Despite the development of therapeutic agents that selectively target cancer cells, relapse driven by acquired drug resistance and resulting treatment failure remains a significant issue. The highly conserved Hedgehog (HH) signaling pathway performs multiple roles in both development and tissue homeostasis, and its aberrant regulation is known to drive the pathogenesis of numerous human malignancies. However, the role of HH signaling in mediating disease progression and drug resistance remains unclear. This is especially true for myeloid malignancies. The HH pathway, and in particular the protein Smoothened (SMO), has been shown to be essential for regulating stem cell fate in chronic myeloid leukemia (CML). Evidence suggests that HH pathway activity is critical for maintaining the drug-resistant properties and survival of CML leukemic stem cells (LSCs), and that dual inhibition of BCR-ABL1 and SMO may comprise an effective therapeutic strategy for the eradication of these cells in patients. This review will explore the evolutionary origins of HH signaling, highlighting its roles in development and disease, which are mediated by canonical and non-canonical HH signaling. Development of small molecule inhibitors of HH signaling and clinical trials using these inhibitors as therapeutic agents in cancer and their potential resistance mechanisms, are also discussed, with a focus on CML. Drosophila melanogaster .,44.43,44Numerous small molecule inhibitors of HH signaling have been developed for the treatment of a variety of human cancers. Many of these are direct SMO antagonists, binding to the SMO receptor and blocking downstream activation of GLI and other HH effector proteins ,52. ThesCML is a myeloproliferative disease characterized by the presence of a constitutively active BCR-ABL1 tyrosine kinase fusion gene that plays a key role in driving the oncogenic signaling pathways of the disease. While the advent of tyrosine kinase inhibitors (TKI) has been effective in managing the disease, functional cure is challenging to attain due to BCR-ABL1-independent resistance mechanisms and various treatment escape mechanisms available to leukemic stem cells (LSC) ,55,56,57−/− HSCs retrovirally transduced with BCR-ABL1/GFP were less able to induce leukemia when injected into immunodeficient mice; disease latency was extended by more than three months in this group compared to the control group, and only 60% of recipients developed lethal disease . Ot. Ot26]. As discussed above, non-canonical HH signaling or SMO-independent mechanisms are also drivers of resistance to SMO inhibitors. For example, in gastrointestinal cancer, HH signaling increases gene expression of ATP-binding cassette subfamily G member 2 (ABCG2) via GL1, enhancing drug efflux and reducing drug concentrations in cancer cells, which could generate chemoresistance . In pancAn important question raised by these studies of resistance to SMO inhibitors relates to the origin of HH pathway activation in CML. Canonical HH signaling commences with the binding of HH ligands to the transmembrane protein PTCH. HH ligands can be supplied to target cells in an autocrine manner, or from surrounding stromal cells or CML cells in a paracrine manner B–D. HoweSince the characterization of the HH gene in 1980, significant advancements have been made in establishing its importance both in the development and in driving the pathogenesis of cancer. Despite the development of several HH pathway inhibitors that have been tested in clinical studies for a range of different solid tumor pathologies, clinical studies of these inhibitors in hematological malignancies, especially CML, remain limited. Even for existing SMO inhibitors, toxicity and resistance remain significant issues. Thus, complementary therapeutic strategies including the use of next-generation SMO inhibitors, combination therapies, and genetic suppression of HH pathway proteins using shRNA or CRISPR-Cas9, are urgently required.


Atm gene lead to Ataxia–Telangiectasia (AT), a recessive disorder characterized by ataxic movements consequent to cerebellar atrophy or dysfunction, along with immune alterations, genomic instability, and predisposition to cancer. AT patients show variable phenotypes ranging from neurologic abnormalities and cognitive impairments to more recently described neuropsychiatric features pointing to symptoms hardly ascribable to the canonical functions of ATM in DNA damage response (DDR). Indeed, evidence suggests that cognitive abilities rely on the proper functioning of DSB machinery and specific synaptic changes in central neurons of ATM-deficient mice unveiled unexpected roles of ATM at the synapse. Thus, in the present review, upon a brief recall of DNA damage responses, we focus our attention on the role of ATM in neuronal physiology and pathology and we discuss recent findings showing structural and functional changes in hippocampal and cortical synapses of AT mouse models. Collectively, a deeper knowledge of ATM-dependent mechanisms in neurons is necessary not only for a better comprehension of AT neurological phenotypes, but also for a higher understanding of the pathological mechanisms in neurodevelopmental and degenerative disorders involving ATM dysfunctions.Ataxia–Telangiectasia Mutated (ATM) is a serine/threonine protein kinase principally known to orchestrate DNA repair processes upon DNA double-strand breaks (DSBs). Mutations in the  Atm (AT mutated) gene are associated to the neurodegenerative condition Ataxia–Telangiectasia (AT). AT is a recessive disorder with an extremely variable phenotype, characterized by uncoordinated and ataxic movements as a result of cerebellar atrophy or dysfunction  ,94 93,94Unfortunately, the mechanisms leading DNA repair kinases to be directly involved in AD pathogenesis are still unclear. Most studies have investigated proteins of the BER pathway, especially the enzyme 8-oxoguanine glycosylase 1 (OGG1), in mild cognitive impairment subjects and sporadic AD patients. OGG1 is the protein that catalyzes the incision of DNA at sites of the oxidation product 8-hydroxy-2′-deoxyguanosine (8-OHdG) and its activity has been found consistently reduced in clinical studies ,98,100. Considering the proteins belonging to the NER pathway, biochemical analysis revealed significantly increased levels of ERCC2 and ERCC3 in post-mortem brain tissues of AD patients at the early stages of the disease compared to control subjects .Finally, proteins involved in the repair of DSBs have also been described to be altered in AD. In particular, reduced levels of the DNA-dependent protein kinase (DNA-PK) have been measured in AD lysates . Also, rAD transgenic mice, which recapitulate key aspects of pathology, have increased neuronal DSBs at baseline and more severe and prolonged DSBs after physiological experiences such as explorative behavior, confirming the strict relation between synaptic plasticity and DSBs. Interestingly, administration of levetiracetam suppresses aberrant neuronal activity, improves learning and memory, and normalizes levels of DSBs .In vitro, Aβ inhibits DNA-PK-dependent NHEJ and contributes to the accumulation of DSBs in PC12 cells . RemarkaOverall, it is clear that increased DSB formation together with low DNA repair efficacy represent a toxic condition with negative impacts on (i) genome stability , (ii) neThe involvement of ATM in AD pathogenesis has been supported by data obtained from autoptic specimens of AD patients and AD mouse models. Indeed, ATM protein levels are altered in the lysates of human frontal cortex and cerebellum of AD patients. Results indicate a reduction in ATM signaling in the frontal cortex, whereas increased ATM levels were reported in the cerebellum of AD patients, pointing to specific roles of this kinase in brain areas diversely affected by the pathology . In AD mAtm KO mice is abnormal, and astrocytes from Atm KO mice show significant expressions of oxidative and endoplasmic reticulum stress and a senescence-like reaction [Atm deficiency may disturb DNA repair and accelerate aging and neuroinflammation.In glial cells of mutant ATM Drosophila melanogaster flies, ATM impairment or deficiency may trigger innate immune responses that can contribute to neurodegeneration . The hisreaction ,113. NotThus, clinical and preclinical evidence supports the assumption that ATM may represent a new player contributing to neurodegeneration and synaptic dysfunction in AD. Concerning neurodegeneration, ATM signaling is implicated in cell death pathways and is necessary for apoptosis of post-mitotic neurons triggered by genotoxic or oxidative stress ,114. ATM−/− brains, suggesting that DBN-loss alone is not sufficient to induce synapse dysfunction. Indeed, Kreis et al. demonstrated that an excess of reactive oxygen species (ROS) stimulates ATM-dependent phosphorylation of DBN, enhancing protein stability and improving stress resilience in dendritic spines [A direct role of ATM in synaptic dysfunctions in AD was hypothesized, considering that ATM directly modulates synaptic function and composition of hippocampal neurons ,45,47. Ac spines . ConsideAtm-deficient neurons and mice through a KCC2-dependent mechanism, supporting a possible contribution of ATM to synaptic dysfunctions in AD.As well as controlling spine structure, ATM can also be implicated in altering glutamatergic transmission. Importantly, by immunostaining and electrophysiological analyses, synaptic kainate receptors (KARs) have been shown to be impaired in a mouse model of AD, in addition to AMPA and NMDA receptor dysregulation . Of noteOverall, these data demonstrate a central role of ATM in the crossing pathways underlying AD pathogenesis. ATM is a messenger of cell death pathways triggered by Aβ but is a kinase that can control spine shape and synaptic transmission as well. Therefore, ATM can be considered a new key synaptic element able to regulate dendritic spine plasticity, required for proper brain function.In this review, starting from the assumption that AT patients display cognitive and often psychiatric symptoms hardly ascribable to the canonic role of ATM in DNA damage response, we discussed recent and less recent findings related to new meanings of DNA damage formation in neurons and new functions of ATM in neuronal physiology and pathology. Indeed, the evidence that, in response to physiological neuronal activity, DSBs generate in the promoters of stimulus-inducible genes directly leads one to conclude that the correct functioning of DNA damage response machinery is fundamental for proper neuronal function. Also, the excitatory-to-inhibitory switch of GABA, the developmental process occurring at the early postnatal phase necessary in mediating the hyperpolarizing action of GABA neurotransmitters, relies on DNA repair proteins. In particular, genetic studies and results collected with pharmacological inhibitors revealed ATM as a key player in this process. Changes in the GABA switch are at the bases of several neurodevelopmental diseases including autism spectrum disorders and, accordingly, the pharmacological tuning of ATM kinase activity ameliorates electrophysiological defects and cognitive abilities in animal models of autism. Thus, these findings extend the potential investigation of ATM to neurodevelopmental disorders and since, in neurons, DSB repair seems to specifically occur through the activation of the NPAS4–NuA4 complex, the pharmacological targeting of ATM in autism should not affect ability of neurons to repair DNA damages, as they are governed by completely different processes and protein repertoires. Atm−/− mice [The selective ability of ATM to control the GABA switch in the hippocampal but not in cortical structure is not surprising. Indeed, increased levels of reactive oxygen species (ROS) have been described in the striatum and cerebellum but not in the cortex of −/− mice . Also, r−/− mice . Finally−/− mice . Thus, tCollectively, while several studies have demonstrated the emergent involvement of ATM not only in AT but also in neurodevelopmental and neurodegenerative conditions, a further characterization is necessary to clearly identify (i) new and specific roles of ATM in different brain structures and (ii) consequences linked to its pharmacological inhibition. Results collected so far support researchers in expanding their interests to ATM in new and unexpected disorders.


