Human mesenchymal stem cells modulate allogeneic immune cell responses

Advances in therapies using mesenchymal stem cells and their exosomes for treatment of peripheral nerve injury: state of the art and future perspectives

"Peripheral nerve injury" refers to damage or trauma affecting nerves outside the brain and spinal cord. Peripheral nerve injury results in movements or sensation impairments, and represents a serious public health problem. Although severed peripheral nerves have been effectively joined and various therapies have been offered, recovery of sensory or motor functions remains limited, and efficacious therapies for complete repair of a nerve injury remain elusive. The emerging field of mesenchymal stem cells and their exosome-based therapies hold promise for enhancing nerve regeneration and function. Mesenchymal stem cells, as large living cells responsive to the environment, secrete various factors and exosomes. The latter are nano-sized extracellular vesicles containing bioactive molecules such as proteins, microRNA, and messenger RNA derived from parent mesenchymal stem cells. Exosomes have pivotal roles in cell-to-cell communication and nervous tissue function, offering solutions to changes associated with cell-based therapies. Despite ongoing investigations, mesenchymal stem cells and mesenchymal stem cell-derived exosome-based therapies are in the exploratory stage. A comprehensive review of the latest preclinical experiments and clinical trials is essential for deep understanding of therapeutic strategies and for facilitating clinical translation. This review initially explores current investigations of mesenchymal stem cells and mesenchymal stem cell-derived exosomes in peripheral nerve injury, exploring the underlying mechanisms. Subsequently, it provides an overview of the current status of mesenchymal stem cell and exosome-based therapies in clinical trials, followed by a comparative analysis of therapies utilizing mesenchymal stem cells and exosomes. Finally, the review addresses the limitations and challenges associated with use of mesenchymal stem cell-derived exosomes, offering potential solutions and guiding future directions.

Cell and gene therapeutic approaches in non-alcoholic fatty liver disease

Non-Alcoholic Fatty Liver Disease (NAFLD) refers to a range of conditions marked by the buildup of triglycerides in liver cells, accompanied by inflammation, which contributes to liver damage, clinical symptoms, and histopathological alterations. Multiple molecular pathways contribute to NAFLD pathogenesis, including immune dysregulation, endoplasmic reticulum stress, and tissue injury. Both the innate and adaptive immune systems play crucial roles in disease progression, with intricate crosstalk between liver and immune cells driving NAFLD development. Among emerging therapeutic strategies, cell and gene-based therapies have shown promise. This study reviews the pathophysiological mechanisms of NAFLD and explores the therapeutic potential of cell-based interventions, highlighting their immunomodulatory effects, inhibition of hepatic stellate cells, promotion of hepatocyte regeneration, and potential for hepatocyte differentiation. Additionally, we examine gene delivery vectors designed to target NAFLD, focusing on their role in engineering hepatocytes through gene addition or editing to enhance therapeutic efficacy.

Mesenchymal stromal cell therapy: Progress to date and future outlook

In clinical trials, mesenchymal stromal/stem cells (MSCs) have consistently demonstrated safety. However, demonstration of efficacy has been inconsistent and many MSC trials have failed to meet their efficacy endpoint. This disappointing reality is reflected by the limited number MSC therapies approved by regulatory agencies, despite the large number of MSC trials registered on clinicaltrials.gov. Notably, there has been a recent approval of an MSC therapy for pediatric graft-vs.-host disease in the United States, marking the first MSC therapy approved by the U.S. Food and Drug Administration. This review provides a background of the history and potential therapeutic value of MSCs, an overview of MSC products with regulatory approval, and a summary of registered MSC trials. It concludes with a discussion on current and ongoing challenges and questions surrounding MSC therapy that remains to be resolved before becoming available for routine clinical use outside of clinical trials.

Innovations in Vascular Repair from Mechanical Intervention to Regenerative Therapies

BACKGROUND

Vascular diseases, including atherosclerosis and thrombosis, are leading causes of morbidity and mortality worldwide, often resulting in vessel stenosis that impairs blood flow and leads to severe clinical outcomes. Traditional mechanical interventions, such as balloon angioplasty and bare-metal stents, provided initial solutions but were limited by restenosis and thrombosis. The advent of drug-eluting stents improved short-term outcomes by inhibiting vascular smooth muscle cell proliferation, however, they faced challenges including delayed reendothelialization and late-stage thrombosis.

METHODS

This review highlights the progression from mechanical to biological interventions in treating vascular stenosis and underscores the need for integrated approaches that combine mechanical precision with regenerative therapies.

RESULTS

To address long-term complications, bioresorbable stents were developed to provide temporary scaffolding that gradually dissolves, yet they still encounter challenges with mechanical integrity and optimal degradation rates. Consequently, emerging therapies now focus on biological approaches, such as gene therapy, extracellular vesicle treatments, and cell therapies, that aim to promote vascular repair at the cellular level. These strategies offer the potential for true vascular regeneration by enhancing endothelialization, modulating immune responses, and stimulating angiogenesis.

CONCLUSION

Integrating mechanical precision with regenerative biological therapies offers a promising future for treating vascular stenosis. A comprehensive approach combining these modalities could achieve sustainable vascular health.

Milking mesenchymal stem cells: Updated protocols for cell lysate, secretome, and exosome extraction, and comparative analysis of their therapeutic potential

The potential of the cell lysate, secretome, and extracellular vesicles (EVs) of mesenchymal stem cells (MSCs) to modulate the immune response and promote tissue regeneration has positioned them as a promising option for cell-free therapy. Currently, many clinical trials in stem cells-derived EVs and secretome are in progress various diseases and sometimes the results are failing. The major challenge on this roadmap is the lack of a standard extraction method for exosome, secretome, and lysate. The most optimal method for obtaining the secretome of MSCs for clinical utilization involves a comprehensive approach that includes non-destructive collection methods, time optimization, multiple collection rounds, optimization of culture conditions, and quality control measures. Further research and clinical studies are warranted to validate and refine these methods for safe and effective utilization of the MSC exosome, secretome, and lysate in various clinical applications. To address these challenges, it is imperative to establish a standardized and unified methodology to ensure reliable evaluation of these extractions in clinical trials. This review seeks to outline the pros and cons of methods for the preparation of MSCs-derived exosome, and secretome/lysate, and comparative analysis of their therapeutic potential.

Insights on the Characteristics and Therapeutic Potential of Mesenchymal Stem Cell-derived Exosomes for Mitigation of Alzheimer's Disease's Pathogenicity: A Systematic Review

Alzheimer's disease (AD) remains a progressive neurodegenerative disease with no cure. Treatment of AD relies on administering drugs that only subside the symptoms. In recent studies, mesenchymal stem cell (MSC)-exosomes have been marked to possess therapeutic potential for treating AD. This study aims to systematically review and analyse findings that focus on the isolation, characterisation, and sources of MSC-derived exosomes used to unravel the therapeutic potential of these exosomes targeting AD using in vitro and in vivo models. It is hypothesised that MSC-exosomes exhibit high therapeutic potential for AD treatment by exerting various modes of action. PubMed, Scopus, and Medline were used to find relevant published works from January 2016 until December 2020, using assigned keywords including "Alzheimer's disease", "secretome", and "exosomes". Only research articles meeting the predefined inclusion/exclusion criteria were selected and analysed. The risk of bias was assessed using the Office of Health Assessment and Translation tool (OHAT). A total of 17 eligible in vivo and in vitro studies were included in this review. Bone marrow-derived stem cells (BMSCs) were the most used source for exosome isolation, even though studies on exosomes from adipose-derived stem cells (ADSCs) and human umbilical cord stem cells (HUCSCs) provide more information on the characteristics. When the risk of bias was assessed, the studies presented various levels of biases. Notably, the in vitro and in vivo studies revealed neuroprotective properties of MSC-exosomes through different modes of action to alleviate AD pathology. Our review discovered that most MSC exosomes could degrade Aβ plaques, enhance neurogenesis, extenuate neuroinflammatory response through microglial activation, regulate apoptosis and reduce oxidative stress. Delivery of exosomal micro-RNAs was also found to reduce neuroinflammation. Findings from this review provided convincing systematic evidence highlighting the therapeutic properties of MSC-derived exosomes as a prospective source for cell-free (acellular) therapy in treating AD.

Functional aligned mesenchymal stem cell sheets fabricated using micropatterned thermo-responsive cell culture surfaces

Mesenchymal stem cells (MSCs) are frequently applied for cell transplantation and regenerative therapy because they secrete diverse therapeutic cytokines that prompt immuno-stimulatory and tissue repair processes. Furthermore, cultured MSC sheets exhibit enhanced cytokine secretion compared to their MSC suspensions, and represent a durable, versatile format for tissue engineering as singular, multi-layered, or multi-cell type sandwiched, transplantable constructs. Tissue engineered implants with various cellular orientations have been reported. In this study, patterned, temperature-responsive culture surfaces were used to prepare oriented MSC sheets. Patterned culture surfaces were fabricated by grafting polyacrylamide (PAAm) onto commercial poly(N-isopropylacrylamide) (PNIPAAm)-modified plastic via photopolymerization using a stripe-patterned photomask. Patterned surfaces were characterized using x-ray photoelectron spectroscopy, fluorescently labelled fibronectin and albumin adsorption assays, wetting (contact angle) measurements, atomic force microscopy, and scanning electron microscopy. Striped grafted patterns of PAAm were fabricated on the PNIPAAm-coated culture substrates, and PAAm polymerized within the PNIPAAm overlayer. Cell-aligned MSC sheets were then produced from MSC culture on this patterned surface, secreting higher amounts of therapeutic cytokines (vascular endothelial growth factor, hepatocyte growth factor, and transforming growth factor-β) than non-aligned MSC control sheets. In addition, aligned MSC sheets maintained enhanced cell multi-potent differentiation capabilities. New, aligned MSC sheets might exhibit improved functional properties for cell sheet transplant therapies.

