavy menstrual bleeding in women with and without uterine leiomyoma. Strict regulation of the menstrual cycle via these medications is particularly beneficial in women suffering from anovulation. Despite the aforementioned benefits, current evidence suggests medical therapies provide short-term relief, with many patients ultimately opting to pursue surgical therapies [The steroid hormones 17herapies , 33.Given our current understanding of the importance of the gonadal hormones for initiation and continued growth of uterine leiomyomata, many physicians previously recommended against the use of such medications in women with uterine leiomyomata. Despite these fears, combined oral contraceptives have been utilized for women with leiomyomata and a meta-analysis found no association with progression of disease while using these medications . In factThe current data are limited regarding the effects of estrogen and progesterone. Estrogen and progesterone treatment, usually with combined oral contraceptive pills, may control abnormal uterine bleeding  and may not stimulate leiomyoma ECM.Progesterone containing oral, injectable, and implantable contraceptives act to reduce blood loss by providing an inhibitory effect on endometrial cell proliferation leading to a thinner lining with less material to be shed during progestin withdrawal. However, as was the case with combined oral contraceptives, studies utilizing progesterone only contraceptives in the treatment of symptomatic uterine leiomyomata have demonstrated mixed results. To this point, there are studies in which the authors note reduction in leiomyomata size with progesterone only therapy, while others report an increase in leiomyomata size –38. A weThe levonorgestrel releasing intrauterine device (LNG-IUD) acts at the level of the endometrium to repress estrogenic stimulated growth thereby producing a thinned endometrial lining. In addition, there is virtually no uptake of levonorgestrel into the systemic circulation .Progestin releasing intrauterine devices are effective at treating abnormal uterine bleeding associated with anovulation and is now approved by the Food and Drug Administration for this indication . Small sβ-estradiol. Several in vitro studies revealed that uterine leiomyoma cells harbor intrinsic aromatase activity, thereby providing a direct source of steroid hormone to drive further growth through the development of an aberrant extracellular matrix [Aromatase (CYP19) is an enzyme responsible for ovarian and peripheral conversion of androgens, namely, testosterone, to 17r matrix . This fiBased on their mechanism of action, aromatase inhibitors were hypothesized to have fewer side effects than the GnRH agonist, leuprolide acetate, with the benefit of a rapid effect. Several publications have shown reductions in leiomyomata volume and symptoms with the use of these agents –45.β-estradiol within 24 hours of first use [β-estradiol levels [One study using the aromatase inhibitor, CGS 20267, revealed the ability of that agent to inhibit ovarian and peripheral conversion of androgens to 17irst use . A smalll levels . A subsel levels . The stuA Cochrane review published in 2013 on aromatase inhibitors used for the management of uterine leiomyomas focused on one randomized control trial with 70 patients that met inclusion criteria . The autβ-estradiol, and progesterone, respectively. Compounds that regulate ovarian stimulation and thereby decrease gonadal hormone production are attractive treatment options for women suffering from gonadal hormone-stimulated diseases such as leiomyomas.In normal human physiology, sex steroid hormone production is a highly regulated process with major control centering at the hypothalamus, which is below the third ventricle and directly above the chiasma and pituitary gland. This gland exerts control over sex steroid production via the release of gonadotropin-releasing hormone (GnRH). When released in a specific, pulsatile fashion, GnRH induces the release of the pituitary gonadotropins Follicle Stimulating Hormone (FSH) and Luteinizing Hormone (LH), which in turn act at the level of the ovary to stimulate production of the sex-steroids, 17As a class of medication, GnRH agonist  has historically been considered the most effective presurgical therapy for symptomatic leiomyoma. They induce a premenarchal state notable for hypoestrogenism, by downregulation of the hypothalamic-pituitary-ovarian axis, amenorrhea, improvement in symptoms , and rapid reduction in leiomyomata volume. That being said, the benefits achieved come with an unavoidable side effect profile to include vasomotor symptoms, vaginal dryness, sleep