Bladder cancer (BC) is the ninth most common cancer and the thirteenth most common cause of mortality worldwide. Bacillus Calmette Guerin (BCG) instillation is a common treatment option for BC. BCG therapy is associated with the less adversary effects, compared to chemotherapy, radiotherapy, and other conventional treatments. BCG could inhibit the progression and recurrence of BC by triggering apoptosis pathways, arrest cell cycle, autophagy, and neutrophil extracellular traps (NETs) formation. However, BCG therapy is not efficient for metastatic cancer. NETs and autophagy were induced by BCG and help to suppress the growth of tumor cells especially in the primary stages of BC. Activated neutrophils can stimulate autophagy pathway and release NETs in the presence of microbial pathogenesis, inflammatory agents, and tumor cells. Autophagy can also regulate NETs formation and induce production of reactive oxygen species (ROS) and NETs. Moreover, miRNAs are important regulator of gene expression. These small non-coding RNAs are also considered as an essential factor to control the levels of tumor development. However, the interaction between BCG and miRNAs has not been well-understood yet. Therefore, the present study discusses the roles of miRNAs in regulations of autophagy and NETs formation in BCG therapy in the treatment of BC. The roles of autophagy and NETs formation in BC treatment and efficiency of BCG are also discussed. Mycobacterium bovis, is considerably similar to Mycobacterium tuberculosis in antigenic composition and has been used for treating BC (Bladder cancer (BC) is one of the several types of cancers arising from the tissues of the urinary bladder and is the thirteenth most common cause of mortality and the ninth most common cancer worldwide . Conventating BC . In thisating BC . Autophaating BC –11. Autoating BC . Autophaating BC , 14. Anoating BC . Additioating BC . Furtherating BC . BCG theating BC . Dysreguating BC . Interesating BC –22. Althin situ (CIS) (stage Tis), and high-grade papillary tumors (stage Ta)  , 25.In these situations, BCG therapy could be correlated with a decreased risk of recurrence compared with transurethral resection alone, and the risk of progression to invasive disease would also be reduced by using BCG therapeutic approach –28. In aNeutrophils as a crucial element of innate immunity in any organisms play important roles in responding to different inflammatory and invading pathogens such as microbes, bacteria and fungi . These pNeutrophils have been reportedly to involve in different biological functions including phagocytosis, secretion of chemo-attractant and degranulation, and respiratory burst. Recent evidence has demonstrated a new biological function for neutrophils that is releasing of NETs , 36. NETThe role of NETs in tumor progression remains poorly understood. The findings of the both animal and human studies suggest a potential association between tumor progression and intra-tumoral NET deposition in both experimental models and in human cancer patients –38. Zychin vitro study demonstrating that lung carcinoma cells display 4–5 fold increased adhesion to NETs as compared with unstimulated neutrophil monolayers -9 that inhibits tumor cell apoptosis in the respiratory tract and can increase tumor angiogenesis and neovascularization , 49. Nev in vivo . On the  in vivo . One und in vivo . Therefo in vivo .Collectively, neutrophil-induced NETs act as an inhibitor for development of tumor metastasis through elastase, MPO, and other enzymes. In contrast, a few evidence demonstrated that produced NETs from the TANs in microenvironment of tumor could lead to progress of tumor cells.in vitro. Therefore, BCG-induced chemokine secretion by neutrophils is sufficient to recruit macrophages, which eventually recruit T cells. According to these findings, Suttman and their colleagues, suggest that BCG administration can result in the influx of neutrophils that coordinate the subsequent macrophages and T cell recruitment via the release of chemokines  samples  display autophagy-mediated spontaneous NET release . CurrentAtg5-knockout mouse neutrophils, that display decreased autophagic activity, kept the capacity to release extracellular DNA. Moreover, PI3K is able to prevent NET formation inhibition by human neutrophils . However, further investigations certainly should be performed to clarify the matter.In the next section, the role of autophagy in cancer and angiogenesis will be discussed.Findings of the studies on the role of autophagy process as a driver of cell death or a pro-survival process in response to specific stressors are controversial. Autophagy has been initially described as a cytoprotective process under nutrient deprivation, whereas recent findings of several studies have demonstrated that autophagy process is a cell death driver in which it is involved in promoting cell death.Recently, the paradoxical role of autophagy in cancer progression or suppression has been widely evaluated. Actually, cancer type, genetic context, and stage were affected by autophagy which can determine tumor cell destiny . Some stIn conclusion, the evidence demonstrates that autophagy can regulate proliferation in a context-dependent manner. These studies express coordination of autophagy with proliferation that support a dual function of autophagy in one of the essential indexes of cancer.Tumor angiogenesis occur with formation new blood vessels from the existing vasculature. To angiogenesis, tumor needs to some growth factors such as vascular endothelial growth factor (VEGF) and tumor growth factor-β (TGF-β). Angiogenesis supports tumor growth by providing nutrients for cancer cells, consequently aiding in tumor growth, invasion, and metastasis , 106. AdThe process of migration and metastasis initiates when the cells lose contact with adjacent cells, detach from extracellular matrix (ECM), undergo EMT, and eventually become motile. Anoikis, as a type of apoptosis, occurs after tumor cells detach from surrounding ECM. However, tumor cells can evade from anoikis via autophagy induction that provides Anoikis resistance . When thCollectively, autophagy can suppress incidence of invasion and metastasis by inhibiting inflammation and tissue necrosis. But if the tumor cells detach from ECM, elevated levels of autophagy help them avoid apoptotic cell death and maintain latency in a distant site , 110. ThMycobacterium tuberculosis secrete many antigens including the ag85 complex, we concluded that generated antigens could be targeted into the autophagic pathway. It seems that such an event would promote the production of peptides from ag85 complex and their subsequent loading on to MHC II proteins. A study evaluated the effect of induction autophagy on the efficacy of BCG vaccine containing the immunodominant Ag85B. Their results showed that induction of autophagy increases Ag85B presentation through MHCII pathway and thereby elevates vaccine efficacy. Also, autophagy increases Ag85B presentation by macrophages -dependent miR155 expression, which establishes signaling cross talk among mitogen-activated protein kinases (MAPKs), protein kinase Cδ (PKCδ), and phosphatidylinositol 3-kinase (PI3K) and recruitment of c-ETS and NF-κB to miR-155 promoter. Finally, they indicated the cellular reprogramming was organized by miR155 during immune responses to mycobacterial infection  infections. Differentially expression of miRNAs in neutrophils can predominantly effect the signaling pathways leading to cytokine productions. The reduced expression in MT cases could indicate a lack of inhibition on signaling pathways, which may result in elevated production of pro-inflammatory cytokines such as IFN-γ .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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


These three patients were excluded from the second dose. Of the remaining six patients, one developed mild anaphylaxis within the observation period at the vaccination hub and five delayed facial erythematous edema and maculopapular lesions, requiring antihistamines and short-course corticosteroid treatment. Spontaneous reporting is paramount to adjourning vaccination guidance and preventive measures in order to contribute to the development of a safe vaccine strategy. Dermatologist’ expertise might provide better characterization, treatment, and screening of individuals at high risk of skin adverse reactions.Vaccines are actually the most effective strategy to control the COVID-19 spread and reduce mortality, but adverse reactions can occur. Skin involvement with novel messenger RNA coronavirus vaccines seems frequent but is not completely characterized. A real-world experience in the recent vaccination campaign among health care workers in Sardinia  is reported. In over a total of 1577 persons vaccinated, 9 cases of skin adverse reactions were observed (0.5%). All reactions have been reported to the Italian Pharmacovigilance Authority. Eight occurred in women (mean age 46 years), and five were physicians and four nurses. All patients had a significant allergology history but not for the known vaccine excipients. After dose one, no injection site reactions were observed, but widespread pruritus ( The novel messenger RNA (mRNA) technology vaccines are a crucial part of the worldwide fight against coronavirus disease 2019 (COVID-19), and the Pfizer-BioNTech vaccine has been the first issued in Italy for the health care workers’ vaccination program. Reported adverse effects in clinical trials include minimal local skin reactions, especially following the required second dose of the vaccine, without systemic adverse reactions . Forty-tn = 5) and/or polysorbate 80 (n = 12) was documented in a minority of patients, and most of the patients received the second dose safely [However, the Centers for Disease Control and Prevention (CDC) recommends to avoid a second dose if a severe or immediate allergic reaction to the first dose of an mRNA COVID-19 vaccine has occurred . AssessmThe present short case series documents the real-world experience in the recent vaccination campaign among health care workers in Sardinia, a major island in the Mediterranean basin, and all reactions have been reported to the Italian Pharmacovigilance Authority.Of over a total of 1577 persons vaccinated during the first vaccination round, which ended in January 2021, 9 cases of skin adverse reactions were observed (0.5%). As regards demographics , eight oAll patients had a significant allergology history: atopy in five, penicillin allergy in four, additional drug allergy in three, and contact dermatitis in three patients. However, none of the patients had a documented allergy to substances regarded as potentially predisposing to mRNA vaccines, such as latex, polyethylene glycol, polyoxyl castor oil, or polysorbate. Angioedema and anaphylaxis were reported in three patients. It is noteworthy that the Italian guidelines on the allergology screening for patients with a history of asthma and allergy were released quite after the first dose of the vaccine had been performed , and theAs regards presentation of skin adverse events, and timing, no injection site reactions were observed. After the first dose, two patients did not manifest any reaction, three patients noted late-onset widespread pruritus, and one showed mild transitory facial erythema, not requiring intervention. In the remaining three patients, a maculopapular rash developed 48 h after injection. Allergology consulting excluded administration of the second dose in the latter three patients, while the risk for the other six patients was considered low and the vaccination was completed. One patient experienced glottis edema, within the observation timing at the vaccination hub, receiving epinephrine, but with fast and complete recovery. The other five patients, 24–48 h after injection, developed facial erythematous edema and widespread itching maculo-papular lesions , Mild geAs dermatologists, we are actively committed to supporting the Vaccine Adverse Event Reporting System (VAERS) and enhancing continuous safety monitoring . Severe Our experience confirms that Pfizer-BioNTech vaccine skin reactions are uncommon (0.5%) but suggests implementing allergology screening and prophylaxis measures, not to undervalue delayed skin reactions. Clinical trials and post-marketing experience focus on anaphylactic reactions that occurred within a 30 min observation window, and patients were treated immediately with complete resolution of symptoms ,8. HowevAlerting signs after dose one  that shoIn our experience, the personal allergy history was positive for penicillin and other drug reactions, instead of the allergens considered related to the messenger RNA (mRNA) vaccine, such as polyethylene glycol, polyoxyl castor oil, or polysorbate.Another uncovered issue is the opportunity of a premedication regimen, such as with non-sedating antihistamines for patients with mild symptoms at dose one ,4,7. MajThe low rate of reactions and favorable course in all the nine patients might be helpful to reassure patients as well as health care providers that the vaccination program is safe and affordable even in allergic patients.Careful surveillance over time and spontaneous reporting of mRNA-based COVID-19 vaccine safety are crucial measures to better characterize morphology and timing, as well as predisposing conditions. Dermatologists’ expertise in proper diagnosis will contribute to the definition of the spectrum of skin adverse reactions and provide insights into the possible mechanisms, as well as suggest appropriate screening for high-risk individuals. Our case series does not reach a statistical power, and large epidemiological studies will be hopefully provided by nation-wide registers. No premedication was supplied to the patients, following the Italian recommendation for SARS-CoV-2 at the vaccination hub. So, only the vaccine composition should be associated with the reactions. As regards skin testing, patients with more severe reactions were evaluated by the allergologists and were negative for vaccine excipients and cross-reactive substance sensitization. The fact that the skin reaction in some patients was triggered only by the second dose is a common finding with drugs adverse reactions and was confirmed in recent 388 mRNA COVID-19 vaccine studies. It is for this reason that intradermal testing for a local anesthetic is no more routinely performed, as in several cases, the reaction was negative at testing, while the local injection during following surgery or a dentistry procedure triggered true anaphylaxis.As the world fights COVID-19, the medical community is gaining more experience in the risk–benefit assessment before vaccination, and guidance should be regularly updated. Avoidance of any hazard is necessary to reassure patients of the need to accept this important preventative measure.