Mesenchymal Stem Cell-Loaded Hydrogel Improves Surgical Treatment for Chronic Cerebral Ischemia

Chronic cerebral ischemia (CCI) results in a prolonged insufficient blood supply to the brain tissue, leading to impaired neuronal function and subsequent impairment of cognitive and motor abilities. Our previous research showed that in mice with bilateral carotid artery stenosis, the collateral neovascularization post Encephalo-myo-synangiosis (EMS) treatment could be facilitated by bone marrow mesenchymal stem cells (MSCs) transplantation. Considering the advantages of biomaterials, we synthesized and modified a gelatin hydrogel for MSCs encapsulation. We then applied this hydrogel on the brain surface during EMS operation in rats with CCI, and evaluated its impact on cognitive performance and collateral circulation. Consequently, MSCs encapsulated in hydrogel significantly augment the therapeutic effects of EMS, potentially by promoting neovascularization, facilitating neuronal differentiation, and suppressing neuroinflammation. Furthermore, taking advantage of multi-RNA-sequencing and in silico analysis, we revealed that MSCs loaded in hydrogel regulate PDCD4 and CASP2 through the overexpression of miR-183-5p and miR-96-5p, thereby downregulating the expression of apoptosis-related proteins and inhibiting early apoptosis. In conclusion, a gelatin hydrogel to enhance the functionality of MSCs has been developed, and its combination with EMS treatment can improve the therapeutic effect in rats with CCI, suggesting its potential clinical benefit.

Multiroute administration of Wharton’s jelly mesenchymal stem cells in chronic complete spinal cord injury: A phase I safety and feasibility study

BACKGROUND

Traumatic spinal cord injury (SCI) is a life-altering condition that results in long-term complications, including progressive neurodegeneration and cord atrophy. It presents a significant unmet medical need with extensive social and economic burdens.

AIM

To evaluate the safety and preliminary efficacy of allogeneic mesenchymal stem cells derived from Wharton’s jelly (WJ-MSCs) in patients with chronic complete SCI. The primary objective was to assess whether WJ-MSCs could facilitate neurological recovery and improve the quality of life in this patient population.

METHODS

This open-label, multicenter phase I study investigated the effects of administering WJ-MSCs via three delivery routes: Intrathecal (for localized spinal targeting); intramuscular (for targeting end organ); and intravenous (for systemic immunomodulation). While all three routes were used concurrently to enhance therapeutic synergy, neurological, sensory, and functional scales were used to assess overall efficacy. Participants with chronic SCI (duration of at least 6 months) who had significant impairment and disability were eligible for inclusion. WJ-MSCs were administered twice monthly for 2 months, with each route receiving a dose of 1 × 10⁶ cells/kg. Patients were closely monitored for 1 year following treatment.

RESULTS

At baseline, participants displayed considerable functional deficits, as indicated by the following scores: Functional independence measure of 77.5 ± 2.26; Modified Ashworth Scale of 15.83 ± 4.83; American Spinal Injury Association (ASIA) Motor score of 1.67 ± 2.66; ASIA Light Touch and Pin-Prick scores of 62 ± 18.42 each; Wexner Incontinence Score of 20; and Qualiveen Short Form, a validated questionnaire specifically designed to assess the impact of urinary dysfunction on quality of life in individuals with SCI, score of 32. Following WJ-MSC therapy, significant improvements were observed in all neurological functions over the 1-year follow-up. Notably, the ASIA Motor score improved significantly (χ² = 23.938, P < 0.001), and Qualiveen Short Form scores demonstrated a substantial enhancement in quality of life (z = -2.214, P < 0.05).

CONCLUSION

This phase I study, conducted without a control group, suggests that the administration of WJ-MSCs through multiple routes is both safe and potentially effective in patients with chronic complete SCI. However, the observed neurological improvements cannot be solely attributed to WJ-MSC therapy, as concurrent pharmacological and rehabilitative interventions were not controlled. These findings indicated that WJ-MSC therapy may offer a promising approach for enhancing neurological function and quality of life in this challenging patient population. Further research with larger cohorts and extended follow-up is necessary to validate these preliminary results.

From current landscape to future horizon in stem cell therapy for tissue regeneration and wound healing: bridging the gap

Stem cell therapy has emerged as a groundbreaking approach in regenerative medicine, offering immense potential for tissue regeneration and wound healing. Stem cells, with their ability to self-renew and differentiate into specialized cell types, provide innovative therapeutic strategies for variety of medical conditions. Key stem cell types, including embryonic, induced pluripotent, and adult stem cells such as mesenchymal and hematopoietic stem cells, play pivotal roles in regenerative processes and wound repair. In tissue regeneration, stem cells replenish damaged or necrotic cells by differentiating into specialized cell types like bone, muscle, or nerve cells, thus restoring the structural and functional integrity of tissues. In wound healing, stem cells stimulate angiogenesis, generate new skin cells, and modulate immune responses to enhance repair. This multifaceted therapeutic potential has paved the way for clinical applications in cardiovascular, neurological, musculoskeletal, and autoimmune disorders, as well as skin and burn injuries. This review highlights recent advancements in stem cell therapy, exploring its clinical applications and addressing challenges such as immune rejection, ethical concerns, scalability, and the need for long-term clinical trials. The article underscores the importance of continued research to fully realize the transformative potential of stem cell therapy in modern medicine.

Multimodal Function of Mesenchymal Stem Cells in Psoriasis Treatment

Psoriasis is a chronic inflammatory disease mediated by the innate and adaptive immune systems, and its pathogenesis involves multiple aspects, including abnormal interleukin (IL)-23-Th17 axis, dysfunction of Tregs and other immune cells, and a complex relationship between keratinocytes and the vascular endothelium. Dysfunction of mesenchymal stem cells in psoriatic skin may also be the main reason for the dysregulated inflammatory response. Mesenchymal stem cells, a type of adult stem cells with multidifferentiation potential, are involved in the regulation of multiple links and targets in the pathogenesis of psoriasis. Thus, a detailed exploration of these mechanisms may lead to the development of new therapeutic strategies for the treatment of psoriasis. In this paper, the role of mesenchymal stem cells in skin homeostasis, the pathogenesis of psoriasis, and the multimodal function of using mesenchymal stem cells in the treatment of psoriasis are reviewed.

NKG2D-CAR-targeted iPSC-derived MSCs efficiently target solid tumors expressing NKG2D ligand

Mesenchymal stem cells (MSCs) hold potential in cancer therapy; however, insufficient tumor homing ability and heterogeneity limit their therapeutic benefits. Obviously, the homogeneous induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (iMSCs) with enhanced ability of tumor targeting could be the solution. In this study, a CAR containing the NKG2D extracellular domain was targeted at the B2M locus of iPSCs to generate NKG2D-CAR-iPSCs, which were subsequently differentiated into NKG2D-CAR-iMSCs. In vitro, NKG2D-CAR significantly enhanced migration and adhesion of iMSCs to a variety of solid tumor cells expressing NKG2D ligands. RNA sequencing (RNA-seq) revealed significant upregulation of genes related to cell adhesion, migration, and binding in NKG2D-CAR-iMSCs. In A549 xenograft model, NKG2D-CAR-iMSCs demonstrated a 57% improvement in tumor-homing ability compared with iMSCs. In conclusion, our findings demonstrate enhanced targeting specificity of NKG2D-CAR-iMSCs to tumor cells expressing NKG2D ligands in vitro and in vivo, facilitating future investigation of iMSCs as an off-the-shelf living carrier for targeted delivery of anti-tumor agents.

Engineering the Immune Response to Biomaterials

Biomaterials are increasingly used as implants in the body, but they often elicit tissue reactions due to the immune system recognizing them as foreign bodies. These reactions typically involve the activation of innate immunity and the initiation of an inflammatory response, which can persist as chronic inflammation, causing implant failure. To reduce these risks, various strategies have been developed to modify the material composition, surface characteristics, or mechanical properties of biomaterials. Moreover, bioactive materials have emerged as a new class of biomaterials that can induce desirable tissue responses and form a strong bond between the implant and the host tissue. In recent years, different immunomodulatory strategies have been incorporated into biomaterials as drug delivery systems. Furthermore, more advanced molecule and cell-based immunomodulators have been developed and integrated with biomaterials. These emerging strategies will enable better control of the immune response to biomaterials and improve the function and longevity of implants and, ultimately, the outcome of biomaterial-based therapies.