To what extent does regenerative medicine with stem cell therapy help to address infertility issues for future clinical application?Regenerative medicine using different stem cell sources is yielding promising results in terms of protecting the ovarian reserve from damage and senescence, and improving fertility potential in various preclinical settings.Regenerative medicine using stem cell therapy is emerging as a potential strategy to address a number of issues in the field of human reproduction. Indeed, different types of adult and fetal mesenchymal stem cells (MSCs) have been tested with promising results, owing to their ability to differentiate into different tissue lineages, move toward specific injured sites (homing), and generate a secretome with wound-healing, proangiogenic, and antioxidant capacities.Guided by the checklist for preferred reporting items for systematic reviews and meta-analyses, we retrieved relevant studies from PubMed, Medline, and Embase databases until June 2023 using the following keywords: ‘mesenchymal stem cells’ AND ‘ovarian follicles’ OR ‘ovarian tissue culture’ OR ‘ovarian follicle culture’ OR ‘cumulus oocyte complex’. Only peer-reviewed published articles written in English were included.The primary outcome for the experimental strategies was evaluation of the ovarian reserve, with a focus on follicle survival, number, and growth. Secondary outcomes involved analyses of other parameters associated with the follicle pool, such as hormones and growth factors, ovarian tissue viability markers including oxidative stress levels, oocyte growth and maturation rates, and of course pregnancy outcomes.in vitro culture of granulosa cells, ovarian tissue and isolated ovarian follicles; ovarian tissue transplantation; and systemic or intraovarian injection after gonadotoxic or age-related follicle pool decline. Protecting the ovarian reserve from aging and gonadotoxic damage has been widely tested in vitro and in vivo using murine models and is now yielding initial data in the first ever case series of patients with premature ovarian insufficiency. Use of MSCs as feeder cells in ovarian tissue culture was found to improve follicle outcomes and oocyte competence, bringing us one step closer to future clinical application. MSCs also have proved effective at boosting revascularization in the transplantation site when grafting ovarian tissue in experimental animal models.Preclinical studies exploring MSCs from different animal origins and tissue sources in specific conditions were selected (n = 112), including: in vitro using various mammal experimental models and in vivo using murine models), there is still a lot of work to do before this approach can be considered safe and successfully implemented in a clinical setting.While preclinical results look promising in terms of protecting the ovarian reserve in different experimental models , Fonds Spéciaux de Recherche, and the Fondation St Luc. None of the authors have any competing interest to disclose.N/A. WHAT DOES THIS MEAN FOR PATIENTS?‘Regenerative medicine’ describes a potential clinical approach for managing various pathological conditions (i.e. diseases or injury) that have no current treatment options, including many in the field of human reproduction. The techniques involved are based on the use of mesenchymal stem cells (MSCs), which are non-specialized cells that can give rise to infinitely more cells of the same type, as well as other cell types. Stem cells have the potential to regenerate and produce signals that promote wound healing (i.e. tissue regeneration) in different organs. For this reason, various experimental strategies are under development to exploit the ability of stem cells to protect or restore fertility. More specifically, stem cells may help protect the ovary (and the follicles/eggs it contains) against different types of injury, caused either by the aging process or use of chemotherapy after a cancer diagnosis. Both conditions significantly decrease a woman’s fertility and chance of pregnancy. Would MSC infusion or localized therapy help repair damaged ovaries? We undertook a careful review of all studies that investigated any strategy using MSCs in either animal models or human studies, to provide evidence that MSCs could improve fertility outcomes. Studies that evaluated ‘ovarian reserve’—that is the reproductive potential left within a woman’s two ovaries based on number and quality of eggs—were our primary interest. The results showed that different types of MSCs have been tested in attempts to enhance fertility in various contexts. Among these, they improve follicle survival and growth, and are also able to reverse chemotherapy-induced ovarian damage and improve follicle pool survival by boosting ovarian re-growth of blood vessels. Based on recently gathered data, studies in regenerative medicine are yielding encouraging results in terms of restoring fertility. However, work is still needed to optimize techniques and test their safety before they can become available to patients.Regenerative medicine is emerging as a potential tool to manage various pathological conditions that have no current treatment. There is particular interest in reproductive medicine, since the number of ovarian follicles, which are the main functional units of the ovary and responsible for female fertility, is finite at birth and continues to fall during the reproductive lifespan, with no ability to regenerate , as well as other cell types, by differentiation (potency). They represent populations of non-specialized cells that have the potential to differentiate into specialized cellular subtypes . Stem ceThe present review will focus exclusively on fetal and adult stem cells since their use as therapeutic tools is not contentious and is actually considered the most promising for regenerative medicine and tissue engineering purposes. Fetal stem cells can be isolated from various surplus fetal tissues, such as amnion, chorion, amniotic fluid and the umbilical cord, and show greater multilineage differentiation capacity than adult stem cells. Adult, or somatic, stem cells are located in all organs and tissues to varying degrees, with the function of maintaining and repairing them , ovarian tissue, and isolated ovarian follicles; ovarian tissue transplantation; and systemic or intraovarian injection after gonadotoxic or age-related follicle pool decline. To this end, we took a systematic approach, reviewing all papers that investigated any of these strategies in either animal models or human studies. The primary outcome was evaluation of the ovarian reserve, with a focus on follicle survival, number, and growth. Secondary outcomes involved analyses of other parameters associated with the follicle pool, such as follicle-related markers like hormones and growth factors, ovarian tissue viability-linked markers like oxidative stress levels, oocyte growth and maturation rates and, of course, pregnancy outcomes.The aim of this review was to provide evidence of and information on use of MSCs to improve fertility outcomes. We explored MSCs from different animal origins and tissue sources in specific conditions, including: In line with preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines . Ethics in vivo administration of MSCs has been performed both locally (by intraovarian injections) and systemically (by i.v. or i.p. injection), a number of authors set out to investigate MSC homing capacities to different organs. To track injected MSCs, they implemented various approaches, including: viral transfection with green fluorescent protein in six studies  and BM-MSCs (38 studies). Other sources include AT-MSCs (22 studies), Men-MSCs (8 studies), AF-MSCs (7 studies), P-MSCs (7 studies), and S-MSCs (2 studies). Various animal models, including murine, ovine, equine, and human, have been applied to isolate and expand MSCs following different experimental designs. Since in vitro and in vivo in the presence of specific molecular signals, such as stromal cell-derived factor 1 (SDF-1), which is enhanced in damaged organs as well as by LIPUS. SDF-1 is a member of the chemokine family, able to drive cell homing through its link to the CXC4 receptor and activation of signals such as phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt)   membrane-bound vesicles secreted by cells after invagination of the plasma membrane, before being released into the extracellular space. They can contain proteins, such as cytokines and growth factors, as well as microRNAs (miRNAs) produced by stem cells for paracrine communication purposes, executing comparable functions to their cells of origin in various in vitro. Discarded medium is richer than isolated exosomes, as it also contains the entire free protein component constituting the secretome. It may, however, also contain discarded solutes from MSC metabolism, which could hamper the overall effect on follicle survival and growth. The only study directly comparing the impact of MSC-derived medium and MSCs themselves was performed on porcine cumulus–oocyte complexes (COCs) and no significant difference was observed in terms of oocyte maturation or embryo development  , a diminished ovarian reserve (DOR or POI), or an aging damage model by exposing them to H2O2  and bone morphogenic protein 15 (BMP15)  ; enhance (BMP15) ; and finin vitro .Ovaries were pretreated with chemotherapeutic drugs (cyclophosphamide and cisplatin) in three studies , survivin , whose presence was first confirmed in MSC This favorable paracrine signaling results in not only GC survival, but also broader beneficial effects on the ovarian reserve. Indeed, hormone function appeared to be restored, showing improved hormone values in many studies (decrease in FSH and increase in AMH and E2). Along with endocrine function restoration, effective protection of the follicle pool was also evidenced by greater numbers of oocytes and embryos  stress was investigated in one study as a potential trigger of follicle death, using markers like inositol-requiring enzyme 1α and glucose-regulated protein 78  recruited 20 patients with POI (<39 years of age) for a new study investigating both intra-arterial catheterization and stem cell mobilization in peripheral blood using granulocyte-colony stimulating factor. The second technique relying on peripheral blood, which is much less invasive than the original approach, appears to have a systemic effect on both ovaries after stem cell injection, thanks to their homing ability to distant damaged sites, as previously suggested by several animal studies  treated by intraovarian injection of AT-MSCs . The majority of studies consider follicle recovery after CHT exposure, with numerous in vitro culture technique toward legitimate clinical application. Similarly, MSCs have also proved effective at boosting revascularization of the grafting site in the context of ovarian tissue transplantation. Indeed, data from preclinical studies using human ovarian tissue xenografting models appear robust and reproducible, suggesting a possible role for MSCs in counteracting large-scale ovarian follicle pool loss after grafting, which is still one of the main limiting factors of the technique.Other promising clinical applications involving MSCs are emerging from the literature, in our quest to enhance fertility outcomes. Ovarian tissue co-culture with MSCs, used as feeder cells to improve follicle survival, growth, and oocyte competence, may serve to propel the ovarian tissue To sum up, all gathered data on the one hand show that regenerative medicine techniques are quickly gaining ground among the innovative techniques being developed for future clinical application in the field of reproductive medicine. On the other hand, there is still a lot of work to do before MSCs can be safely and effectively used to improve follicle outcomes in different clinical applications. We are moving in the right direction but need to delve deeper to advance our fundamental understanding of these multipotent cells.