Vaccines and therapeutics targeting viral surface glycoproteins are a major component of disease prevention for respiratory viral diseases. Over the years, vaccines have proven to be the most successful intervention for preventing disease. Technological advances in vaccine platforms that focus on viral surface glycoproteins have provided solutions for current and emerging pathogens like SARS-CoV-2, and our understanding of the structural basis for antibody neutralization is guiding the selection of other vaccine targets for respiratory viruses like RSV. This review discusses the role of viral surface glycoproteins in disease intervention approaches. Acute respiratory tract infections (ARI) constitute a considerable worldwide disease threat and burden that has been made plainly evident by the number of COVID-19 cases caused by SARS-CoV-2 (CoV-2). Usually, influenza virus (flu) is the most widely recognized cause of ARI associated with respiratory illness and substantial disease burden in adults and elderly individuals . For exaThe greatest hurdle for control of respiratory viruses is that there are few licensed vaccines and limited antivirals available. Another challenge and concern is that infection with some RNA viruses does not always provide durable protection against reinfection, as is the case with RSV , althougThe goal of vaccination is to prevent or reduce disease and control pathogen transmission. Various vaccine approaches may be needed to protect high-risk groups that are at the extremes of age, i.e., very young or old, or have underlying conditions or are immune suppressed in order to provide long-lived acquired immunity. However, as respiratory virus infection chiefly occurs in the respiratory epithelium, serum antibody does not protect the upper respiratory tract , and mucRSV is a negative-sense, non-segmented enveloped RNA virus causing substantial morbidity and some mortality in adults and children ,11. RSV Important facets that affect RSV vaccine development are the absence of an ideal animal model and the lack of established correlates of protection. The RSV vaccine conundrum is complicated as no animal model fully replicates RSV disease, and all older adults are seropositive but not necessarily protected. The field has relied on preclinical models, particularly BALB/c mice, to develop correlates of protection that make it difficult to define immunogenicity endpoints as RSV is only semi-permissive in this model. Recently, there has been a substantial effort to develop RSV vaccines that incorporate the fusion (F) protein that facilitates viral fusion with host cells ,18. The The F protein is conserved between RSV strains, is immunogenic, and provides protection against RSV challenge in preclinical studies . The F pInfluenza viruses are negative sense, single-stranded enveloped RNA viruses with segmented genomes that are responsible for approximately 250,000–500,000 deaths annually . CurrentThere are currently two types of influenza vaccines commercially available for use in humans: (a) inactivated and (b) live-attenuated vaccines, both of which stimulate protective antibody responses . InactivVaccine development is a lengthy process that is intolerable during a pandemic such as that caused by SARS-CoV-2. Briefly, the process begins with vaccine design and evaluation in animal models, it is then followed by preclinical experiments and toxicology studies, before an application is filed with the FDA for use as an investigational new drug. Thereafter, Phase I, II, and III clinical trials are established to confirm immunogenicity and dose, and evaluate safety and efficacy. If the outcome of Phase III trials meets pre-defined endpoints, a biologics license application is filed with the FDA. The SARS-CoV-2 pandemic required rapid development of vaccines in an unprecedented timeframe (Operation Warp Speed, ,33,34. ATherapeutic intervention of respiratory virus infection and replication has involved strategies that target virus entry mediated by viral surface glycoproteins. There are several antiviral drugs that act as virus entry inhibitors, protease and transcriptase inhibitors, maturation and virus particle inhibitors, all of which affect critical steps of the virus life cycle. Notably, blocking of viral surface glycoproteins can prevent host cell receptor attachment, virus internalization, and infection . Some RNInfluenza virus HA is a favorable target for anti-influenza drugs but effective HA inhibitors have not been developed due to the emergence of drug-resistant viruses with amino acid substitutions on the HA . AlthougIt is important to note that other antivirals have been shown to be effective in targeting the influenza life cycle are also approved and available for use by clinicians. The matrix 2 protein inhibitors, amantadine and rimantadine were first shown to be effective against influenza A  but haveAntiviral drug use at early timepoints after influenza virus exposure is appropriate for most individuals, however widespread prophylactic administration is only recommended for specific settings e.g., aged care where established outbreaks place vulnerable patients at risk and where administration of the antivirals is being used as part of a larger containment strategy . SurveilAs the S protein of SARS-CoV-2 has a key role in the receptor recognition and cell membrane fusion process, it is being targeted by antiviral drugs ,62. Seve


Stem cell and immune cell therapies are being investigated as a potential therapeutic modality for CNS disorders, performing functions such as targeted drug or growth factor delivery, tumor cell destruction, or inflammatory regulation. Despite promising preclinical studies, delivery routes for maximizing cell engraftment, such as stereotactic or intrathecal injection, are invasive and carry risks of hemorrhage and infection. Recent developments in MRI-guided focused ultrasound (MRgFUS) technology have significant implications for treating focal CNS pathologies including neurodegenerative, vascular and malignant processes. MRgFUS is currently employed in the clinic for treating essential tremor and Parkinson's Disease by producing precise, incisionless, transcranial lesions. This non-invasive technology can also be modified for non-destructive applications to safely and transiently open the blood-brain barrier (BBB) to deliver a range of therapeutics, including cells. This review is meant to familiarize the neuro-interventionalist with this topic and discusses the use of MRgFUS for facilitating cellular delivery to the brain. A detailed and comprehensive description is provided on routes of cell administration, imaging strategies for targeting and tracking cellular delivery and engraftment, biophysical mechanisms of BBB enhanced permeability, supportive proof-of-concept studies, and potential for clinical translation. Modest improvements in motor and cognitive function were noted in PD patients, but survival of transplanted fetal dopaminergic cells was low, and a cohort of patients also developed post-engraftment dyskinesias, possibly due to patchy reinnervation , but one factors , enzymes factors , or chim factors . They ca factors .Research probing the biochemical and mechanical underpinnings of stem cell differentiation continues to grow with ever increasing preclinical and clinical studies. Stem cells maintain their definition as undifferentiated cells with self-renewal capacity that are mainly classified based on “potency,” or capacity to develop into one or all of the three germ layers; further classification schemes are based on sourcing technique or location. Human Embryonic Stem Cells (hESCs) and induced Pluripotent Stem Cells (iPSCs) exhibit pluripotency i.e., capacity to differentiate into somatic cells of all three embryonic germ layers. Applications employing hESCs, which are derived from the embryonic inner cell mass, are limited due to ethical constraints and the risk of tumorigenicity if not fully differentiated into the tissue of interest. iPSCs are created via transfecting somatic cells  with reprogramming transcriptional factors . ClinicaNeural stem cells (NSCs) and Mesenchymal stem cells (MSCs) are common stem cell types under study for neurologic cell therapies. NSCs were discovered to reside within the subventricular zone of the lateral ventricles and subgranular zone of the dentate gyrus, two areas of adult neurogenesis which have been implicated in learning, memory and mood regulation , 14. Theex vivo would be required. Many clinical trials use the immortalized NK-92 cell line, due to relative ease of expansion and implementation (compared to autologous harvesting). To circumvent the immunosuppressive environment of brain tumors, which downregulates NK activity, NK cells can be engineered ex vivo to overexpress activating cytokines (Il-12 or IL-15) to form “activated” NK cells, which increases tumor cell killing efficacy  and intravenous (IV) administration, and are commonly employed for procedural simplicity. There was initial concern for the IV route being a potential nidus for pulmonary thromboembolism , but a rHyperosmolar BBB disruption involves intravascular delivery of an agent, typically mannitol, that increases oncotic pressure and drives fluid outside of microvascular epithelial cells, causing shrinkage and thus paracellular passage of therapeutics, including stem cells, into the brain . A drawbIntranasal delivery is a developing administration approach that is not yet fully understood but thought to bypass the BBB by relying on migration along olfactory and trigeminal nerve tracts and into CSF flow tracts . Many stImplantable devices such as the Ommaya reservoir have successfully been used for delivering growth factors, analgesics and chemotherapy directly into CSF circulation. This approach has notable drawbacks that would preclude the delivery of cells due to clogging and pump failure . CollectChoosing one of the aforementioned delivery routes is governed by specific preferences such as the required accuracy of targeting or minimizing the degree of invasiveness. The choice can also be dictated by characteristics of the CNS pathology, such as focality. A condition like PD for example has lesions typically occurring in one region compared to Multiple Sclerosis (MS) where lesions are in multiple regions. Engraftment rates of cells in some studies have not been encouraging. For example, one study investigating IV injection of MSCs into a traumatic brain injury (TBI) rat model yielded <4% of cells reaching arterial circulation . TherefoThe variation in induced effects is controlled by the mode of application, which can be continuous or pulsed , and further modified by varying the duration and intensity of the applied ultrasound energy. Thermal tissue effects predominate with continuous exposures, and temperatures can rise to 60°C in the focal region within seconds, leading to tissue destruction by the process of coagulative necrosis. With