The use of MSCs in steroid-refractory acute GvHD in Europe: a survey from the EBMT cellular therapy & immunobiology working party

Acute graft-versus-host disease (aGvHD) remains a significant complication of allogeneic hematopoietic cell transplantation, with 40% of patients failing to respond to high-dose steroids. Ruxolitinib has become the standard treatment for steroid-refractory aGvHD (SR-GvHD), but its failure in approximately one-third of cases highlights the need for alternative therapies. Mesenchymal stromal cells (MSCs), known for their immunomodulatory properties, are suggested as a treatment option, but their role in SR-GvHD remains unclear. To better understand MSC therapy outcomes, the EBMT Cellular Therapy & Immunobiology Working Party conducted a survey of centers treating >20 SR-GvHD patients with MSCs between 2007 and 2020. Data from 313 patients were analyzed, revealing a 44.5% overall response rate at day 28. Responders at day 7 had a higher likelihood of maintaining responses by day 28. Using a landmark analysis, the overall survival at 12 months, conditional on being alive at day 28, was 39.2%. Survival at 12 months was 48.6% for responders, compared to 24.4% for non-responders. Despite manufacturing variabilities, MSCs produced by academic pharma appear effective in SR-GvHD, offering a viable treatment alternative for heavily pretreated patients. These findings support further investigation of MSCs to establish standardized protocols and validate their efficacy as third-line therapy for SR-GvHD.

Comparison of circulating immune signatures across different consensus molecular subtypes (CMS) and between left- and right-sided lesions in stage II colorectal cancer using single-cell mass cytometry

BACKGROUND

Patients with stage II colorectal cancer (CRC) show considerable variability in prognosis. Circulating immune cells play a vital role in systemic tumor surveillance. This study aimed to determine the clinical significance of the frequency and phenotype of circulating immune cell subsets in patients with stage II CRC.

METHODS

We applied a 37-marker-cell-lineage-agnostic panel to perform single-cell mass cytometry on peripheral blood mononuclear cells (PBMCs) from 73 patients with stage II CRC and 21 patients with stage III CRC. To categorize the stage II patients into consensus molecular subtypes (CMS), we performed RNA sequencing on tumor and adjacent normal tissues from 51 of the 73 patients. We then compared the immune cell phenotypes and frequencies based on tumor location and CMS classification in patients with stage II CRC. Wilcoxon test was employed to compare the mean frequencies of cell clusters between different tumor locations. Krustal-Wallis analysis with post-hoc Dunn test was used to assess differences across multiple CMS groups.

RESULTS

Stage II CRC patients with left- and right-sided tumors, as well as in different CMS groups, exhibit significantly different tumor characteristics. Single-cell mass cytometry revealed profound interpatient variability in immune cell subpopulation distribution and phenotypes in PBMCs in stage II CRC. We identified unique T:monocyte complexes in the peripheral blood of patients with stage II CRC, with significantly higher frequencies in these patients compared to those with stage III CRC. Left- and right-sided stage II CRCs differed in peripheral immunity. Patients with right-sided CRC had significantly higher frequencies of circulating CD8+CD27-CD28- immunosenescent T cell subsets compared to patients with left-sided CRC. Significant variations were observed in the subpopulations of the T:monocyte complex, T cells, and monocytes across different CMS groups Patients with CMS1 tumors (immune-active) exhibited significantly higher frequencies of CD4+ central memory and CD8+ terminal effector T cell: classical monocyte complexes, as well as CD8+ terminal effector T cells in the circulation.

CONCLUSIONS

The frequency and phenotype of circulating immune cells are influenced by tumor side and CMS subtypes in stage II CRC. These observations provide a basis for further investigation into the mechanisms linking tumors and systemic immunity.

Clinical Progress in Mesenchymal Stem Cell Therapy: A Focus on Rheumatic Diseases

BACKGROUND

Rheumatic diseases are chronic immune-mediated disorders affecting multiple organ systems and significantly impairing patients' quality of life. Current treatments primarily provide symptomatic relief without offering a cure. Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic option due to their ability to differentiate into various cell types and their immunomodulatory, anti-inflammatory, and regenerative properties. This review aims to summarize the clinical progress of MSC therapy in rheumatic diseases, highlight key findings from preclinical and clinical studies, and discuss challenges and future directions.

METHODOLOGY

A comprehensive review of preclinical and clinical studies on MSC therapy in rheumatic diseases, including systemic lupus erythematosus, rheumatoid arthritis, ankylosing spondylitis, osteoarthritis, osteoporosis, Sjögren's syndrome, Crohn's disease, fibromyalgia, systemic sclerosis, dermatomyositis, and polymyositis, was conducted. Emerging strategies to enhance MSC efficacy and overcome current limitations were also analyzed.

RESULTS AND DISCUSSION

Evidence from preclinical and clinical studies suggests that MSC therapy can reduce inflammation, modulate immune responses, and promote tissue repair in various rheumatic diseases. Clinical trials have demonstrated potential benefits, including symptom relief and disease progression delay. However, challenges such as variability in treatment response, optimal cell source and dosing, long-term safety concerns, and regulatory hurdles remain significant barriers to clinical translation. Standardized protocols and further research are required to optimize MSC application.

CONCLUSION

MSC therapy holds promise for managing rheumatic diseases, offering potential disease-modifying effects beyond conventional treatments. However, large-scale, well-controlled clinical trials are essential to establish efficacy, safety, and long-term therapeutic potential. Addressing current limitations through optimized treatment protocols and regulatory frameworks will be key to its successful integration into clinical practice.

Adipose-mesenchymal stem cells enhance the formation of auricular cartilage in vitro and in vivo

Patients suffering from microtia have limited treatment options for auricular reconstruction due to donor-site morbidity, complications, and unaesthetic outcome. Therefore, tissue engineering emerged as an alternative therapeutic option. Here, we generated and characterized human auricular cartilage using differentiated human adipose mesenchymal stem cells (hASCs) combined with human auricular chondrocytes. The differentiated hASCs were analysed for their morphology, phenotype, gene, and protein expression of chondrogenic markers, and biochemical composition at different time points in 2D and 3D in vitro. Importantly, we improved conditions for chondrogenic differentiation of hASCs in vitro to enhance their proliferation, survival, and deposition of cartilaginous-matrix proteins. In particular, gene expression analysis revealed an upregulation of cartilage oligomeric matrix protein (COMP) and aggrecan core protein (ACAN) in hASCs using the improved differentiation protocol in vitro. Additionally, we observed that co-seeding of hASCs with chondrocytes in a 1:5 ratio significantly enhanced the de novo auricular cartilage formation in a collagen-I bioink after 8 weeks on immunodeficient rat. In particular, the co-culture resulted in reduced shrinkage, and increased cartilage matrix production as confirmed by GAG deposition in vivo. Our results demonstrate that in co-cultures, hASCs stimulate cartilage formation due to a synergistic effect: hASCs' differentiation into chondrocytes and a trophic effect of hASCs on human auricular chondrocytes. Here we demonstrate the successful use of an hASC-chondrocyte co-culture technique for auricular cartilage tissue engineering in 3D collagen-I bioink. This co-culture approach omits the major drawbacks of traditional cartilage transplantation and thus, represents a fundamental step towards clinical translation.

Immune rejection of human mesenchymal stem cells compared to extracellular vesicles in mice with renal artery stenosis

Renal artery stenosis (RAS) is the leading cause of secondary hypertension worldwide. However, current medical and surgical treatment modalities provide minimal benefits for kidney injury. Recent preclinical RAS models have demonstrated promising potential of human mesenchymal stem cells (MSC) and their daughter extracellular vesicles (EV) in improving murine renal function and attenuating inflammation. However, the extent and mechanisms underlying immune rejection of xenogeneic MSCs or EVs are yet undetermined. Therefore, adipose tissue was harvested from adult healthy patients. Adipose-derived MSCs were extracted and cultured, and EVs were isolated from their supernatants via ultra-centrifugation. Then, mice randomly assigned to RAS or sham surgery were divided into 6 groups: sham surgery, RAS, sham + MSC, RAS + MSC, sham + EV, and RAS + EV. Two weeks after intra-aortic injection of MSCs (5 × 105) or EVs (20 µg protein), we compared the intrarenal T-cell and macrophage accumulation, splenic B-cell numbers, circulating cytokines and anti-human antibodies levels among the groups. MSCs and EVs did not influence intrarenal immune cell infiltrations. However, MSCs significantly increased circulating anti-human antibodies. In the spleen, RAS + EV mice showed higher memory IgM+ B-cells but reduced CD19+ B-cells compared to RAS + MSC. In vitro T-cell recall assay showed that both MSCs and EVs exhibited reduced IFN-γ release upon re-stimulation, indicating an immunosuppressive effect. Therefore, xenogeneic MSCs induced a greater humoral response in mice, while EVs triggered a splenic cellular response, but neither elicits discernible kidney rejection. Our results provide key insights into the immunomodulatory mechanisms of MSCs and EVs and immune mechanisms underlying xenograft rejection.

Combinatorial extracellular matrix tissue chips for optimizing mesenchymal stromal cell microenvironment and manufacturing

Despite the therapeutic potential of mesenchymal stromal cells (MSC), there is limited understanding of optimal extracellular matrix (ECM) environments to manufacture these cells. We developed tissue chips to study the effects of multi-factorial ECM environments under manufacturable stiffness ranges and multi-component ECM compositions. Manufacturing qualities of cell expansion potential, immunomodulation, and differentiation capacity were examined. The results show stiffness effects, with 900 kPa substrates supporting higher proliferation and osteogenic differentiation, along with anti-inflammatory IL-10 expression, whereas 150 kPa substrates promoted adipogenic differentiation at 150 kPa, suggesting that optimal ECM environments may differ based on manufacturing goals. ECM biochemistries containing fibronectin and laminin further modulated MSC manufacturing qualities across various stiffnesses. Proteomic and transcriptomic analyses revealed unique ECM combinations that induced higher levels of angiogenic and immunomodulatory cytokines, compared to single factor ECMs. These findings demonstrate that optimized ECM environments enhance MSC manufacturing quality.

