Phase I/IIa Feasibility Trial of Autologous Quality- and Quantity-Cultured Peripheral Blood Mononuclear Cell Therapy for Non-Healing Extremity Ulcers

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.

Effectiveness of quality and quantity mononuclear cells for enhancing wound healing in diabetic ischemic limb animal model

This study set forth to investigate the efficacy of Quality and Quantity mononuclear cells (QQMNCs) for promoting wound healing and limb salvage in a severe ischemic wound model using diabetic mice. Female BALB/c nude mice induced with diabetes were used to create ischemic limb models in a controlled experimental design. Intramuscular injections of human QQMNCs were compared to phosphate-buffered saline (PBS) and peripheral blood mononuclear cells (PBMNCs) relative to their effects on wound healing and limb salvage. In vitro analysis demonstrated that the QQMNC group had significantly higher median percentages of CD34+ cells, CD34+CD133+ cells, CD206+ cells, and FOXP3+ cells compared to the PBMNC group (all p < 0.05), which suggests an enhanced regenerative and immunomodulatory profile. Kaplan-Meier survival analysis showed a significantly higher number of completely healed wounds in the QQMNC group than in the PBMNC group (p = 0.044). The histological evaluation showed that the QQMNC group had a significantly thinner epithelial thickness than the PBMNC (p = 0.032) and PBS groups (p = 0.002), and a significantly greater T cell density than the PBS group (p = 0.033), which suggests more efficient tissue repair. Moreover, the QQMNC group exhibited the highest percentage of minor tissue loss (57% for forefoot and toe gangrene), and the lowest incidence of severe limb loss (0% for lower leg gangrene). The findings of this study highlight the effectiveness of QQMNCs for promoting wound healing and limb salvage in diabetic ischemic animal model; however, clinical trials are needed to further assess their efficacy in this clinical context.

Serum-free Quality and Quantity Control Culture Improves the Angiogenic Potential of Peripheral Blood Mononuclear Cells Harvested from Patients with Connective Tissue Diseases

Objectives

The number and quality of endothelial progenitor cells decrease in patients with connective tissue diseases. This limits the efficacy of mononuclear cell therapy for ischemic ulcers associated with connective tissue diseases. To overcome these problems, we developed a serum-free quality and quantity control culture method that potentially improves the function of endothelial progenitor cells and expands their numbers. Here, we show the effect of quality and quantity control culture on mononuclear cells from patients with connective tissue diseases.

Methods

Peripheral blood mononuclear cells were isolated from C57BL/6JJmsSlc-lpr/lpr mice with systemic lupus erythematosus, patients with connective tissue diseases, and healthy volunteers. Mononuclear cells were cultured using the quality and quantity control culture method, and the number of endothelial progenitor cells was analyzed using flow cytometry, an endothelial progenitor cell culture assay, and an endothelial progenitor cell colony-forming assay. Flow cytometry was also used to examine mononuclear cell subpopulations. A human umbilical vein endothelial cell tube-forming assay was used to examine the function of quality and quantity control cultured mononuclear cells.

Results

Mice with systemic lupus erythematosus showed a significantly lower number of endothelial progenitor cells, which increased to the same levels as those of the control mice after quality and quantity control culture. In humans, the numbers of endothelial progenitor cells and M2 macrophages were significantly increased and the number of proinflammatory cells was decreased after quality and quantity control culture in both healthy volunteers and patients with connective tissue diseases. The human umbilical vein endothelial cell tube formation assay showed higher angiogenic potential in quality and quantity control cultured mononuclear cells from patients with connective tissue diseases than that in quality and quantity control cultured mononuclear cells from healthy controls.

Conclusions

Our study suggests that the quality and quantity control culture method is effective in recovering the angiogenic ability of mononuclear cells from patients with connective tissue diseases.

Anti-inflammatory Prowess of endothelial progenitor cells in the realm of biology and medicine

Endothelial inflammation plays a crucial role in vascular-related diseases, a leading cause of global mortality. Among various cellular players, endothelial progenitor cells (EPCs) emerge as non-differentiated endothelial cells circulating in the bloodstream. Recent evidence highlights the transformative role of EPCs in shifting from an inflammatory/immunosuppressive crisis to an anti-inflammatory/immunomodulatory response. Despite the importance of these functions, the regulatory mechanisms governing EPC activities and their physiological significance in vascular regenerative medicine remain elusive. Surprisingly, the current literature lacks a comprehensive review of EPCs' effects on inflammatory processes. This narrative review aims to fill this gap by exploring the cutting-edge role of EPCs against inflammation, from molecular intricacies to broader medical perspectives. By examining how EPCs modulate inflammatory responses, we aim to unravel their anti-inflammatory significance in vascular regenerative medicine, deepening insights into EPCs' molecular mechanisms and guiding future therapeutic strategies targeting vascular-related diseases.

