Mesenchymal stem cells: a promising way in therapies of graft-versus-host disease

Human placental mesenchymal stromal cells promote the formation of CD8+CD122+PD-1+Tregs via CD73/Foxo1 to alleviate liver injury in graft-versus-host disease mice

BACKGROUND

Human placental mesenchymal stromal cells (hPMSCs) are known to limit graft-versus-host disease (GVHD). CD8+CD122+PD-1+Tregs have been shown to improve the survival of GVHD mice. However, the regulatory roles of hPMSCs in this subgroup remain unclear. Here, the regulatory mechanism of hPMSCs in reducing liver fibrosis in GVHD mice by promoting CD8+CD122+PD-1+Tregs formation and controlling the balance of IL-6 and IL-10 were explored.

METHODS

A GVHD mouse model was constructed using C57BL/6J and BALB/c mice and treated with hPMSCs. LX-2 cells were explored to study the effects of IL-6 and IL-10 on the activation of hepatic stellate cells (HSCs). The percentage of CD8+CD122+PD-1+Tregs and IL-10 secretion were determined using FCM. Changes in hepatic tissue were analysed by HE, Masson, multiple immunohistochemical staining and ELISA, and the effects of IL-6 and IL-10 on LX-2 cells were detected using western blotting.

RESULTS

hPMSCs enhanced CD8+CD122+PD-1+Treg formation via the CD73/Foxo1 and promoted IL-10, p53, and MMP-8 levels, but inhibited IL-6, HLF, α-SMA, Col1α1, and Fn levels in the liver of GVHD mice through CD73. Positive and negative correlations of IL-6 and IL-10 between HLF were found in liver tissue, respectively. IL-6 upregulated HLF, α-SMA, and Col1α1 expression via JAK2/STAT3 pathway, whereas IL-10 upregulated p53 and inhibited α-SMA and Col1α1 expression in LX-2 cells by activating STAT3.

CONCLUSIONS

hPMSCs promoted CD8+CD122+PD-1+Treg formation and IL-10 secretion but inhibited HSCs activation and α-SMA and Col1α1 expression by CD73, thus controlling the balance of IL-6 and IL-10, and alleviating liver injury in GVHD mice.

Repeated Infusions of Bone-Marrow-Derived Mesenchymal Stem Cells over 8 Weeks for Steroid-Refractory Chronic Graft-versus-Host Disease: A Prospective, Phase I/II Clinical Study

Chronic graft-versus-host disease (cGVHD) is a long-term complication of allogeneic hematopoietic stem cell transplantation associated with poor quality of life and increased morbidity and mortality. Currently, there are several approved treatments for patients who do not respond to steroids, such as ruxolitinib. Nevertheless, a significant proportion of patients fail second-line treatment, indicating the need for novel approaches. Mesenchymal stem cells (MSCs) have been considered a potential treatment approach for steroid-refractory cGVHD. To evaluate the safety and efficacy of repeated infusions of MSCs, we administered intravenous MSCs every two weeks to ten patients with severe steroid-refractory cGVHD in a prospective phase I clinical trial. Each patient received a total of four doses, with each dose containing 1 × 106 cells/kg body weight from the same donor and same passage. Patients were assessed for their response to treatment using the 2014 National Institutes of Health (NIH) response criteria during each visit. Ten patients with diverse organ involvement were enrolled, collectively undergoing 40 infusions as planned. Remarkably, the MSC infusions were well tolerated without severe adverse events. Eight weeks after the initial MSC infusion, all ten patients showed partial responses characterized by the amelioration of clinical symptoms and enhancement of their quality of life. The overall response rate was 60%, with a complete response rate of 20% and a partial response (PR) rate of 40% at the last follow-up. Overall survival was 80%, with a median follow-up of 381 days. Two patients died due to relapse of their primary disease. Immunological analyses revealed a reduction in inflammatory markers, including Suppression of Tumorigenicity 2 (ST2), C-X-C motif chemokine ligand (CXCL)10, and Secreted phosphoprotein 1(SPP1), following the MSC treatment. Repeated MSC infusions proved to be both feasible and safe, and they may be an effective salvage therapy in patients with steroid-refractory cGVHD. Further large-scale clinical studies with long-term follow-up are needed in the future to determine the role of MSCs in cGVHD.

Mesenchymal stromal cells derived from various tissues: Biological, clinical and cryopreservation aspects: Update from 2015 review

Mesenchymal stromal cells (MSCs) have become one of the most investigated and applied cells for cellular therapy and regenerative medicine. In this update of our review published in 2015, we show that studies continue to abound regarding the characterization of MSCs to distinguish them from other similar cell types, the discovery of new tissue sources of MSCs, and the confirmation of their properties and functions that render them suitable as a therapeutic. Because cryopreservation is widely recognized as the only technology that would enable the on-demand availability of MSCs, here we show that although the traditional method of cryopreserving cells by slow cooling in the presence of 10% dimethyl sulfoxide (Me2SO) continues to be used by many, several novel MSC cryopreservation approaches have emerged. As in our previous review, we conclude from these recent reports that viable and functional MSCs from diverse tissues can be recovered after cryopreservation using a variety of cryoprotectants, freezing protocols, storage temperatures, and periods of storage. We also show that for logistical reasons there are now more studies devoted to the cryopreservation of tissues from which MSCs are derived. A new topic included in this review covers the application in COVID-19 of MSCs arising from their immunomodulatory and antiviral properties. Due to the inherent heterogeneity in MSC populations from different sources there is still no standardized procedure for their isolation, identification, functional characterization, cryopreservation, and route of administration, and not likely to be a "one-size-fits-all" approach in their applications in cell-based therapy and regenerative medicine.

Mesenchymal Stem Cell-Derived Exosomes in Various Chronic Liver Diseases: Hype or Hope?

Chronic liver conditions are associated with high mortality rates and have a large adverse effect on human well-being as well as a significant financial burden. Currently, the only effective treatment available for the effects of liver failure and cirrhosis resulting from the progression of several chronic liver diseases is liver transplantation carried out at the original location. This implies that developing novel and effective treatments is imperative. Regenerative medicine has long been associated with stem cell therapy. Mesenchymal stem cells (MSCs), a type of cell with great differentiation potential, have become the preferred source for stem cell therapy. According to recent studies, MSCs' paracrine products-rather than their capacity for differentiation-play a significant therapeutic effect. MSC exosomes, a type of extracellular vesicle (MSC-EV), came into view as the paracrine substances of MSCs. According to research, MSC exosomes can maintain tissue homeostasis, which is necessary for healthy tissue function. All tissues contain them, and they take part in a variety of biological activities that support cellular activity and tissue regeneration in order to preserve tissue homeostasis. The outcomes support the use of MSCs and the exosomes they produce as a therapeutic option for a range of diseases. This review provides a brief overview of the source of MSC-EVs and outlines their physiological roles and biochemical capabilities. The elucidation of the role of MSC-EVs in the recovery and repair of hepatic tissues, as well as their contribution to maintaining tissue homeostasis, is discussed in relation to different chronic liver diseases. This review aims to provide new insights into the unique roles that MSC-EVs play in the treatment of chronic liver diseases.