Studies have shown separately that sexual minority populations generally experience poorer chronic health outcomes compared with those who identify as heterosexual, as do rural populations compared with urban dwellers. This Canadian national observational study explored healthcare patterns at the little-understood intersections of lesbian, gay, or bisexual (LGB) identity with residence in rural and remote communities, beyond chronic disease status. The secondary analysis applied logistic regressions on multiple linked datasets from representative health surveys, administrative hospital records, and a geocoded index of community remoteness to examine differences in the risk of potentially avoidable cardiometabolic-related hospitalization among adults of working age. Among those with an underlying cardiometabolic condition and residing in more rural and remote communities, a significantly higher hospitalization risk was found for LGB-identified persons compared with their heterosexual peers , adjusting for sociodemographic characteristics, behavioral risk factors, and primary healthcare access. In models stratified by sex, the association remained significant among gay and bisexual men  but not among lesbian and bisexual women . More research is needed leveraging linkable datasets to better understand the complex and multiplicative influences of sexual minority status and rurality on cardiometabolic health to inform equity-enhancing preventive healthcare interventions. A growing volume of literature from different countries and regions demonstrates that sexual minority populations tend to experience disparities in sexual, mental, and behavioral health outcomes, some of which may be syndemically damaging to cardiometabolic health ,2,3,4,5.The syndemics approach to understanding multiple drivers of cardiometabolic health inequalities has been grounded in the analysis that adverse outcomes are the result both directly and indirectly of heightened exposure to stressors from social stigma and discrimination associated with belonging to a sexual minority group, known as the minority stress model ,15,16,17Meanwhile, rural populations are widely shown to experience worse health outcomes than their urban peers, including adverse cardiometabolic outcomes and disproportionate premature mortality, likely associated with poorer access to primary care and other socioenvironmental inequalities ,19,20,21Little is known about cardiometabolic health outcomes at the intersection of disease progression, sexual minority status, and rural status. There has been a particular scarcity of healthcare research using representative samples distinguishing rural and urban LGB persons . This quThis study used linkable microdata files from three types of sources—population health surveys, routine hospital discharge records, and a geocoded remoteness index—to examine differences in hospitalization risk among sexual minority versus heterosexual adults of working age across rural and remote communities in Canada. General characteristics of each source can be found in First, to obtain sufficient sample sizes of LGB-identified respondents, we pooled ten years of interview data from the 2008–2017 Canadian Community Health Survey (CCHS), a large-scale cross-sectional survey program implemented by Statistics Canada to help inform health policies and programs. The CCHS collects information annually on a number of health-related variables among individuals living in private households, designed to represent 97% of the total population . The preTo obtain sufficient sample sizes of cardiometabolic-related hospitalizations, we then pooled ten years of administrative health data from the 2008/09–2017/18 Discharge Abstract Database (DAD), a national database updated annually  on separations from acute care institutions in 12 of the country’s 13 jurisdictions (excluding the province of Quebec) . Given CThird, we linked the CCHS and DAD datasets to the Index of Remoteness (IR), a continuous measure developed by Statistics Canada to gage all inhabited communities in terms of relative accessibility to services, road networks, and population centers . For easWe conducted descriptive and multiple logistic regression analyses, stratified by sex . The multiple regression models were adjusted for residential remoteness as well as a number of person-level confounding factors in terms of sociodemographics , behavior-related risk factors , healthcare access (having a regular provider), and health status . Bootstrapped sampling weights were applied to the linked data to ensure the population representation of the results and robust 95% confidence intervals (CIs), assuming the characteristics over the period of observation reflected the combined average. All (unweighted) sample and (weighted) population counts were rounded and vetted to meet Statistics Canada data privacy and disclosure protocols.The cohort sample included 202,820 respondents ages 18–59 years with valid sexual identity information, representing 14,190,300 person-years of exposure to the risk of cardiometabolic-related hospitalization. As seen in Significantly fewer LGB persons reported having a regular healthcare provider than heterosexual persons (80% versus 85%) . This wap = 0.36), after controlling for primary healthcare access and other characteristics (not shown). However, when limiting the analysis to higher-risk adults  residing in more rural and remote communities, a different picture emerged. Findings illustrated a significant association of belonging to a sexual minority group with cardiometabolic-related hospitalization; LGB persons were approximately four times as likely to be hospitalized as heterosexual persons , adjusting for other factors  , model 2n = 5400 LGB-identified and 195,420 heterosexual-identified respondents aged 18–59) and a range of other sociodemographic, healthcare, and community characteristics [This study used multiple pooled and linked record-level and geographically based microdata sources in a secondary analysis of one of the largest known national cohort samples of women and men of working age with complete information on sexual identity  sources do not distinguish health status as a contributor to hospitalization risk . When liA limitation of this study was the exclusion of survey respondents without valid sexual identity information, as well as the lack of capture of other dimensions of sexual orientation . While the proportion of nonresponses to the question on sexual identity was very small (0.97%), the characteristics of those who do not disclose such sensitive information according to predetermined categories may be different from those who do . AlthougThe present study reinforces the need for further research to support evidence-based clinical care to surmount stigma-related health disparities and meet the unique needs of sexual minority populations across different residential settings ,40. Stud


Plant virus nanoparticles (PVNPs) have garnered considerable interest as a promising nanotechnology approach to combat cancer. Owing to their biocompatibility, stability, and adjustable surface functionality, PVNPs hold tremendous potential for both therapeutic and imaging applications. The versatility of PVNPs is evident from their ability to be tailored to transport a range of therapeutic agents, including chemotherapy drugs, siRNA, and immunomodulators, thereby facilitating targeted delivery to the tumor microenvironment (TME). Furthermore, PVNPs may be customized with targeting ligands to selectively bind to cancer cell receptors, reducing off-target effects. Additionally, PVNPs possess immunogenic properties and can be engineered to exhibit tumor-associated antigens, thereby stimulating anti-tumor immune responses. In conclusion, the potential of PVNPs as a versatile platform for fighting cancer is immense, and further research is required to fully explore their potential and translate them into clinical applications. Nanomedicine, a burgeoning area of multidisciplinary research, has exhibited enormous potential for transformation into a highly innovative development . DespiteNanomedicines encompass a broad range of nanomaterials, showcasing a particle size that spans from 1 nm to more than 400 nm, and represent a highly diversified array of materials. These materials may consist entirely of metal, as exemplified by gold and silver nanoparticles , or may Plant VNPs have been examined as an exclusive category of nanocarriers for biomedical applications, as documented in previous research . In addiPlant VNPs exhibit either a rod shape (tobacco mosaic virus (TMV) and potato virus X (PVX)) or an icosahedral shape (cowpea mosaic virus (CPMV)). These differing shapes elicit distinct nanoparticle responses in vivo. Tobacco mosaic virus is capable of assembling into VLPs without necessitating drug payload conjugation on the nanoparticle surface or within its inner channel, albeit to a limited degree. In contrast, potato virus X requires its RNA genome for self-assembly and can only carry a payload on its outer surface. Cowpea mosaic virus, on the other hand, can self-assemble into empty virus-like particles in the absence of its RNA genome and can therefore contain a payload both internally and externally within its protein shell.Despite being non-infectious in humans, the multivalent, repetitive coat protein assemblies of the VNPs and VLPs function as pathogen-associated molecular patterns (PAMPs), serving as danger signals to the immune system . VNPs adFor instance, TMV, PVX, and papaya mosaic virus VNPs are capable of eliciting robust cellular immune responses against fused antigenic epitopes . The potHence, VNPs function as exemplary epitope delivery vehicles for antigens and adjuvants of great applicability in vaccine and immunotherapeutic formulations . The preIn this review, we present a multitude of examples to analyze the manner in which the structural composition of plant viruses contributes to their efficacious utilization in the realm of cancer diagnostics and therapy. Furthermore, we delve into the origins of the implementation of plant virus architecture as nanoparticles in medical applications, along with the prospects of their propitious employment as pioneering cancer immunotherapies.For over a century, the history of the tobacco mosaic virus (TMV) has been significant and noteworthy. It all started when Beijerinck identified the mosaic disease of tobacco as a fluid that is capable of spreading, which was later referred to as a “virus” in modern language . TMV gotTMV represents the Tobamovirus genus and is part of the alphavirus-like supergroup. The virions of TMV are rod-shaped, measuring 300 × 18 nm, and have a hollow center that contains 95% capsid protein (CP) and 5% RNA. The capsid protein (CP) subunits interact with 3 nts in a helical pattern around the RNA. The virions remain stable for many decades and their ability to infect sap remains unchanged even after being heated to 90 °C .TMV’s application as a prototype system has been driving