Intravenous infusion umbilical cord-derived mesenchymal stem cell in primary immune thrombocytopenia: A two-year follow-up

Multipotent mesenchymal stromal/stem cell-based therapies for acute respiratory distress syndrome: current progress, challenges, and future frontiers

Acute respiratory distress syndrome (ARDS) is a critical, life-threatening condition marked by severe inflammation and impaired lung function. Mesenchymal stromal/stem cells (MSCs) present a promising therapeutic avenue due to their immunomodulatory, anti-inflammatory, and regenerative capabilities. This review comprehensively evaluates MSC-based strategies for ARDS treatment, including direct administration, tissue engineering, extracellular vesicles (EVs), nanoparticles, natural products, artificial intelligence (AI), gene modification, and MSC preconditioning. Direct MSC administration has demonstrated therapeutic potential but necessitates optimization to overcome challenges related to effective cell delivery, homing, and integration into damaged lung tissue. Tissue engineering methods, such as 3D-printed scaffolds and MSC sheets, enhance MSC survival and functionality within lung tissue. EVs and MSC-derived nanoparticles offer scalable and safer alternatives to cell-based therapies. Likewise, natural products and bioactive compounds derived from plants can augment MSC function and resilience, offering complementary strategies to enhance therapeutic outcomes. In addition, AI technologies could aid in optimizing MSC delivery and dosing, and gene editing tools like CRISPR/Cas9 allow precise modification of MSCs to enhance their therapeutic properties and target specific ARDS mechanisms. Preconditioning MSCs with hypoxia, growth factors, or pharmacological agents further enhances their therapeutic potential. While MSC therapies hold significant promise for ARDS, extensive research and clinical trials are essential to determine optimal protocols and ensure long-term safety and effectiveness.

Efficacy and safety of human umbilical cord-derived mesenchymal stem cells in the treatment of refractory immune thrombocytopenia: a prospective, single arm, phase I trial

Patients with refractory immune thrombocytopenia (ITP) frequently encounter substantial bleeding risks and demonstrate limited responsiveness to existing therapies. Umbilical cord-derived mesenchymal stem cells (UC-MSCs) present a promising alternative, capitalizing on their low immunogenicity and potent immunomodulatory effects for treating diverse autoimmune disorders. This prospective phase I trial enrolled eighteen eligible patients to explore the safety and efficacy of UC-MSCs in treating refractory ITP. The research design included administering UC-MSCs at escalating doses of 0.5 × 106 cells/kg, 1.0 × 106 cells/kg, and 2.0 × 106 cells/kg weekly for four consecutive weeks across three cohorts during the dose-escalation phase, followed by a dose of 2.0 × 106 cells/kg weekly for the dose-expansion phase. Adverse events, platelet counts, and changes in peripheral blood immunity were monitored and recorded throughout the administration and follow-up period. Ultimately, 12 (with an addition of three patients in the 2.0 × 106 cells/kg group due to dose-limiting toxicity) and six patients were enrolled in the dose-escalation and dose-expansion phase, respectively. Thirteen patients (13/18, 72.2%) experienced one or more treatment emergent adverse events. Serious adverse events occurred in four patients (4/18, 22.2%), including gastrointestinal hemorrhage (2/4), profuse menstruation (1/4), and acute myocardial infarction (1/4). The response rates were 41.7% in the dose-escalation phase (5/12, two received 1.0 × 106 cells/kg per week, and three received 2.0 × 106 cells/kg per week) and 50.0% (3/6) in the dose-expansion phase. The overall response rate was 44.4% (8/18) among all enrolled patients. To sum up, UC-MSCs are effective and well tolerated in treating refractory ITP (ClinicalTrials.gov ID: NCT04014166).