Mesenchymal stem cell-derived exosomes for managing graft-versus-host disease: An updated view

Graft-versus-host disease (GvHD) is the most common complication after stem cell transplantation, and also it is one of the primary limiting factors for the use of hematopoietic stem cell transplantation (HSCT) in the treatment of hematologic cancers. GvHD, a systemic inflammatory disease, is caused by donor T cells recognizing the recipient's foreign antigens. In addition, an immune dysregulation, caused by autoreactive immune cells, complicates potent inflammatory process following HSCT. While there is no one approved treatment method for GvHD, corticosteroids are the most common first-line treatment. Exosomes are biological vesicles between 30 and 120 nm in diameter, which carry various biologically active molecules. They are known to play a key role in the paracrine effect of mesenchymal stem cells with therapeutic and tissue repair effects, including an immunosuppressive potential. Exosomes are unable to replicate themselves but because of their small size and fluid-like structure, they can pass through physiological barriers. Exosome are relatively easy to prepare and they can be quickly sterilized by a filtration process. Administration of exosomes, derived from mesenchymal stem cells, effectively reduced GvHD symptoms and significantly increased HSCT recipients' survival. Mesenchymal stem cell-derived exosome therapy reduced clinical symptoms of GvHD in patients after HSCT. Studies in patients with GvHD described that that mesenchymal stem cell-derived exosomes inhibited the release of IFN-γ and TNF-α by activated natural killer (NK cells), thereby reducing the lethal function of NK cells and inflammatory responses. Current review provides a comprehensive overview about the use of mesenchymal stem cells and their derived exosomes for the treatment of GvHD.

Understanding and treatment of cutaneous graft-versus-host-disease

The skin is the outermost mechanical barrier where dynamic immune reactions take place and is the most commonly affected site in both acute and chronic graft-versus-host disease (GVHD). If not properly treated, pain and pruritis resulting from cutaneous GVHD can increase the risk of secondary infection due to erosions, ulcerations, and damage of underlying tissues. Furthermore, resulting disfiguration can cause distress and significantly impact patients' quality of life. Thus, a deeper understanding of skin-specific findings of GVHD is needed. This review will highlight some promising results of recent pre-clinical studies on the pathophysiology of skin GVHD and summarize the diagnostic and staging/grading procedures according to the clinical manifestations of skin GVHD. In addition, we will summarize outcomes of various GVHD treatments, including skin-specific response rates.

Potential Therapeutic Use of Stem Cells for Prion Diseases

Prion diseases are neurodegenerative disorders that are progressive, incurable, and deadly. The prion consists of PrPSc, the misfolded pathogenic isoform of the cellular prion protein (PrPC). PrPC is involved in a variety of physiological functions, including cellular proliferation, adhesion, differentiation, and neural development. Prion protein is expressed on the membrane surface of a variety of stem cells (SCs), where it plays an important role in the pluripotency and self-renewal matrix, as well as in SC differentiation. SCs have been found to multiply the pathogenic form of the prion protein, implying their potential as an in vitro model for prion diseases. Furthermore, due to their capability to self-renew, differentiate, immunomodulate, and regenerate tissue, SCs are prospective cell treatments in many neurodegenerative conditions, including prion diseases. Regenerative medicine has become a new revolution in disease treatment in recent years, particularly with the introduction of SC therapy. Here, we review the data demonstrating prion diseases' biology and molecular mechanism. SC biology, therapeutic potential, and its role in understanding prion disease mechanisms are highlighted. Moreover, we summarize preclinical studies that use SCs in prion diseases.

Hematopoietic Stem Cells Transplant (HSCT)-Related Chronic Pulmonary Diseases: An Overview

Recipients of HSCT have a high risk of infective and non-infective pulmonary diseases. Most patients with pulmonary involvement present multiple pathogenetic mechanisms simultaneously with complex interactions. Therefore, it can be difficult to distinguish the contributions of each one and to perform studies on this subject. In this opinion article, we discuss only chronic pulmonary manifestations, focusing on LONIPCs (late-onset non-infectious pulmonary complications). This term embraces drug-related toxicity, allergies, and chronic pulmonary graft versus host disease (GvHD) in all its recently identified clinical variants. Among LONIPCs, GvHD represents the most critical in terms of morbidity and mortality, despite the rapid development of new treatment options. A recently emerging perspective suggests that pulmonary lung rejection in transplant patients shares striking similarities with the pathogenesis of GvHD. In a pulmonary transplant, the donor organ is damaged by the host immune system, whereas in GvHD, the donor immune system damages the host organs. It constitutes the most significant breakthrough in recent years and is highly promising for both hematologists and thoracic transplant surgeons. The number of patients with LONIPCs is scarce, with heterogenous clinical characteristics often involving several pathogenetic mechanisms, making it challenging to conduct randomized controlled trials. Therefore, the body of evidence in this field is scarce and generally of low quality, leading to jeopardized choices in terms of immunosuppressive treatment. Moreover, it risks being outdated by common practice due to the quick evolution of knowledge about the diagnosis and treatment of LONIPCs. The literature is even more pitiful for children with pulmonary involvement related to HSCT.

Reconstitution and post-thaw storage of cryopreserved human mesenchymal stromal cells: Pitfalls and optimizations for clinically compatible formulants

Introduction

The regenerative and immunomodulatory properties of multipotent mesenchymal stromal cells (MSCs) make them an intriguing asset for therapeutic applications. An off-the-shelf approach, using pre-expanded cryopreserved allogenic MSCs, bypasses many practical difficulties of cellular therapy. Reconstitution of a MSC product away from cytotoxic cryoprotectants towards a preferred administration solution might be favorable for several indications. Variations in MSC handling accompanied by a non-standardized use of reconstitution solutions complicate a general clinical standardization of MSC cellular therapies. In this study, we aimed to identify a simple and clinically compatible approach for thawing, reconstitution, and post-thaw storage of cryopreserved MSCs.