pulsed FUS (pFUS) exposures, mechanical tissue effects predominate, and temperature elevations are minimal (within the range 4–5°C) –64. GlobReliable BBB opening (BBBO) is achieved with the combination of MRgFUS and IV injection of ultrasound contrast agents  which are typically 1–10 micron lipid or albumin based spheres containing a bio-inert gas. Early pFUS studies without using MBs demonstrated that meaningful mechanical effects, such as those required for permeabilizing the BBB, could not be generated without the presence of tissue damage . A landmAcoustic cavitation is one of the non-thermal pFUS based mechanisms for generating bioeffects. This occurs in the form of expansion of the MBs during the negative pressure part of the ultrasound cycle and contraction during the positive pressure part. Upon pFUS exposure, the MBs transmit these mechanical oscillations onto the endothelial cells, which can alter BBB permeability. Low pressure amplitudes, in which MB oscillations remain stable , are employed to induce transient BBB opening through a number of proposed paracellular and transcellular mechanisms. If the pressure amplitude becomes too high, the MBs undergo unstable oscillations  where they expand and eventually collapse. This is undesirable in BBBO where shock waves generated can damage cells of the microvasculature. Hence, monitoring for cavitation is crucial for this application of MRgFUS .Most human MRgFUS treatments in the brain are performed using a hemispherical 1,024-element ultrasound transducer array that communicates with the MRI system . Each of* images are obtained from the MRI scanner and transferred to the MRgFUS graphic user interface (GUI). The target treatment volume is identified using an overlay on the MR images. The location of the region of treatment will determine which of the 1,024 ultrasound transducer elements will be activated during treatment. The beam is then steered electronically, automatically rastering  through the treatment volume with user defined spacing . Histological analysis showed limited damage and red blood cell extravasation in non-target areas, and 32 viable NSCs per square millimeter of sonicated brain tissue, with neuronal specific biomarkers present 4–24 h after treating . AnotherIn addition to stem cells, immune cells have also been investigated using MRgFUS BBBO. CAR NK-92 cells were administered IV in a murine model of HER2-amplifed brain metastasis. Interestingly, IV injection of the NK cells immediately before BBBO resulted in a 5-fold increase in the number of cells observed to be delivered compared to injecting cells after BBBO . A folloInvestigations evaluating the potential of magnetic enhancement of MRgFUS for cellular delivery were also conducted. Dual labeled, fluorescent/super paramagnetic iron-oxide nanoparticle (SPION), human NPCs (hNPCs) were administered following MRgFUS BBBO. The procedural timeline for this study is shown in More recently, BBBO via low intensity ultrasound was evaluated in a brain-ischemia rat model, induced by middle-cerebral artery occlusion. Although this study was limited by using unfocused low intensity ultrasound and not pFUS, the results are noteworthy in that they demonstrated significant increases in IV-administered MSC engraftment and slight improvement in neurological outcomes, compared to IV injection of the MSCs alone. The authors acknowledged that using a focused beam would allow better spatial control of delivery and treatment .The results described above provide important proof-of-concept validation using MRgFUS for enhancing cellular delivery, as well as first insights into the mechanisms involved in in this process. The general consensus is that physical/structural alterations generated , such as those facilitating smaller agent delivery, are less likely to be involved due to the relatively larger size of cells, which can be orders of magnitude greater. Other potential mechanisms involved are presented in the following section (“FUS effects on cell homing”). Preclinical studies of MRgFUS assisted cell delivery for other CNS pathologies are underway. Established animal models of MS  or AD 7 are cons* weighted MRI and histology  in that stem cells also follow a sequence of chemoattraction, margination, rolling, adhesion, and diapedesis. This is due to similar expression profiles of integrins, cytokine and chemokine receptors  , 86. Manistology .In subsequent studies, the same group showed how pFUS mediated delivery of MSCs improved disease outcomes. This included improved survival in a model of cisplatin induced acute kidney injury (AKI) , and impThe studies described above were carried out using pFUS treatments without the use of microbubbles. Instead, higher acoustic pressures were used, being approximately 5-fold greater than those used for BBB opening. These treatments also targeted the parenchyma as opposed to the vasculature. In previous studies, the mechanical effects generated by these treatments appeared as widening of intercellular spaces and were shown to enhance interstitial transport of a range of therapeutic formulations  in skeletal muscle , 95, solMRgFUS studies have also been conducted in the brain to investigate the generation of CCTFs and CAMs for the purpose of enhancing cell homing. Kovacs et al. mapped the proteomic and transcriptomic time course of MRgFUS mediated BBBO in a murine model. Within 5 min of exposure, expression of  and CAM was observed, as well as stromal derived factor (SDF1-α), a significant chemokine utilized by lymphocytes and mesenchymal stem cells, within 2 h . These rin vivo. Experimental studies evaluating cell labeling techniques for the purpose of tracking must verify that they do not negatively affect cell viability and/or key cellular functions . The duration and modality of monitoring will depend on a multitude of factors such as the therapeutic application .The ability to monitor activity of exogenous cells , as well as potential immunogenic or tumorigenic complications, is essential for evaluating the efficacy of CNS cellular therapies, in addition to monitoring engraftment response in the patient. Clinically relevant intracranial cell tracking modalities involve structural (MRI) and tracer-based (PET/SPECT) imaging, each of which have their own specific direct and indirect methods of cell tracking Direct cell labeling involves cells that are treated with an agent before administration, allowing them to be detectable upon reaching a threshold concentration. Direct techniques places emphasis on nanoparticle fabrication, as their large surface area and other tunable characteristics allow for greater contrast or uptake of imaging agents . DespiteIndirect cell labeling requires viral or non-viral transfection of a gene transcript into the cell that encodes a reporter protein that generates a detectable signal based off of its interactions with an administered contrast/tracer agent  . Since tHigh soft-tissue resolution of MRI allows cellular grafts to be identified precisely within intracerebral regions. SPION-based cell tracking, which demarcates engrafted cells through changes in T2 relaxivity, is a common direct labeling method. The 1st generation of SPIONS , currently only available for preclinical studies in the US, was first reported in a brain trauma patient for tracking cell migration for a temporal lobe injection of autologous NSCs labeled with Feridex . Second 19F MRI is another direct method which involves direct spin detection of the biologically safe isotope fluorine-19, enabling highly sensitive and quantitative “hot-spot” imaging as seen with PET/SPECT studies. One study demonstrated labeling of intracerebrally administered natural killer cells with fluorine-19, which importantly showed no cytotoxicity and change in NK cell therapeutic efficacy . In anotHighly sensitive “hot spot” signaling in Positron Emission Tomography (PET) and Single-Photon Emission Computed Tomography (SPECT) imaging, ensures that visualized signals are coming from the cells that were delivered. The half-lives (HL) of radionuclide agents available for direct labeling should be taken into consideration when specifying the required duration of tracking of the delivered cells. Indium-Tropolone labeling of MSCs has been shown to have no effect on proliferation or differentiation , but thiMagnetic particle imaging (MPI) is a developing modality that involves applying external magnetic fields  to directly detect exogenously administered SPIONs  108). S. S108). CNS pathologies throughout the diagnostic spectrum may vary in their progression, effects on BBB integrity, and subsequent cellular and inflammatory responses. Clinical presentations may overlap and involve mass effect symptoms (headache/nausea), excitotoxicity , neuropathy, focal deficits in cognition, motor, sensory, gait, coordination, possible behavioral changes, and at its worst, the inability to perform life-sustaining functions. For a given CNS condition, the selection and modification of the therapeutic cell type is informed by the symptoms presented and the desired mechanism of action . By employing the advantages of increased target specificity and cell homing and retention using pFUS, cellular therapy applications in the brain may obtain better clinical outcomes. The following section will outline potential benefits of employing MRgFUS delivery approaches for certain CNS disorders.Neurodegenerative conditions are expected to become more prevalent in the years to come as life expectancy continues to increase. PD alone is projected to affect 14 million people world-wide by 2040 . PharmacMRgFUS cell therapies can potentially play a role in post-glioma resection consolidation therapy and treatment of brain metastases. Recurrence remains a significant issue in the management of glioblastoma (GBM), a devastating condition with a 12–18-month median survival . This maMultiple Sclerosis involves autoimmune destruction of the white matter tracts throughout the CNS which follows an unpredictable spatiotemporal progression. Because of its multifocal nature, the therapeutic approach of a MRgFUS stem-cell delivery regiment may be beneficial for disease modifying therapies of MS or for treating acute flares, while other routes such as direct injection may be less optimal . Since tOverlapping cell signaling pathways and mechanisms that activate cell death and neuroprotective mechanisms exist between ischemic stroke and TBI . In ischWith significant improvements in FDA-approved cell manufacturing practices, rapidly accumulating clinical trial results supporting the safety of MRgFUS-mediated BBBO, and the report of studies demonstrating the potential of delivering chemotherapeutics, antibodies, drug-loaded-NPs across the BBB with this modality, it is foreseeable that neuro-interventionalists will be interested in the delivery of therapeutic cells using this method as the best next step . Before In conclusion, the question of whether an MRgFUS assisted cell delivery approach can significantly reduce neurological disease morbidity/mortality, and hospital costs , is being discussed as FUS technology undergoes widespread adoption. The continued investigation of MRgFUS technology for this specific therapeutic purpose will be aided by many more preclinical studies combining different cell types with tracking methods. Overall, the results from these studies are encouraging and provide motivation to further pursue this application and evaluate its feasibility for clinical translation .More recently, it was announced that MRgFUS ablation for tremor-dominant Parkinson's will receive Medicare coverage. Intracranial MRgFUS treatments can be carried out with any MRI with a modified table to house the hemispherical transducer array and currently, there are 800 systems in the US in operation (See footnote 1), and many more worldwide. As clinical trials exploring one-time stereotactic injections of stem cell therapies are ongoing and show promise, the aspects of repeatability and non-invasiveness of MRgFUS delivery will enable greater inclusion of patients who may be poor surgical candidates. The combination of cellular therapeutics and MRgFUS mediated delivery shows great potential for helping to usher in the next generation of treatment paradigms for CNS disorders.NA, DG, EM, and VF contributed to the conception and design of the manuscript. NA wrote the first completed draft. DG, EM, and VF provided critical reviews of the first, second, and third versions of the manuscript. All authors read and approved the final submitted version of the manuscript.