Role Of Mesenchymal Stem Cells Research Articles

The application potential of iMSCs and iMSC-EVs in diseases.

The immune system, functioning as the body's "defense army", plays a role in surveillance, defense. Any disruptions in immune system can lead to the development of immune-related diseases. Extensive researches have demonstrated the crucial immunoregulatory role of mesenchymal stem cells (MSCs) in these diseases. Of particular interest is the ability to induce somatic cells under specific conditions, generating a new cell type with stem cell characteristics known as induced pluripotent stem cell (iPSC). The differentiation of iPSCs into MSCs, specifically induced pluripotent stem cell-derived mesenchymal stem cells (iMSCs), hold promise as a potential solution to the challenges of MSCs, potentially serving as an alternative to traditional drug therapies. Moreover, the products of iMSCs, termed induced pluripotent stem cell-derived mesenchymal stem cell-derived extracellular vesicles (iMSC-EVs), may exhibit functions similar to iMSCs. With the biological advantages of EVs, they have become the focus of "cell-free therapy". Here, we provided a comprehensive summary of the biological impact of iMSCs on immune cells, explored the applications of iMSCs and iMSC-EVs in diseases, and briefly discussed the fundamental characteristics of EVs. Finally, we overviewed the current advantages and challenges associated with iMSCs and iMSC-EVs. It is our hope that this review related to iMSCs and iMSC-EVs will contribute to the development of new approaches for the treatment of diseases.

The Role of Mesenchymal Stem Cells in Hair Regeneration and Hair Cycle.

The health of hair is directly related to people's health and appearance. Hair has key physiological functions, including skin protection and temperature regulation. Hair follicle (HF) is a vital mini-organ that directly impacts hair growth. Besides, various signaling pathways and molecules regulate the growth cycle transition of HFs. Hair and its regeneration studies have attracted much interest in recent years with the increasing rate of alopecia. Mesenchymal stem cells (MSCs), as pluripotent stem cells, can differentiate into fat, bone, and cartilage and stimulate regeneration and immunological regulation. MSCs have been widely employed to treat various clinical diseases, such as bone and cartilage injury, nerve injury, and lung injury. Besides, MSCs can be used for treatment of hair diseases due to their regenerative and immunomodulatory abilities. This review aimed to assess MSCs' treatment for alopecia, pertinent signaling pathways, and new material for hair regeneration in the last 5 years.

Immunologic barriers in liver transplantation: a single-cell analysis of the role of mesenchymal stem cells.

This study aimed to analyze the biomarkers that may reliably indicate rejection or tolerance and the mechanism that underlie the induction and maintenance of liver transplantation (LT) tolerance related to immunosuppressant or mesenchymal stem cells (MSCs). LT models of Lewis-Lewis and F344-Lewis rats were established. Lewis-Lewis rats model served as a control (Syn). F344-Lewis rats were treated with immunosuppressant alone (Allo+IS) or in combination with MSCs (Allo+IS+MSCs). Intrahepatic cell composition particularly immune cells was compared between the groups by single-cell sequencing. Analysis of subclusters, KEGG pathway analysis, and pseudotime trajectory analysis were performed to explore the potential immunoregulatory mechanisms of immunosuppressant alone or combined with MSCs. Immunosuppressants alone or combined with MSCs increases the liver tolerance, to a certain extent. Single-cell sequencing identified intrahepatic cell composition signature, including cell subpopulations of B cells, cholangiocytes, endothelial cells, erythrocytes, hepatic stellate cells, hepatocytes, mononuclear phagocytes, neutrophils, T cells, and plasmacytoid dendritic cells. Immunosuppressant particularly its combination with MSCs altered the landscape of intrahepatic cells in transplanted livers, as well as gene expression patterns in immune cells. MSCs may be included in the differentiation of T cells, classical monocytes, and non-classical monocytes. These findings provided novel insights for better understanding the heterogeneity and biological functions of intrahepatic immune cells after LT treated by IS alone or in combination with MSCs. The identified markers of immune cells may serve as the immunotherapeutic targets for MSC treatment of liver transplant rejection.