Methods

Human adipose tissue-derived MSCs were expanded in human platelet lysate (hPL) supplemented culture medium and cryopreserved using a dimethyl sulfoxide (DMSO)-based cryoprotectant. Isotonic solutions (saline, Ringer's acetate and phosphate buffered saline (PBS)) with or without 2% human serum albumin (HSA) were used as thawing, reconstitution, and storage solutions. MSCs were reconstituted to 5 × 10⁶ MSCs/mL for evaluating MSC stability. Total MSC numbers and viability were determined using 7-aminoactinomycin D (7-AAD) and flow cytometry.

Results

For thawing cryopreserved MSCs the presence of protein was proven to be essential. Up to 50% of MSCs were lost when protein-free thawing solutions were used. Reconstitution and post-thaw storage of MSCs in culture medium and widely used PBS demonstrated poor MSC stability (>40% cell loss) and viability (<80%) after 1 h of storage at room temperature. Reconstitution in simple isotonic saline appeared to be a good alternative for post-thaw storage, ensuring >90% viability with no observed cell loss for at least 4 h. Reconstitution of MSCs to low concentrations was identified as critical. Diluting MSCs to <10⁵/mL in protein-free vehicles resulted in instant cell loss (>40% cell loss) and lower viability (<80%). Addition of clinical grade HSA could prevent cell loss during thawing and dilution.

Conclusion

This study identified a clinically compatible method for MSC thawing and reconstitution that ensures high MSC yield, viability, and stability. The strength of the method lies within the simplicity of implementation which offers an accessible way to streamline MSC therapies across different laboratories and clinical trials, improving standardization in this field.

Harnessing and honing mesenchymal stem/stromal cells for the amelioration of graft-versus-host disease

Allogeneic hematopoietic stem cell transplantation is a deterministic curative procedure for various hematologic disorders and congenital immunodeficiency. Despite its increased use, the mortality rate for patients undergoing this procedure remains high, mainly due to the perceived risk of exacerbating graft-versus-host disease (GVHD). However, even with immunosuppressive agents, some patients still develop GVHD. Advanced mesenchymal stem/stromal cell (MSC) strategies have been proposed to achieve better therapeutic outcomes, given their immunosuppressive potential. However, the efficacy and trial designs have varied among the studies, and some research findings appear contradictory due to the challenges in characterizing the in vivo effects of MSCs. This review aims to provide real insights into this clinical entity, emphasizing diagnostic, and therapeutic considerations and generating pathophysiology hypotheses to identify research avenues. The indications and timing for the clinical application of MSCs are still subject to debate.

Cord Blood Plasma and Placental Mesenchymal Stem Cells-Derived Exosomes Increase Ex Vivo Expansion of Human Cord Blood Hematopoietic Stem Cells While Maintaining Their Stemness

BACKGROUND

Mesenchymal stem cells (MSCs) have been used for ex vivo expansion of umbilical cord blood (UCB) hematopoietic stem cells (HSCs) to maintain their primitive characters and long-term reconstitution abilities during transplantation. Therapeutic effects of MSCs mainly rely on paracrine mechanisms, including secretion of exosomes (Exos). The objective of this study was to examine the effect of cord blood plasma (CBP)-derived Exos (CBP Exos) and Placental MSCs-derived Exos (MSCs Exos) on the expansion of UCB HSCs to increase their numbers and keep their primitive characteristics.

METHODS

CD34⁺ cells were isolated from UCB, cultured for 10 days, and the expanded HSCs were sub-cultured in semisolid methylcellulose media for primitive colony forming units (CFUs) assay. MSCs were cultured from placental chorionic plates.

RESULTS

CBP Exos and MSCs Exos compared with the control group significantly increased the number of total nucleated cells (TNCs), invitro expansion of CD34⁺ cells, primitive subpopulations of CD34⁺38⁺ and CD34⁺38^-Lin^- cells (p < 0.001). The expanded cells showed a significantly higher number of total CFUs in the Exos groups (p < 0.01).

CONCLUSION

CBP- and placental-derived exosomes are associated with significant ex vivo expansion of UCB HSCs, while maintaining their primitive characters and may eliminate the need for transplantation of an additional unit of UCB.

How mesenchymal stem cell cotransplantation with hematopoietic stem cells can improve engraftment in animal models

BACKGROUND

Bone marrow transplantation (BMT) can be applied to both hematopoietic and nonhematopoietic diseases; nonetheless, it still comes with a number of challenges and limitations that contribute to treatment failure. Bearing this in mind, a possible way to increase the success rate of BMT would be cotransplantation of mesenchymal stem cells (MSCs) and hematopoietic stem cells (HSCs) to improve the bone marrow niche and secrete molecules that enhance the hematopoietic engraftment.

AIM

To analyze HSC and MSC characteristics and their interactions through cotransplantation in murine models.

METHODS

We searched for original articles indexed in PubMed and Scopus during the last decade that used HSC and MSC cotransplantation and in vivo BMT in animal models while evaluating cell engraftment. We excluded in vitro studies or studies that involved graft versus host disease or other hematological diseases and publications in languages other than English. In PubMed, we initially identified 555 articles and after selection, only 12 were chosen. In Scopus, 2010 were identified, and six were left after the screening and eligibility process.

RESULTS

Of the 2565 articles found in the databases, only 18 original studies met the eligibility criteria. HSC distribution by source showed similar ratios, with human umbilical cord blood or animal bone marrow being administered mainly with a dose of 1 × 10⁷ cells by intravenous or intrabone routes. However, MSCs had a high prevalence of human donors with a variety of sources (umbilical cord blood, bone marrow, tonsil, adipose tissue or fetal lung), using a lower dose, mainly 10⁶ cells and ranging 10⁴ to 1.5 × 10⁷ cells, utilizing the same routes. MSCs were characterized prior to administration in almost every experiment. The recipient used was mostly immunodeficient mice submitted to low-dose irradiation or chemotherapy. The main technique of engraftment for HSC and MSC cotransplantation evaluation was chimerism, followed by hematopoietic reconstitution and survival analysis. Besides the engraftment, homing and cellularity were also evaluated in some studies.

CONCLUSION

The preclinical findings validate the potential of MSCs to enable HSC engraftment in vivo in both xenogeneic and allogeneic hematopoietic cell transplantation animal models, in the absence of toxicity.

Single-cell RNA sequencing reveals the potential mechanism of heterogeneity of immunomodulatory properties of foreskin and umbilical cord mesenchymal stromal cells

BACKGROUND

Mesenchymal stromal cells (MSCs) are heterogeneous populations. Heterogeneity exists within the same tissue and between different tissues. Some studies have found enormous heterogeneity in immunomodulatory function among MSCs derived from different tissues. Moreover, the underlying mechanism of heterogeneity in immunomodulatory abilities is still unclear.