the field of virology research even in modern times. TMV was the first virus to go through chemical purification , detectiThe genome of TMV, consisting of a single positive-sense RNA molecule, spans 6395 nucleotides (nts) and encompasses four open reading frames (ORF) . The 5′-TMV is presently being employed extensively as a tool for biological research and biotechnology applications . VariousPVX is a plant virus that belongs to the Potexvirus genus of the Alphaflexiviridae family. It is regarded as the type member and is one of the oldest known viruses to infect potato plants, with scientific publications dating back to . This viPVX is a type of plant virus whose virions are made up of flexuous filaments that measure about 460–480 nm in length, 13 nm in diameter, and with a helical pitch of 3.4 nm. The genome of PVX is around 6.4 kb long and has both a 5′ cap and a 3′ poly(A) terminus. It consists of five open reading frames, with four considered essential for cell-to-cell and systemic movement, including one that encodes the viral replicase. Infected cells tend to have X-bodies, or cellular inclusions located near the nucleus, commonly observed in their vicinity .PVX is recognized as one of the top 10 plant viruses in molecular plant pathology due to its significant contributions as a model for studying plant–virus interactions. It has played a crucial role in advancing plant biology, including the development of antiviral gene silencing mechanisms, creating viral vectors for foreign gene expression, using green fluorescent protein (GFP) to track plant virus infection, discovering the function of viral movement proteins in transport through plasmodesmata, and cloning the Rx gene in potato through map-based cloning. The Rx gene is considered the first antiviral R gene isolated from potato ,36,37.PVX has greatly contributed to the initial characterization of the homology-dependent post-transcriptional gene silencing (PTGS) pathway, which is responsible for destroying viral RNAs. The PTGS mechanism targets highly structured regions of viral genomes or replication intermediates that can be cleaved by plant-specific Dicer enzymes, resulting in the formation of siRNAs . These studies were crucial and involved using PVX as an expression vector carrying cDNAs that encode foreign sequences such as green fluorescent protein (GFP), enabling the monitoring of siRNA production and mRNA turnover ,39.Improved PVX-based vectors are considered suitable for expressing any desired gene in PVX host plants. These vectors are favorable for protein overexpression, investigation of protein functions in plants, or utilization in virus-induced gene silencing mechanisms .The CPMV belongs to the Comovirus genus and is the representative member of this group. The Comovirus genus features a total of 13 other members that are part of the larger Comoviridae family . The famNicotiana benthamiana has proved to be an important experimental host. The virus is transmitted by various beetles that have biting mouthparts, and it has been reported in Africa, the Philippines, and Iran, but not in North and South America  bombesin-(7–14) can target the gastrin-releasing peptide receptor that is over-expressed in human prostate cancers. The phenomenon of tumor homing was observed through the utilization of human prostate tumor xenografts on the chicken chorioallantoic membrane model, through intravital imaging techniques .The filamentous PVX can be engineered to display green fluorescent protein (GFP) or mCherry as probes for optical imaging in human cancer cells and within a preclinical mouse model . Plant v3+, Zr4+, or Gd3+), or fluorescent dyes  and subjected to 808 nm irradiation [These unique structural and chemical properties of PVNPs make them highly suitable for combining therapeutic and diagnostic agents’ potentialities for in vivo applications . Metal–padiation . Gd-loadadiation . The capadiation .Engineered TMV-MOF  hybrid nanoparticles augmented the retention of these VNPs in murine models . ParticlIn yet another study, TMV VNPs were modified to target VCAM-1, the vascular cell adhesion molecule, and these particles were loaded with Gd-dodecane tetraacetic acid (Gd-DOTA). This led to highly sensitive recognition and visualization of atherosclerotic plaques in ApoE-/- mice, employing low doses of contrast agent and this resulted in enhanced relaxivity and moderate tumbling of the Gd-DOTA-TMV carrier with improved signal-to-noise ratio. Moreover, these coupling complexes showed greater imaging sensitivity, thus affording a 40-fold decrease in Gd dose compared to the standard clinical doses .Recent studies have shown that some PVNPs alone are immunogenic and highly effective as a monotherapy . Toward + and CD8+ T cell responses and promotes systemic tumor-specific cytotoxic CD8+ T cell activity [PVNP ISV is a treatment for solid tumors that involves several mechanistic processes. Firstly, the PVNP is transported into the tumor and assimilated by immune cells. Secondly, these activated innate immune cells release cytokines and chemokines to attract more immune cells to combat the tumor. Thirdly, T-lymphocytes become activated and are lured to the tumor to combat tumor cells with their cognate antigens. This results in tumor lysis. Finally, the activated T-lymphocytes travel throughout the body attacking metastatic tumors . For exaactivity .In the context of immunotherapy, PVNPs can also act as a nanocarrier for tumor antigens, or immune adjuvants for improving immunotherapeutic efficacy of vaccines ,105. In The integration of PVNP-based monotherapy and any therapy that induces tumor cell lysis and release of tumor-associated antigens (TAAs) might be one of the possible strategies to overcome complexity and tumor heterogeneity . The comWhen utilizing PVNPs, there are numerous challenges and limitations to consider. Firstly, in vivo biological barriers such as interactions with serum, immune cells, or antibodies can impact the use of native or functionalized PVNPs in clinical settings. Secondly, anti-PVNP antibodies can alter the way immune cells interact with PVNPs, potentially leading to their elimination before reaching the target site. Thirdly, the formation of protein corona (PC) can impede the development of PVNPs for in vivo applications. Fourthly, since PVNPs often target non-immune cells or tissues, clearance by the immune system should be minimized. Fifthly, expressing certain peptides genetically as part of coat proteins may impair capsid formation, which is necessary for effective infection and PVNP generation in plants. In the context of in situ vaccinations, there is also concern about viral escape from the site of injection, which could result in adverse side effects, in addition to the concern regarding virotherapy and the presence of neutralizing antibodies. Undoubtedly, the presence of existing circulating antibodies can increase the risk of adverse effects.Although PVNPs are safe for animals, some regulatory issues need to be considered. PVNPs require high throughput manufacturing, dedicated facilities, and adaptations to plant molecular farming. Further research on regulatory pathways, immune system effects, and novel administration methods, such as chimeras or semi-synthetic nanoparticles, is needed. PVNP production processes must adhere to manufacturing standards and quality control measures to ensure safety and consistency, as determined by regulatory agencies.PVNPs offer significant potential for various therapeutic applications, including but not limited to vaccines, imaging agents, cancer therapies, and drug delivery. The ongoing research endeavors to optimize VNP design, functionalization strategies, and targeting approaches to enhance their therapeutic efficacy. The capacity to modify viruses is constantly expanding, allowing for new therapeutic strategies. By incorporating bioactivatable aspects into the design of innovative viral reagents, researchers can create more flexible and effective treatment options. Directed evolution using mutagenesis strategies can be used to assemble virus libraries that meet specific objectives. Bioinformatics analysis can align different viral capsid genes/protein sequences or protein structures, leading to the generation of novel viruses with unique properties. Computer technologies like machine learning and mathematical modeling can also aid in the development of PVNPs for clinical cancer immunotherapy. In addition, collaborative interdisciplinary partnerships and investments in research infrastructure are crucial in stimulating innovation, expediting scientific progress, and revealing novel possibilities for VNP utilization. Nanoengineering research on VNPs is advancing their design, fabrication, and manufacturing, with various formulations and approaches on the cusp of clinical impact. The structural versatility of VNPs also presents new clinical opportunities across various dose forms. Given the incremental progress of VNP technology in the clinic, investigating pharmaceutical formulation technology may prove instrumental in improving prospects for further translational development. At the preclinical stage, conducting comprehensive research on the formulation of viral nanoparticles (VNP) in various dosage forms would facilitate the modification of VNP’s shelf life stability and compatibility with clinically significant routes of administration. This would in turn enhance the efficacy and safety of the product, while also providing a forecast for future costs and patient convenience.Conventional cancer treatment involves chemotherapeutic drug delivery through the circulatory system, causing dispersion and premature drug release before the tumor site. Drug dosage must be significantly increased to ensure efficacy at the target site. This approach may cause unwanted damage to cells and tissues. Precision cancer medicine aims to improve drug efficacy by targeting nanoparticles, demonstrating clinical potential. Plant VNPs are promising due to their self-assembling architecture and easy production. PVNPs offer quality control for uniform particle shape and size, unlike synthetic nanomaterials. Plant VNPs offer biocompatibility, efficacy, low cost, easy manufacturing, and optimal cargo loading capacity. Plant VNPs offer biodegradability, genetic engineering customization, and superior modification efficacy over synthetic nanomaterials, which rely on chemical synthesis and are persistent in the body. The fact that PVNPs can be used as theranostics for cancer detection and treatment could be a game changer for health outcomes in low- and middle-income countries. In these parts of the world, health burdens will increase and strain what little infrastructure is currently available for escalating elderly populations. The potential of plant VNPs could mitigate future health challenges for populations around the planet, particularly in the Global South. It is for this reason that plant VLPs must continue to be under exploration as a plausible solution for future health challenges.