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.


Blood coagulation factors can enter the brain under pathological conditions that affect the blood–brain interface. Besides their contribution to pathological brain states, such as neural hyperexcitability, neurodegeneration, and scar formation, coagulation factors have been linked to several physiological brain functions. It is for example well established that the coagulation factor thrombin modulates synaptic plasticity; it affects neural excitability and induces epileptic seizures via activation of protease-activated receptors in the brain. However, major limitations of current experimental and clinical approaches have prevented us from obtaining a profound mechanistic understanding of “neuro-coagulation” in health and disease. Here, we present how novel human relevant models, i.e., Organ-on-Chips equipped with advanced sensors, can help overcoming some of the limitations in the field, thus providing a perspective toward a better understanding of neuro-coagulation in brain homeostasis. They hardly create or maintain 3D vascular structures, and adjacent pericytes, astrocytes, and basal membranes do not form. Organotypic tissue cultures demonstrate some of these cellular features. However, they are blood-free preparations. Vasculature either does not form properly as seen in the case of iPSC-derived organoids, or it degenerates in the absence of physiological blood flow in cultured brain slices . While the development and implementation of such sensors is not trivial, recent developments in sensor fabrication and microfabrication and nanofabrication allow integration of sophisticated sensors in OoC , and specific molecules , all highly relevant parameters in neuro-coagulation and inflammation.Recent advances in microfabrication and nanofabrication have enabled the development of sensors with high sensitivity, selectivity, and robustness while keeping dimensions small. These advanced sensors preferably should access all planes of the tissue volume or even be embedded within the tissue itself. Furthermore, it is imperative that the implementation of these distributed and integrated sensors does not come at the cost of perfusion or optical access , meaning the architecture must be maximally open.Long-term stable high-resolution sampling and artificial excitation of neuronal signals are now available by the use of flexible sensor microprobes based on polymeric substrates such as polyimide (Chung et al. As medical science becomes more interdisciplinary, the development and integration of novel advanced sensors into innovative translational OoC-platforms will allow us to identify and probe complex cell–cell interactions at the NVU. We are confident that this technology-based approach will shed new important light on the mechanism according to which neuro-coagulation affects complex brain function in health and diseases, such as traumatic brain injury, epilepsy, and neurodegeneration.


Hydrocarbons are degraded by specialized types of bacteria, archaea, and fungi. Their occurrence in marine hydrocarbon seeps and sediments prompted a study of their role and their potential interactions, using the hydrocarbon-rich hydrothermal sediments of Guaymas Basin in the Gulf of California as a model system. This sedimented vent site is characterized by localized hydrothermal circulation that introduces seawater sulfate into methane- and hydrocarbon-rich sediments, and thus selects for diverse hydrocarbon-degrading communities of which methane, alkane- and aromatics-oxidizing sulfate-reducing bacteria and archaea have been especially well-studied. Current molecular and cultivation surveys are detecting diverse fungi in Guaymas Basin hydrothermal sediments, and draw attention to possible fungal-bacterial interactions. In this Hypothesis and Theory article, we report on background, recent results and outcomes, and underlying hypotheses that guide current experiments on this topic in the Edgcomb and Teske labs in 2021, and that we will revisit during our ongoing investigations of bacterial, archaeal, and fungal communities in the deep sedimentary subsurface of Guaymas Basin. Lower concentrations of n-alkanes and aliphatic hydrocarbons and lower (<1) n-C17/pristine and n-C18/phytane ratios closer to the sediment surface are consistent with microbial biodegradation of those compounds , cyclic alkanes, and polyaromatic hydrocarbons (PAH) . Hydroca2-dependent oxygenase-catalyzed reactions add one or both atoms of diatomic oxygen using monooxygenase or dioxygenase enzymes, respectively. The initial C-H activation is essential for channeling hydrocarbons as substrates to catabolic routes and for making them amenable to further degradation  that resemble nitrate reductases in utilizing molybdenum as a co-factor , nutrients , and the particular spectrum of aliphatic and aromatic hydrocarbons. Since sulfate concentrations in seawater and surficial benthic sediments are two or three orders of magnitude higher than nitrate or oxygen concentrations, sulfate-reducing bacteria are naturally ubiquitous in marine hydrocarbon seeps, and have evolved numerous lineages that oxidize aliphatic and aromatic hydrocarbons, either as specialists in utilizing specific carbon sources or as generalists who can utilize a wider substrate spectrum; collectively they are now perhaps the best-studied group of anaerobic hydrocarbon oxidizers .13C-carbon enrichment in light alkanes, caused by preferential microbial oxidation of 12C-carbon compounds  matched the theoretical stoichiometric degradation ratios for hexadecane (12:1) and phenanthrene (8:1) when coupled to sulfate reduction  archaeal lineage  is performed by the deltaproteobacterial genus Smithella associated with acetoclastic and hydrogenotrophic methanogens  and produce methane by disproportionating acetate using methyl-coenzyme M reductase; the acetate is obtained via beta-oxidation of alkanes that are activated by alkyl-coenzyme M reductase  were collected by piston coring outside the hydrothermal spreading center, from the northwestern flanking region of Guaymas Basin -organic acids, alkanes, and aromatics  is the most frequently detected deltaproteobacterial lineage in off-axis subsurface sediments  are oxidized using cytochrome P450 monoxygenases, while unsaturated alkenes, alkynes, and alicyclics, are more recalcitrant, and fungi are considered to be able to partially oxidize them . Low andPseudomonas, Acinetobacter, and Bacillus , salinity (2–10% NaCl), and pH (2–10)  . Bacteriudomonas  and Haloalomonas  also synalomonas , and theAureobasidium sp., Penicillium sp., Cladosporium sp.), as well as basal fungi  known to be degraders of recalcitrant carbon sources . Interestingly, our isolate of the wide-spread marine yeast Rhodotorula, obtained from microbial-mat covered hydrothermal sediment in the Mat Mound Massif area . To evaluate the role of fungi in hydrocarbon degradation, a deeper culturing effort was needed in order to obtain the broadest possible diversity of in situ fungi from different sites and depths. The Edgcomb lab is collaborating with Gaetan Burgaud at the University of Brest, France, to carry out high-throughput fungal culturing efforts. This collaboration has yielded ∼200 unique fungal isolates from subsurface Guaymas sediments, and all isolates in the collection are currently being tested for production of biosurfactants.In parallel to the sequencing survey, an initial cultivation survey  using hysif area , maintai2 or acetate  in this hydrothermal setting along temperature, depth and substrate gradients. Correlation analyses, analyses of genomic potential in metagenomes and MAGs, and studies of cultured fungal isolates will reveal the likely nutritional sources  that allow bacteria, archaea, and fungi to survive in this habitat.There is growing evidence that hydrocarbon biodegradation is an active process in Guaymas Basin sediments. Yet there are many avenues of investigation to pursue in order to obtain a more complete understanding of the roles played by diverse microorganisms in the utilization of hydrocarbons as an energy source. The recent International Ocean Discovery Program Expedition 385 (IODP X385) drilled hundreds of meters into the seafloor of Guaymas Basin at eight different sites . The thiin situ community that is actively contributing to nutrient cycling in the deep subsurface Guaymas biosphere (Periodic historical magmatic sill intrusions, which have “baked” buried sediments surrounding each sill, invariably have had a major effect on the modern pool of available nutrients remaining in sediments in close proximity to buried sills . Currentiosphere . In the Finally, studies of enrichment cultures, cultured isolates, and co-cultures can provide critical information on whether interactions between microbial taxa enhance their ability to access otherwise refractory organic carbon substrates found in Guaymas Basin sediments, including diverse hydrocarbons. Promising isolates and enrichments could possibly be engineered to remediate and clean-up oil spills with minimal ecosystem disturbance. For example, experiments that prime indigenous soil bacteria capable of hydrocarbon degradation for oil bioremediation show that horizontally transferred gene vectors encoding genes for petroleum hydrocarbon degradation persist in indigenous populations only when under selection pressure, but disappear when the hydrocarbon source is removed .Using new molecular assays and long-term enrichments, diverse fungal-bacterial syntrophic interactions might be discovered that allow these partners to survive in the anoxic deep biosphere by adapting to different carbon and energy sources, and by cooperating in accessing substrates that individual taxa cannot access alone. In this way, it will be possible to go beyond studies of individual fungal and sulfate-reducing species and their capabilities to oxidize hydrocarbon and low-molecular weight organic compounds, and to explore the possibility that selected, fungi, fungal-bacteria co-cultures and syntrophic cultures enhance the accessibility of particular hydrocarbons through successive or simultaneous reactions.The original contributions presented in the study are included in the article/VE led the fungal-bacterial interactions project and designed the experiments. PM performed the experiments. AT wrote the first draft of the manuscript. All authors commented and edited the manuscript in turn.