METHODS

Foreskin mesenchymal stromal cells (FSMSCs) and human umbilical cord mesenchymal stromal cells (HuMSCs) were isolated and cultured until the third passage. According to the International Association for Cell Therapy standard, we confirmed the cell type. Then, FSMSCs and HuMSCs were cocultured with human peripheral blood mononuclear cells (PBMCs) stimulated by lipopolysaccharide (LPS) in vitro. Furthermore, the supernatant was sampled for an enzyme-linked immunosorbent assay to investigate the secretion of IL-1β, IL-6, IL-10, TNF-α, and TGF-β1. Finally, we performed single-cell RNA sequencing (scRNA-seq) of FSMSCs and HuMSCs.

RESULTS

We successfully identified FSMSCs and HuMSCs as MSCs. When cocultured with LPS pretreated PBMCs, FSMSCs and HuMSCs could effectively reduced the secretion of IL-1β and TNF-α. However, FSMSCs stimulated the PBMCs to secrete more IL-10, TGF-β1, and IL-6. Furthermore, 4 cell subsets were identified from integrated scRNA-seq data, including proliferative MSCs (MKI67⁺, CD146^low+, NG2⁺, PDGFRB^-), pericytes (CD146^high+, PDGFRB⁺, MKI67^-, CD31^-, CD45^-, CD34^-), immune MSCs (CXCL12^high+, PTGIS^high+, PDGFRB⁺, CD146^-, MKI67^-) and progenitor proliferative MSCs (CXCL12^low+, PTGIS^low+, PDGFRB⁺, CD146^-, MKI67^-). Among them, we found that immune MSCs with strengthened transcriptional activity were similar to pericytes with regard to the degree of differentiated. Various of immune-related genes, gene sets, and regulons were also enriched in immune MSCs. Moreover, immune MSCs were determined to be close to other cell subsets in cell-cell communication analysis. Finally, we found that the proportion of immune MSCs in foreskin tissue was highest when comparing the subset compositions of MSCs derived from different tissues.

CONCLUSIONS

FSMSCs show better immunomodulatory capacity than HuMSCs in vitro. Moreover, immune MSCs may play a vital role in the heterogeneity of immunoregulatory properties. This study provides new insights suggesting that immune MSCs can be isolated to exert stable immunoregulatory functions without being limited by the heterogeneity of MSCs derived from different tissues.

Stem Cells from Human Exfoliated Deciduous Teeth Attenuate Atopic Dermatitis Symptoms in Mice through Modulating Immune Balance and Skin Barrier Function

Atopic dermatitis (AD) is a chronic skin inflammatory disease associated with immune abnormalities and disrupted skin barrier function. Mesenchymal stem cells (MSCs) have been suggested as an alternative therapeutic option in AD. Stem cells from human exfoliated deciduous teeth (SHEDs) are a unique postnatal stem cell population with high immunomodulatory properties. The aim of this study was to explore the effects of SHEDs on AD in the BALB/c mouse model induced by 2,4-dinitrochlorobenzene (DNCB). SHEDs were administrated intravenously or subcutaneously, and clinical severity, histopathological findings, skin barrier function, and organ indexes were evaluated. Skin tissue cytokine mRNA levels and serum cytokine protein levels were further analysed. SHED administration significantly alleviated AD clinical severity, including dermatitis scores, ear thickness, scratching behaviour, and infiltration of mast cells. In addition, disrupted skin barrier function and enlarged spleens were restored by SHED administration. Further, SHED treatment reduced the levels of IgE, IgG1, and thymic stromal lymphopoietin (TSLP) in the serum and the modulated expression of Th1-, Th2-, and Th17-associated cytokines in skin lesions. In conclusion, SHEDs attenuated AD-like skin lesions in mice by modulating the immune balance and skin barrier function. SHEDs could be a potential new treatment agent for AD.

Enhanced PDGFR/Wnt/β-catenin activity of mesenchymal stem cells with high migration ability rescue bone loss of osteoporosis

Osteoporosis is a widespread disease characterized by bone mass loss and microarchitectural deterioration. The significant side effects of clinical drugs make mesenchymal stem cells (MSCs)-based therapy gain increasing focus in the treatment of osteoporosis. MSCs need to migrate to the site of damage and undergo differentiation in order to participate in the subsequent bone repair process. Therefore, the homing ability of MSCs may be related to the repair ability. Here, we proposed a novel method to screen MSCs with high migration capacity and confirmed that these MSCs exhibited higher osteogenic differentiation ability both in vivo and in vitro. Further researches indicated that MSCs with high migration ability could partly rescue the bone loss of ovarectomized (OVX) rats. Higher expression of Platelet-derived growth factors receptor β- (PDGFRβ) and more nuclear transduction of β-catenin in MSCs with high migration ability may be responsible for biological functions. This article may provide a method to improve the efficacy of MSCs-based therapy in the clinic.

Therapeutic Strategy of Mesenchymal-Stem-Cell-Derived Extracellular Vesicles as Regenerative Medicine

Extracellular vesicles (EVs) are lipid bilayer membrane particles that play critical roles in intracellular communication through EV-encapsulated informative content, including proteins, lipids, and nucleic acids. Mesenchymal stem cells (MSCs) are pluripotent stem cells with self-renewal ability derived from bone marrow, fat, umbilical cord, menstruation blood, pulp, etc., which they use to induce tissue regeneration by their direct recruitment into injured tissues, including the heart, liver, lung, kidney, etc., or secreting factors, such as vascular endothelial growth factor or insulin-like growth factor. Recently, MSC-derived EVs have been shown to have regenerative effects against various diseases, partially due to the post-transcriptional regulation of target genes by miRNAs. Furthermore, EVs have garnered attention as novel drug delivery systems, because they can specially encapsulate various target molecules. In this review, we summarize the regenerative effects and molecular mechanisms of MSC-derived EVs.

Genetically engineered mesenchymal stromal cells as a new trend for treatment of severe acute graft-versus-host disease

Mesenchymal stem cells (MSCs) are a population of non-hematopoietic and self-renewing cells characterized by the potential to differentiate into different cell subtypes. MSCs have interesting features which have attracted a lot of attention in various clinical investigations. Some basic features of MSCs are including the weak immunogenicity (absence of MHC-II and costimulatory ligands accompanied by the low expression of MHC-I) and the potential of plasticity and multi-organ homing via expressing related surface molecules. MSCs by immunomodulatory effects could also ameliorate several immune-pathological conditions like graft-versus-host diseases (GVHD). The efficacy and potency of MSCs are the main objections of MSCs therapeutic applications. It suggested that improving the MSC immunosuppressive characteristic via genetic engineering to produce therapeutic molecules consider as one of the best options for this purpose. In this review, we explain the functions, immunologic properties, and clinical applications of MSCs to discuss the beneficial application of genetically modified MSCs in GVHD.