Advances in stem cell-based therapeutic transfers for glioblastoma treatment

INTRODUCTION

Glioblastoma (GBM), a highly malignant brain tumor, has a poor prognosis despite standard treatments like surgery, chemotherapy, and radiation. Glioblastoma stem cells (GSCs) play a critical role in recurrence and therapy resistance. Stem cell-based therapies have emerged as innovative approaches, leveraging the tumor-targeting abilities of stem cells to deliver treatments directly to GBM.

AREAS COVERED

This review focuses on using intact stem cells or subtypes for GBM therapy, excluding antigenic characteristics. The stem cell-based therapies explored include neural, mesenchymal, glioblastoma, hematopoietic and adipose-derived stem cells that have been investigated in both clinical and preclinical settings. A systematic search in PubMed, EMBASE, ClinicalTrials.gov, and Scopus had identified research up until January 2024. Key mechanisms reviewed include immune modulation, angiogenesis inhibition, and apoptosis induction. Discussion of completed and ongoing trials include emphasis on safety, efficacy, challenges, and study design limitations.

EXPERT OPINION

Stem cell-based therapies hold promise for treating GBM by targeting GSCs and improving treatment outcomes. Despite some potential advantages, challenges such as tumorigenesis risks, delivery complexities, and sustained therapeutic effects persist. Future research should prioritize optimizing stem cell modifications, combining them with current treatments, and conducting large-scale trials to ensure safety and efficacy. Integrating stem cell therapies into GBM treatment could provide more effective and less invasive options for patients.

The impact of the inflammatory pulmonary microenvironment on the behavior and function of mesenchymal stromal cells

INTRODUCTION

Acute respiratory distress syndrome is characterized by the dysregulation and activation of several inflammatory pathways which lead to widespread inflammation in the lungs. Presently, direct therapy is unavailable and the use of mesenchymal stromal cells as a direct therapy has been proposed, as early-phase studies have shown promise.

AREAS COVERED

MSCs exert various therapeutic effects on the inflammatory microenvironment, such as anti-microbial effects, restoration of the alveolar-capillary barrier, and exuding various anti-inflammatory effects. However, to exert these effects MSCs need to be submitted to specific external stimuli which can affect their immunomodulation, survival, migration and metabolic state. This review references several articles found through targeted searches in PubMed [Accessed between November 2024 and March 2025], for key terms such as 'mesenchymal stromal cells', 'inflammatory microenvironment', anti-inflammatory', 'metabolism', and 'immunomodulation'.

EXPERT OPINION

The advancement of MSCs therapy in the treatment of ARDS has not progressed as effectively as one might have anticipated. Several clinical findings have established patient subgroups based on inflammatory cytokine profiles and severity of ARDS. This variation in patients may influence the clinical efficacy of MSCs and instead of concluding that MSCs therapy is not worth pursuing, more research is needed to develop an appropriate therapy.

Study protocol for a randomized clinical trial evaluating the safety and efficacy of autologous adipose-derived stem cell therapy for ulcers in patients with critical limb ischemia

BACKGROUND

Peripheral artery disease (PAD) can develop into critical limb ischemia (CLI), which is characterized by resting pain at rest, ulcerations, or gangrene, with a high risk of amputation. The optimum course of treatment at this point is arterial revascularization, although this has a significant financial cost and is not always feasible or successful in reducing pain, healing ulcers, or preventing amputations. In situations where traditional alternatives for treating PAD have been exhausted, recent developments in cell therapy may offer a viable substitute.

OBJECTIVE

The purpose of this study is to assess the safety and effectiveness of using expanded autologous adipose-derived stem cells (ASCs) in cellular therapy for the treatment of PAD patients who developed chronic artery ulcers.

METHODS

An open randomized clinical trial will be carried out with two groups of twenty patients with CLI: In group 1, 2g of abdominal adipose tissue will be taken to produce ASCs. These cells will then be expanded in a lab (cell processing center) for 14-21 days before being applied to the lesion using bio-dressings and perilesional subcutaneous injections. Group 2 will receive conventional treatment with hydrogel-based dressing. There will be regular clinical assessments, supplementary tests, and photo documentation. The main efficacy outcome will be partial or complete healing of the wound. Safety outcomes will be monitored for infections, gangrene, amputations, and death. Participants will be monitored for 90 days. Cases of major amputation of the studied limb will not be included. The results will be evaluated by an independent external evaluator who is blind to the groups. Considering the high prevalence and socioeconomic consequences related to CLI and limb amputation, this study is expected to provide a positive social and financial impact on the Brazilian Unified Health System. ClinicalTrials.gov: NCT06326203.

Dimethyloxallyl Glycine Preconditioning Promotes the Anti-inflammatory and Anti-fibrotic Effects of Human Umbilical Cord Mesenchymal Stem Cells on Kidney Damage in Systemic Lupus Erythematosus Related to TGF-β/Smad Signaling Pathway

Systemic lupus erythematosus (SLE) is a chronic inflammatory autoimmune disease lacking effective treatments without adverse effects. Dimethyloxallyl glycine (DMOG) enhanced mesenchymal stem cells (MSC) capabilities, but it remains unclear how DMOG-pretreatment of MSCs augments their SLE treatment. Here, we explore the therapeutic potential of DMOG-pretreated human umbilical cord MSCs (hUC-MSCs) in a mouse lupus nephritis (LN) model. In vitro experiments showed that DMOG could alleviate the mRNA levels of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-6 and increase the mRNA level of IL-13 in lipopolysaccharide (LPS)-induced inflammation in hUC-MSCs. DMOG enhanced the migratory and invasive abilities of the hUC-MSCs. In vivo animal studies revealed that DMOG-pretreated hUC-MSCs exhibited more pronounced inhibition of lymphadenectasis and reduced kidney weight and urinary protein content than MSCs alone. DMOG-pretreated hUC-MSCs improved renal morphological structure and alleviated inflammatory cell infiltration and renal fibrosis, evidenced by the reduced mRNA levels of fibrosis markers, including fibronectin (Fn), collagen alpha-1 chain (Colα1), collagen alpha-3 chain (Colα3), and TNF-α, IFN-γ, and IL-6 cytokines. Further investigation revealed that DMOG-pretreated hUC-MSCs down-regulated the expressions of transforming growth factor (Tgf)-β1 and its downstream effectors Smad2 and Smad3, recognized as central mediators in renal fibrosis (P < 0.05). The findings suggest that DMOG-pretreated hUC-MSCs can augment the therapeutic efficacy of hUC-MSCs in LN by enhancing their anti-inflammatory and antifibrotic effects, and the TGF-β/Smad signaling pathway may be involved in this process.

Emerging role of mesenchymal stem cell-derived exosomes in the repair of acute kidney injury

Acute kidney injury (AKI) is a clinical syndrome characterized by a rapid deterioration in kidney function and has a significant impact on patient health and survival. Mesenchymal stem cells (MSCs) have the potential to enhance renal function by suppressing the expression of cell cycle inhibitors and reducing the expression of senescence markers and microRNAs via paracrine and endocrine mechanisms. MSC-derived exosomes can alleviate AKI symptoms by regulating DNA damage, apoptosis, and other related signaling pathways through the delivery of proteins, microRNAs, long-chain noncoding RNAs, and circular RNAs. This technique is both safe and effective. MSC-derived exosomes may have great application prospects in the treatment of AKI. Understanding the underlying mechanisms will foster the development of new and promising therapeutic strategies against AKI. This review focused on recent advancements in the role of MSCs in AKI repair as well as the mechanisms underlying the role of MSCs and their secreted exosomes. It is anticipated that novel and profound insights into the functionality of MSCs and their derived exosomes will emerge.

Advancement of Nanomaterials- and Biomaterials-Based Technologies for Wound Healing and Tissue Regenerative Applications

Patients and healthcare systems face significant social and financial challenges due to the increasing number of individuals with chronic external and internal wounds that fail to heal. The complexity of the healing process remains a serious health concern, despite the effectiveness of conventional wound dressings in promoting healing. Recent advancements in materials science and fabrication techniques have led to the development of innovative dressings that enhance wound healing. To further expedite the healing process, novel approaches such as nanoparticles, 3D-printed wound dressings, and biomolecule-infused dressings have emerged, along with cell-based methods. Additionally, gene therapy technologies are being harnessed to generate stem cell derivatives that are more functional, selective, and responsive than their natural counterparts. This review highlights the significant potential of biomaterials, nanoparticles, 3D bioprinting, and gene- and cell-based therapies in wound healing. However, it also underscores the necessity for further research to address the existing challenges and integrate these strategies into standard clinical practice.

A Systematic Review of Regenerative Medicine Therapies for Axial Spine Pain of Facet Joint Origin

PURPOSE OF REVIEW

This review aims to assess the effectiveness of mesenchymal stem cells (MSCs) and platelet-rich plasma (PRP) injections in treating axial spinal pain originating from the facet joints. A systematic evaluation of available evidence on these biological therapies was conducted to determine their clinical utility.

RECENT FINDINGS

Recent studies emphasize the therapeutic promise of intraarticular biologics, including MSCs, PRP, and alpha-2-macroglobulin, in managing facet joint-related axial spinal pain. Emerging evidence suggests improvements in pain relief, physical function, and quality of life following these treatments. Based on our search criteria, 20 publications were identified and considered for inclusion. Of these, 4 randomized controlled trials (RCTs) and 6 observational studies met the inclusion criteria. Among the RCTs, 3 trials involved lumbar facet joints, and one trial involved cervical facet joints using PRP. Among the observational studies, 4 studies used PRP, with 3 focusing on the lumbar spine and one study, with 2 publications, on the cervical spine, and only 2 studies evaluated stem cell treatments. The summary of evidence utilizing various criteria, including Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) evidence synthesis, the evidence for PRP injections in facet joints is Level II, or moderate, and Level IV, or limited, overall, with low certainty. For PRP, the recommendation is moderate, and for MSCs, the recommendation is weak.