Complete en bloc surgical resection offers the best opportunity for the cure of primary retroperitoneal sarcomas (RPS). The potential for disease recurrence, in the form of both loco-regional recurrence and distant metastases, underpins the rationale for postoperative surveillance. There is a paucity of high-quality evidence underpinning follow-up for RPS patients, and most practice guidelines draw from expert opinion and evidence from soft tissue sarcomas of the extremities. The available observational retrospective data analysis has failed to demonstrate that high-intensity radiological surveillance improves the overall survival in patients. The lack of a robust evidence base has given rise to variations in approaches to post-operative surveillance strategies adopted by specialist centres managing RPS across the world. More high-quality prospective research is needed and planned to more clearly support surveillance approaches that balance oncologic outcomes, patient-centric care, and health service value. Risk stratification tools exist and are available for use in routine practice. Their use will likely support more individualised post-operative surveillance moving forward. Surveillance will likely be underpinned by serial radiological imaging for the medium term. However, developments in genomics offer hope for biomarkers such as ctDNA to impact patient care positively in the future and further support individualised patient care pathways. Retroperitoneal soft tissue sarcomas (RPS) are rare malignant tumours with a broad set of histological subtypes. Currently, the best hope for cure is through complete en bloc surgical resection at primary presentation, incorporating adherent adjacent viscera with the specimen . ThroughCurrently, there is a paucity of high-quality evidence underpinning post-operative surveillance for RPS patients, and most practice guidelines draw from expert opinion and evidence from soft tissue sarcomas of the extremities. This is problematic due to the substantial differences in both methods of detecting recurrence and the consequences for patient outcomes . Small oMore frequent surveillance strategies can be a substantial burden. They impact health services through costs associated with radiological imaging and health care worker time as well as patients who have to take time away from their own productive economic and social activities. The psychological impact of intensive surveillance may be complex. Some patients experience anxiety and heightened awareness of a cancer diagnosis around the time of surveillance investigations, whilst others find solace in the reassurance of ongoing imaging. The cost-effectiveness and impact on quality of life of postoperative surveillance for primary RPS are yet to be established.In light of the diversity of RPS subtypes, some centres have adopted a standard protocol for all postoperative patients, regardless of final histological diagnosis and recurrence risk. This pragmatic approach has advantages for standardising implementation within a health service. Other centres adopt a surveillance protocol stratified according to the risk of recurrence derived from the final tumour grade. The European Society for Medical Oncology guidelines is one example advocating for a binary low- vs. high-risk-based stratification . It may Similar to RPS, extremity soft tissue sarcoma patients undergo routine post-surgical surveillance. There are some data from randomised studies available to extrapolate from and inform management in RPS patients. The Trial for Optimal Surveillance in Sarcomas (TOSS)  was a raThe Surveillance After Extremity Tumour Surgery (SAFETY) trial is a multi-centre 2 × 2 factorial randomised controlled trial of patients with resected non-metastatic primary soft tissue sarcoma . In a siFocusing on patient anxiety through the Fear of Cancer Recurrence Inventory scores as its primary outcome, with other PROMs and oncological secondary outcomes, another ongoing trial (NCT04751409) is evaluating sarcoma surveillance regimes . This stA modelling study using data from a relatively small cohort of extremity STS patients in Australia determined that CT chest alone as a surveillance imaging modality is more cost-effective than magnetic resonance imaging (MRI) alone or in combination with CT chest and computerised tomography positron emission tomography (CTPET) alone . HoweverWhilst conducting rigorous randomised clinical trials studying surveillance regimes for sarcoma patients is difficult, such research is certainly warranted to strengthen the limited current evidence base to inform future best practice recommendations, a fact widely accepted by sarcoma clinicians . ExposinCurrently, decisions for sarcoma patient follow-up regimes may not be evidence-based, with marked variation in the practice of both imaging techniques and intensity of follow-up ,20,21. VEarlier detection of LR of RPS within the abdomen through contrast-enhanced CT may allow for a better prospect of resection and avoid morbid sequelae associated with large recurrences, such as gastric compression . CT is tMore intensive follow-up regimes are recommended by these organisations for those RPS patients stratified as having a higher recurrence risk. Closer surveillance intervals, typically every 3 months, are recommended for between 2–3 years following primary resection.The 2021 US NCNN guidelines stipulate patient assessment at 3–6 months for 2–3 years, followed by every six months until the fifth year and annually thereafter. These patient assessments should be conducted with both physical assessment and radiological imaging by way of CT of the chest, abdomen, and pelvis, with abdominal MRI an acceptable alternative for abdominal recurrence examination .The TARPSWG guidance consists of a consensus document that advocates for lifelong surveillance following RPS resection given the disease’s enduring potential risk of recurrence . This phThe ESMO guidelines do not differentiate recommendations for RPS from other sarcomas . They rePoor patient survival outcomes are associated with recurrent RPS ,27. The Data-driven decision-making can use individual patient risk estimates for both recurrence and risk of death, which can again be derived from nomograms after surgery for the first recurrence. These can help stratify patients into higher-risk categories for whom more frequent surveillance strategies may be adopted. Furthermore, the intensity of follow-up may also increase following a second or subsequent surgically resected recurrent disease because the disease-free period is likely to shorten.High-grade LPS infers a higher risk for both LR and DM compared to LMS, for which DM, primarily in the lung, is the most common manifestation of disease recurrence. A number of patient and tumour factors influence the risk of further disease following pulmonary metastasectomy; these include older age, a disease-free interval of under a year, synchronous disease, histological type, and treatment modality . A greatThere are several genetic syndromes associated with an increased risk of RPS. Neurofibromatosis type 1 (NF-1) is a complex condition inherited in an autosomal dominant manner. NF1 tumour suppressor gene germline mutations underlie the disorder. In addition to dermal neurofibromas, patients frequently have cutaneous manifestations such as Lisch nodules and café-au-lait spots. Skeletal abnormalities, brain tumours, and learning disabilities are common, in addition to a predisposition to peripheral nerve tumours, including malignant peripheral nerve sheath tumours (MPNST) . While MConstitutional pathological TP53 gene variations lie behind the increased cancer risk in Li-Fraumeni and TP53-related heritable cancer syndromes. They predispose to a large number of malignancies in addition to sarcoma, with a cancer diagnosis almost certain by the seventh decade of life . RoutineWith the aspiration to achieve data-driven, patient-centred, individualised care, tools to provide actionable estimates of prognosis for patients diagnosed with RPS are a valuable contribution. Nomograms devoted to this patient group have provided a marked improvement in this aspect of patient care over the past few years.A number of disease-, patient-, and therapy-specific factors are implicated in the risk of adverse oncological events (LR and DM) and overall survival after surgical excision of RPS. The specific histological subtype of RPS tumours, as well as with their grade and size, clear resection margins, and patient age are implicated in patient prognosis . ModelliIn addition to nomograms based on factors present at the time of index resection, prognostic prediction modelling at the time of the first LR from the RPS have also been developed. The prediction tool models disease-free and overall survival at six years. This initiative from the TARPSWG incorporates patient age at the time of the second operation, tumour multifocality and grade, completeness of resection at the second operation, histological subtype, use of chemoradiotherapy at the primary operation, and how many organs were initially resected . This stAs already mentioned, the risk of LR persists for many years for some histological subtypes, specifically well-differentiated LPS and low-grade dedifferentiated LPS . HoweverFor informing patient surveillance strategies stratified by risk, a dynamic prognostic modelling tool may allow patients to move between higher and lower risk pathways during their follow-up. This offers an evidence-based method for equitably deploying finite health system resources and minimising unnecessary patient follow-up burden. Residual recurrence risk can be quickly calculated at each follow-up encounter to revisit the most appropriate pathway for ongoing surveillance.Although intensive short-interval follow-up is advocated for certain post-surgical RPS patients , the benMore research is needed into the patient-reported outcomes associated with postoperative surveillance. Surgical treatment for RPS may involve extensive multi-visceral resection. A 1-year prospective cohort study from Milan found a post-operative Clavien Dindo complication grade 3 or higher in one-quarter of patients with a 1.3% mortality rate. Enduring neuropathic pain was found in two fifths of patients, particularly if some psoas muscle was resected. Despite this, there was a non-significant increase in quality of life for patients compared to baseline, with comparable scores to the general local population .A thematic analysis of interviews with patients and families treated for predominantly extremity sarcomas has shed some interesting light on patient experience and perspectives around surveillance . A past In the absence of a strong evidence base for meaningful patient survival benefit, caution should be exercised before routinely embarking on high-intensity surveillance for all post-surgical RPS patients. Similarly, such a well-intentioned practice may be causing unintended harm through psychological patient burden and overconsumption of limited health service resources.Contemporary management of recurrent RPS, both LR and DM, often includes a period of further expectant monitoring to establish the biological behaviour of the disease and for the presence of any additional synchronous occult disease to become clear. Interventions are rarely initiated immediately after identifying a possible recurrence, leading to a substantial time lapse between detection and active therapies. Therefore, the intrinsic delay associated with less intensive surveillance protocols for detecting recurrent disease may not lead to observable patient harm.To address the evidence gap in post-RPS resection surveillance, hope is on the horizon by way of the SARveillance trial . This trAny eligible sarcoma patient who does not wish to participate in the randomised protocol of SARveillance will be able to choose their own level of surveillance intensity as part of a patient preference arm . This isThe study’s analysis will also include health economics, and prospective data will help to develop and validate a recurrence risk prediction model. If able to deliver on its intentions, SARveillance should be able to establish and drive cost-effective, clinically efficacious, patient-centred standardisation and follow-up protocols for broad application to sarcoma patients globally.Liquid biopsy is a term for the genomic technologies able to identify, quantify, and profile material derived from tumours to be detected in the peripheral circulation and elsewhere . This noOngoing post-operative follow-up for patients with resected retroperitoneal sarcoma is routine internationally, but with substantial variation in practice, reflecting the current paucity of high-quality evidence to guide practice. More high-quality prospective research is needed and planned to more clearly support surveillance approaches that balance oncologic outcomes, patient-centric care, and health service value. Risk stratification tools exist and are available for use in routine practice. Their use will likely support more individualised post-operative surveillance moving forward. For the medium term, surveillance will likely be underpinned by serial radiological imaging. However, developments in genomics offer hope for biomarkers such as ctDNA to impact patient care positively in the future and further support individualised patient care pathways.