A Prospective, Multi-Center, Randomized, Controlled Clinical Trial to Explore the Role of Mesenchymal Stem Cells in Preventing Graft Versus Host Disease

Background: There are few studies currently available on the prevention of GVHD by mesenchymal stem cells (MSCs) that use a systematic approach to prevent both aGVHD and cGVHD simultaneously. The clinical investigation of MSCs preventing either aGVHD or cGVHD independently is the main focus of the earlier studies. Aim:Using the strategy of co-transplantation of MSCs and HSCs and phased application of MSCs after transplantation (MSCs 100-day scheme), we seek to develop a secure and dependable system that can avoid both aGVHD and cGVHD based on our preliminary research. Method:Patients undergoing haploidentical adult hematopoietic stem cell transplantation will receive unaltered, fourth-generation UC-MSCs(Umbilical Cord). In addition to the usual GVHD preventive measures, UC-MSCs are given four hours before the transplantation of peripheral blood stem cells on day 0. UC-MSCs are administered once weekly for 1-4 weeks, once every 2-8 weeks, and once every 4-12 weeks after transplantation. The dose needed for each transfusion is 1 10 6/kg. Our research will look at how well UC-MSCs prevent GVHD following haplo-HSCT, as well as recurrence rates after transplantation, transplant-related issues, and the state of immunological reconstruction. the frequency, severity, 1- and 2-year survival rates, cumulative death rates, and the occurrence of aGVHD and cGVHD.Real-time tracking will be performed to monitor the occurrence of aGVHD and cGVHD, as well as their severity, frequency, 1-year and 2-year survival rates, and cumulative mortality rates. The analysis of the differences between the control group and the experiment will take into account the pre-transplant ferritin levels, CMV serological status of the donor-recipient, blood type matching situation, HLA locus matching situation, disease remission status, residual disease conditions, recipient age, donor-recipient gender matching situation, stem cell quantities (nucleated cells and CD34+ cell counts), and stem cell numbers (nucleated cells and CD34+ cell counts). Results: 96 patients from the MSCs group and 96 patients from the control group are now accessible for statistical purposes. Demographic factors for age and gender distribution do not differ considerably. Acute myeloid leukemia, acute lymphoblastic leukemia, myelodysplastic syndrome-EB2, and acute mixed cell leukemia,which were all classified as having the same level of risk. The cumulative incidence of aGVHD grades II to IV is 19.8% in the MSCs group, while grades III to IV is 0%. Comparable indications for the control group are 43.8% and 9.3%, respectively. The overall incidence of aGVHD differs between the two groups in a statistically significant way (P=0.0047). The rates of moderate and severe cGVHD in the control group were 10.4% and 9.4%, respectively, whereas they were 13.5% and 4.2% in the MSCs group. Over the course of 1 year, the cumulative incidence of cGVHD for the MSCs group was 36.5%, compared to 39.6% for the control group. Regarding the overall two-year OS, there is no discernible difference between the MSCs group and the control group (P=0.43).While the MSCs group outperformed the control group in terms of GRFS (GVHD free and relapse free survival). Conclusion: The strategy of MSCs 100-day scheme infusion can successfully lower the incidence of acute and chronic GVHD and is beneficial for enhancing patient GRFS.

The Role of Mesenchymal Stem Cells in Modulating the Immune System and Repairing Lung Damage in ARDS Patients with SARS-COV-2

The Role of Mesenchymal Stem Cells in Modulating the Immune System and Repairing Lung Damage in ARDS Patients with SARS-COV-2

The Role of Mesenchymal Stem Cells in Cancer Immunotherapy.

Mesenchymal stem cells (MSCs) are getting attention in the field of cancer immunotherapy. The main effects of MSCs on tumors are homing and regulation of inflammatory and immune responses. Indeed, cancer immunotherapy has become a promising treatment and MSCs play a potential role in regulating the efficacy of immunotherapy. In addition, MSCs are an ideal carrier for immunomodulatory protein transmission. As such MSCs combined with immunotherapy drugs could act synergistically against tumors, throwing a great impact on cancer therapy. And MSCs may have potential in the treatment of cytokine storm or cytokine release syndrome (CRS). It is assumed that MSCs can form chimeric antigen receptor MSCs (CAR-MSCs). Whether CAR-MSCs can provide a new idea of cancer immunotherapy is unknown. It is a prime time to review the latest progress of MSCs in cancer immunotherapy, in order to clarify to fully understand the role of MSCs in cancer therapy in clinical practice.