Graph-Based 3-Dimensional Spatial Gene Neighborhood Networks of Single Cells in Gels and Tissues

Objective: We developed 3-dimensional spatially resolved gene neighborhood network embedding (3D-spaGNN-E) to find subcellular gene proximity relationships and identify key subcellular motifs in cell-cell communication (CCC). Impact Statement: The pipeline combines 3D imaging-based spatial transcriptomics and graph-based deep learning to identify subcellular motifs. Introduction: Advancements in imaging and experimental technology allow the study of 3D spatially resolved transcriptomics and capture better spatial context than approximating the samples as 2D. However, the third spatial dimension increases the data complexity and requires new analyses. Methods: 3D-spaGNN-E detects single transcripts in 3D cell culture samples and identifies subcellular gene proximity relationships. Then, a graph autoencoder projects the gene proximity relationships into a latent space. We then applied explainability analysis to identify subcellular CCC motifs. Results: We first applied the pipeline to mesenchymal stem cells (MSCs) cultured in hydrogel. After clustering the cells based on the RNA count, we identified cells belonging to the same cluster as homotypic and those belonging to different clusters as heterotypic. We identified changes in local gene proximity near the border between homotypic and heterotypic cells. When applying the pipeline to the MSC-peripheral blood mononuclear cell (PBMC) coculture system, we identified CD4+ and CD8+ T cells. Local gene proximity and autoencoder embedding changes can distinguish strong and weak suppression of different immune cells. Lastly, we compared astrocyte-neuron CCC in mouse hypothalamus and cortex by analyzing 3D multiplexed-error-robust fluorescence in situ hybridization (MERFISH) data and identified regional gene proximity differences. Conclusion: 3D-spaGNN-E distinguished distinct CCCs in cell culture and tissue by examining subcellular motifs.

Increasing robustness of in vitro assay for immnosuppressive effect of mesenchymal stromal/stem cells: The role of inflammatory cytokine production by peripheral blood mononuclear cells

Introduction

The Quality by Design (QbD) approach for developing cell therapy products using mesenchymal stromal/stem cells (MSCs) is a promising method for designing manufacturing processes to improve the quality of MSC products. It is crucial to ensure the reproducibility and robustness of the test system for evaluating critical quality attributes (CQAs) in the QbD approach for manufacturing of pharmaceutical products. In this study, we explored the key factors involved in establishing a robust evaluation system for the immunosuppressive effect of MSCs, which can be an example of a CQA in developing and manufacturing therapeutic MSCs for treating graft-versus-host disease, etc, and we have identified method attributes to increase the robustness of a simple in vitro assay to assess the immunosuppressive effects of MSCs.

Methods

We evaluated the performance of an assay system to examine the proliferation of peripheral blood mononuclear cells (PBMCs) activated with the mitogen phytohemagglutinin (PHA) when co-cultured with MSCs, the so-called one-way mixed lymphocyte reaction (MLR) assay. The MLR assay was performed on the same MSCs using 10 PBMC lots from different donors. In addition, 13 cytokine production levels in PHA-stimulated PBMCs were assessed.

Results

The PHA-stimulated proliferation response of PBMCs, the action of MSCs in the MLR test, and the cytokine release of the respective PBMCs significantly differed among the PBMC lots (p < 0.05). A correlation analysis between the amounts of cytokines released by PBMCs and the immunosuppressive potency of MSCs showed that IFNγ, TNFα, CXCL10, PD-L1, HGF, and CCL5 production in PBMCs was significantly correlated with the MSC-mediated inhibition of PBMC proliferation (p < 0.05). Therefore, we selected two PBMC lots with high PBMC proliferation and PHA-stimulated cytokine (such as IFNγ and TNFα) release for the subsequent one-way MLR assay. The robustness of the established test system was confirmed by repeating the assay several times on different days for the same MSCs (coefficient of variation <0.2).

Conclusions

To make robust the MSC immunosuppressive potency assay system, controlling the quality of PBMCs used for the assay is essential. Evaluating the inflammatory cytokine production capacity of PBMCs is effective in assessing the quality of the MLR assay system.

Apoptotic vesicles derived from bone marrow mesenchymal stem cells increase angiogenesis in a hind limb ischemia model via the NAMPT/SIRT1/FOXO1 axis

BACKGROUND

Chronic limb-threatening ischemia (CLTI) is the most severe form of peripheral arterial disease (PAD). Mesenchymal stem cell (MSC) transplantation holds promise as a treatment for CLTI; however, the harsh local environment poses challenges to its effectiveness. Apoptotic vesicles (ApoVs) are extracellular vesicles produced by cells undergoing apoptosis, and they can carry various biomolecules from their parent cells, including proteins, RNA, DNA, lipids, ions, and gas neurotransmitters. ApoVs play significant roles in anti-inflammatory responses, anti-tumor activities, and tissue regeneration through intercellular communication, and they have demonstrated potential as drug carriers. In this study, we investigated the potential of bone marrow stem cell (BMSC)-derived ApoVs for treating CLTI.

METHODS

In vivo, we explored the therapeutic effect of ApoVs on a hindlimb ischemia model through Laser Doppler, matrigel plug assay, and histological analysis. In vitro, we analyzed the effects of ApoVs on the proliferation, migration, and angiogenesis of HUVECs and explored the uptake process of ApoVs. In addition, Proteomic analysis, western blotting, quantitative real-time PCR, shRNA, and siRNA were used to analyze ApoVs-induced HUVECs activation and downstream signaling pathways.

RESULTS

BMSCs transplantation showed improvement in a hind limb ischemia model, and this effect still exists after apoptosis of BMSCs. Subsequently, ApoVs of BMSCs were isolated and found to improve mouse hind limb ischemia in vivo. In vitro, ApoVs can be ingested by HUVECs through dynamin-, clathrin-, and caveolin-mediated endocytosis and promote its proliferation, migration, and angiogenesis. Mechanistically, ApoVs transferred NAMPT to HUVECs, therefore activating the NAMPT/SIRT1/FOXO1 axis, influencing the transcriptional activity of FOXO1, and promoting angiogenesis.

CONCLUSIONS

Our results demonstrate that the transplanted BMSCs can ameliorate hindlimb ischemia by releasing ApoVs during apoptosis. The main mechanism of this effect is promoting the proliferation, migration, and angiogenesis of HUVECs through the NAMPT/SIRT1/FOXO1 axis. This study provides different insights into the therapeutic mechanisms through BMSCs and suggests a promising direction for ApoVs transplantation.

CLINICAL TRIAL NUMBER

Not applicable.

Matrix stiffness and viscoelasticity influence human mesenchymal stem cell immunomodulation

Human mesenchymal stem cells (hMSCs) have immense wound healing potential due to their immunomodulatory behavior. To control this behavior and reduce heterogeneity, researchers look to biomaterials, as matrix stiffness and viscoelasticity have been shown to control hMSC immunomodulation. However, the understanding of the effects of these biophysical cues on hMSC immunomodulation remains limited; a broad study investigating the potentially synergistic effects of matrix stiffness and viscoelasticity on hMSC immunomodulation is needed in order to support future work developing biomaterials for hMSC wound healing applications. We developed polyacrylamide (PAAm) gels with varying matrix stiffnesses with or without a viscoelastic element and explored the effects of these on hMSC-matrix interactions and immunomodulatory cytokine expression in both a normal growth media and an immunomodulatory growth media mimetic of a chronic, non-healing wound. Expression of IL-10, VEGF, and PGE2 were upregulated in immunomodulatory growth media over normal growth media, demonstrating the synergistic effects of biochemical signaling on hMSC immunomodulatory behavior. In addition, the addition of a viscoelastic element had both inhibitory and accentuating effects based on the cytokine and biochemical signaling in the cell culture media. Overall, this study provides a broad perspective on the immunomodulatory behavior of hMSCs due to stiffness and viscoelasticity.

TissueGene-C induces anti-inflammatory activity and M2 macrophage polarization via activation of prostaglandin E2 signaling

BACKGROUND AND AIM

Osteoarthritis (OA) is the most common form of degenerative joint disease that commonly affects the knees, hips and hands. OA is a mechano-inflammatory disease characterized by low-grade inflammation, which results in breakdown of the cartilage extracellular matrix within joints, leading to pain, stiffness and inflammation. TissueGene-C (TG-C) is a cell and gene therapy investigational drug for treating knee OA that comprises human allogeneic chondrocytes and an irradiated modified cell line stably expressing transforming growth factor beta 1 (TGF-β1). Previous pre-clinical animal studies have shown that TG-C provides pain relief via its anti-inflammatory effects and cartilage structural improvement in a rat OA model. The goal of this study was to investigate the mechanism of action of TG-C, explore its anti-inflammatory activity and identify the TG-C-derived active factor(s) responsible for its efficacy.

METHODS

In this study, we utilized THP-1 cell line to develop an macrophage polarization model to test the anti-inflammatory activity of TG-C.