Chromatin modifications and epigenetics are important pathogenesis mechanisms leading to various neurologic and psychiatric disorders including epilepsy, drug addictions, depression, autistic spectrum, learning disabilities and schizophrenia. Recently, the disruption of the chromatin remodeling BAF complex has been linked to several neurodevelopmental syndromes, commonly referred to as PBAFopathies.Here, we review the implication of PBAF complex genes in schizophrenia and we outline syndromes caused by mutations in these chromatin-modifying enzymes labelled as PBAFopathies to discuss the functional consequences of reported mutations in the literature.We comprehensively review the scientific literature using Pubmed database and other search platforms such as Google scholar to state the role of PBAF complex genes in schizophrenia and to reveal the most frequent genes mutations reported in literature.Our review revealed that the human analogs of the subfamily of ATP-dependent chromatin remodeling complexes, which are known in eukaryotes as the mammalian SWI/SNF complex  are crucial for the regulation of genes expression and cells differentiation. They involve two well-known complexes which are SWI/SNF-A (known as BAF complex) and SWI/SNF-B (known as Polybromo-associated BAF or PBAF complex). SWI/SNF is a multisubunit chromatin-remodeling complex that performs fundamental roles in gene regulation, cell lineage specification, and organismal development and mutations that inactivate SWI/SNF subunits are found in nearly 20% of human cancers and in various developmental disorders, forming a continuum or spectrum of diseases. Since the first description of BRG1/BRM mutations in schizophrenia, other mutations of the SWI/SNF subunits have been reported: SMARCA1, SMARCA2, SMARCA4/BRG1, etc. Single nucleotide polymorphisms (SNPs) in these and other genes of PBAF have been also associated with schizophrenia.This review focuses on the PBAF SWI/SNF subunits to find out if schizophrenia may be considered as a member of the spectrum of PBAFopathies.None Declared


Diabetic ulcers (DUs) are one of the most serious complications of diabetes mellitus. The application of a functional dressing is a crucial step in DU treatment and is associated with the patient's recovery and prognosis. However, traditional dressings with a simple structure and a single function cannot meet clinical requirements. Therefore, researchers have turned their attention to advanced polymer dressings and hydrogels to solve the therapeutic bottleneck of DU treatment. Hydrogels are a class of gels with a three-dimensional network structure that have good moisturizing properties and permeability and promote autolytic debridement and material exchange. Moreover, hydrogels mimic the natural environment of the extracellular matrix, providing suitable surroundings for cell proliferation. Thus, hydrogels with different mechanical strengths and biological properties have been extensively explored as DU dressing platforms. In this review, we define different types of hydrogels and elaborate the mechanisms by which they repair DUs. Moreover, we summarize the pathological process of DUs and review various additives used for their treatment. Finally, we examine the limitations and obstacles that exist in the development of the clinically relevant applications of these appealing technologies.This review defines different types of hydrogels and carefully elaboratethe mechanisms by which they repair diabetic ulcers (DUs), summarizes thepathological process of DUs, and reviews various bioactivators used for theirtreatment. Diabetes mellitus is a chronic, long-term worldwide epidemic disease , 2. AccoDiabetic ulcers (DUs) are one of the most serious complications of diabetes mellitus, in particular diabetic foot ulcers (DFUs) , and theThe standard treatment for DUs includes debridement, antibiotics to control the infection, foot decompression, and closure with a dressing . CliniciAt present, there are two main concepts in academia in the field of wound healing, dry healing and wet healing , and medIn this review, we review the pathogenic process of DUs, define the different types of natural polymeric hydrogels used for DU therapy, and elaborate on the mechanisms by which hydrogels repair these wounds. In addition, we summarize the bioactive substances used for DU treatment and discuss their advantages and disadvantages and propose future directions. Finally, we debate the challenges and prospects for the further clinical translation of hydrogels. We hope to provide novel ideas and a theoretical basis for regenerative medicine and tissue engineering research.The DU healing process does not follow the general wound healing pattern  and is often prolonged due to the chronic and persistent inflammatory phase, which is the result of the interaction of multiple risk factors. Hyperglycemia, the initiating factor of DUs, leads to vasculopathy and neuropathy; and under the combined effects of the above lesions, diabetic wounds initially form. Moreover, the combination of persistent inflammation, excessive oxidative stress, and infection leads to the gradual deterioration of diabetic wounds to eventually form chronic nonhealing wounds, i.e., DUs.Hyperglycemia is a factor that initiates abnormal metabolic pathways in patients with DUs and is the main cause of prolonged wound healing, which presents as two main types of damage: angiopathy and neuropathy. The mechanisms underlying the chronic complications of hyperglycemia have not been fully elucidated. Currently, many researchers have focused on four pathways: the polyol pathway, protein kinase C (PKC) pathway, hexosamine biosynthesis pathway (HBP), and the accumulation of advanced glycosylation end products (AGEs)+ as a coenzyme. Under normal conditions, only a small amount of glucose enters the polyol pathway -butana-mide (NB) groups to encapsulate lyophilized amnion-derived conditioned medium (AM-CM)  and D-mannuronic acid (M) structural units with either continuous G chain segments (GGGG) and M chain segments (MMMM) or alternating MGMG chain segments , 169. ItThe most useful property of alginates is their ability to react with cations  to produce strong gels or insoluble polymers. Wang et al. developed a pH-responsive calcium alginate hydrogel loaded with protamine nanoparticles and hyaluronan oligosaccharide (HAO). Ca-alginate is used as a pH-sensitive dressing because of its increased abilities to swell and disrupt hydration in alkaline wound fluid in DUs. Mediated by protamine nanoparticles, this hydrogel showed significant inhibition of both gram-positive and gram-negative bacteria, reducing the chronic inflammation caused by the bacteria at the wound site. In addition, the hydrogels promoted angiogenesis in diabetic wounds through HAO-mediated enhancement of vascular endothelial growth factor (VEGF) expression, thereby accelerating the wound healing process . Excessi3+). Antibacterial experiments showed that the PVA-SA-rGO-Tb3+ hydrogels inhibited S. aureus and P. aeruginosa biofilms, and the antibacterial activity improved by 3.5 and 2 orders of magnitude compared with the PVA-SA-rGO and PVA-SA-Tb3+ hydrogels, respectively. More importantly, since the antibacterial effects of the PVA-SA-rGO-Tb3+ hydrogel are independent of antibiotics, there is no need to worry about the development of organismal drug resistance [In recent years, semisynthetic hydrogels combining alginate and synthetic polymers have been favored. Chen et al. synthesized novel tea polyphenol nanospheres (TPNs) and encapsulated them in PVA/alginate hydrogels (TPNs@H). Animal experiments and molecular mechanistic studies demonstrated that TPNs@H could promote wound healing in diabetic rats by regulating the PI3K/AKT signaling pathway . Wang etsistance .2+) and sodium alginate (SA) via dynamic coordinate and hydrogen bonds. Histidine is cross-linked with zinc ions (Zn2+) and sodium alginate (SA) via dynamic coordinate and hydrogen bonds, respectively, forming a histidine-sodium alginate-Zn2+ (denoted as HSZH) hydrogel. In vivo experiments showed that the mean healing time in the HSZH group was approximately 13 days, while the complete closure time in the control group was approximately 27 days. The HSZH hydrogel with double dynamic key crosslinking has a strong ability to promote wound healing, and the healing rate is more than 100% higher than that of the control group. This work provides a new strategy for designing wound dressing materials in which weakly cross-linked materials based on tissue-friendly small molecules heal wounds more effectively than highly cross-linked materials based on long-chain polymers [It is important to note that the hydrogels in the above study  were synthesized based on long-chain polymers. As a result, these hydrogels cannot be used directly for tissue regeneration, and they take at least a few days to degrade in the wound, which may prolong the regeneration time. Yao et al. therefore developed a new healing hydrogel based on histidine. Histidine is cross-linked with zinc ions  . Due to (Table ). Wang et al. prepared a GelMA hydrogel loaded with VH-EVs for the treatment of diabetic wounds. VH-EVs are formed by extracellular vesicles from epidermal stem cells coated with VH-298 (a stabilizer of HIF-1α) , and OCS-polypyrrole conductive nanoparticles. Conductive hydrogels combine the advantages of hydrogels and conducting polymers (CPs) to provide suitable electrical conductivity and mechanical properties for neurovascular regeneration. In vitro and in vivo studies have shown that the hydrogel can induce neurovascular regeneration by increasing the intracellular Ca2+ concentration, thereby promoting protein phosphorylation in the MEK/ERK and PI3K/AKT pathways. The wound model of diabetic rats further demonstrated that conductive hydrogels based on ECM can promote collagen deposition and diabetic wound regeneration. Compared with previous studies, this study provides us with a new idea to promote diabetic wound neurovascular regeneration . Guo et GelMA as a tissue engineering biomaterial has attracted more and more attention in recent years, because GelMA provides biological support for cells and maintains specific physical and chemical properties. There are many laboratory studies on GelMA hydrogels, but there are still many problems before clinical application, including the