Autologous mesenchymal stromal cells embedded with Tissucol Duo® for prevention of air leak after anatomical lung resection: results of a prospective phase I/II clinical trial with long-term follow-up

BackgroundProlonged air leak (PAL) is the most frequent complication after pulmonary resection. Several measures have been described to prevent the occurrence of PAL in high-risk patients, however, the potential role of mesenchymal stem cells (MSCs) applied in the parenchymal suture line to prevent postoperative air leak in this setting has not been fully addressed. ObjectiveTo analyse the feasibility, safety and potential clinical efficacy of the implantation of autologous MSCs embedded in Tissucol Duo® as a prophylactic alternative to prevent postoperative prolonged air leak after pulmonary resection in high-risk patients.Study designPhase I/II single-arm prospective clinical trial.MethodsSix patients with high risk of PAL undergoing elective pulmonary resection were included. Autologous bone marrow-derived MSCs were expanded at our Good Manufacturing Practice (GMP) Facility and implanted (embedded in a Tissucol Duo® carrier) in the parenchymal suture line during pulmonary resection surgery. Patients were monitored in the early postoperative period and evaluated for possible complications or adverse reactions. In addition, all patients were followed-up to 5 years for clinical outcomes.ResultsThe median age of patients included was 66 years (range: 55–70 years), and male/female ratio was 5/1. Autologous MSCs were expanded in five cases, in one case MSCs expansion was insufficient. There were no adverse effects related to cell implantation. Regarding efficacy, median air leak duration was 0 days (range: 0–2 days). The incidence of PAL was nil. Radiologically, only one patient presented pneumothorax in the chest X-ray at discharge. No adverse effects related to the procedure were recorded during the follow-up.ConclusionsThe use of autologous MSCs for prevention of PAL in patients with high risk of PAL is feasible, safe and potentially effective.Trial registration No. EudraCT: 2013-000535-27. Clinicaltrials.gov idenfier: NCT02045745.

Bone marrow mesenchymal stem cells to ameliorate experimental autoimmune encephalomyelitis via modifying expression patterns of miRNAs.

Clinical and experimental studies highlighted the significant therapeutic role of Mesenchymal stem cells (MSCs) in neurodegenerative diseases. MSCs possess potent immunomodulatory properties by releasing exosomes, which generate a suitable microenvironment. microRNAs (miRNAs), as one of several effective bioactive molecules of exosomes, influence cellular communication and activities in recipient cells. Recent studies revealed that miRNAs could control the progression of multiple sclerosis (MS) via differentiation and function of T helper cells (Th). Here, we investigated the therapeutic effects of syngeneic-derived BM-MSC in experimental autoimmune encephalomyelitis (EAE) mouse model of MS by evaluating expression profile of miRNAs, pro- and anti-inflammatory in serum and brain tissues. Three-time scheme groups (6th day, 6th & 12th days, and 12th day, of post-EAE induction) were applied to determine the therapeutic effects of intraperitoneally received 1*106 of BM-MSCs. The expression levels of mature isoforms of miR-193, miR-146a, miR-155, miR-21, and miR-326 showed that BM-MSCs treatment attenuated the EAE clinical score and reduced clinical inflammation as well as demyelination. The improved neurological functional outcome associated with enhanced expression of miR-193 and miR-146a, but decreased expression levels of miR-155, miR-21, and miR-326 were followed by suppressing effects on Th1/Th17 immune responses (reduced levels of IFN-γand IL-17 cytokine expression) and induction of Treg cells, immunoregulatory responses (increase of IL-10, TGF-β, and IL-4) in treatment groups. Our findings suggest that BM-MSCs administration might change expression patterns of miRNAs and downstream interactions followed by immune system modulation. However, there is a need to carry out future human clinical trials and complementary experiments.

The efficacy of mesenchymal stem cell treatment and colistin-fosfomycin combination on colistin-resistant Acinetobacter baumannii sepsis model.