RESULTS

Our data showed that TG-C induces the polarization of M2 macrophages and the upregulation of interleukin 10 (IL-10) and interleukin 1 receptor antagonist (IL-1ra) while inhibiting tumor necrosis factor alpha (TNF-α) expression. Additionally, this study identified prostaglandin E2 (PGE2) as the main bioactive factor responsible for the anti-inflammatory activity of TG-C.

CONCLUSIONS

Our results demonstrated that PGE2 is expressed by the TG-C chondrocyte component and modulated by TGF-β1 derived from the second component of TG-C. Finally, the present study provides insight into the mechanism of action of TG-C in the treatment of OA.

Mesenchymal stem cells alleviate idiopathic pneumonia syndrome by facilitating M2 polarization via CCL2/CCR2 axis and further inducing formation of regulatory CCR2 + CD4 + T cells

BACKGROUND

Our previous study revealed that mesenchymal stem cells (MSCs) can secrete large amounts of the chemokine CCL2 under inflammatory conditions and alleviate idiopathic pneumonia syndrome (IPS) by promoting regulatory CCR2 + CD4 + T-cell formation through the CCL2‒CCR2 axis. Given the abundance of macrophages in lung tissue, how these macrophages are regulated by MSC-based prophylaxis via IPS and their interactions with T cells in lung tissue during allo-HSCT are still not fully understood.

METHODS

An IPS mouse model was established, and MSC-based prophylaxis was administered. In vitro coculture systems and an IPS model were used to study the interactions among MSCs, macrophages and T cells.

RESULTS

Prophylactic administration of MSCs induced M2 polarization and alleviated acute graft-versus-host disease (aGVHD) and lung injury in an IPS mouse model. In vitro coculture studies revealed that M2 polarization was induced by MSC-released CCL2 and that these M2 macrophages promoted the formation of regulatory CCR2 + CD4 + T cells. Blocking the CCL2-CCR2 interaction in vitro reversed MSC-induced M2 polarization and abolished the induction of CCR2 + CD4 + T-cell formation. Additionally, in vivo administration of a CCL2 or CCR2 antagonist in the IPS mouse model exacerbated aGVHD and lung injury, accompanied by a reduction in M2 macrophages and reduced formation of regulatory CCR2 + CD4 + T cells in lung tissue.

CONCLUSIONS

MSCs alleviate IPS by facilitating M2 polarization via the CCL2‒CCR2 axis and further inducing the formation of regulatory CCR2 + CD4 + T cells.

Amniotic epithelial Cell microvesicles uptake inhibits PBMCs and Jurkat cells activation by inducing mitochondria-dependent apoptosis

Amniotic epithelial cells (AECs) exhibit significant immunomodulatory and pro-regenerative properties, largely due to their intrinsic paracrine functions that are currently harnessed through the collection of their secretomes. While there is increasing evidence of the role of bioactive components freely secreted or carried by exosomes, the bioactive cargo of AEC microvesicles (MVs) and their crosstalk with the immune cells remains to be fully explored. We showed that under intrinsic conditions or in response to LPS, AEC-derived MV carries components such as lipid-mediated signaling molecules, ER, and mitochondria. They foster the intra/interspecific mitochondrial transfer into immune cells (PBMCs and Jurkat cells) in vitro and in vivo on the zebrafish larvae model of injury. The internalization of MV cargoes through macropinocytosis induces hyperpolarization of PBMC mitochondrial membranes and triggers MV-mediated apoptosis. This powerful immune suppressive mechanism triggered by AEC-MV cargo delivery paves the way for controlled and targeted cell-free therapeutic approaches.

Machine learning-based bulk RNA analysis reveals a prognostic signature of 13 cell death patterns and potential therapeutic target of SMAD3 in acute myeloid leukemia

BACKGROUND

Dysregulation or abnormality of the programmed cell death (PCD) pathway is closely related to the occurrence and development of many tumors, including acute myeloid leukemia (AML). Studying the abnormal characteristics of PCD pathway-related molecular markers can provide a basis for prognosis prediction and targeted drug design in AML patients.

METHODS

A total of 1394 genes representing 13 different PCD pathways were examined in AML patients and healthy donors. The upregulated genes were analyzed for their ability to predict overall survival (OS) individually, and these prognostic genes were subsequently combined to construct a PCD-related prognostic signature via an integrated approach consisting of 101 models based on ten machine learning algorithms. RNA transcriptome and clinical data from multiple AML cohorts (TCGA-AML, GSE106291, GSE146173 and Beat AML) were obtained to develop and validate the AML prognostic model.

RESULTS

A total of 214 upregulated PCD-related genes were identified in AML patients, 39 of which were proven to be prognostic genes in the training cohort. On the basis of the average C-index and number of model genes identified from the machine learning combinations, a PCD index was developed and validated for predicting AML OS. A prognostic nomogram was then generated and validated on the basis of the PCD index, age and ELN risk stratification in the Beat AML cohort and the GSE146173 cohort, revealing satisfactory predictive power (AUC values ≥ 0.7). With different mutation patterns, a higher PCD index was associated with a worse OS. The PCD index was significantly related to higher scores for immunosuppressive cells and mature leukemia cell subtypes. As the gene most closely related to the PCD index, the expression of SMAD3 was further validated in vitro. AML cells harboring KMT2A rearrangements were more sensitive to the SMAD3 inhibitor SIS3, and the expression of the autophagy-related molecular marker LC3 was increased in KMT2A-rearranged cell lines after SIS3 monotherapy and combined treatment.

CONCLUSION

The PCD index and SMAD3 gene expression levels have potential prognostic value and can be used in targeted therapy for AML, and these findings can lead to the development of effective strategies for the combined treatment of high-risk AML patients.

Mesenchymal stem cells and their extracellular vesicle therapy for neurological disorders: traumatic brain injury and beyond

Traumatic brain injury (TBI) is a complex condition involving mechanisms that lead to brain dysfunction and nerve damage, resulting in significant morbidity and mortality globally. Affecting ~50 million people annually, TBI's impact includes a high death rate, exceeding that of heart disease and cancer. Complications arising from TBI encompass concussion, cerebral hemorrhage, tumors, encephalitis, delayed apoptosis, and necrosis. Current treatment methods, such as pharmacotherapy with dihydropyridines, high-pressure oxygen therapy, behavioral therapy, and non-invasive brain stimulation, have shown limited efficacy. A comprehensive understanding of vascular components is essential for developing new treatments to improve blood vessel-related brain damage. Recently, mesenchymal stem cells (MSCs) have shown promising results in repairing and mitigating brain damage. Studies indicate that MSCs can promote neurogenesis and angiogenesis through various mechanisms, including releasing bioactive molecules and extracellular vesicles (EVs), which help reduce neuroinflammation. In research, the distinctive characteristics of MSCs have positioned them as highly desirable cell sources. Extensive investigations have been conducted on the regulatory properties of MSCs and their manipulation, tagging, and transportation techniques for brain-related applications. This review explores the progress and prospects of MSC therapy in TBI, focusing on mechanisms of action, therapeutic benefits, and the challenges and potential limitations of using MSCs in treating neurological disorders.

Recent advances in mesenchymal stem cell therapy for multiple sclerosis: clinical applications and challenges

Multiple sclerosis (MS), a chronic autoimmune disorder of the central nervous system (CNS), is characterized by inflammation, demyelination, and neurodegeneration, leading to diverse clinical manifestations such as fatigue, sensory impairment, and cognitive dysfunction. Current pharmacological treatments primarily target immune modulation but fail to arrest disease progression or entirely reverse CNS damage. Mesenchymal stem cell (MSC) therapy offers a promising alternative, leveraging its immunomodulatory, neuroprotective, and regenerative capabilities. This review provides an in-depth analysis of MSC mechanisms of action, including immune system regulation, promotion of remyelination, and neuroregeneration. It examines preclinical studies and clinical trials evaluating the efficacy, safety, and limitations of MSC therapy in various MS phenotypes. Special attention is given to challenges such as delivery routes, dosing regimens, and integrating MSCs with conventional therapies. By highlighting advancements and ongoing challenges, this review underscores the potential of MSCs to revolutionize MS treatment, paving the way for personalized and combinatory therapeutic approaches.

Effect of Mechanical Force Stress on the Inflammatory Response in Human Periodontal Ligament Cells

Human periodontal ligament (hPDL) is continuously exposed to mechanical forces that can induce inflammatory responses in resident stem cells (hPDLSCs). Here, we review the impact of mechanical force on hPDLSCs, focusing on the activation of inflammatory cytokines and related signalling pathways, which subsequently influence periodontal tissue remodelling. The effects of various mechanical forces, including compressive, shear, and tensile forces, on hPDLSCs are discussed. The review highlights the role of pro-inflammatory cytokines such as IL-1β, IL-6, and TNF-α in mediating inflammatory responses, as well as the counteracting effects of anti-inflammatory cytokines like IL-4 and IL-10. Additionally, we underscore the involvement of toll-like receptors (TLRs), particularly TLR4, in transducing mechanical stress signals and modulating cytokine production. This review demonstrates that hPDLSCs respond to different mechanical forces with specific gene expression changes that direct inflammatory and bone remodelling signals, leading to increased osteoblast and osteoclast activity. Moreover, hPDLSCs, together with contiguous hPDL cells, respond to various mechanical forces by regulating the immune function of several immune cells. This complex relationship between the mechanical force stress, inflammation, and the cellular response in hPDLSCs warrants further research to develop therapeutic strategies for periodontal and related diseases.