Human Placenta-derived Mesenchymal Stromal Cells Transfusion in a Critically Ill Infant Diagnosed with Coronavirus Disease 2019 (COVID-19): A Case Report

Coronavirus disease 2019 (COVID-19) is still an emergency in many countries. Herein, we report treatment with human placental-derived mesenchymal stromal cells transfusion (hPD-MSCT) in a critically ill infant diagnosed with COVID-19. A 28-day-old male infant with a history of pneumonia was referred to our center with decreased SpO₂ (92%) and fever (38.5 °C). Real-time reverse transcription polymerase chain reaction (RT-PCR) and chest computed tomography (CT) confirmed COVID-19 infection. Considering the deteriorating clinical status of the patient despite the routine treatments (SpO₂ 82%), human placental derived mesenchymal stromal cells (hPD-MSCs) was transfused to him on day 9 and 11 (7 × 10⁶ cells/session). The patient’s general condition started to change 3 days after hPD-MSCT and poor feeding and low SpO₂ improved day by day. On day 20, the patient was discharged (SpO₂ 97%) and our one-year follow-up showed a successful response to the treatment with no reported complications. hPD-MSCT may be considered as a possible treatment option in infants/children diagnosed with COVID-19 who fail to respond to conventional therapies. However, required dose, safety, and mechanistic studies are still warranted to further investigate this treatment.

Hematopoietic stem cell transplantation with mesenchymal stromal cells in children with metachromatic leukodystrophy

Metachromatic leukodystrophy (MLD) is a lysosomal storage disorder primarily affecting the white matter of the nervous system that results from a deficiency of the arylsulfatase A (ARSA). Mesenchymal stem cells (MSCs) are able to secrete ARSA and have shown beneficial effects in MLD patients. In this retrospective analysis, 10 pediatric MLD patients (MSCG) underwent allogeneic hematopoietic stem cell transplantation (HSCT) and received two applications of 2 x 106 MSCs/kg bodyweight at day +30 and +60 after HSCT between 2007 and 2018. MSC safety, occurrence of graft-versus-host disease (GvHD), blood ARSA levels, chimerism, cell regeneration and engraftment, MRI changes, and the gross motor function were assessed within the first year of HSCT. The long-term data included clinical outcomes and safety aspects of MSCs. Data were compared to a control cohort of seven pediatric MLD patients (CG) who underwent HSCT only. The application of MSC in pediatric MLD patients after allogeneic HSCT was safe and well tolerated and long-term potentially MSC-related adverse effects up to 13.5 years after HSCT were not observed. Patients achieved significantly higher ARSA levels (CG: median 1.03 nmol∙10-6, range 0.41-1.73 | MSCG: median 1.58 nmol∙10-6, range 0.44-2.6; p<0.05), as well as significantly higher leukocyte (p<0.05) and thrombocyte (p<0.001) levels within 365 days of MSC application compared to CG patients. Statistically significant effects on acute GvHD, regeneration of immune cells, engraftment, MRI changes, gross motor function, and clinical outcomes were not detected. In conclusion, the application of MSCs in pediatric MLD patients after allogeneic HSCT was safe and well tolerated. The two applications of 2 x 106/kg allogeneic MSCs were followed by improved engraftment and hematopoiesis within the first year after HSCT. Larger, prospective trials are necessary to evaluate the impact of MSC application on engraftment and hematopoietic recovery.

Small Extracellular Vesicles Derived From MSCs Have Immunomodulatory Effects to Enhance Delivery of ASO-210 for Psoriasis Treatment

Mesenchymal stem cells (MSCs) have been increasingly used for treating autoimmune diseases due to their immune modulation functions, but inefficient homing to the target tissue and safety issues limits their wide application. Recently, increasing studies demonstrate small extracellular vesicles (sEVs) as key mediators of MSCs to exert their immunomodulatory effects. In this study, we found that sEVs derived from human umbilical cord MSCs stimulated by IFN-γ (IFNγ-sEVs) inhibited proliferation and activation of peripheral blood mononuclear cells and T cells in vitro. Furthermore, we confirmed that IFNγ-sEVs reduced psoriasis symptoms including thickness, erythema, and scales of skin lesions; exhausted Th17 cells, increased Th2 cells; and reduced enrichment of inflammatory cytokines such as IL-17A, IFN-γ, IL-6, and TNF-α in both spleen and skin lesions in vivo. Importantly, IFNγ-sEVs significantly improved the delivery efficiency and stability of ASO-210, the antisense oligonucleotides of miR-210 block the immune imbalance and subsequent psoriasis development. Our results reveal MSC-sEVs as promising cell-free therapeutic agents and ideal delivery vehicles of antisense oligonucleotides for psoriasis treatment.

Mesenchymal stem cell (MSC)-derived exosomes as novel vehicles for delivery of miRNAs in cancer therapy

Mesenchymal stem cells (MSCs) are known as promising sources for cancer therapy and can be utilized as vehicles in cancer gene therapy. MSC-derived exosomes are central mediators in the therapeutic functions of MSCs, known as the novel cell-free alternatives to MSC-based cell therapy. MSC-derived exosomes show advantages including higher safety as well as more stability and convenience for storage, transport and administration compared to MSCs transplant therapy. Unmodified MSC-derived exosomes can promote or inhibit tumors while modified MSC-derived exosomes are involved in the suppression of cancer development and progression via the delivery of several therapeutics molecules including chemotherapeutic drugs, miRNAs, anti-miRNAs, specific siRNAs, and suicide gene mRNAs. In most malignancies, dysregulation of miRNAs not only occurs as a consequence of cancer progression but also is directly involved during tumor initiation and development due to their roles as oncogenes (oncomiRs) or tumor suppressors (TS-miRNAs). MiRNA restoration is usually achieved by overexpression of TS-miRNAs using synthetic miRNA mimics and viral vectors or even downregulation of oncomiRs using anti-miRNAs. Similar to other therapeutic molecules, the efficacy of miRNAs restoration in cancer therapy depends on the effectiveness of the delivery system. In the present review, we first provided an overview of the properties and potentials of MSCs in cancer therapy as well as the application of MSC-derived exosomes in cancer therapy. Finally, we specifically focused on harnessing the MSC-derived exosomes for the aim of miRNA delivery in cancer therapy.