disturbances, myalgia, arthralgia, mood-swings, and potential cognitive impairment , 48, 49.In one of the large scale clinical trials assessing leuprolide efficacy in women with symptomatic leiomyomata, 128 women were enrolled and placed into either the treatment or placebo arm . Those iSimilar studies have been performed and produced similar results with all showing a 30–65% reduction of leiomyomata within 6 months of treatment with leuprolide acetate –55. HoweOn a molecular level, GnRH agonists decrease the expression of factors important for fibroid growth to include Transforming Growth Factor-Beta, Epidermal Growth Factor, and Insulin-like Growth Factor. Further data from our laboratory has shown reduction of the extracellular components collagen -1, fibronectin, and versican with leuprolide acetate treatment , 57.Similar to the GnRH agonists, GnRH antagonists including cetrorelix acetate, ganirelix acetate, and Nal-Glu have been shown in clinical trials to reduce leiomyoma volume via induction of a hypoestrogenic state –62. HoweProgesterone receptor A and B  protein has been shown to be elevated within leiomyomata, as compared against adjacent myometrium , 64. AddMifepristone, also known as RU 38486 & RU486, is the most extensively studied progesterone receptor antagonist in leiomyomata –69. ThisA Cochrane review evaluated the usefulness of mifepristone for symptomatic leiomyomata . Of all Overall, the weight of the evidence suggests that treatment with mifepristone leads to a reduction in patient symptoms associated with leiomyomata that is comparable to GnRH analogs without detrimental effects on bone mineral density. However, given the unopposed estrogen stimulation of the endometrium with development of endometrial hyperplasia, caution must be taken given the potential for development of estrogen-dependent endometrial cancers. It is for this reason that approval has not been sought from the Food and Drug Administration for use of these medications in women with symptomatic leiomyomata.Selective progesterone receptor modulators (SPRMs) are a class of medications that are structurally similar to the antiprogestin mifepristone. Similar to the more widely known Selective Estrogen Receptor Modulators (SERMs), SPRMs have tissue-specific agonist and antagonist effects making them prime agents for use in the treatment of uterine leiomyomata. Members of this class of medication include telapristone acetate , asoprisnil , and ulipristal acetate . in vitro and animal work, the drug went to clinical trial for treatment of symptomatic uterine fibroids in humans. These in vitro models have shown that asoprisnil downregulates growth factors and synthesis of collagens, which are important in increasing leiomyoma, bulk [Asoprisnil (J867) was originally developed by Schering and TAP Pharmaceutical Products in the mid to late 1990s . The majma, bulk , 77. Desma, bulk –80. A pama, bulk .Telapristone acetate (CDB-4124) was developed at the National Institutes of Health, Contraception Development Branch . The phaSimilar to telapristone acetate, ulipristal acetate (CDB-2914) was developed by the National Institutes of Health, Contraception Development Branch. This drug was made available as an emergency form of contraception in Europe in 2009 and subsequently approved in the United States in 2010 . In thisGiven the enthusiasm for the use of SPRMs in the management of leiomyoma, a group at the National Institutes of Health (NIH), National Institute of Child Health and Disease Branch (NICHD), performed a randomized control trial including 22 premenopausal women with symptomatic uterine leiomyomata , 86. WomSubsequent to the NIH trials, a European group evaluated the ability of ulipristal acetate to reduce symptoms and tumor burden in symptomatic uterine leiomyomata. The PGL4001  Efficacy Assessment in Reduction of symptoms due to uterine Leiomyoma (PEARL) I trial compared ulipristal acetate to placebo in the preoperative management of 242 premenopausal women suffering from symptomatic leiomyomata . The autThe authors of the PEARL I trial then performed a noninferiority trial comparing ulipristal acetate (5 mg and 10 mg) to leuprolide acetate . The stuThe leaders of the European group subsequently performed a third clinical trial with repeated intermittent open-label UPA courses, each followed by randomized double-blind norethisterone acetate (NETA) or placebo including 291 premenopausal women with symptomatic leiomyomata. The authors found the median fibroid volume change from baseline was −63%, −67%, and −72% after treatment courses 2, 3, and 4, respectively. The authors conclude that repeat courses of ulipristal acetate control symptoms