This study examines the role of mesenchymal stem cells (MSCs) in an experimental sepsis model developed with colistin-resistant Acinetobacter baumannii (CRAB). BALB-c mice were divided into treatment groups (MSC, MSC + colistin (C)-fosfomycin (F), and C-F and control groups (positive and negative)). CRAB was administered to mice through intraperitoneal injection. Three hours later, C, F, and MSC were given intraperitoneally to the treatment groups. Colistin administration was repeated every 12 h, F administration was done every 4 h, and the second dose of MSC was administered after 48 h. Mice were sacrificed at 24 and 72 h. The bacterial load was determined as colony-forming units per gram (cfu/g). Histopathological examination was conducted on the left lung, liver, and both kidneys. IL-6 and C-reactive protein (CRP) levels in mouse sera were determined by enzyme-linked immunosorbent assay. Among the treatment groups, the C-F group had the lowest colony count in the lung (1.24 ± 1.66 cfu/g) and liver (1.03 ± 1.08 cfu/g). The highest bacterial clearance was observed at 72 h compared to 24 h in the MSC-treated groups (p = 0.008). The MSC + C-F group showed the lowest histopathological score in the liver and kidney (p = 0.009). In the negative control group, the IL-6 level at the 24th hour was the lowest (p < 0.001). Among the treatment groups, the CRP level was the lowest in the MSC + C-F group at 24 and 72 h. In a CRAB sepsis model, adding MSCs to a colistin-fosfomycin treatment may be beneficial in terms of reducing bacterial loads and preventing histopathological damage.

A Review of Exosomes in Regenerative Cosmetic Dermatology

Exosomes are the small extracellular vesicles secreted by almost all living cell types. They are a main component of cellular communication. To mediate intercellular communication, exosomes transport cellular cargo such as proteins, miRNA, nucleic acids, and various metabolites[Formula: see text]. Although specifics of their role in cellular physiology have yet to be uncovered, interest in exosomes and their functionality has exploded due to their diverse treatment and diagnostic capabilities. Already, numerous studies have proven the safety, efficacy, and therapeutic potential of exosomes in the treatment of cancers, neurodegenerative disorders, cardiovascular illness, and orthopedic diseases1. Due to their small size, high membrane permeability, and modifiability, exosomes are of the utmost therapeutic and diagnostic potential[Formula: see text]. As exosomes promote cellular regeneration, their role in general dermatology as well as cosmetic dermatology has become prominent. In the past few years, cosmetic dermatology research proves the potential of exosomes in the processes of skin rejuvenation, postprocedural care, and dermal maintenance. Some of the most popular modalities of treatment include hair restoration, photorejuvenation, daily maintenance, and antiaging. This paper will discuss the biological function, isolation methods, and therapeutic role of mesenchymal stem cell-and platelet-derived exosomes in cosmetic dermatology.

Potential role of mesenchymal stem cells in T cell aging.

Immunosenescence occurs with progressive age. T cell aging is manifested by immunodeficiency and inflammation. The main mechanisms are thymic involution, mitochondrial dysfunction, genetic and epigenetic alterations, loss of protein stability, reduction of T cell receptor (TCR) repertoire, naïve-memory T cell ratio imbalance, T cell senescence, and lack of effector plasticity. Mesenchymal stem cells (MSCs) are thought to hold great potential as anti-aging therapy. However, the role of MCSs in T cell aging remains elusive. This review makes a tentative summary of the potential role of MSCs in the protection against T cell aging. It might provide a new idea to intervene in the aging of the immune system.

Adipose-derived mesenchymal stem cells -conditioned medium effects on Glioma U87 cell line migration, apoptosis, and gene expression

The conditioned medium of mesenchymal stem cells (MSCs) has controversial roles in cancer, either promoting or suppressing tumor growth. Our research on the results of adipose tissue-derived MSC (AD-MSC)-conditioned media on U87 glioma cells was motivated by the disputed role of mesenchymal stem cells (MSCs) in cancer, which may either promote or inhibit tumor growth. Using flow cytometry, AD-MSCs were identified, verified, and their conditioned media was used to treat U87 cells. Through RT-qPCR, scratch assay, and apoptosis analysis, we evaluated gene expression (SOX4, H19, and CCAT1), cell migration, and apoptosis in U87 cells.The conditioned media greatly increased the expression of SOX4 and H19, but not CCAT1. Although there were few differences in migration and apoptosis, both were slightly increased in the treated group.These outcomes have drawn attention to the complexity of the interactions between MSCs and glioma cells. This complexity requires further research to identify the specific mechanisms governing MSC-mediated impacts on the development of glioblastoma multiforme (GBM).