Highlighting the interaction between immunomodulatory properties of mesenchymal stem cells and signaling pathways contribute to Graft Versus Host Disease management

Background Allogeneic hematopoietic stem cell transplantation (Allo-HSCT) has been increasingly used as a therapeutic approach for hematological malignancies. Several potential strategies have been developed for treating or preventing allo-HSCT complications, specifically graft-versus-host disease (GVHD). GVHD could significantly affect the morbidity and mortality of patients after allo-HSCT. Curative treatment and prophylaxis regimens for GVHD could reduce GVHD incidence and improve survival rate. Among these therapeutic strategies, mesenchymal stem cell (MSCs) mediated immunomodulation has been explored widely in clinical trials. MSCs immunomodulation ability in GVHD correlates with the interactions of MSCs with innate and adaptive immune cells. However, signaling pathways responsible for MSCs' impact on GVHD regulation, like JAK/STAT, NOTCH, MAPK/ERK, and NFκβ signaling pathways, have not been clearly described yet. This review aims to illuminate the effect of MSCs-mediated immunomodulation in GVHD management after allo-HSCT representing the role of MSCs therapy on signaling pathways in GVHD. Conclusion MSCs could potentially modulate immune responses, prevent GVHD, and improve survival after allo-HSCT. Previous studies have investigated different signaling pathways' contributions to MSCs immunoregulatory ability. Accordingly, targeting signaling pathways components involved in MSCs related GVHD regulation is proven to be beneficial.

Effect of extracellular matrix proteins on the differentiation of human pluripotent stem cells into mesenchymal stem cells

The transplantation of human mesenchymal stem cells (hMSCs), such as bone marrow stem cells (BMSCs) and adipose-derived stem cells (ADSCs), has shown beneficial effects in protecting transplanted tissues and cells...

Immune response to allogeneic equine mesenchymal stromal cells

Background

Mesenchymal stromal cells (MSCs) are believed to be hypoimmunogeneic with potential use for allogeneic administration.

Methods

Bone marrow was harvested from Connemara (n = 1), Standardbred (n = 6), and Thoroughbred (n = 3) horses. MSCs were grouped by their level of expression of major histocompatibility factor II (MHC II). MSCs were then sub-grouped by those MSCs derived from universal blood donor horses. MSCs were isolated and cultured using media containing fetal bovine serum until adequate numbers were acquired. The MSCs were cultured in xenogen-free media for 48 h prior to use and during all assays. Autologous and allogeneic MSCs were then directly co-cultured with responder leukocytes from the Connemara horse in varying concentrations of MSCs to leukocytes (1:1, 1:10, and 1:100). MSCs were also cultured with complement present and heat-inactivated complement to determine whether complement alone would decrease MSC viability. MSCs underwent haplotyping of their equine leukocyte antigen (ELA) to determine whether the MHC factors were matched or mismatched between the donor MSCs and the responder leukocytes.

Results

All allogeneic MSCs were found to be ELA mismatched with the responder leukocytes. MHC II-low and universal blood donor MSCs caused no peripheral blood mononuclear cell (PBMC) proliferation, no increase in B cells, and no activation of CD8 lymphocytes. Universal blood donor MSCs stimulated a significant increase in the number of T regulatory cells. Neutrophil interaction with MSCs showed that universal blood donor and MHC II-high allogeneic MSCs at the 6 h time point in co-culture caused greater neutrophil activation than the other co-culture groups. Complement-mediated cytotoxicity did not consistently cause MSC death in cultures with active complement as compared to those with inactivated complement. Gene expression assays revealed that the universal blood donor group and the MHC II-low MSCs were more metabolically active both in the anabolic and catabolic gene categories when cultured with allogeneic lymphocytes as compared to the other co-cultures. These upregulated genes included CD59, FGF-2, HGF, IDO, IL-10, IL-RA, IL-2, SOX2, TGF-β1, ADAMSTS-4, ADAMSTS-5, CCL2, CXCLB/IL-8, IFNγ, IL-1β, and TNFα.

Conclusions

MHC II-low MSCs are the most appropriate type of allogeneic MSC to prevent activation of the innate and cell-mediated component of the adaptive immune systems and have increased gene expression as compared to other allogeneic MSCs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02624-y.

A novel study on the immunomodulatory effect of umbilical cord derived mesenchymal stem cells pretreated with traditional Chinese medicine Asarinin

Allogeneic hematopoietic stem cell transplantation (HSCT) remains the key for the treatment of malignant hematological diseases, and acute graft-versus-host disease (aGVHD) that might occur after allogenic transplantation can be life threatening and promote disease recurrence. GVHD damages the various parts of the body by upregulating T helper 1 cytokines (Th1) cytokines and stimulating CD4、CD8 + T cells. GVHD can exhibit significant immunoregulatory effects, but could be easily affected by the mesenchymal stem cells (MSC) environment, and hence the MSC immunosuppressive effects on GVHD remain unpredictable. Hence, to better understand the role of MSC in the prevention and treatment of GVHD, umbilical cord derived mesenchymal stem cells (UC-MSC) were pre-treated with Chinese medicine Asarinin and IFN-γ. In the mix lymphocyte reaction, we found that Asarinin pre-treated UC-MSC can exert significantly greater inhibition towards the proliferation of CD4 and CD8 + T cells, down-regulate Th1 type cytokines, up-regulate Th2 type cytokines, and reduce the inflammatory damage to liver, lung and intestine of aGVHD mice model. Moreover, Asarinin can cooperate with IFN-γto promote UC-MSC to secrete indoleamine 2,3-dioxygenase (IDO). Our findings establish that Asarinin pre-treated UC-MSC can significantly promote the immunosuppressive effects of MSC on aGVHD after hematopoietic stem cell transplantation.

Mesenchymal Stromal Cells Enhance Vascularization and Epithelialization within 7 Days after Gingival Augmentation with Collagen Matrices in Rabbits

Soft gingival tissue deficiency remains a severe problem leading to postoperative recession, peri-implantitis, and bone resorption. The use of collagen matrices does not always lead to complete rebuilding of the gingiva volume. The application of mesenchymal stromal cells (MSCs) simultaneously with collagen materials represents a promising approach for the restoration of soft gingival tissues. However, short-term effects of MSCs-enriched collagen grafts after gingival augmentation have not yet been studied properly. Mucograft and Mucoderm matrices were implanted in rabbits (n = 12) simultaneously with the intraoperative injection of rabbit bone marrow-derived mesenchymal stromal cells (BM-MSCs) or without cells. Collagen matrices were implanted under the flap or by the surface technique without intentional primary closure. The samples were harvested seven days after implantation, histological staining with hematoxylin and eosin, and immunohistochemical staining for VEGF, IGF1, and TGF were performed. The use of Mucoderm led to better augmentation outcomes on day 7 compared with Mucograft (p < 0.0001). Gingival augmentation in combination with the local administration of BM-MSCs led to better regeneration of the soft gingival tissues independently of the type of implanted collagen matrices (p < 0.0001). Furthermore, injection of BM-MSCs significantly enhanced gingival vascularization and epithelization with a clear positive correlation between vascular growth and epithelial response. Administration of BM-MSCs in combination with various collagen materials may potentially improve gingiva regeneration.