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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Since the discovery of hepatitis B virus (HBV) over five decades ago, there have been many independent studies showing presence of HBV genomes in cells of the immune system. However, the nature of HBV lymphotropism and its significance with respect to HBV biology, persistence and the pathogenesis of liver and extrahepatic disorders remains underappreciated. This is in contrast to studies of other viral pathogens in which the capability to infect immune cells is an area of active investigation. Indeed, in some viral infections, lymphotropism may be essential, and even a primary mechanism of viral persistence, and a major contributor to disease pathogenesis. Nevertheless, there are advances in understanding of HBV lymphotropism in recent years due to cumulative evidence showing that: (i) lymphoid cells are a reservoir of replicating HBV, (ii) are a site of HBV-host DNA integration and (iii) virus genomic diversification leading to pathogenic variants, and (iv) they play a role in HBV resistance to antiviral therapy and (v) likely contribute to reactivation of hepatitis B. Further support for HBV lymphotropic nature is provided by studies in a model infection with the closely related woodchuck hepatitis virus (WHV) naturally infecting susceptible marmots. This animal model faithfully reproduces many aspects of HBV biology, including its replication scheme, tissue tropism, and induction of both symptomatic and silent infections, immunological processes accompanying infection, and progressing liver disease culminating in hepatocellular carcinoma. The most robust evidence came from the ability of WHV to establish persistent infection of the immune system that may not engage the liver when small quantities of virus are experimentally administered or naturally transmitted into virus-naïve animals. Although the concept of HBV lymphotropism is not new, it remains controversial and not accepted by conventional HBV researchers. This review summarizes research advances on HBV and hepadnaviral lymphotropism including the role of immune cells infection in viral persistence and the pathogenesis of HBV-induced liver and extrahepatic diseases. Finally, we discuss the role of immune cells in HBV diagnosis and assessment of antiviral therapy efficacy. Hepatitis B Virus (HBV) is known as a hepatotropic virus that can cause life-threatening liver diseases, such as chronic hepatitis B (CHB), cirrhosis and hepatocellular carcinoma (HCC). Early studies revealed many exciting facets of the HBV biology including its ability to infect and persist in cells of the immune system; an entity that was subsequently termed hepadnaviral lymphotropism. However research on this subject has largely subsided. Identification of the nature of this event and its significance to HBV biology, course of infection and pathogenesis of liver and extrahepatic disorders received limited attention and is currently underappreciated by many HBV researchers. This is in sharp contrast to studies on other non-cytopathic, long-term persisting viral pathogens in which the ability to infect immune cells were actively investigated. In fact, lymphotropism was found to be essential to the persistence and to the pathogenesis of disease induced by many viruses. There are several examples of these viruses, including human immunodeficiency virus type 1 (HIV), hepatitis C virus (HCV), Epstein B virus, cytomegalovirus, measles virus, and a classical model of persistent lymphotropic infection with lymphocytic choriomeningitis virus . Neverth3–106 copies/mL or virus genome equivalents, vge, to <100–200 vge/mL). Molecular indicators of WHV replication, virus mRNA and covalently closed circular DNA (cccDNA) are detectable in the liver and cells of the immune system which, among others sites, include peripheral blood mononuclear cells (PBMC)   and molecular infection markers are summarized. In humans, resolution of acute HBV infection occurs after HBV surface antigen (HBsAg) clearance and development of anti-HBsAg antibodies (anti-HBs). Antibodies to HBV core antigen (anti-HBc) develop in the pre-acute phase of infection and remain throughout the lifespan. Similarly, symptomatic WHV infection in woodchucks begins as acute WHV hepatitis that is serum WHV surface antigen (WHsAg) positive that spontaneously resolves in the majority of adult animals with development of antibodies to WHsAg (anti-WHs). This self-limited acute hepatitis is followed by essentially asymptomatic, life-long virus persistence termed as secondary occult infection (SOI) or seropositive-occult HBV infection (OBI) . SOI is s (PBMC) . Similarn humans . Chronicn humans . In addin humans . This inon (POI) , also teon (POI) . Despiteon (POI) . Nonetheon (POI) . Althougon (POI) .In this review, we summarize the advances made over the last five decades in HBV research and hepadnaviral lymphotropism. We also discuss the role of immune cells’ infection in HBV persistence, the pathogenesis of liver and immunoproliferative diseases, and extrahepatic assessment for hepatitis B diagnosis and treatment.5–107 virus genome copies or vge/mL (via immunoelectron microscopy intracellularly located HBV envelope and nucleocapsid (core) proteins  with the lowest limits of detection only 10r vge/mL . Other lproteins . These cproteins ] and relproteins . Other wopoiesis . Early sopoiesis . Differeopoiesis . HBV nucopoiesis . Nonetheopoiesis .<200 copies/μg total RNA) compared to HBV-susceptible human HepaRG cells . However, the usage of distinct receptors to infect different cell types is well known among viruses , preS2 (middle), or S  envelope proteins were constructed . The N-t viruses .via Southern and Northern blot analyses   . FollowiFurther, a WHV site capable of strict host and cell-type specific recognition was identified in the extreme N-terminal portion of the virus preS1 protein . The cruEarly studies identified, with a high degree of confidence, that HBV infects both circulating and lymphoid organ residing immune cells. They suggested that these cells are a site of active HBV replication and might produce infectious virus under certain circumstances. The findings in the woodchuck infection model strongly supported these possibilities and the essentially lymphotropic nature of WHV. Other HBV animal models were less extensively studied but still provided insight on hepadnaviral lymphotropism .The advent of polymerase chain reaction (PCR) enabled development of sensitive and standardized methods for detection and quantitation of hepadnavirus genomes and replication intermediates, including mRNA and cccDNA . The newex vivo with cell stimulating mitogens  Stimulation of circulating or lymphatic organ-derived immune cells mitogens . Mitogenmitogens ; (2) Dirmitogens ; (3) Enumitogens , and (4)mitogens . These smitogens .in vitro exposure to virus. However, the signal may originate from viral particles or virus free DNA fragments adhered to the cell surface or tissue from contaminating blood or culture medium. Therefore, removal of these potential contaminants is done by limited digestion of the cell surface with trypsin and DNase followed by extensive washing prior to extraction of nucleic acid, as reported  and to a lesser degree B cells may passively carry phagocytosed virus. The ultimate confirmation of hepadnaviral lymphotropism is demonstration of the infected immune cells capability to produce infectious virus that is able to establish productive replication in susceptible cells in vitro or in vivo using a relevant animal model.The first indication of hepadnavirus lymphotropism is usually detection of virus DNA in PBMC, lymphoid organs and their immune cells isolated from naturally infected hosts or immune cells after reported . It is areported . Virus pAs noted, early studies using bone marrow from HBV-infected individuals showed that HBV can replicate and assemble virions in bone marrow cells, and healthy hematopoietic stem cells were susceptible to HBV infection. Since then, a number of studies have investigated HBV tropism toward both hematopoietic and mesenchymal stem cells . In thisde novo synthesis of HBV proteins, a dose-dependent inhibition of virus replication by an antiviral drug, tenofovir disoproxil fumurate, and by secretion of infectious virus  Detection of WHV-specific DNA and cccDNA; (2) Transmission of infection to virus-naïve hepatocytes and PBMC by WHV secreted by naturally infected splenocytes or PBMC; (3) Infection of healthy woodchucks with WHV produced by naturally infected splenocytes, and (4) Infection of healthy woodchucks with WHV recovered after passage in hepatocytes that were initially exposed to WHV released from naturally infected splenocytes or PBMC. In woodchucks, WHV produced by naturally infected splenocytes established classical acute hepatitis (for further details see page 8), while WHV passaged in hepatocytes induced an asymptomatic, seronegative but WHV DNA-positive infection. We have since learned that such pattern of serum WHsAg and anti-WHc negative but WHV DNA reactive infection reflects POI and that the variable infection outcomes seen in this study were due to different amounts of virus administered . PBMC collected from animals with secondary occult and primary occult infection were also WHV genome reactive, but at a significantly lower frequency   . The detV or HCV . The numV or HCV , while HV or HCV . Overalli.v. administered to two naïve woodchucks  and in liver biopsies (>2 × 106 vge/104 cells) were detected throughout the animal follow-up. In addition to WHV DNA and mRNA, full length WHV DNA was identified in liver biopsies from the first animal and in autopsy serum and hepatic and splenic tissues from the second woodchuck using PCR with back-to-back primers