Characterization of dynamical changes in vital signs during allogeneic human umbilical cord-derived mesenchymal stem cells infusion

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs), a kind of adult stem cell, were studied for clinical applications in regenerative medicine. To date, the safety evaluations of intravenous infusion of allogeneic hUC-MSCs were focused on fever, infection, malignancy, and death. However, the characteristics of dynamical changes in vital signs during hUC-MSCs infusion are largely unknown. In this study, twenty participants with allogeneic hUC-MSCs transplanted (MSC group) and twenty sex- and age-matched individuals with cardiovascular disease who treated with the equal volume of 0.9% normal saline were recruited (NS group). Heart rate, respiratory rate, oxygen saturation, systolic and diastolic blood pressure, and temperature were monitored at intervals of 15 min during infusion. Adverse events were recorded during infusion and within seven days after infusion. No adverse events were observed during and after infusion in both groups. Compared with the baseline, the mean systolic blood pressure (SBP) levels were significantly decreased at 15 min, 30 min, 45 min and 60 min in the MSC group (all P < 0.05) during infusion. In addition, SBP changed significantly from baseline during hUC-MSCs infusion when compared with that of NS group (P < 0.05). Repeated measures analysis of variance confirmed difference over time on the SBP levels (P < 0.05). Our results showed that the process of allogeneic hUC-MSCs intravenous infusion was safe and the vital signs were stable, whereas a slight decrease in SBP was observed.

Knowledge mapping of immune thrombocytopenia: a bibliometric study

Background

Immune thrombocytopenia (ITP) is an autoimmune disease characterized by isolated thrombocytopenia. Recently, the pathophysiology and novel drugs of ITP have been the focus of researchers with plenty of publications emerging. Bibliometrics is the process of extracting measurable data through statistical analysis of published research studies to provide an insight into the trends and hotspots.

Objective

This study aimed to provide an insight into developing trends and hotspots in the field of ITP by bibliometric analysis.

Methods

By using three bibliometric mapping tools (bibliometrix R package, VOSviewer, CiteSpace), we summarized the overview information of retrieved publications, as well as the analysis of keyword co-occurrence and reference co-citation.

Results

A total of 3299 publications with 78066 citations on ITP research were included in the analysis. The keyword co-occurrence network identified 4 clusters relating to the diagnosis, pathophysiology, and treatment of ITP respectively. Then the reference co-citation analysis produced 12 clusters with a well-structured and highly credible clustering model, and they can be divided into 5 trends: second-line treatment, chronic ITP, novel therapy and pathogenesis, COVID-19 vaccine. Treg cells, spleen tyrosine kinase, and mesenchymal stem cells were the latest hotspots with strong burstness.

Conclusion

This bibliometric analysis provided a comprehensive insight into research hotspots and trends on ITP, which would enrich the review of the ITP research.

Therapeutic potential of MSCs and MSC-derived extracellular vesicles in immune thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired autoimmune disease involving a variety of immune cells and factors. Despite being a benign disease, it is still considered incurable due to its complex pathogenesis. Mesenchymal stem cells (MSCs), with low immunogenicity, pluripotent differentiation, and immunomodulatory ability, are widely used in a variety of autoimmune diseases. In recent years, impaired bone marrow mesenchymal stem cells (BMMSCs) were found to play an important role in the pathogenesis of ITP; and the therapeutic role of MSCs in ITP has also been supported by increasing evidence with encouraging efficacy. MSCs hold promise as a new approach to treat or even cure refractory ITP. Extracellular vesicles (EVs), as novel carriers in the "paracrine" mechanism of MSCs, are the focus of MSCs. Encouragingly, several studies suggested that EVs may perform similar functions as MSCs to treat ITP. This review summarized the role of MSCs in the pathophysiology and treatment of ITP.

Current therapeutic strategies and perspectives in refractory ITP: What have we learned recently?

Immune thrombocytopenia (ITP) is an acquired autoimmune bleeding disorder featured by increased platelet destruction and deficient megakaryocyte maturation. First-line treatments include corticosteroids, intravenous immunoglobulin and intravenous anti-D immunoglobulin. Second-line treatments consist of rituximab, thrombopoietin receptor agonists and splenectomy. Although most patients benefit from these treatments, an individualized treatment approach is warranted due to the large heterogeneity among ITP patients. In addition, ITP patients may relapse and there remains a subset of patients who become refractory to treatments. The management of these refractory patients is still a challenge. This review aims to summarize emerging therapeutic approaches for refractory ITP in several categories according to their different targets, including macrophages, platelets/megakaryocytes, T cells, B cells, and endothelial cells. Moreover, current management strategies and combination regimens of refractory ITP are also discussed.