Application of novel strategies in chronic wound management with focusing on pressure ulcers: new perspective

Invading blood cells, extracellular tissue, and soluble mediators all play important roles in the wound-healing process. There is a substantial global burden of disease and mortality attributable to skin defects that do not heal. About 1% to 2% of the population in industrialized nations suffers from chronic wounds that don't heal, despite healthcare breakthroughs; this condition is very costly, costing about $25 billion each year in the US alone. Amputation, infection (affecting as many as 25% of chronic wounds), sepsis, and dermal replacements are all consequences of conventional therapeutic approaches like growth factor therapy and diabetic foot ulcers account for 85% of lower limb amputations. Despite these obstacles, scientists are constantly looking for new ways to speed healing and close wounds. The unique immunomodulatory capabilities and multipotency of mesenchymal stem cells (MSCs) have made them a potential therapeutic choice in tissue engineering and regenerative medicine. Animal models of wound healing have shown that MSCs can speed up the process by as much as 40% through enhancing angiogenesis, modulating inflammation, and promoting fibroblast migration. Clinical trials provide more evidence of their effectiveness; for instance, one RCT found that, after 12 weeks, patients treated with MSCs had a 72% smaller wound size than those in the control group. This review offers a thorough examination of MSCs by combining the latest research with preclinical evidence. Highlighting their potential to transform treatment paradigms, it delves into their biological properties, how they work during regeneration and healing, and therapeutic usefulness in controlling chronic wounds.

Traumatic brain Injury: Comprehensive overview from pathophysiology to Mesenchymal stem Cell-Based therapies

Traumatic brain injury (TBI) is a disastrous phenomenon which is considered to cause high mortality and morbidity rate. Regarding the importance of TBI due to its prevalence and its effects on the brain and other organs, finding new therapeutic methods and improvement of conventional therapies seems to be vital. TBI involves a complex physiological mechanism, with inflammation being a key component among various contributing factors. After incidence of TBI, inflammation can act as a double-edged sword in the process. Inflammation actually plays its role both as initiator and progressive index during TBI which can accumulate myeloid and lymphoid immune cells and trigger cell death pathways. Through this study we made this concept bold that that besides conventional therapies that could be used for traumatic brain injury, treatments based on mesenchyme stem cells (MSCs) and their derivatives including secretomes and exosomes demonstrate more efficacies particularly in preventing secondary injuries caused by TBI. Of note, we highlighted the valuable features of MSC-based therapies such as self-direction toward inflamed tissues and amplifying neuro-regenerative aspects. We listed possible challenges in the way of reaching this therapy to clinic to provide a clear and updated of the field.

Empagliflozin in diabetic cardiomyopathy: elucidating mechanisms, therapeutic potentials, and future directions

Diabetic cardiomyopathy (DCM) represents a significant health burden, exacerbated by the global increase in type 2 diabetes mellitus (T2DM). This condition contributes substantially to the morbidity and mortality associated with diabetes, primarily through myocardial dysfunction independent of coronary artery disease. Current treatment strategies focus on managing symptoms rather than targeting the underlying pathophysiological mechanisms, highlighting a critical need for specific therapeutic interventions. This review explores the multifaceted role of empagliflozin, a sodium-glucose cotransporter 2 (SGLT-2) inhibitor, in addressing the complex etiology of DCM. We discuss the key mechanisms by which hyperglycemia contributes to cardiac dysfunction, including oxidative stress, mitochondrial impairment, and inflammation, and how empagliflozin mitigates these effects. Empagliflozin's effects on reducing hospitalization for heart failure and potentially lowering cardiovascular mortality mark it as a promising candidate for DCM management. By elucidating the underlying mechanisms through which empagliflozin operates, this review underscores its therapeutic potential and paves the way for future research into its broader applications in diabetic cardiac care. This synthesis aims to foster a deeper understanding of DCM and encourage the integration of empagliflozin into treatment paradigms, offering hope for improved outcomes in patients suffering from this debilitating condition.

The Differentiation and Regeneration Potential of ABCB5+ Mesenchymal Stem Cells: A Review and Clinical Perspectives

Mesenchymal stem cells (MSCs) are a family of multipotent stem cells that show self-renewal under proliferation, multilineage differentiation, immunomodulation, and trophic function. Thus, these cells, such as adipose tissue-derived mesenchymal stem cells (ADSCs), bone marrow-derived MSCs (BM-MSCs), and umbilical cord-derived mesenchymal stem cells (UC-MSCs), carry great promise for novel clinical treatment options. However, the challenges associated with the isolation of MSCs and the instability of their in vitro expansion remain significant barriers to their clinical application. The plasma membrane-spanning P-glycoprotein ATP-binding cassette subfamily B member 5 positive MSCs (ABCB5+ MSCs) derived from human skin specimens offer a distinctive advantage over other MSCs. They can be easily extracted from the dermis and expanded. In culture, ABCB5+ MSCs demonstrate robust innate homeostasis and a classic trilineage differentiation. Additionally, their ability to modulate the recipients' immune system highlights their potential for allogeneic applications in regenerative medicine. In this review, we primarily discuss the differentiation potential of ABCB5+ MSCs and their perspectives in regenerative medicine.

Therapeutic potential of mesenchymal stem cells on cholesterol homeostasis-associated genes in AD-like rats

Cholesterol is vital for nerve processes. Changes in cholesterol homeostasis lead to neurodegeneration and Alzheimer's disease (AD). In recent years, extensive research has confirmed the influential role of adipose tissue mesenchymal stem cells (MSCs) in managing AD. The present study aims is to investigate a new approach concerning AD by MSCs with particular reference to the cholesterol homeostasis pathway and its regulatory miRNAs in an AD-like rat model. Three groups of 24 male Wistar rats have been divided: healthy rats (control), Alzheimer's rats (AD), and Alzheimer's rats that received MSCs (AD + MSC). Cholesterol level was measured using the GC-mass technique. The mRNA and expression levels of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), apolipoprotein E (APOE), ATP-binding cassette transporter A1 (ABCA1), and CYP46A1 genes, as well as their regulating miRNAs, were assessed using real-time polymerase chain reaction (RT-PCR) and western blotting techniques, respectively. Intraventricular transplantation of MSCs improved behavioral disorders and decreased the count of Aβ plaques in brain tissue. Transplantation of these cells also led to a significant decrease in cholesterol levels and HMGCR, ApoE, and ABCA1 and a remarkable increase in CYP46A1 mRNAs and protein expression. These cells considerably changed the expression of microRNAs regulating these genes. These results indicated that the examined miRNAs could be used as promising biomarkers for AD management. Additionally, the potential therapeutic role of MSCs in improving cholesterol levels the expression levels of the targeted miRNAs and their related genes in the cholesterol homeostasis pathway was established.

Recent advances in the role of mesenchymal stem cells as modulators in autoinflammatory diseases

Mesenchymal stem cells (MSCs), recognized for their self-renewal and multi-lineage differentiation capabilities, have garnered considerable wide attention since their discovery in bone marrow. Recent studies have underscored the potential of MSCs in immune regulation, particularly in the context of autoimmune diseases, which arise from immune system imbalances and necessitate long-term treatment. Traditional immunosuppressive drugs, while effective, can lead to drug tolerance and adverse effects, including a heightened risk of infections and malignancies. Consequently, adjuvant therapy incorporating MSCs has emerged as a promising new treatment strategy, leveraging their immunomodulatory properties. This paper reviews the immunomodulatory mechanisms of MSCs and their application in autoimmune diseases, highlighting their potential to regulate immune responses and reduce inflammation. The immunomodulatory mechanisms of MSCs are primarily mediated through direct cell contact and paracrine activity with immune cells. This review lays the groundwork for the broader clinical application of MSCs in the future and underscores their significant scientific value and application prospects. Further research is expected to enhance the efficacy and safety of MSCs-based treatments for autoimmune diseases.

Revealing the Therapeutic Potential of Stem Cells in Burn Healing: A Deeper Understanding of the Therapeutic Mechanisms of Epidermal Stem Cells and Mesenchymal Stem Cells

Background: Burns are a global public health issue and a major cause of disability and death around the world. Stem cells, which are the undifferentiated cells with the potential for indefinite proliferation and multilineage differentiation, have the ability to replace injured skin and facilitate the wound repair process through paracrine mechanisms. In light of this, the present study aims to conduct a bibliometric analysis in order to identify research hotspots of stem cell-related burns and assess global research tendencies. Methods: To achieve this objective, we retrieved scientific publications on burns associated with stem cells covering the period from January 1, 1978, to October 13, 2022, from the Web of Science Core Collection (WoSCC). Bibliometric analyses, including production and collaboration analyses between countries, institutions, authors, and journals, as well as keyword and topic analyses, were conducted using the bibliometrix R package, CiteSpace, and VOSviewer. Results: A total of 1648 burns associated with stem cell documents were published and listed on WOSCC. The most contributive country, institution, journal, and author were the United States, LV Prasad Eye Institute, Burns, and Scheffer C.G. Tseng, respectively. More importantly, combined with historical direct citation network, trend topic analysis, keyword co-occurrence network, and substantial literature analysis, we eventually summarized the research hotspots and frontiers on burns associated stem cell reasearch. Conclusion: The present study obtained deep insight into the developing trends and research hotspots on burns associated with stem cells, which arouses growing concerns and implies increasing clinical implications. The mechanism and therapeutics of epidermal stem cells (ESCs) for burn wounds and the mechanism of mesenchymal stem cells (MSCs) and MSC-derived exosomes for burns wounds are two research hotspots in this field.