located at the WHV nick region  and at autopsy were negative along with normal histology. Serum WHsAg and anti-WHc were not detected, whereas WHV DNA and mRNA were found in PBMC, bone marrow and pancreas at autopsy. Thus, although the animal acquired WHV infection, the liver was uninfected. In subsequent studies, we appreciated that this pattern reflected persistent primary occult infection or POI  of the same WHV inoculum induced classical acute hepatitis that progressed to chronic hepatitis in some animals. Taken together, the findings revealed that: (1) The immune system is the primary target and can be the only site of hepadnavirus replication when virus enters the host at very low doses (< 103 virions); (2) A reproducible animal model of POI was established, and (3) WHV administered i.v. at > 103 virions invades both the immune system and the liver and causes serologically and histologically evident hepatitis. These observations have led to the concept of a liver pathogenic vs. a liver non-pathogenic dose of hepadnavirus.The following study aimed to determine the dose of WHV required to establish primary occult infection in adult immunocompetent woodchucks and uncover virological characteristics and potential transmission of this form of infection . Healthyepatitis . The resi.v. injection with 10–100 WHV DNase digestion-protected virions and followed throughout the injected animals’ lifespan , as previously noted (see page 6) (The finding of HBV and WHV DNA integrations into immune cell and lymphatic organ genomes provided further compelling evidence of the viruses’ lymphotropic nature . The pre page 6) . HBV DNA page 6) .n = 53) with CHB associated or not with HCC demonstrated numerous integrations with both coding and non-coding regions of human genome. Many of the genes fused with HBV sequences were identified as those associated with the oncogenic processes in lymphoid and hepatic tumors, including oncogenes and tumor suppressor genes. Some of the integration sites were shared between PBMC and HCC. In the same study, a patient with CHB and extrahepatic lymphoid cell malignancy diagnosed as dendritic cell sarcoma (DCS) was investigated. HBV DNA, RNA, and cccDNA were detected in the patient’s PBMC and DCS tissue, as well as HBV envelope and nucleocapsid proteins were found by Western immunoblotting in this lymphoproliferative cancer. Ten unique HBV junctions with host coding genes were identified and, interestingly, HBV genotype in the tumor was distinct from that in the patient’s plasma and PBMC, i.e., genotype D versus C, respectively. This study pointed out the importance of thorough analysis of immune cells from HBV-infected patients for the presence of virus and its integration. This study provides further invaluable insights to recognition of the relationship between HBV and immune system malignancies and suspected virus-oncogenic potential , identified multiple WHV DNA-host genome junctions in PBMC and lymphatic organs, including bone marrow, spleen and lymph nodes, using inverse-PCR (invPCR) designed to specifically detect WHV X gene or WHV preS region integrations . WHV-hosFurther investigations are required to determine the consequences of HBV and WHV integration considering immune cell physiological functions and a contribution to the pro-oncogenic processes culminating in lymphoproliferative disorders, such as non-Hodgkin’s lymphoma and chronic lymphocytic leukemia . RecogniThe conversion of hepadnavirus relaxed circular DNA to cccDNA is the first step in the replication cycle, followed by transcription of cccDNA to mRNA, and then translation of the mRNA to virus proteins. Owing to an error-prone reverse transcriptase, the hepadnaviral genome is more susceptible to sequence variation than other DNA viruses. These genomic changes may occur in any virus sequence, the frequency of which is proportional to the duration of virus infection and viral fitness. The pathological implications of these mutations are unclear but recent data suggest tendency toward compartmentalization of HBV variants with possible autonomous evolution of variants in the immune cell compartment.vs. liver in the same transplant patient  Persistence of HBV in PBMC without coinciding liver infection, as in liver transplant recipients ; (2) Per patient . Beyond  patient . The gen patient .vs. wild-type virus populations in the liver and PBMC, respectively. Other data suggested that HBV might persist and evolve differently in PBMC than in the liver due to a different cellular microenvironment ide analog therapy and hepatitis B immune globin (HBIG) administration, resulting in undetectable serum HBsAg and HBV DNA, HBV replication continued after transplant in both liver and PBMC. Furthermore, while the liver carried predominantly antiviral drug-resistant variants, PBMC harbored wild-type HBV sequences . This noironment . In anotironment . The finironment . This isironment . The HBVironment . CollectUsing the woodchuck HBV model to determine whether infection of immune cells is a property of wild-type WHV or a particular variant predisposed to infect these cells, WHV derived from cultured splenocytes of an animal with chronic hepatitis, which carried identical WHV sequence in serum, liver and the immune system, was serially passaged in cultured virus-naïve splenocytes and WCM-260 hepatocyte line . It was in utero, and possible reactivation of asymptomatic infection; (3) The site of virus presence and replication despite otherwise successful antiviral therapy; (4) The site of autonomous, liver-independent evolution of virus variants; (5) The place of virus genome integration possibly underlying lymphatic system disorders, and (6) An easily accessible source of clinical and research material for diagnostic and treatment evaluation purposes, and assessment of the efficacy of novel anti-HBV approaches. Based on the findings summarized in the previous sections, the issues mentioned above will be discussed and supplemented with additional information , asymptomatic infections with these viruses when sensitive investigative methods are applied. Since the amounts of HBV and WHV are ∼10 to 100-fold lower in immune cells than in serum or hepatocytes their detection is challenging by standard approaches and therefore testing of larger sample amounts and serial samples from a given infected host could augment detection frequency . The patormation .ex vivo treatment of PBMC with mitogens offers an opportunity to detect virus or confirm its presence in situations of very low viral loads or the apparent absence of virus in these cells  Different pharmacokinetics with respect to penetration of antiviral agents into immune cells and hepatocytes (As cumulative data indicate, HBV can propagate within immune cells in the context of otherwise successful antiviral therapy, and evolve into distinct variants compared to virus in the liver. HBV variants occurring in serum are assumed to mainly originate from the infected liver and to a lesser degree from immune cells or other possible extrahepatic locations. Thus, analysis of variants in serum samples may be a practical alternative to compare hepatic or liver . Further in PBMC . It was  in PBMC . Further in PBMC . The dev in PBMC . Other patocytes .Hepatitis B virus integration into the PBMC genome was identified in early investigations on hepadnaviruses, however host sites involved in formation of virus-host junctions was recently recognized . Detaileex vivo stimulation of PBMC with individual mitogens or their cocktails, which augments virus genome expression and replication, offers a unique opportunity for assessing elimination of virus in cases where liver biopsy is virus non-reactive. As indicated previously, examination of PBMC provides an advantage for OBI detection, particularly its seronegative form, i.e., HBsAg, anti-HBc, and anti-HBs negative (The easy access to PBMC allows serial sampling and investigation of possible scenarios to enhance clinical diagnosis and monitoring of HBV, including detection and assessment of replication status during progression and resolution of hepatitis B. PBMC also provide valuable material for evaluating the efficacy of novel antiviral therapies. This may allow future comprehensive assessment of the status of HBV infection, including virus clearance due to treatment using advanced molecular techniques, i.e., analysis of PBMC and HBV transcriptomes and single-immune cell RNA-sequencing. However, there remains an ongoing need to evaluate HBV in the liver. Although HBV DNA loads and replication levels are generally lower in PBMC than in the liver, viral kinetics in PBMC follow well those in hepatic tissue, based on data from a few comparative studies in HBV-infected humans . These knegative , as it wnegative . The sennegative ] and in Despite evidence from studies on other non-cytopathic viruses establishing persistent infections, research on HBV lymphotropism has been hampered by difficulties in virus detection in the immune cell compartment as well as by an underappreciation for the role of lymphotropism in hepadnaviral biology and pathogenicity. The authors are hopeful that this review emphasizes the importance of this subject and will encourage further definitive studies.TM conceived, designed, and wrote the draft. CC edited the manuscript and provided the additional information. PM-C provided the complementary data and reviewed the manuscript. All authors contributed to the article and approved the submitted version.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.