Alloreactive Immune Response Associated to Human Mesenchymal Stromal Cells Treatment: A Systematic Review

The well-known immunomodulatory and regenerative properties of mesenchymal stromal cells (MSCs) are the reason why they are being used for the treatment of many diseases. Because they are considered hypoimmunogenic, MSCs treatments are performed without considering histocompatibility barriers and without anticipating possible immune rejections. However, recent preclinical studies describe the generation of alloantibodies and the immune rejection of MSCs. This has led to an increasing number of clinical trials evaluating the immunological profile of patients after treatment with MSCs. The objective of this systematic review was to evaluate the generation of donor specific antibodies (DSA) after allogeneic MSC (allo-MSC) therapy and the impact on safety or tolerability. Data from 555 patients were included in the systematic review, 356 were treated with allo-MSC and the rest were treated with placebo or control drugs. A mean of 11.51% of allo-MSC-treated patients developed DSA. Specifically, 14.95% of these patients developed DSA and 6.33% of them developed cPRA. Neither the production of DSA after treatment nor the presence of DSA at baseline (presensitization) were correlated with safety and/or tolerability of the treatment. The number of doses administrated and human leucocyte antigen (HLA) mismatches between donor and recipient did not affect the production of DSA. The safety of allo-MSC therapy has been proved in all the studies and the generation of alloantibodies might not have clinical relevance. However, there are very few studies in the area. More studies with adequate designs are needed to confirm these results.

Ruxolitinib early administration reduces acute GVHD after alternative donor hematopoietic stem cell transplantation in acute leukemia

This study aimed to observe the safety and clinical efficacy of early application of ruxolitinib to prevent acute graft-versus-host disease (aGVHD) after alternative donor transplantation in acute leukemia. There were 57 patients undergoing allo-HSCT at the Affiliated Cancer Hospital of Zhengzhou University from July 2017 to October 2019. They were divided into control(16 patients) and ruxolitinib (41 patients) groups. For aGVHD prophylaxis, the control group received post-transplantation cyclophosphamide, antithymocyte globulin-Fresenius, cyclosporine A, and mycophenolate mofetil, while in the ruxolitinib group, ruxolitinib 5 mg/d in adults or 0.07–0.1 mg/(kg d) in children was administered from the day of neutrophil engraftment to 100 days post-transplantation based on control group. We found 55 patients had successful reconstitution of hematopoiesis; No significant difference was found in cGVHD, hemorrhagic cystitis, pulmonary infection, intestinal infection, Epstein-Barr virus infection, cytomegalovirus infection, relapse, death, and nonrelapse mortality. The incidences of aGVHD (50 vs. 22%, P = 0.046) and grade II–IV aGVHD (42.9 vs. 12.2%, P = 0.013) were significantly higher in the control group than in the ruxolitinib group. No significant differences were observed in overall survival (P = 0.514), disease-free survival (P = 0.691), and cumulative platelet transfusion within 100 days post-transplantation between two groups. This suggests early application of ruxolitinib can reduce the incidence and severity of aGVHD and patients are well tolerated.

Long-Term Follow-Up After the Application of Mesenchymal Stromal Cells in Children and Adolescents with Steroid-Refractory Graft-Versus-Host Disease

Steroid-refractory graft-versus-host disease (GvHD) is a life-threatening complication after allogeneic hematopoietic stem cell transplantation (alloHSCT). Alternative treatment options are often insufficient. Several studies have proven the efficacy of mesenchymal stromal cells (MSCs) in the treatment of therapy-refractory acute GvHD in adult and pediatric patients. Long-term data in pediatric patients are scarce. In this retrospective analysis, a total of 25 patients with a median age of 10.6 years (range 0.6-22.1 years) who received bone marrow-derived MSCs after alloHSCT for the treatment of steroid-refractory III and IV GvHD were analyzed. The median observation period of the surviving patients was 9.3 years (1.3-12.7 years) after HSCT. Among the 25 patients, 10 (40.0%) died [relapse (n = 3), multiorgan failure (n = 6), cardiorespiratory failure (n = 1)] at median 0.5 years (0.2-2.3 years) after HSCT. Partial response and complete remission (PR, CR) of the GvHD were achieved in 76.0% and 24.0% of the patients, respectively. Transplant-related mortality was 0% in the patients who achieved CR after MSC treatment and 26.3% for those with PR. A median improvement by one intestinal or liver GvHD stage (range 1-4) could be achieved after MSC application. No potentially MSC-related long-term adverse effects, for example, secondary malignancy, were identified. In conclusion, the intravenous application of allogeneic MSCs was safe and proved effective for the treatment of steroid-refractory GvHD. However, larger, prospective, and randomized trials are needed to evaluate these findings.

Platelet production using adipose-derived mesenchymal stem cells: Mechanistic studies and clinical application

Megakaryocytes (MKs) are platelet progenitor stem cells found in the bone marrow. Platelets obtained from blood draws can be used for therapeutic applications, especially platelet transfusion. The needs for platelet transfusions for clinical situation is increasing, due in part to the growing number of patients undergoing chemotherapy. Platelets obtained from donors, however, have the disadvantages of a limited storage lifespan and the risk of donor-related infection. Extensive effort has therefore been directed at manufacturing platelets ex vivo. Here, we review ex vivo technologies for MK development, focusing on human adipose tissue-derived mesenchymal stem/stromal cell line (ASCL)-based strategies and their potential clinical application. Bone marrow and adipose tissues contain mesenchymal stem/stromal cells that have an ability to differentiate into MKs, which release platelets. Taking advantage of this mechanism, we developed a donor-independent system for manufacturing platelets for clinical application using ASCL established from adipose-derived mesenchymal stem/stromal cells (ASCs). Culture of ASCs with endogenous thrombopoietin and its receptor c-MPL, and endogenous genes such as p45NF-E2 leads to MK differentiation and subsequent platelet production. ASCs compose heterogeneous cells, however, and are not suitable for clinical application. Thus, we established ASCLs, which expand into a more homogeneous population, and fulfill the criteria for mesenchymal stem cells set by the International Society for Cellular Therapy. Using our ASCL culture system with MK lineage induction medium without recombinant thrombopoietin led to peak production of platelets within 12 days, which may be sufficient for clinical application.