The Extensive Regulation of MicroRNA in Immune Thrombocytopenia

MicroRNA (miRNA) is a small, single-stranded, non-coding RNA molecule that plays a variety of key roles in different biological processes through post-transcriptional regulation of gene expression. MiRNA has been proved to be a variety of cellular processes involved in development, differentiation, signal transduction, and is an important regulator of immune and autoimmune diseases. Therefore, it may act as potent modulators of the immune system and play an important role in the development of several autoimmune diseases. Immune thrombocytopenia (ITP) is an autoimmune systemic disease characterized by a low platelet count. Several studies suggest that like other autoimmune disorders, miRNAs are deeply involved in the pathogenesis of ITP, interacting with the function of innate and adaptive immune responses. In this review, we discuss emerging knowledge about the function of miRNAs in ITP and describe miRNAs in terms of their role in the immune system and autoimmune response. These findings suggest that miRNA may be a useful therapeutic target for ITP by regulating the immune system. In the future, we need to have a more comprehensive understanding of miRNAs and how they regulate the immune system of patients with ITP.

The Mechanistic Effects and Clinical Applications of Various Derived Mesenchymal Stem Cells in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is an acquired autoimmune disorder characterized by persistent thrombocytopenia resulting from increased platelet destruction and a loss of autoimmune tolerance. The pathogenesis of ITP is highly complex. Although ITP may be effectively controlled with currently available medications in some patients, a subset of cases remain refractory. The application of mesenchymal stem cells (MSCs) for human hematopoietic stem cell transplantation has increasingly demonstrated that MSCs modulate innate or adaptive immunity, thus resulting in a tolerant microenvironment. Functional defects and immunomodulatory disorders have been observed after the use of bone marrow mesenchymal stem cells (BM-MSCs) from patients with ITP. Here, we summarize the underlying mechanisms and clinical applications of various derived MSCs for ITP treatment, focusing on the main mechanisms underlying the functional defects and immune dysfunction of BM-MSCs from patients with ITP. Functional effects associated with the activation of the p53 pathway include decreased activity of the phosphatidylinositol 3 kinase/Akt pathway and activation of the TNFAIP3/NF-κB/SMAD7 pathway. Immune dysfunction appears to be associated with an impaired ability of BM-MSCs to induce various types of immune cells in ITP. At present, research focusing on MSCs in ITP remains in preliminary stages. The application of autologous or exogenous MSCs in the clinical treatment of ITP has been attempted in only a small case study and must be validated in larger-scale clinical trials.

Biological Characteristics of Umbilical Cord Mesenchymal Stem Cells and Its Therapeutic Potential for Hematological Disorders

Umbilical cord mesenchymal stem cells (UC-MSCs) are a class of multifunctional stem cells isolated and cultured from umbilical cord. They possessed the characteristics of highly self-renewal, multi-directional differentiation potential and low immunogenicity. Its application in the field of tissue engineering and gene therapy has achieved a series of results. Recent studies have confirmed their characteristics of inhibiting tumor cell proliferation and migration to nest of cancer. The ability of UC-MSCs to support hematopoietic microenvironment and suppress immune system suggests that they can improve engraftment after hematopoietic stem cell transplantation, which shows great potential in treatment of hematologic diseases. This review will focus on the latest advances in biological characteristics and mechanism of UC-MSCs in treatment of hematological diseases.

Insights on chronic immune thrombocytopenia pathogenesis: A bench to bedside update

Immune thrombocytopenia (ITP) is a heterogeneous disease with an unpredictable course. Chronicity can develop in up to two-thirds of adults and 20-25% of children, representing a significant burden on patients' quality of life. Despite acceptable responses to treatment, precise etiology and pathophysiology phenomena driving evolution to chronicity remain undefined. We analyzed reported risk factors for chronic ITP and associated them with proposed underlying mechanisms in its pathogenesis, including bone marrow (BM) microenvironment disturbances, clinical features, and immunological markers. Their understanding has diagnostic implications, such as screening for the presence of specific antibodies or BM examination employing molecular tools, which could help predict prognosis and recognize main pathogenic pathways in each patient. Identifying these underlying mechanisms could guide the use of personalized therapies such as all-trans retinoic acid, mTor inhibitors, FcRn inhibitors, oseltamivir, and others. Further research should lead to tailored treatments and chronic course prevention, improving patients' quality of life.