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Per- and polyfluoroalkyl substances (PFAS) are ubiquitously found in the environment due to their widespread commercial use and high chemical stability. Humans are exposed primarily through ingestion of contaminated water and food and epidemiological studies over the last several decades have shown that PFAS levels are associated with adverse chronic health effects, including cardiometabolic disorders such as hyperlipidemia and non-alcoholic fatty liver disease. Perhaps the most well-established effects, as demonstrated in animal studies and human epidemiological studies, are the metabolic alterations PFAS exposure can lead to, especially on lipid homeostasis and signaling. This altered lipid metabolism has often been linked to conditions such as dyslipidemia, leading to fatty liver disease and steatosis. Western diets enriched in high fat and high cholesterol containing foods may be an important human exposure route of PFAS and may also act as an important modulator of associated toxicities. In fact, the chemical structure of PFAS resemble fatty acids and may activate some of the same signaling cascades critical for endogenous metabolism. In this review we aim to outline known dietary exposure sources of PFAS, describe the detrimental metabolic health effects associated with PFAS exposure, and focus on studies examining emerging interaction of dietary effects with PFAS exposure that further alter the dysregulated metabolic state. A few single nucleotide polymorphisms and their associated genes have been identified in genome-wide association studies of NAFLD, e.g., PNPLA3, TM6SF2, HSD17B13, MBOA7, PPP1R3B, LYPLAL1, and GCKR (Liu Z. et al., *3-Leiden.CETP mice, which exhibit human-like lipoprotein metabolism through cholesteryl ester transfer protein expression and delayed apoB clearance (Pouwer et al., *3-Leiden.CETP mice were fed a Western-type diet and exposure to PFBS, PFHxS, or PFOS for 4–6 weeks (Bijland et al., Studies over the past several decades in animals and humans have demonstrated the range of health effects linked to PFAS exposure. Because of this, it is important to gain a better understanding of the mechanisms involved in PFAS-induced manipulation of lipid metabolism. Studies using rodents are key to learning these mechanisms and how they can be translated to humans. However, in most published rodent studies, the animals have been fed a standard diet, containing low fat and negligible cholesterol. Only a few studies have examined the effects of PFAS exposure in combination with a diet similar to one consumed by a majority of humans in western societies that is high in fat and cholesterol. Nevertheless, the ability of PFAS exposure simultaneous with a high-fat diet to cause hypolipidemia and increase hepatic steatosis remains a disputed topic. A study conducted by Wang et al. looked at male BALB/c mice exposed to 5–20 mg/kg PFOA via oral gavage for 14 days while being fed either a regular or high-fat diet (Wang et al., Although current animal studies highlight a relationship between diet and PFAS exposure, inconsistencies exist among the studies on the changes in lipid metabolism and cardiometabolic profiles that are produced. Numerous studies have highlighted the association between PFAS exposure in humans to hyperlipidemia and fatty liver disease, while studies in rodents conversely report hypolipidemia. When diet is further introduced as a variable, most rodent studies investigating mice exposed to PFAS and a high fat diet reported an exacerbation of results found in standard diet studies, namely increased hepatic steatosis and hypolipidemia. These studies varied across the mouse strains and models used (Tan et al., The PFAS family of synthetic chemicals are pervasive throughout the environment and exposure is known to occur via multiple routes, including indoor dust and air, drinking water, and diet. PFAS exposure is associated with hyperlipidemia in humans, while animal studies commonly report hypolipidemia. Furthermore, epidemiological studies in humans have linked PFAS exposure to fatty liver disease. Several recent studies exploring dietary modulation of PFAS toxicity report an exacerbation of hepatic steatosis and hypolipidemia. However, the specific interactions of diet with PFAS toxicity remains unclear, and some studies have shown PFASs to have a protective effect against high-fat diet-induced hepatic steatosis, especially when the condition is pre-existing. The manufacture of long-chain PFAS has been halted because of substantial public and media attention due to their documented water pollution and toxicity in the U.S., European Union, and Australia. However, regulations on PFAS substances in other areas of the world are absent, and information regarding PFAS contamination and exposure levels in many nations is lacking. Furthermore, PFAS contamination can negatively impacts humans in more ways than simply direct human exposure. The ubiquitous nature of PFAS in the environment has also been shown to disturb natural ecosystems by disrupting aspects of animal development, life cycles, and reproduction. While companies have halted the manufacture of long-chain PFAS, short-chain emerging PFAS, such as GenX, are being produced in their place. Toxicities of short-chain PFAS are not well-understood and more studies are required in order to evaluate the risks associated with them. Despite increased awareness and documentation, both long- and short-chain PFAS remain present in drinking water sources worldwide, and regulators in nations across the globe may need to reexamine risk assessment and toxicity studies in order to accurately evaluate the NOAEL and LOAEL for human populations.KR and ZI wrote and edited the manuscript. MP and WL wrote, edited, and oversaw the completion of the review. All authors have read and approved of the manuscript.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.


Senescent cells accumulate with age in various tissues and organs, leading to the decline in tissue function and deterioration of many age-related diseases and aging. Senolytics have emerged as an effective therapeutic approach to eliminate senescent cells to improve aging phenotypes and associated co-morbidities. Despite their promising potential, only a handful of senolytics have been reported, including a natural flavonoid fisetin discovered by our group. Fisetin has been shown to reduce senescence, suppress age-related pathology, and extend healthspan in aged mice. However, its moderate potency, potential mutagenic risk and poor bioavailability have limited its further clinical applications. By leveraging drug design, medicinal chemistry and high-content imaging analysis, we have successfully optimized the senolytic activity of fisetin, leading to the identification of two improved fisetin senolytic analogs (FAs) with reduced toxicity in non-senescent cells. The improved senolytic activity of these FAs was demonstrated in murine and human senescent cell models as well as in accelerated aging and naturally aged mouse models. The analysis of the senolytic activity of the FAs as well as several other recently identified senolytics, including a senolytic lipid, will be presented.


The oral cavity is an intricate environment subjected to various chemical, physical, and thermal injuries. The effectiveness of the local and systemically administered drugs is limited mainly due to their toxicities and poor oral bioavailability that leads to the limited effectiveness of the drugs in the target tissues. To address these issues, nanoparticle drug delivery systems based on metals, liposomes, polymeric particles, and core shells have been developed in recent years. Nano drug delivery systems have applications in the treatment of patients suffering from temporomandibular joint disorders such as preventing degeneration of cartilage in patients suffering from rheumatoid arthritis and osteoarthritis and alleviating the pain along with it. The antibacterial dental applications of nano-drug delivery systems such as silver and copper-based nanoparticles include these agents used to arrest dental caries, multiple steps in root canal treatment, and patients suffering from periodontitis. Nanoparticles have been used in adjunct with antifungals to treat oral fungal infections such as candida albicans in denture wearers. Acyclovir being the most commonly used antiviral has been used in combination with nanoparticles against an array of viral infections such as the herpes simplex virus. Nanoparticles based combination agents offer more favorable drug release in a controlled manner along with efficient delivery at the site of action. This review presents an updated overview of the recently developed nanoparticles delivery systems for the management of temporomandibular joint disorders along with the treatment of different oral infections. The oral cavity is an intricate environment that is subjected to various chemical, physical, and thermal injuries. The oral cavity is also a site of infections and pathological changes to the temporomandibular joint (TMJ). Many bacterial, viral, and fungal infections are found affecting the oral cavity such as dental caries, periodontitis, endodontic diseases, candidiasis, herpes simplex virus, and varicella zoster infection . TemporoDifferent types of nanoparticles combinations are used in the drug delivery systems such as silver nanoparticles, copper nanoparticles, and chitosan-based nanoparticles along with lipid-carrier-based nanoparticles . Each ofThe temporomandibular joint is one of the most vital joints of the human body as it is involved in performing important functions such as guiding the mandibular movements and regulating the stresses that are produced throughout the day such as mastication, speech, and deglutition . About tDegeneration of the TMJ cartilage is among the common features in patients suffering from osteoarthritis, rheumatoid arthritis, and psoriatic arthritis, which then further leads to jaw pain and limited movements that are functionally debilitating ,19,20. CNanoparticles are present in various different sizes in nanometers which readily enter the target cells by endocytosis mechanism. Biosynthetic molecules such as poly lactic co-glycolic acid (PLGA) and poly lactic acid (PLA) or chitosan and gelatin  are used to make nanoparticles . ChondroReactive oxygen species (ROS) are also responsible for inducing inflammatory reactions that lead to cartilage degeneration. So, therefore, targeting these ROS via nanoparticles can be beneficial in protecting the TMJ cartilage. Nanoparticle’s antioxidants have been purposed as options for such cases .Inflammation of the temporomandibular joint is a frequent pathology that is suffered by many patients, and it affects adjacent tissues of the joint as well. Most commonly, such patients are treated with non-steroidal anti-inflammatory drugs (NSAIDs). When taking the NSAIDs in a conventional way such as oral administration, to reach the desired level of efficacy required, it can take many days or weeks since they are administered systemically and required repeated doses .To enhance the beneficial properties of the NSAIDs, naproxen is incorporated in nanostructured lipid carriers (NLC) for intra-articular injection for the reduction of inflammation in TMJ disorders . NaproxeMethotrexate (MTX) based nanoparticles have been developed in combination with NLC to treat patients with rheumatoid arthritis presenting frequently with TMJ disorders. In such cases, the swelling had significantly reduced during a period of 28 days when administered in rats . PaclitaNanolipid carriers-naproxen (NLC NPX) efficacy in reduction of inflammation was measured by leukocyte infiltration in TMJ of rats. In the initial first 10 days of injection of NLC NPX, the leukocyte infiltration was reduced but after the 10th day, the effect had abrogated .Arthritis affects many joints in conditions such as rheumatoid arthritis, especially the temporomandibular joint. Methotrexate is primarily used as an antiarthritic drug to control ongoing arthritic effects. Recently, in many in vivo studies, methotrexate has been incorporated in nanolipid carriers to target specific joints only. In comparison with the conventional way of taking methotrexate, when MTX is combined with NLC, superior anti-arthritic