Synergistic effect of ex-vivo quality and quantity cultured mononuclear cells and mesenchymal stem cell therapy in ischemic hind limb model mice

Introduction

Chronic limb-threatening ischemia (CLTI) is a condition characterized by peripheral arterial disease and tissue damage caused by reduced blood flow. New therapies using various cell types, such as mesenchymal stem cells (MSCs) and mononuclear cells (MNCs), have been developed for the patients unresponsive to conventional therapies. MSCs are promising because of their ability to secrete growth factors essential for vascularization, whereas MNCs contain endothelial progenitor cells that are important for blood vessel formation. However, conventional methods for isolating these cells have limitations, especially in patients with diabetes with dysfunctional cells. To overcome this problem, a culture method called quality and quantity cultured peripheral blood MNCs (MNC-QQ) was developed to efficiently produce high-quality cells from small amounts of peripheral blood. Combining MSCs with MNC-QQs has been hypothesized to enhance therapeutic outcomes. This study aimed to examine the angiogenic efficacy of MSCs with MNC-QQs in models with severe lower limb ischemia.

Methods

MNC-QQ was manufactured from the peripheral blood of healthy volunteers, while human bone marrow derived MSCs were purchased. To verify the effects of the MSC and MNC-QQs combination in angiogenesis, we conducted the HUVEC tube formation assay. For in vivo experiments, we created an ischemic limb model using BALB/c nude mice. Saline, MSCs alone, and a combination of MSCs and MNC-QQs were administered intramuscularly into the ischemic limbs. Blood flow was measured over time using laser doppler, and the ischemic limbs were harvested 21 days later for HE staining and immunostaining for histological assessment.

Results

In-vitro studies demonstrated increased angiogenesis when MSCs were combined with MNC-QQs compared with MSCs alone. In vivo experiments using a mouse model of severe lower limb ischemia showed that combination therapy significantly improved blood flow recovery and limb salvage compared with MSCs alone or saline treatment. Histological analysis revealed enhanced vessel density, arteriogenesis, muscle regeneration, and reduced fibrosis in the MSC + MNC-QQ group compared with those in the saline group. Although the specific interactions between MSCs and MNC-QQs have not been fully elucidated, combined therapy leverages the benefits of both cell types, resulting in improved outcomes for vascular regeneration.

Conclusions

This study highlights the potential of the simultaneous transplantation of MSCs and MNC-QQs as a promising therapeutic approach for CLTI, offering sustained long-term benefits for patients.

The Efficacy of Stem Cells in Wound Healing: A Systematic Review

Wound healing is an intricate process involving coordinated interactions among inflammatory cells, skin fibroblasts, keratinocytes, and endothelial cells. Successful tissue repair hinges on controlled inflammation, angiogenesis, and remodeling facilitated by the exchange of cytokines and growth factors. Comorbid conditions can disrupt this process, leading to significant morbidity and mortality. Stem cell therapy has emerged as a promising strategy for enhancing wound healing, utilizing cells from diverse sources such as endothelial progenitor cells, bone marrow, adipose tissue, dermal, and inducible pluripotent stem cells. In this systematic review, we comprehensively investigated stem cell therapies in chronic wounds, summarizing the clinical, translational, and primary literature. A systematic search across PubMed, Embase, Web of Science, Google Scholar, and Cochrane Library yielded 22,454 articles, reduced to 44 studies after rigorous screening. Notably, adipose tissue-derived mesenchymal stem cells (AD-MSCs) emerged as an optimal choice due to their abundant supply, easy isolation, ex vivo proliferative capacities, and pro-angiogenic factor secretion. AD-MSCs have shown efficacy in various conditions, including peripheral arterial disease, diabetic wounds, hypertensive ulcers, bullous diabeticorum, venous ulcers, and post-Mohs micrographic surgery wounds. Delivery methods varied, encompassing topical application, scaffold incorporation, combination with plasma-rich proteins, and atelocollagen administration. Integration with local wound care practices resulted in reduced pain, shorter healing times, and improved cosmesis. Stem cell transplantation represents a potential therapeutic avenue, as transplanted stem cells not only differentiate into diverse skin cell types but also release essential cytokines and growth factors, fostering increased angiogenesis. This approach holds promise for intractable wounds, particularly chronic lower-leg wounds, and as a post-Mohs micrographic surgery intervention for healing defects through secondary intention. The potential reduction in healthcare costs and enhancement of patient quality of life further underscore the attractiveness of stem cell applications in wound care. This systematic review explores the clinical utilization of stem cells and stem cell products, providing valuable insights into their role as ancillary methods in treating chronic wounds.