Current Status and Future Prospects of Perinatal Stem Cells

The placenta is a temporary organ that is discarded after birth and is one of the most promising sources of various cells and tissues for use in regenerative medicine and tissue engineering, both in experimental and clinical settings. The placenta has unique, intrinsic features because it plays many roles during gestation: it is formed by cells from two individuals (mother and fetus), contributes to the development and growth of an allogeneic fetus, and has two independent and interacting circulatory systems. Different stem and progenitor cell types can be isolated from the different perinatal tissues making them particularly interesting candidates for use in cell therapy and regenerative medicine. The primary source of perinatal stem cells is cord blood. Cord blood has been a well-known source of hematopoietic stem/progenitor cells since 1974. Biobanked cord blood has been used to treat different hematological and immunological disorders for over 30 years. Other perinatal tissues that are routinely discarded as medical waste contain non-hematopoietic cells with potential therapeutic value. Indeed, in advanced perinatal cell therapy trials, mesenchymal stromal cells are the most commonly used. Here, we review one by one the different perinatal tissues and the different perinatal stem cells isolated with their phenotypical characteristics and the preclinical uses of these cells in numerous pathologies. An overview of clinical applications of perinatal derived cells is also described with special emphasis on the clinical trials being carried out to treat COVID19 pneumonia. Furthermore, we describe the use of new technologies in the field of perinatal stem cells and the future directions and challenges of this fascinating and rapidly progressing field of perinatal cells and regenerative medicine.

Human umbilical cord-derived mesenchymal stem cells ameliorate insulin resistance via PTEN-mediated crosstalk between the PI3K/Akt and Erk/MAPKs signaling pathways in the skeletal muscles of db/db mice

Background

Globally, 1 in 11 adults have diabetes mellitus, and 90% of the cases are type 2 diabetes mellitus. Insulin resistance is a central defect in type 2 diabetes mellitus, and although multiple drugs have been developed to ameliorate insulin resistance, the limitations and accompanying side effects cannot be ignored. Thus, more effective methods are required to improve insulin resistance.

Methods

In the current study, db/m and db/db mice were injected with human umbilical cord-derived mesenchymal stem cells (HUC-MSCs) via tail vein injection, intraperitoneal injection, and skeletal muscle injection. Body weight, fasting blood glucose, and the survival rates were monitored. Furthermore, the anti-insulin resistance effects and potential mechanisms of transplanted HUC-MSCs were investigated in db/db mice in vivo.

Results

The results showed that HUC-MSC transplantation by skeletal muscle injection was safer compared with tail vein injection and intraperitoneal injection, and the survival rate reached 100% in the skeletal muscle injection transplanted mice. HUC-MSCs can stabilize localization and differentiation in skeletal muscle tissue and significantly ameliorate insulin resistance. Potential regulatory mechanisms are associated with downregulation of inflammation, regulating the balance between PI3K/Akt and ERK/MAPK signaling pathway via PTEN, but was not associated with the IGF-1/IGF-1R signaling pathway.

Conclusions

These results suggest HUC-MSC transplantation may be a novel therapeutic direction to prevent insulin resistance and increase insulin sensitivity, and skeletal muscle injection was the safest and most effective way.

Role of bone marrow-derived mesenchymal stem cell defects in CD8+ CD28- suppressor T-lymphocyte induction in patients with immune thrombocytopenia and associated mechanisms

Many immune dysfunctions participate in immune thrombocytopenia (ITP) pathogenesis, including numeric and functional defects in suppressor T (Ts) cells and immune-regulation abnormalities in mesenchymal stem cells (MSCs). Recent studies showed that MSCs can promote Ts cell differentiation. Thus, we compared the Ts cell induction ability of bone marrow-derived MSCs (BM-MSCs) between patients with ITP and normal controls (NCs), and examined the mechanism of this difference. Co-culture of CD8⁺ T cells with BM-MSCs revealed that BM-MSCs elevated Ts cell percentage and function, but the efficiency was lower in patients with ITP than in NCs. Blockade experiments showed that blockade of interleukin 6 (IL-6) partially reversed Ts cell induction by BM-MSCs. Addition of exogenous IL-6 down-regulated Ts cell apoptosis. Moreover, BM-MSCs enhanced IL-10 secretion and inhibition ability of Ts cells. IL-6 secretion, regulatory abilities of IL-10 expression in Ts cells, and the enhanced efficiency of Ts cells inhibition function by BM-MSCs were all decreased in patients with ITP. All-trans retinoic acid preconditioning promoted BM-MSC induction of Ts cell percentages and umbilical cord-derived (UC) MSCs efficiently improved ITP Ts cell numbers and dysfunction. In conclusion, defects of BM-MSCs in Ts cell induction are involved in ITP pathogenesis, and exogenous UC-MSCs may be useful for ITP therapy.