Fibronectin-coated polyurethane meniscal scaffolding supplemented with MSCs improves scaffold integration and proteoglycan production in a rabbit model.

The role of mesenchymal stem cells (MSC) in supporting the formation of new meniscal tissue in a meniscal scaffold is not well understood. The objective of this study was to assess the quality of the meniscal tissue produced in a fibronectin (FN)-coated polyurethane (PU) meniscal scaffold after a meniscal injury was made in an experimental rabbit model. Twelve New Zealand white rabbits were divided in two groups after performing a medial meniscectomy of the anterior horn. In group 1, the meniscal defect was reconstructed with a non-MSC supplemented FN-coated PU scaffold. On the other hand, the same scaffold supplemented with MSCs was used in group 2. The animals were sacrificed at 12week after index surgery. A modified scoring system was used for histological assessment. This new scoring (ranging from 0 to 15) includes a structural evaluation (meniscal scaffold interface and extracellular matrix production) and tissue quality evaluation (proteoglycan and type I-collagen content). The meniscal scaffold was found loose in the joint in three cases, corresponding to two cases in group 1 and 1 case in group 2. No differences were observed between the groups in terms of the total score (7.0 ± 0.9 vs. 9.4 ± 2.6, p = 0.09). However, differences were observed in group 2 in which 2 out of the 5 scored items, scaffold integration (1 ± 0.0 vs. 1.9 ± 0.6, p = 0.03) and proteoglycan production (1.2 ± 0.3 vs. 2.4 ± 0.2, p = 0.001). A trend to a higher production of Type I-Collagen production was also observed in group 2 (1.1 ± 0.4 vs. 1.4 ± 0.7, p = 0.05). In a rabbit model at 12weeks, the adhesion of MSCs to a FN-coated PU scaffold improves scaffold integration, proteoglycan production and the characteristics of the new meniscal-like tissue obtained when compared to a non-supplemented scaffold. This fact could be a major step toward improving the adhesion of the MSCs to meniscal scaffolds and, consequently, the obtention of better quality meniscal tissue.

A Supportive Role of Mesenchymal Stem Cells on Insulin-Producing Langerhans Islets with a Specific Emphasis on The Secretome.

Type 1 Diabetes (T1D) is a chronic autoimmune disease characterized by a gradual destruction of insulin-producing β-cells in the endocrine pancreas due to innate and specific immune responses, leading to impaired glucose homeostasis. T1D patients usually require regular insulin injections after meals to maintain normal serum glucose levels. In severe cases, pancreas or Langerhans islet transplantation can assist in reaching a sufficient β-mass to normalize glucose homeostasis. The latter procedure is limited because of low donor availability, high islet loss, and immune rejection. There is still a need to develop new technologies to improve islet survival and implantation and to keep the islets functional. Mesenchymal stem cells (MSCs) are multipotent non-hematopoietic progenitor cells with high plasticity that can support human pancreatic islet function both in vitro and in vivo and islet co-transplantation with MSCs is more effective than islet transplantation alone in attenuating diabetes progression. The beneficial effect of MSCs on islet function is due to a combined effect on angiogenesis, suppression of immune responses, and secretion of growth factors essential for islet survival and function. In this review, various aspects of MSCs related to islet function and diabetes are described.

Role of mesenchymal stem cells and taurine in chronic pancreatitis in adult albino rats