Therapeutic application of regeneration-associated cells: a novel source of regenerative medicine

Chronic diseases with comorbidities or associated risk factors may impair the function of regenerative cells and the regenerative microenvironment. Following this consideration, the vasculogenic conditioning culture (VCC) method was developed to boost the regenerative microenvironment to achieve regeneration-associated cells (RACs), which contain vasculogenic endothelial progenitor cells (EPCs) and anti-inflammatory/anti-immunity cells. Preclinical and clinical studies demonstrate that RAC transplantation is a safe and convenient cell population for promoting ischemic tissue recovery based on its strong vasculogenicity and functionality. The outputs of the scientific reports reviewed in the present study shed light on the fact that RAC transplantation is efficient in curing various diseases. Here, we compactly highlight the universal features of RACs and the latest progress in their translation toward clinics.

A scientometrics analysis and visualisation of diabetic foot research from 1955 to 2022

Diabetic foot (DF) has become a serious health problem in modern society, and it has been a hotspot of research for a long time. However, little scientometric analysis has been carried out on DF. In the present study, we analysed 8633 literature reports on DF in the Web of Science Core Collection from database inception until April 23, 2022. VOSviewer (Centre for Science and Technology Studies at Leiden University, Leiden, the Netherlands) and CiteSpace (College of Computing and Informatics, Drexel University, Philadelphia, United States) were employed to address high-impact countries and institutions, journals, references, research hotspots, and key research fields in DF research. Our analysis findings indicated that publications on DF have increased markedly since 2016 and were primarily published in the United States of America. The recent studies focus on the amniotic membrane, foot ulcers, osteomyelitis, and diabetic wound healing. The five keyword clusters, which included DF ulcer and wound healing therapies, management and guidelines, neuropathy and plantar pressure, amputation and ischemia, and DF infection and osteomyelitis, are helpful for enhancing prevention, standardising treatment, avoiding complications, and improving prognosis. These findings indicated a method for future therapies and research in DF.

Effect of MNCQQ Cells on Migration of Human Dermal Fibroblast in Diabetic Condition

A major symptom of diabetes mellitus (DM) is unfit hyperglycemia, which leads to impaired wound healing. It has been reported that the migration of fibroblasts can be suppressed under high glucose (HG) conditions. In our previous study, we introduced a serum-free culture method for mononuclear cells (MNCs) called quantity and quality control culture (QQc), which could improve the vasculogenic and tissue regeneration ability of MNCs. In this study, we described a culture model in which we applied a high glucose condition in human dermal fibroblasts to simulate the hyperglycemia condition in diabetic patients. MNC-QQ cells were cocultured with fibroblasts in this model to evaluate its role in improving fibroblasts dysfunction induced by HG and investigate its molecular mechanism. It was proven in this study that the impaired migration of fibroblasts induced by high glucose could be remarkably enhanced by coculture with MNC-QQ cells. PDGF B is known to play important roles in fibroblasts migration. Quantitative PCR revealed that MNC-QQ cells enhanced the gene expressions of PDGF B in fibroblasts under HG. Taken with these results, our data suggested a possibility that MNC-QQ cells accelerate wound healing via improving the fibroblasts migration and promote the gene expressions of PDGF B under diabetic conditions.

A review on contemporary nanomaterial-based therapeutics for the treatment of diabetic foot ulcers (DFUs) with special reference to the Indian scenario

Diabetes mellitus (DM) is a predominant chronic metabolic syndrome, resulting in various complications and high mortality associated with diabetic foot ulcers (DFUs). Approximately 15-30% of diabetic patients suffer from DFUs, which is expected to increase annually. The major challenges in treating DFUs are associated with wound infections, alterations to inflammatory responses, angiogenesis and lack of extracellular matrix (ECM) components. Furthermore, the lack of targeted therapy and efficient wound dressings for diabetic wounds often results in extended hospitalization and limb amputations. Hence, it is essential to develop and improve DFU-specific therapies. Nanomaterial-based innovative approaches have tremendous potential for preventing and treating wound infections of bacterial origin. They have greater benefits compared to traditional wound dressing approaches. In this approach, the physiochemical features of nanomaterials allow researchers to employ different methods for diabetic wound healing applications. In this review, the status and prevalence of diabetes mellitus (DM) and amputations due to DFUs in India, the pathophysiology of DFUs and their complications are discussed. Additionally, nanomaterial-based approaches such as the use of nanoemulsions, nanoparticles, nanoliposomes and nanofibers for the treatment of DFUs are studied. Besides, emerging therapeutics such as bioengineered skin substitutes and nanomaterial-based innovative approaches such as antibacterial hyperthermia therapy and gene therapy for the treatment of DFUs are highlighted. The present nanomaterial-based techniques provide a strong base for future therapeutic approaches for skin regeneration strategies in the treatment of diabetic wounds.