Intravenous Infusion of Umbilical Cord Mesenchymal Stem Cells Maintains and Partially Improves Visual Function in Patients with Advanced Retinitis Pigmentosa

Retinitis pigmentosa (RP) is a hereditary retinal degeneration disease with no effective therapeutic approaches. Inflammatory and immune disorders are thought to play an important role in the pathogenesis of RP. Human umbilical cord mesenchymal stem cells (UCMSCs), with multiple biological functions such as anti-inflammation and immunoregulation, have been applied in different systemic diseases. We conducted a phase I/II clinical trial aiming to evaluate the safety and efficacy of intravenous administration of UCMSCs in advanced RP patients. All 32 subjects were intravenously infused with one dose of 10⁸ UCMSCs and were followed up for 12 months. No serious local or systemic adverse effects occurred in the whole follow-up. Most patients improved their best corrected visual acuity (BCVA) in the first 3 months. The proportions of patients with improved or maintained BCVA were 96.9%, 95.3%, 93.8%, 95.4%, 90.6%, and 90.6% at the 1st, 2nd, 3rd, 6th, 9th, and 12th month follow-up, respectively. Most of the patients (81.3%) maintained or improved their visual acuities for 12 months. The average NEI VFQ-25 questionnaire scores were significantly improved at the third month (P < 0.05). The average visual field sensitivity and flash visual evoked potential showed no significant difference (P = 0.185, P = 0.711). Our results indicated that the intravenous infusion of UCMSCs was safe for advanced RP patients. Most of the patients improved or maintained their visual functions in a long term. The life qualities were improved significantly in the first 3 months, suggesting that the intravenous infusion of UCMSCs may be a promising therapeutic approach for advanced RP patients.

miRNA-98-5p Targeting IGF2BP1 Induces Mesenchymal Stem Cell Apoptosis by Modulating PI3K/Akt and p53 in Immune Thrombocytopenia

Immune thrombocytopenia (ITP) is a common hematological autoimmune disease, in which defective mesenchymal stem cells (MSCs) are potentially involved. Our previous study suggested that MSCs in ITP patients displayed enhanced apoptosis. MicroRNAs (miRNAs) play important roles in ITP by affecting megakaryopoiesis, platelet production and immunoregulation, whereas the roles of miRNAs in ITP-MSCs remain unknown. In a previous study, we performed microarray analysis to obtain mRNA and miRNA profiles of ITP-MSCs. In the present study, we reanalyze the data and identify miR-98-5p as a candidate miRNA contributing to MSC deficiency in ITP. miR-98-5p acts through targeting insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1), and the subsequent downregulation of insulin-like growth factor 2 (IGF-2) causes inhibition of the phosphatidylinositol 3-kinase (PI3K)/Akt pathway, which is involved in the process of MSC deficiency. Furthermore, miR-98-5p upregulates p53 by inhibiting β-transducin repeat-containing protein (β-TrCP)-dependent p53 ubiquitination. Moreover, miR-98-5p overexpression impairs the therapeutic effect of MSCs in ITP mice. All-trans retinoic acid (ATRA) protects MSCs from apoptosis by downregulating miR-98-5p, thus providing a potential therapeutic approach for ITP. Our findings demonstrate that miR-98-5p is a critical regulator of ITP-MSCs, which will help us thoroughly understand the pathogenesis of ITP.