Chronic pancreatitis (CP) is an inflammatory disease of the pancreas that leads to pancreatic fibrosis. The current treatment of the disease is not efficient or adequate. Therefore, more efficient interventions are required to diminish the substantial burden of the disease. The present study aimed to assess the potential therapeutic value of bone marrow-derived mesenchymal stem cells (BMSCs) and/or taurine supplementation in CP-induced, using intraperitoneal injection of L-arginine. Forty-five rats were randomly divided into five groups (9 rats each): 1) control group, 2) CP group, 3) CP+BMSCs, 4) CP+Taurine, and 5) CP+BMSCs+Taurine. At the end of the experimental period, the pancreatic tissues were collected, weighed, and prepared for light, electron, and immunohistochemical (α-SMA) microscopic examination. The CP group showed destruction of the pancreatic tissues including fatty degeneration, minimal zymogen granules, and focal degranulation of the rER. Some of the islets degenerated with intense immunoreactivity of α-SMA in the stroma. The groups treated with BMSCs or taurine alone showed improvement of the pancreatic architecture with the presence of some cytoplasmic vacuolation, fewer zymogen granules than the control group, and minimal inflammatory cell infiltrate. The CP+BMSCs+Taurine group showed apparently normal architecture. The combined therapy of both BMSCs and taurine could ameliorate CP progression by suppressing inflammation and fibrosis.

The Role of Mesenchymal Stem Cells in Liver Regeneration

Background: Inflammation of the liver caused by cholestasis, viral infection, alcohol, autoimmune reactions, toxins, or metabolism will result in a prolonged immune response. As a result, simultaneous inflammation and tissue remodelling occur, resulting in fibrosis and eventually leading to cirrhosis. The main treatment for end-stage liver cirrhosis is liver transplantation. However, it is often not possible for patients to undergo this life-saving procedure. On the other hand, stem cell transplantation may be a potential strategy to prevent disease progression and improve the degree of fibrosis.&#x0D; Discussion: Inflammation of the liver activates hepatic stellate cells, which are perisinusoidal cells in the Disse cavity that contain vitamin A. Hepatic stellate cells activation results in retinoid storage loss and transformation into myofibroblast-like cells that express α-smooth muscle action (α-SMA) and produce collagen which plays a major role in fibrosis. Liver regeneration due to chronic liver damage is played by mesenchymal cells through the mesenchymal-epithelial or epithelial-mesenchymal transition (MET/EMT) process. Administration by the intrahepatic route is thought to be the ideal route because fewer cells are lost in the circulation and more mesenchymal stem cells differentiates into hepatocytes in the damaged liver area. However, intrasplenic route maybe an alternative with easier administration technique. There are special considerations regarding the risks, including the risk of carcinogenesis and viral transmission.&#x0D; Conclusion: Mesenchymal stem cells transplantation may be a potential therapeutic strategy for patients with end stage liver disease in the future. However, future research is needed regarding the risk of carcinogenesis and viral transmission following the procedure.

Therapeutic role of mesenchymal stem cells and platelet-rich plasma on skin burn healing and rejuvenation: A focus on scar regulation, oxido-inflammatory stress and apoptotic mechanisms

Cell-based therapies have great promise in accelerating and improving burn wound healing. It is a growing need to scale their competence to meet the clinical demands. In this study, the bone marrow mesenchymal stem cells (BMSCs) and platelet-rich plasma (PRP) were tested on the repair of induced burn wounds in a murine model. After the induction of thermal injury, rats were injected with BMSCs and/or PRP in the burn area. After 4 weeks of post-burn, our findings revealed that local treatment of burnt skin with BMSCs and/or PRP offered substantial outcomes when compared with the untreated group. Injected burn with BMSCs and/or PRP enhanced the wound contraction rate and decreased the burn area and period of epithelization. Significant increases in VEGF together with declines in MMP-9 and TGF-β1 were observed in burnt areas after being treated with BMSCs and/or PRP therapy that indicated improved angiogenesis, and re-epithelization. Furthermore, both MSCs and PRP modulated the burn's oxidative and inflammatory microenvironment as indicated by increases in SOD, CAT, and GSH besides declines in MDA, IL-6, TNF-α, NF-κB, NO, and iNOS. Notable increases in Bcl-2 levels and decreases in Cas-3 and Bax levels were recorded in burnt skin that received both agents concomitantly. Interestingly, the histopathological examination validates the healing power of BMSCs and/or PRP. Collectively, BMSCs and PRP have pioneered therapeutics candidates for clinical application in burn healing possibly via antioxidant, anti-inflammatory, and anti-apoptotic mechanisms along with regulating angiogenesis and scar formation.