The potential of mesenchymal stem cell coexpressing cytosine deaminase and secretory IL18-FC chimeric cytokine in suppressing glioblastoma recurrence

Glioblastoma multiforme (GBM) patients have a high recurrence rate of 90%, and the 5-year survival rate is only about 5%. Cytosine deaminase (CDA)/5-fluorocytosine (5-FC) gene therapy is a promising glioma treatment as 5-FC can cross the blood-brain barrier (BBB), while 5-fluorouracil (5-FU) cannot. Furthermore, 5-FU can assist reversing the immunological status of cold solid tumors. This study developed mesenchymal stem cells (MSCs) co-expressing yeast CDA and the secretory IL18-FC superkine to prevent recurrent tumor progression by simultaneously exerting cytotoxic effects and enhancing immune responses. IL18 was fused with Igk and IgG2a FC domains to enhance its secretion and serum half-life. The study confirmed the expression and activity of the CDA enzyme, as well as the expression, secretion, and activity of secretory IL18 and IL18-FC superkine, which were expressed by lentiviruses transduced-MSCs. In the transwell tumor-tropism assay, it was observed that the genetically modified MSCs retained their selective tumor-tropism ability following transduction. CDA-expressing MSCs, in the presence of 5-FC (200 µg/ml), induced cell cycle arrest and apoptosis in glioma cells through bystander effects in an indirect transwell co-culture system. They reduced the viability of the direct co-culture system when they constituted only 12.5 % of the cell population. The effectiveness of engineered MSCs in suppressing tumor progression was assessed by intracerebral administration of a lethal dose of GL261 cells combined in a ratio of 1:1 with MSCs expressing CDA, or CDA and sIL18, or CDA and sIL18-FC, into C57BL/6 mice. PET scan showed no conspicuous tumor mass in the MSC-CDA-sIL18-FC group that received 5-FC treatment. The pathological analysis showed that tumor progression suppressed in this group until 20th day after cell inoculation. Cytokine assessment showed that both interferon-gamma (IFN-γ) and interleukin-4 (IL-4) increased in the serum of MSC-CDA-sIL18 and MSC-CDA-sIL18-FC, treated with normal saline (NS) compared to those of the control group. The MSC-CDA-sIL18-FC group that received 5-FC treatment showed reduced serum levels of IL-6 and a considerably improved survival rate compared to the control group. Therefore, MSCs co-expressing yeast CDA and secretory IL18-FC, with tumor tropism capability, may serve as a supplementary approach to standard GBM treatment to effectively inhibit tumor progression and prevent recurrence.

Autologous Microfragmented Adipose Tissue Injection in Refractory Complex Crohn's Perianal Fistulas: Long-Term Results at 6.7 Years Mean Follow-up

BACKGROUND

Nowadays, there is a clear need for new viable therapeutic options to face complex perianal Crohn's disease (PCD). Results of our previous pilot study demonstrated the efficacy and safety of local injection of autologous microfragmented adipose tissue (MFat) in this setting. This study aims to evaluate the long-term follow-up results in the same cohort of patients.

METHODS

Data on clinical and radiological remission and surgical recurrence rates were prospectively collected on the 15 patients with complex fistulizing PCD refractory to combined bio-surgical therapy, originally treated with local MFat injection, with a mean 6.7 years follow-up.

RESULTS

In our previous study, at 24-week follow-up, combined remission was reported in 66.7% of patients, while clinical remission was achieved in 93% of cases. At a 6.7-year follow-up, 9 of the 10 healed patients maintained remission. The patient with recurrence was successfully reoperated. Three out of 5 patients who failed primary combined remission were retreated, with 2 obtaining combined remission and 1 failing. One patient refused any subsequent treatment due to good quality of life. The last patient presented delayed healing at a 1-year follow-up. Overall success rate after rescue therapy at the final follow-up reached 86.6%. Safety was maintained throughout all follow-up periods.

CONCLUSIONS

This is the longest follow-up published trial on MFat injection for PCD. Our results show that patients who achieved closure in the first 24 weeks sustained response at long-term evaluation. In addition, there may be a rationale in repeating treatment as rescue therapy in not responding to patients.

Mesenchymal stem cell therapy in veterinary ophthalmology: clinical evidence and prospects

Mesenchymal stem cell (MSC) therapy presents a promising strategy for treating various ocular conditions in veterinary medicine. This review explores the therapeutic potential of MSCs in managing corneal ulcers, immune-mediated keratitis, chronic superficial keratitis, keratoconjunctivitis sicca, retinal degeneration, and ocular burns in feline, equine, and canine patients. Studies have demonstrated the immunomodulatory and regenerative properties of MSCs, highlighting their ability to mitigate inflammation and promote tissue regeneration. Experimental studies have shown the potential of MSC therapy in reducing corneal opacity and vascularization, indicating significant therapeutic advantages. Delivery methods play a crucial role in optimizing the therapeutic efficacy of MSCs in ocular diseases. Various delivery methods, such as intravitreal injection, subconjunctival injection, topical administration, and scaffold-mediated delivery, are being explored to optimize MSC delivery to the target ocular tissues. Clinical trials have shown significant improvements in clinical signs following MSC therapy, underscoring its efficacy in treating ocular diseases. Additionally, tissue engineering approaches incorporating MSCs, growth factors, and scaffolds offer innovative strategies for corneal regeneration and tissue repair. Despite challenges such as standardization of protocols and long-term safety assessment, ongoing research endeavours seek to unlock the full therapeutic potential of MSC therapy in ocular diseases. Future prospects in MSC therapy involve exploring scaffold and hydrogel-based approaches and cell-free therapies leveraging the bioactive molecules released by MSCs. Continued research and development efforts are essential to unlock the full therapeutic potential of MSCs and realize their transformative impact on ocular diseases in veterinary patients.

Feasibility of co-transplantation of umbilical cord blood and third-party mesenchymal stromal cells after (non)myeloablative conditioning in patients with hematological malignancies

Umbilical cord blood (UCB) is an alternative source of stem cells for patients lacking a 9/10 or 10/10 HLA identical donor. However, after UCB transplantation, time to engraftment and immune recovery are prolonged, increasing the risk of fatal complications. Mesenchymal stromal cells (MSC) can support hematopoietic engraftment and have immunosuppressive effects. The primary objective of this phase I/II multicenter study was to determine the feasibility and safety of UCB transplantation with co-infusion of third party MSC, as assessed by treatment related mortality (TRM) at day 100. Secondary objectives were engraftment, immune recovery, occurrence of graft versus host disease (GVHD), infections, disease free survival, relapse incidence and overall survival. Eleven patients were grafted according to this protocol. Allogeneic transplantation after co-infusion appears feasible with 18 % TRM at day 100. Engraftment data show a median time of 16 days to neutrophil and 27 days to platelet recovery, which is shorter than what is usually reported after UCB transplantation. Only 1 episode of acute GVHD was reported. In conclusion, MSC and UCB co-transplantation is feasible and might help overcome some of the drawbacks of UCB transplantation.

PRRX1 upregulates PD-L1 in human mesenchymal stem cells

Mesenchymal stem cells (MSCs) have been demonstrated to be efficacious in clinical applications for the amelioration of immune disorders, including graft-versus-host disease (GvHD) and Crohn's disease. The immunosuppressive role of Programmed death-ligand 1 (PD-L1) in MSCs is pivotal, yet the regulatory mechanisms governing its expression remain to be fully elucidated. In this study, we explored the influence of paired-related homeobox (PRRX1), a determinant of multipotency and self-renewal in MSCs, on the expression of various surface antigens, notably PD-L1. Multiple isoforms of PRRX1 were found to augment the mRNA levels of MSC markers, such as CD26 and CD317, with all isoforms elevating PD-L1 expression at both mRNA and protein levels. This study reveals that PRRX1 may act as a potential immunomodulatory factor in MSCs by regulating the PD-L1 pathway.

Enhancing intrinsic TGF-β signaling via heparan sulfate glycosaminoglycan regulation to promote mesenchymal stem cell capabilities and chondrogenesis for cartilage repair

Osteoarthritis burdens patients due to the limited regenerative capacity of chondrocytes. Traditional cartilage repair often falls short, necessitating innovative approaches. Mesenchymal stem cells (MSCs) show promise for regeneration. Heparan sulfate glycosaminoglycans (HS-GAGs) regulate cellular functions, making them a target for cartilage repair. This study highlights how Heparinase III (HepIII) cleaves intact HS-GAGs in bone marrow-derived MSCs (BM-MSCs), enhancing their capabilities and specifically promoting chondrogenesis. HepIII-treated BM-MSCs cultured in a hanging drop device for three days, significantly increased cell number and aggregation into a cell sphere with early chondrogenesis. HepIII promoted BM-MSCs toward chondrogenesis, increasing type II collagen, intact HS-GAGs, and sulfated GAG content, while upregulating chondrogenic and heparan sulfate proteoglycan genes. Treatment with the TGF-β inhibitor (SB-431542) in HepIII-treated BM-MSCs demonstrated enhanced intrinsic transforming growth factor-β (TGF-β) signaling and fibronectin expression. This approach also boosted BM-MSC self-renewal, immunosuppressive potential, and modified acetylated histone signatures, offering a cost-effective strategy for cartilage repair by addressing inflammation, metabolic changes, and the high costs of traditional TGF-β methods. From the results, HepIII-treated BM-MSCs show potential for use in combination with other biopolymers as injectable gels to improve cartilage repair in osteoarthritis patients in the near future.