Characteristics and clinical applications of Wharton's jelly-derived mesenchymal stromal cells

Mesenchymal stromal cells (MSCs) are widely used in the clinic because they involve fewer ethical issues and safety concerns compared to other stem cells such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs). MSCs derived from umbilical cord Wharton's jelly (WJ-MSCs) have excellent proliferative potential and a faster growth rate and can retain their multipotency for more passages in vitro compared to adult MSCs from bone marrow or adipose tissue. WJ-MSCs are used clinically for repairing tissue injuries of the spinal cord, liver and heart with the aim of regenerating tissue. On the other hand, WJ-MSCs are also used clinically to ameliorate immune-mediated diseases based on their ability to modulate immune responses. In the field of tissue engineering, WJ-MSCs capable of differentiating into multiple cell lineages have been used to produce a variety of engineered tissues in vitro that can then be transplanted in vivo. This review discusses the characteristics of WJ-MSCs, the differences between WJ-MSCs and adult MSCs, clinical studies involving WJ-MSCs and future perspectives of WJ-MSC research and clinical applications. To summarize, WJ-MSCs have shown promise in treating a variety of diseases clinically. However, most clinical trials/studies reported thus far are relatively smaller in scale. The collected evidence is insufficient to support the routine use of WJ-MSC therapy in the clinic. Thus, rigorous clinical trials are needed in the future to obtain more information on WJ-MSC therapy safety and efficacy.

Allogeneic transplantation of mobilized dental pulp stem cells with the mismatched dog leukocyte antigen type is safe and efficacious for total pulp regeneration

Background

We recently demonstrated that autologous transplantation of mobilized dental pulp stem cells (MDPSCs) was a safe and efficacious potential therapy for total pulp regeneration in a clinical study. The autologous MDPSCs, however, have some limitations to overcome, such as limited availability of discarded teeth from older patients. In the present study, we investigated whether MDPSCs can be used for allogeneic applications to expand their therapeutic use.

Methods

Analysis of dog leukocyte antigen (DLA) was performed using polymerase chain reaction from blood. Canine allogeneic MDPSCs with the matched and mismatched DLA were transplanted with granulocyte-colony stimulating factor in collagen into pulpectomized teeth respectively (n = 7, each). Results were evaluated by hematoxylin and eosin staining, Masson trichrome staining, PGP9.5 immunostaining, and BS-1 lectin immunostaining performed 12 weeks after transplantation. The MDPSCs of the same DLA used in the first transplantation were further transplanted into another pulpectomized tooth and evaluated 12 weeks after transplantation.

Results

There was no evidence of toxicity or adverse events of the allogeneic transplantation of the MDPSCs with the mismatched DLA. No adverse event of dual transplantation of the MDPSCs with the matched and mismatched DLA was observed. Regenerated pulp tissues including neovascularization and neuronal extension were quantitatively and qualitatively similar at 12 weeks in both matched and mismatched DLA transplants. Regenerated pulp tissue was similarly observed in the dual transplantation as in the single transplantation of MDPSCs both with the matched and mismatched DLA.

Conclusions

Dual allogeneic transplantation of MDPSCs with the mismatched DLA is a safe and efficacious method for total pulp regeneration.

Electronic supplementary material

The online version of this article (10.1186/s13287-018-0855-8) contains supplementary material, which is available to authorized users.

Umbilical cord mesenchymal stromal cell transplantations: A systemic analysis of clinical trials

The advances and success of umbilical cord-derived mesenchymal stromal cells (UC-MSCs) in experimental disease animal models have fueled the development of targeted therapies in humans. The therapeutic potential of allogeneic transplantation of UC-MSCs has been under examination since 2009. The purpose of this systematic analysis was to review the published results, limitations and obstacles for UC-MSC transplantation. An extensive search strategy was applied to the published literature, 93 peer-reviewed full-text articles and abstracts were found published by early August 2017 that investigated the safety, efficacy and feasibility of UC-MSCs in 2001 patients with 53 distinct pathologies including many systemic/local, acute/chronic conditions. Few data were extracted from the abstracts and/or Chinese-written articles (n = 7, 8%). Importantly, no long-term adverse effects, tumor formation or cell rejection were reported. All studies noted certain degrees of therapeutic benefit as evidenced by clinical symptoms and/or laboratory findings. Thirty-seven percent (n = 34) of studies were found published as a single case (n = 10; 11%) or 2-10 case reports (n = 24; 26%) with no control group. Due to the nature of many stem cell-based studies, the majority of patients also received conventional therapy regimens, which obscured the pure efficacy of the cells transplanted. Randomized, blind, phase 1/2 trials with control groups (placebo-controlled) showed more plausible results. Given that most UC-MSC trials are early phase, the internationally recognized cell isolation and preparation standards should be extended to future phase 2/3 trials to reach more convincing conclusions regarding the safety and efficacy of UC-MSC therapies.