Mesenchymal Stem Cells: A Novel Therapeutic Approach to Enhance Protective Immunomodulation and Erythropoietic Recovery in Malaria

Mesenchymal stem cells (MSCs) are self-renewing, multi-potent heterogeneous stem cells that display strong tissue protective and restorative properties by differentiating into cells of the mesodermal lineages. In addition to multi-lineage differentiation capacity, MSCs play important roles in regulating immune responses, inflammation, and tissue regeneration. MSCs play a role in the outcome of the pathogenesis of several infectious diseases. A unique subset of MSCs accumulates in secondary lymphoid organs during malaria disease progression. These MSCs counteract the capacity of malaria parasites to subvert activating co-stimulatory molecules and to regulate expression of negative co-stimulatory molecules on T lymphocytes. Consequently, MSCs have the capacity to restore the functions of CD34⁺ haematopoietic cells and CD4⁺ and CD8⁺ T cells during malaria infection. These observations suggest that cell-based therapeutics for intervention in malaria may be useful in achieving sterile clearance and preventing disease reactivation. In addition, MSCs provide host protection against malaria by reprogramming erythropoiesis through accelerated formation of colony-forming-units-erythroid (CFU-E) cells in the bone marrow. These findings suggest that MSCs are positive regulators of erythropoiesis, making them attractive targets for treatment of malarial anemia. MSC-based therapies, unlike anti-malarial drugs, display therapeutic effects by targeting a large variety of cellular processes rather than a single pathway. In the present review we focus on these recent research findings and discuss clinical applications of MSC-based therapies for malaria.

Current and Emerging Targeted Therapies for Acute Graft-Versus-Host Disease

Acute graft-versus-host disease (GVHD), the major complication after allogeneic hematopoietic cell transplant (HCT), develops in approximately 50% of patients. The primary treatment is high-dose systemic steroids, but treatment failure is common, and steroid-refractory (SR) GVHD is the leading cause of non-relapse mortality after allogeneic HCT. Ruxolitinib became the first treatment for SR GVHD to obtain US Food and Drug Administration approval, and other new treatments are actively being studied. We searched the literature using the PubMed database and clinical trials using ClinicalTrials.gov to identify the most promising new treatments for GVHD. In this review, we categorize potential new treatments for GVHD by their mechanism of action (e.g., antibodies that deplete T cells or prevent their trafficking to target tissues, proteasome inhibitors, tyrosine kinase inhibitors, and other agents) and summarize the results from clinical trials.

Immunomodulatory Effects of Mesenchymal Stem Cells and Mesenchymal Stem Cell-Derived Extracellular Vesicles in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune disease that affects the joints and other organs for which there is currently no effective treatment. Mesenchymal stem cells (MSCs) have therapeutic potential due to their immunomodulatory and differentiation effects. While extensive experimental studies and clinical trials have demonstrated the effects of MSCs in various diseases, MSCs have been found to cause abnormal differentiation and tumor formation. Therefore, extracellular vesicles derived from MSCs (MSC-EVs) are more effective, less toxic, and more stable than the parental cells. MSC-EVs transfer various nucleic acids, proteins, and lipids from parent cells to recipient cells, and thus participate in chronic inflammatory and immune processes. In this review, we summarize the properties and biological functions of MSCs and MSC-EVs in RA. Improvement in our understanding of the mechanisms underlying MSC and MSC-EVs in RA provides an insight into potential biomarkers and therapeutic strategies for RA.

Inactivated Platelet Lysate Supports the Proliferation and Immunomodulant Characteristics of Mesenchymal Stromal Cells in GMP Culture Conditions

Mesenchymal stromal cells (MSCs) isolated from bone marrow (BM-MSCs) are considered advanced therapy medicinal products (ATMPs) and need to be produced according to good manufacturing practice (GMP) in their clinical use. Human platelet lysate (HPL) is a good GMP-compliant alternative to animal serum, and we have demonstrated that after pathogen inactivation with psoralen, it was safer and more efficient to use psoralen in the production of MSCs following GMP guidelines. In this study, the MSCs cultivated in fetal bovine serum (FBS-MSC) or inactivated HPL (iHPL-MSC) were compared for their immunomodulatory properties. We studied the effects of MSCs on (1) the proliferation of total lymphocytes (Ly) and on naïve T Ly subsets induced to differentiate in Th1 versus Th2 Ly; (2) the immunophenotype of different T-cell subsets; (3) and the cytokine release to verify Th1, Th2, and Th17 polarization. These were analyzed by using an in vitro co-culture system. We observed that iHPL-MSCs showed the same immunomodulatory properties observed in the FBS-MSC co-cultures. Furthermore, a more efficient effect on the increase of naïve T- cells and in the Th1 cytokine release from iHPL was observed. This study confirms that iHPL, used as a medium supplement, may be considered a good alternative to FBS for a GMP-compliant MSC expansion, and also to preserve their immunomodulatory proprieties.

Synergistic Fabrication of Dose-Response Chitosan/Dextran/β-Glycerophosphate Injectable Hydrogel as Cell Delivery Carrier for Cardiac Healing After Acute Myocardial Infarction

The human mesenchymal stem cells (hMSCs) therapy offering an encouraging the new methods to establish the conveying on the chitosan (C)/dextran (D)/β-glycerophosphate (β-GP) loaded with hMSCs to enhance the acute myocardial infarctions. The synthesized hMSCs-CD@β-GP system displayed the ratio of determination modules, size of the pore, absorbency, and the swellings ratio in the assortment of the 65 ka, 149 ± 39.8 µm, 92.2%, 42 ± 1.38, and 29 ± 1.9, respectively. The fabricated hMSCs-CD@β-GP was highly stable and physicochemical investigated and confirmed the suitability of the materials for cardiac regeneration applications. The in vitro examinations of the injectable hydrogels with hMSCs-CD@β-GP have recognized that the improved survival rate of the cells, increased the pro-inflammatory expressions factors, pro-angiogenic factors analysis confirmed the promising results of the ejection of fractions, fibrosis area, vessel density with decreased infractions size, with suggesting that the remarkable improvement of the heart regenerative function after myocardial infarctions. The new synergistic approach of the injectable hydrogels with hMSCs could able appropriate for the effective treatment of cardiac therapies after acute myocardial infarctions.