standard of GelMA synthesis, the standard of gel time, and the safety standard of hydrogel materials. In addition, the use of photoinitiator is unavoidable in order to synthesis hydrogel. We need to ensure that all introduced ingredients are non-toxic and that the degradation components of the hydrogel dressing do not negatively affect the system. We believe that with the continuous development of research, GelMA hydrogel and its composites will surely play a greater role in repair, tissue engineering, controlled release of drugs and other fields.Cellulose is one of the most widely distributed and abundant polysaccharides in nature. In 1838, the French chemist Anselme Payen isolated cellulose from plant fibers using nitric acid and determined its chemical structure . Cellulo® gel has shown limitations in clinical practice, with a 15-gram tube of hydrogel costing about $1,300, making it unaffordable for many diabetic ulcers.Modified cellulose is a hydrophilic material synthesized by the separation and ring opening of polysaccharide hydroxyl groups and propylene oxide under strong alkaline conditions. Commonly used modified cellulose materials include carboxymethyl cellulose (CMC), hydroxypropyl cellulose,and hydroxypropyl methyl cellulose, among which CMC is widely used in wound dressings due to its good biodegradability, histocompatibility, and ability to promote fibroblast proliferation and migration. Regranex® (Becaplermin Gel), a mixture of recombinant human platelet-derived growth factor (rh-PDGF) and carboxymethyl cellulose (CMC), is currently the only FDA-approved hydrogel for the treatment of DFU. Regranex® promotes DU wound healing by promoting fibroblast proliferation, collagen deposition, and accelerated neovascularization. A multicenter, double-blind randomized controlled trial showed that, compared to a placebo gel, Regranex® 100 ug/g significantly increased the incidence of complete wound closure by 43% and decreased the time to achieve complete wound closure by 32% . DespiteTo better help patients, scientists are conducting more research on hydrogels to treat DU. Wang et al. prepared a new composite hydrogel consisting of carbomer 940 (CBM) and CMC loaded with natural polysaccharides derived from the herbal residue of Periplaneta americana. The ethanol extract of P. americana has been developed into a clinical patent liquid preparation, Kangfuxin, which was approved by the China Food and Drug Administration and has been used to treat various skin or mucosa injuries for over 40 years. In vivo experiments showed that the hydrogels accelerated wound healing in a diabetic model rat by promoting wound closure, collagen deposition, M2 macrophage polarization and angiogenesis . Pu et aIn recent years, the preparation of high-performance composite hydrogels by using highly crystalline, hard cellulose for reinforcement has become common. Wang et al. successfully constructed highly efficient self-healing hydrogels by forming dynamic covalent Schiff base bonds between aldehyde-modified methyl-cellulose (MC-CHO) and chitosan-grafted poly(ethylene glycol) (CS-g-PEG). Due to the presence of Schiff base bonds, the initial shape of the gel network is conserved at low strain, while the gel network is broken at large strain. When the strain oscillation returned to a lower value (1%), both modules immediately returned to their initial values, proving that the hydrogel network recovered rapidly after failure. After three cycles, the recovery G′ of the hydrogels was still equivalent to the primary value, indicating that the hydrogel networks were repeatable with the same efficiency. The addition of placental mesenchymal stem cell-derived exosome (PMSC-Exo) endosomal hydrogels with the properties of promoting angiogenesis and inhibiting apoptosis constructed a new platform for diabetic wound healing .(Table ), but there are still some problems to be solved. First, the network structure of traditional cellulose hydrogels has no stress dispersion mechanism, and small external forces can cause the destruction and collapse of the hydrogel structure. Second, although researchers have been able to improve the mechanical strength of cellulose hydrogels by crosslinking or introducing reinforcing components, these two strategies are cumbersome and will affect the biocompatibility and degradation of hydrogels to varying degrees [Notably, some properties of cellulose hydrogels can indeed relieve the limitations of existing hydrogels to some extent Table , but the degrees . TherefoPolysaccharides such as chitosan, sodium alginate and HA are soft in nature, and if used alone to prepare hydrogels, the gel materials are soft and weak and display poor mechanical properties and low mechanical strength . If synt (Table ).Wound hyperglycemia-mediated vasculopathy and neuropathy can cause decreased vasoconstriction and diastolic function and reduced self-regulation of skin blood flow, causing impaired blood circulation in the distal limb. In addition, persistent chronic inflammatory reactions, as well as microbial infections, cause impaired neovascularization, thus limiting the transport of oxygen and nutrients. Therefore, certain substances need to be delivered to accelerate the healing of diabetic wounds. In this section, we will provide a further overview of the various active ingredients used in the treatment of DFUs and their functions and mechanisms of action Table .Table 7BStem cells are a class of cells derived from embryonic, fetal or adult tissues that have a strong capacity for self-renewal and self-replication under specific conditions and the potential to differentiate into a variety of cells, tissues and organs. In recent years, stem cell isolation and culture techniques have been developed, bringing new hope for the treatment of patients with DUs. The mechanism by which stem cells promote wound healing is still under investigation, but it is clear that stem cells differentiate into vascular endothelial cells, fibroblasts and smooth muscle cells, promoting the formation of new functional blood vessels, bringing oxygen and nutrients to the ulcerated wound, discharging the accumulated carbon dioxide and metabolic waste, and directly accelerating wound healing , 252. MoADSC-Evs are the most commonly used extracellular vesicles in DUs. ADSC-Evs are widely available and easily accessible, and they accelerate the healing of DUs mainly by promoting revascularization. In a comparative study by Margherita Pomatto et al, ADSC-Evs displayed improved proangiogenic activity and accelerated DU wound healing compared to BMSC-Evs . Li et aGFs are active proteins or peptides present in living organisms that have a wide range of regulatory effects on growth and development. Most GF receptors exhibit tyrosine protein kinase activity, and when GFs bind to their receptors, they can act through the RTK-Ras-MAPK pathway. VEGF, for example, is a highly specific pro-vascular endothelial GF with the highest activity and specificity among known angiogenic factors. Studies have shown that VEGF binds to VEGFR on the endothelial cell membrane, causing autophosphorylation of the receptor, which in turn leads to the conversion of the inactive Ras-GDP complex to the active Ras-GTP complex, thereby activating MAPK, inducing endothelial cell proliferation and accelerating neovascularization , 258.In recent years, an increasing number of researchers have topically applied GFs  to DFU patients and achieved good therapeutic effects. However, the high concentration of proteolytic enzymes on the wound surface, sudden release of GFs and susceptibility to codelivered substances have greatly limited the application of GF . Lee et S. aureus, methicillin-resistant S. aureus, Escherichia coli, and P. aeruginosa [Due to the specific pathophysiological environment of DU wounds, they are often accompanied by multiple bacterial infections, as necrotic tissues and debris can provide surfaces to which bacterial material can attach and promote the formation of bacterial biofilms, which makes the removal of microorganisms very difficult. In addition, the high levels of inflammatory factors and oxidative stress on the wound surface also hinder wound healing. In this case, the body cannot return to the normal wound healing sequence by itself, and it is necessary to assist the body by administering drugs. Yu et al. applied a skin scaffold made of PF-sodium alginate-gelatin to the wounds of diabetic rats and found that the 3% PF skin scaffold promoted wound healing by promoting collagen deposition and microvascular regeneration; in addition, this scaffold also exhibited anti-inflammatory properties . Khaliq ruginosa . GeneralWith the continuous innovations in nanotechnology, metal nanoparticles have had a substantial impact on the medical field due to their excellent chemical stability, catalytic activity, and electrical conductivity. Among them, AgNPs are widely used in the treatment of DUs due to their known antibacterial and anti-inflammatory properties, and they have been shown to act by inhibiting respiratory enzymes and disrupting microbial cell walls and DNA . Tong etIn addition to AgNPs, other metal nanoparticles have also been used for the treatment of DUs. Li et al. successfully developed calcium ion crosslinked sodium alginate hydrogels containing deferoxamine and copper nanoparticles (SA-DFO/Cu), and a colony formation assay showed that these copper nanoparticles exhibited dose-dependent inhibition of E. coli and S. aureus in vitro. Moreover, DFO and copper synergistically upregulated the expression of HIF-1α and VEGF, thereby regulating angiogenesis . SoledadGlucose oxidase (GOx) is an oxidoreductase with a strong deoxygenation capacity that is widely used in the food industry. As a biocatalyst, GOx can effectively catalyze the oxidation of glucose to gluconic acid and hydrogen peroxide to lower blood glucose on traumatized surfaces. Gluconic acid can lower the pH value of the trauma microenvironment and inhibit bacterial growth and hydrogen peroxide can destroy the proteins that make up the bacterial cell membrane, thus causing bacterial lysis –267. WanAll of the above applications demonstrate the great potential of GOx in the treatment of diabetic wounds, but using this enzyme also has significant drawbacks: GOx is susceptible to the high levels of proteases present in environment of DUs; large amounts of hydrogen