The Potential Role of Mesenchymal Stem Cells Derived Exosomes on the Healing of Grade II Experimentally Induced Skeletal Muscle Injury in Adult Male Albino Rats. Histological Study

Abstract Background Musculoskeletal injuries are the most common cause of severe longterm pain and physical disability. However, there is still no efficient treatment that leads to prevention of muscle fibrosis. Cell-Free therapy using mesenchymal stem cells (MSCs) derived exosomes could provide a new promising therapy. Aim To study the potential role of MSCs-derived exosomes on the healing of experimentally induced grade II skeletal muscle injury in adult male albino rats. Materials and Methods Forty male albino Wister rats were used in this study. Five out of them were used for isolation of exosomes. The rest were randomly divided into three groups. Group I (Sham group), Group II (muscle injury group left for spontaneous healing), Group III (muscle injury treated with exosomes). Rats from each group were subdivided into two subgroups; subgroup “a and b” in which rats were sacrificed after ten days and twenty days, respectively. Muscle specimens were collected and prepared for proper histological techniques. Immuno-histochemical staining for detection of collagen type I and developmental myosin (MHCd) were also done. Morphometric study and statistical analysis were also performed. Results Granulation tissue and inflammatory cellular infiltration with significant increase in the mean area percentage of collagen fibers were noticed in subgroups of untreated muscle injury compared to the corresponding exosomes treated subgroups. This was confirmed by collagen type I immune histochemical reaction. Group III (treated with exosomes) showed better muscle regeneration and significant decrease in muscle fibrosis. Significant increase in immunohistochemical reaction of developmental myosin was noticed in exosomes treated subgroups compared to corresponding untreated muscle injury subgroups. Conclusions Exosomes enhance muscle regeneration after induced muscle injury. Exosomes also decreased muscle fibrosis and improve muscle healing.

Premetastatic Niche Mimicking Bone-On-A-Chip: A Microfluidic Platform to Study Bone Metastasis in Cancer Patients.

Primary cancer modulates the bone microenvironment to sow the seeds of dormancy and metastasis in tumor cells, leading to multiple organ metastasis and death. In this study, 3D printing and bone-on-a-chip (BOC) are combined to develop a BOC platform that mimics the pre-metastatic niches (PMNs) and facilitates elucidation of the interactions between bone-resident cells and metastatic tumor cells under the influence of primary cancer. Photocrosslinkable gelatin methacrylate (GelMA) is used as a 3D culturing hydrogel to encapsulate cells, and circulate tumor culture medium (CM) adjacent to the hydrogel to verify the critical role of mesenchymal stem cells (MSCs) and osteoclasts (RAW264.7s). Three niches: the dormancy niche, the perivascular niche, and the "vicious cycle" niche, are devised to recapitulate bone metastasis in one chip with high cell viability and excellent nutrient exchange. With respect to tumor dormancy and reactivation, the invadopodia formation of A549 lung cancer cells in communication with MSCs and RAW264.7 via the cortactin pathway is researched. As a proof of concept, the functionality and practicality of the platform are demonstrated by analyzing the invadopodia formation and the influence of various cells, and theestablishment of the dynamic niches paves the way to understanding PMN formation and related drug discovery.

The role of mesenchymal stem cells derived exosomes as a novel nanobiotechnology target in the diagnosis and treatment of cancer.

Mesenchymal stem cells (MSCs), one of the most common types of stem cells, are involved in the modulation of the tumor microenvironment (TME). With the advancement of nanotechnology, exosomes, especially exosomes secreted by MSCs, have been found to play an important role in the initiation and development of tumors. In recent years, nanobiotechnology and bioengineering technology have been gradually developed to detect and identify exosomes for diagnosis and modify exosomes for tumor treatment. Several novel therapeutic strategies bioengineer exosomes to carry drugs, proteins, and RNAs, and further deliver their encapsulated cargoes to cancer cells through the properties of exosomes. The unique properties of exosomes in cancer treatment include targeting, low immunogenicity, flexibility in modification, and high biological barrier permeability. Nevertheless, the current comprehensive understanding of the roles of MSCs and their secreted exosomes in cancer development remain inadequate. It is necessary to better understand/update the mechanism of action of MSCs-secreted exosomes in cancer development, providing insights for better modification of exosomes through bioengineering technology and nanobiotechnology. Therefore, this review focuses on the role of MSCs-secreted exosomes and bioengineered exosomes in the development, progression, diagnosis, and treatment of cancer.