effects were noted which reduced inflammation significantly .Anti-arthritic effects of hesperidin (HP) incorporated in gum acacia (GA) with silver nanoparticles (AgNP) has been investigated. HP loaded with GA-AgNP should reduction in swelling and degenerative changes with the primary mechanism of action by interfering with Toll-like receptors (TLR-2 and TLR-4) mechanism which aggravates arthritis .Chitosan-based nanoparticles (CS-NP) have been used as subcutaneous injection as an anti-arthritic treatment modality in rheumatoid arthritis patients. Chitosan-based nanoparticles were prepared using the ionotropic gelation method where 1 g chitosan was fully dissolved in 50 milliliters glacial acetic acid 1%, mixed at 40 degrees to achieve a clear solution with nanoparticles having a size of 102.4 ± 3.2nm. Rats were induced with arthritis that showed a significant decrease in malondialdehyde (MDA) and nitric oxide (NO) levels which resulted in the return of normalcy of antioxidants . FurtherBiofilms in the oral cavity can cause many diseases such as dental caries and periodontal disease . Dental Nanoparticles can incorporate within many antimicrobial and antiplaque agents for better treatment, as presented in Silver and copper have been the most studied metals with their antimicrobial properties used in combination with nanoparticles ,44. As pStreptococcus intermedius, Porphyromonas gingivalis, Fusobacterium nucleatum, Prevotella intermedia, and Aggregatibacter actinomycetememcomitans, all have been found to be susceptible to copper oxide and silver nanoparticles [Silver nanoparticles have been used in a variety of situations such as coating of implants and dressing of wounds . One stuarticles . Differearticles ,53. Thesarticles .Enterococcus faecalis in extracted human teeth. Successful reduction in colony-forming units (CFU) was noted when aPDT nanoparticles were used as compared to controls where higher CFU were noted [Considering endodontic diseases, it encompasses various pathologies from vital pulp to a necrotic pulp with cellulitis and abscesses. To treat such diseases, root canal therapy is most commonly performed in association with antibacterial agents such as intracanal medicaments and systemic antibiotics . Most ofre noted .Chitosan nanoparticles (CS-NP) have been incorporated within the traditionally used sealers, compare its effect with conventional sealers. By using CS-NP, it was found that biofilm formation was inhibited within the dentin-sealer interface as compared to using conventional sealer formulation, after being evaluated for 30 days .Patients suffering from various periodontal conditions require not only mechanical plaque removal, but administration of antibiotics as well. Since most of the antibiotics are given systemically, they lead to unwanted side effects, limited permeability of drugs into the target cells, and at times bacterial resistance as well. So, to avoid such circumstances, local delivery of drugs within the periodontal pockets can overcome such disadvantageous scenarios. Studies do report transportation of the nanoparticles within the junctional epithelium using an intra-pocket delivery system .Chitosan nanoparticles either with PLGA or polyvinyl acetate have been used to treat periodontitis-causing bacteria. When placed inside the periodontal pockets, its antibacterial properties were noted with a reduction in the bacterial count even in the constant presence of salivary stimulation .Minocycline incorporated PEG-PLA nanoparticles have been studied in the periodontal pockets with noted sustained release in vitro over the course of 14 days with the drug remaining effective against the bacteria for over 12 days within significant reduction in the periodontal symptoms, as compared to the control .Subgingival plaque and calculus are known to be one of the primary factors in causing gingivitis and then untreated gingivitis may lead to periodontitis. Such plaque and calculus are not cleaned by the use of toothbrush and requires treatment by the dental surgeons. A study by Hayakumo et al. concluded that use of ozone nanobubble that is produced by nanobubble technology can the used as subgingival irrigation for its antibacterial properties .Host modulation therapy has been an emerging field of interest to the researchers that reduces and even stabilizes or might even regenerate inflammatory tissues by modifying the host response . Host mocandida albicans [Candida albicans, is the primary fungal infection that targets the oral cavity. Conventionally, many antifungal medications such as nystatin and azoles, both systemically and locally, have been employed to tackle the infection but with unwanted side effects as well. Nanoparticles have been incorporated with copper, silver, and palladium, to inhibit the growth of many microorganisms such as albicans . Used asalbicans . Silver candida albicans induced infections due to prolonged wear. So, nanoparticles have been successfully incorporated into PMMA to combat such infections. Silver nanoparticles have been shown to decrease microbial colonization over the prosthesis [Candida glabrata, Candida tropicalis, and Candida albicans [Denture wearers frequently complain of suffering from osthesis . An in valbicans .Candida albicans [Zirconium oxide nanoparticles (ZrO2 NP) incorporation into PMMA has shown to increase the density of the prosthesis along with a decrease in porosity which is responsible to enhance tensile strength, fracture strength, and flexural strength . Due to albicans .Nanoparticles coated with fluconazole have been used using ethylcellulose and Flu- eudragit RS 100 polymers. The results concluded that nanoparticles coated with fluconazole exhibited prolonged release of fluconazole over 90% for a period of 8 h as compared to conventionally used systemic fluconazole with 90% released during the first hour, therefore improved antifungal activity .Nystatin, a very effective antifungal agent used to treat many fungal infections has a very short duration of action in target tissues which limits its use and often requires multiples doses. To overcome this drawback, Nystatin has been incorporated with nanoparticles. Unloaded nystatin was formulated and fully characterized and incorporated into oral gel and toothpaste, with sizes ranging from 300 to 800 nm after loading . It was The oral cavity is populated by various types of microorganisms for e.g., Streptococcus, Eubacteria, and Fusobacterium, with viruses being one of them such as herpes simplex virus 1 and 2 (HSV-1 and HSV-2). These viral infections are a major global public health challenge, with resistance to major drugs against these viruses another hurdle. So, to overcome this challenge, a nanotechnology drug delivery system has been worked upon.Acyclovir is one of the most commonly used antiviral drugs primarily against herpes simplex infections (HSV-1 and HSV-2). When taken orally, one of the limitations of this drug is its poor bioavailability . NanoparAcyclovir IV nanoparticles injections have also been formulated to increase further the bioavailability and efficacy of the drug. Administration of the conventional IV acyclovir commonly causes thrombophlebitis at the injection site . FurtherUsing polylactic-co-glycolic acid (PLGA), nanoparticles novel IV acyclovir has been formulated to overcome this limitation of poor bioavailability. When acyclovir was combined with PLGA, a nanoparticle size of 200–300nm was achieved ,83. WhenChitosan has been primarily used in medical sciences mainly due to its non-toxicities, biocompatibility, biodegradability, and passing through tight capillary junctions which helps in better penetration into target tissues . AlthougHSV-1 is known to affect the oral cavity due to its high transmissibility rate, occurring most commonly during childhood has herpetic gingivostomatitis with recurrent labial lesions. To treat patients infected with HSV-1, many in-vitro studies have been carried on chitosan-loaded nanoparticles. A study by Donalisio et al. found that chitosan-based nanoparticles loaded with acyclovir presented with increased potency against the HSV-1 and HSV-2 viruses as compared to using acyclovir alone with no reported cytotoxicity against the host cells .Interferons are known for the capability to suppress viral replication by inhibiting its translation. A study reports that when chitosan nanoparticles are administered in mice, their splenocytes secreted increased amounts of interferon-gamma ,88.Chloroquine phosphate (CHQ) has been successfully used to treat many infections such as malaria, and some inflammatory disorders too, such as rheumatoid arthritis and lupus erythematosus. CHQ in combination with nanoparticles drug delivery systems has been used to improve the efficacy of the drug at the targeted tissue site ,90.Chloroquine diphosphate in combination with polylactic acid (PLA) nanoparticles (CQ-NP) has been tested to improve its efficacy against HSV-1. It was concluded that the use of CQ-NP significantly improved the antiviral properties of chloroquine diphosphate against HSV-1 .In a recent study by Chakravarty et al., the use of lipid-based, metal-based and polymeric substances as nanoparticles for delivery of antiviral drugs in coronavirus disease-19 (COVID-19) patients has been studied . The sizNanoemulsion, due to its favorable properties can be used to carry antiviral drugs . Few stuDendrimers are drug delivery systems that are used to administer insoluble drugs ,98. DendNanoparticles drug delivery systems have been studied and researched in the past few decades as it offers many significant advantages over the conventional methods of administering drugs such as increased bioavailability and efficiency of drugs at the site of action and decreased systemic adverse effects of the drugs. At the present moment, nanoparticles drug delivery system has limited application in dentistry that needs further studies to enhance its scope for use in dentistry such as to diagnose and treat oral cancers, use of nanoparticles in mouthwashes and toothpastes as an adjunct in non-surgical periodontal treatments, local anesthesia, and treating dental hypersensitivity.At the present moment, the use of nanotechnology especially in dentistry is continuing to expand with its various applications such as in treating temporomandibular joint disorders and oral infections. Nanoparticles offer greater oral bioavailability, few side effects, and increase patient’s compliance when taking drugs in this form. Synthesis of such nanoparticles-based drug delivery systems is playing a pivotal role, especially considering its application in dentistry. Nanoparticles have been used in combination with antibacterials, antivirals, and antifungals to optimize the treatment of dental infections along with temporomandibular joint disorders. In the future, more clinical trials should be conducted to further explore the beneficial effects of nanoparticles drug delivery systems.