peroxide may cause high levels of oxidative stress; and uncontrollable drug release may lead to potential long-term toxicity. To address these issues, Huang et al. encapsulated GOx in a polyacrylic acid-calcium phosphate (PAA-CaPs@Nps@GOx) hydrogel to exhibit excellent stability of enzymatic activity and controlled the degradation rate of the hydrogel by adjusting the concentration of phosphate to control the production of ROS .To treat DUs, researchers have developed other forms of polymer dressings in addition to hydrogels, such as films, sponges, foams, hydrocolloids, and microspheres, and the observed therapeutic effects of these dressings are very encouraging Fig. . In thisFilms are soft elastic structures composed of transparent polymers. Films are widely used in the field of wound repair because of the following advantages: the film surface has very small pores that allow gas exchange while blocking bacterial invasion; their translucency allows changes in the wound to be observed without removing the dressing; and they are soft and fit on the skin well. Moreover, film have an autolytic debridement property, which allows them to remove crusts and necrotic tissues when treating DUs , 283.Absorbency is a crucial property of dressings used for wound healing. Since most films do not have hydrophilic groups or very small pores, they display poor water absorption and are thus limited to use with mildly exuding wounds . HoweverElectrospinning technology is the main way by which nanofiber films are made. Streams of polymer fluids are stretched under a high voltage electrostatic field, and nanofiber films with different fiber structures, large surface areas and high mechanical strengths can be prepared by adjusting the process parameters such as voltage, flow rate, polymer concentration and solvent composition. Luo et al. fabricated nZnO/BCM films with an ideal porous structure, and their unique bead-like morphology resulted in a water vapor transmission rate of 2856.60 g/m2/day, which improved the moist environment of the damaged surface .Nanofiber films are a good type of dressing to promote skin healing. It has been shown that nanofiber films, as polymers, can provide high mechanical strength and assume the role of a fibrous scaffold to provide regenerative support points for broken skin. The hematoporphyrin-doped polyketide films (Hp-PK films) made by Koo et al. provided growth attachment points for cell-dense tissues without a scaffold and transported them to the target site to promote skin regeneration. In addition, nanofiber membranes (NFMs) can improve the hydrophilicity of the film by introducing hydrophilic components, thus providing a favorable environment for skin healing . Liao etRecently, researchers have also linked photodynamic therapy with nanofiber films to create novel photodynamic antimicrobial dressings by carrying aggregated photosensitizers generated by highly efficient ROS with the hope of providing a new direction of thinking and exploration of killing multidrug resistant bacteria and repairing of wounds in special environments .2, the adhesion force of the sponge could reach 104 kPa, which is approximately 10 times that of fibrin glue [Sponges are substances with interconnected porous structures made by the freeze-drying method. As mentioned above, the size and number of pores are closely related to the ability to absorb exudate, and the interconnected porous structure of sponges provides the structural basis for their high water absorption. Moreover, the high porosity of sponges facilitates an adequate oxygen supply, nutrient delivery, and cell proliferation at the wound area. In addition, sponges are lightweight and feel soft on the body. Based on these advantages, sponges are widely used in the management of moderately to highly exuding wounds, such as DUs. Chitosan is the most commonly used polysaccharide in sponge manufacturing. Among the different types of polymers, the unique cationic linear structure of CS, a deacetylated form of chitin . As mentrin glue .To overcome the drawback of their low mechanical strength, researchers have enhanced the mechanical strength of sponges by crosslinking them with other polymers. Feng et al. prepared SF/KGM sponges with adjustable mechanical properties by physically crosslinking silk protein (SF) and konjac glucomannan (KGM). The stress‒strain curves showed that the addition of KGM significantly increased the tensile strength and Young's modulus of the SF/KGM sponges . In addiFoams are wet dressings composed of polyurethane or silicone-based materials . Wet drePolyurethane is the most commonly used raw material for foams. Polyurethanes are synthetic polymers consisting of urethane linkages in the main chain and are formed by polymerization of isocyanates with polyols. Due to the good biocompatibility and mechanical properties of polyurethane, polyurethane-based wound dressings have become a new research hotspot . The looHydrocolloids are new materials made of elastic polymers, glue-forming substances such as sodium carboxymethylcellulose (NaCMC), gelatin and an adhesive that are mixed and processed, and they have shown good flexibility and ductility . HydrocoCentella asiatica (CA)-loaded hydrocolloid dressing (HCD). The results of the mechanical property experiments showed that crosslinked sodium CMC significantly improved the swelling rate of CA-loaded HCDs, while the addition of petroleum resin hydrocarbon (PHR) increased their mechanical strength and flexibility [It has been reported in the literature that the keys to DU management are debridement, frequent dressing changes and a moist healing environment. Based on the advantages mentioned above, hydrocolloids are widely used in the treatment of DUs. Tan et al. prepared a hydrocolloid film by combining the anti-inflammatory antioxidant Vicenin-2 (VCN-2) with sodium alginate (SA). Studies based on the STZ-induced diabetic rat model have shown that VCN-2-containing hydrocolloid membranes can increase the expression of VEGF and TGF-β in a hyperglycemic environment, thereby promoting cell proliferation, migration, and wound healing. Interestingly, VCN-2-containing hydrocolloid films applied topically to diabetic wounds also increased host insulin levels, although the exact mechanism needs to be further investigated . To furtxibility .Due to the limited water absorption properties of natural materials alone, researchers have prepared hydrocolloids by combining various absorbent substances for use in hyperosmolar wounds such as DUs. Wojcik et al. made a highly absorbent hydrocolloid based on curdlan and a highly absorbent Kydex material in combination with agarose and chitosan. The absorption tests showed that this dressing had an excellent ability to absorb exudate, with 1 g of dressing absorbing approximately 15 ml of exudate. Another experiment demonstrated that the maximum absorption capacity (Cmax) of this dressing to serum and plasma reached 1563±57% and 1202±140%, respectively . Of noteMicrospheres are very small spheres or sphere-like bodies with a particle size generally in the range of 1 to 250 μm that are formed by dissolving or uniformly dispersing a drug in a polymeric material. Many techniques are used to prepare microspheres, and the appropriate method needs to be chosen according to the physicochemical properties of the drug and the desired application of the microspheres . The com2O2 into oxygen by binding to catalase. In vivo experiments in diabetic mice demonstrated that the oxygenation and ROS scavenging observed in the Gel/ORM group increased cell survival, accelerated cell migration, stimulated angiogenesis, and reduced oxidative stress and inflammation compared to the nontreated and gel groups. Furthermore, Gel/ORM provides a novel therapeutic solution in the exploration of accelerating chronic diabetic wound healing without the use of drugs [In diabetic wounds, hypoxia is a major factor affecting cell survival, migration and vascularization. In a recent study, Guan et al. developed a novel dressing (Gel/ORM) consisting of a combination of oxygen-releasing microspheres (ORMs) that continuously produce oxygen and a ROS-scavenging hydrogel. These microspheres can continuously convert Hof drugs . HoweverHealing diabetic wounds is challenging due to their complex pathophysiological mechanisms. This paper reviews various additives  and summarizes the recent advances in various hydrophilic polymeric hydrogels  that are currently used for DU treatment.From the literature discussed in this paper, almost all animal experiments have remained at the level of rodents. Although our current research data are not sufficient to support experiments in humans, we could try to carry out experiments on animals (such as pigs) that have skin that is more similar to human skin to lay a foundation for subsequent clinical experiments. Second, most of the studies have focused on only phenotype , but not on specific targets, molecular mechanisms of action, or kinetic reactions. Third, many researchers are currently often adding drugs to hydrogels to obtain better therapeutic effects but do not pay much attention to their pharmacokinetic or pharmacokinetic parameters, which results in sudden release effects and high local drug concentrations, thus affecting experimental safety. Fourth, the microenvironment of DUs is complex and diverse, and even the same patient may display great differences in disease progression processes. Therefore, we should implement individualized strategies and process strategies and adjust our treatment plans in a timely manner. Fifth, intelligent and multifunctional hydrogels could also be studied. Sixth, although most of the hydrogels that have been recently studied in the laboratory claim to have multiple functional properties, in practice, it has been found that it is often difficult to obtain good overall wound closure compared to the normal wound healing process, mainly due to the interactions between multiple associated factors in difficult-to-heal wounds. How to solve this problem is also one of the future research directions for scientists.In summary, research on hydrogels used to treat DUs is developing rapidly. Although there their application is still a certain distance from clinical practice, it is believed that with the concerted efforts of experts, hydrogels will be applied clinically in the near future.