and significantly reduce leiomyoma volume .Taken together, the PEARL trials provided sufficient evidence for the regulatory agencies of the European Union to approve ulipristal acetate as a preoperative treatment of symptomatic leiomyomata. To date, there are insufficient studies in the United States and therefore the Food and Drug Administration has not approved ulipristal for use in symptomatic uterine leiomyoma.Similar to antiprogestins that inhibit progesterone activity in the endometrium, leading to unopposed estrogen stimulation with the potential development of endometrial intraepithelial neoplasia leading to Type I endometrial cancers, many have concerns regarding the long-term treatment of patients with ulipristal acetate. In one early study evaluating CBD-2914 as a contraceptive, 56 normally cycling women were treated with a single dose of ulipristal acetate  or placebo within 48 hours of ovulation and followed with transvaginal ultrasound  and endometrial sampling . Of the 56 endometrial biopsies performed, one patient who received 50 mg of ulipristal acetate was noted to have findings consistent with benign endometrial intraepithelial neoplasia. Repeat luteal phase endometrial sampling performed two months later was negative for pathologic endometrial changes . A singlβ3 (TGF-β3) signaling pathway. First, the RNAseq data revealed a marked increase in Fibrillin transcripts in UPA-treated leiomyoma, as compared to placebo  analysis on placebo and ulipristal acetate treated patient matched leiomyoma and normal myometrium samples from the ulipristal (CBD-2914) clinical trials in an effort to identify novel pathways involved in the UPA-dependent reduction of uterine leiomyoma , 86. Int placebo . Fibrilln tissue .The most significant changes in transcript levels were seen in those coding for the proteoglycan, versican (VCAN). This molecule is negatively charged, with large numbers of hydrophilic glycan components that form high-molecular weight aggregates with hyaluronic acid. Because of its structure, VCAN promotes hydrostatic pressure within the interstitial space. Therefore, reductions in VCAN would, in theory, lead to dehydration of uterine leiomyoma. Our analysis of the RNAseq study revealed VCAN transcripts were 4–6 times higher in leiomyoma than surrounding myometrium (data not shown). Furthermore, mRNA transcripts and protein expression were reduced in UPA-treated leiomyoma, which is consistent with the rapid reduction in leiomyoma volume seen in the CDB and PEARL clinical trials.Taken together, the clinical and laboratory data on ulipristal acetate suggests it may act via the rapid induction/alteration of osmoregulatory genes to change osmotic forces leading to an initial rapid reduction in leiomyoma volume over the first 3 months of treatment followed by a slower reduction in leiomyoma volume . Work reManagement of symptomatic uterine leiomyomata must be individually tailored to patient symptoms, desires for future fertility, age, and location of the leiomyoma. A list of the medications reviewed herein is included within The GnRH agonist, leuprolide acetate, had been considered to be superior to any other medication for reduction of symptoms and tumor burden. However, the side effect profile  limits the usefulness of this class of medications. To circumvent several of the side effects of GnRH analogs, practitioners have employed hormone add-back therapy with good success.The use of combined oral contraceptive pills and progesterone only formulations has demonstrated benefit in treating abnormal uterine bleeding and dysmenorrhea without definitive proof of either reduction or enhancement of uterine leiomyoma volume. Well-designed, randomized control trials should be performed to better elucidate the utility of hormonal medications in the long-term management of uterine leiomyoma.Given the prevalence, and morbidity, associated with uterine leiomyoma the promise of a long-term medical solution is encouraging with the advent of selective progesterone receptor modulators, most notably ulipristal acetate. This medication has been approved by the European regulatory agencies for use as a preoperative agent in women with symptomatic leiomyomata and anemia. Further work using this agent has shown complete resolution of uterine leiomyomata with repeated courses. There had been concern for endometrial pathology given the mechanism of action of the drug, but to this end the risk of development of endometrial hyperplasia or Type I endometrial carcinoma appears to be very low. That being said, it is currently still advisable that treatment with this agent be followed closely for evidence of endometrial pathology.