The potential of human induced pluripotent stem cells for modelling diabetic wound healing in vitro

Fish collagen sponge with human umbilical cord mesenchymal stem cells for diabetic wound repair in rats

Stem cell therapy offers a novel approach to treating difbetic foot ulcers. Fish skin decellularized matrix, a type I collagen, provides a promising carrier for stem cells, creating a supportive microenvironment that enhances cell survival and therapeutic potential. This study aims to investigate the effects and mechanisms of human umbilical cord mesenchymal stem cells (HUCMSCs) loaded onto a fish collagen sponge for wound healing in diabetic rats. The study evaluates stem cell-loading efficiency with fish collagen sponge in vitro, assesses material distribution on diabetic rat wounds, and establishes a wound model. Rats are divided into the Self-healing group, Fish collagen sponge group, and Sponge loaded with HUCMSCs group. Therapeutic effects are evaluated through various analyses, including histopathology and reverse transcription polymerase chain reaction for collagen-related gene expression levels. Compared to the self-healing group, both the fish collagen group and the composite group show faster wound repair and improved healing outcomes. The composite group exhibits superior wound healing quality, with fish collagen contributing to enhanced tissue regeneration through collagen regulation at the wound site. Loading HUCMSCs onto a fish collagen sponge shows promise for treating diabetic wounds by addressing nutrient deficiency and cell supply issues, offering potential benefits for patients undergoing treatment.

Advances in stem cells treatment of diabetic wounds: A bibliometric analysis via CiteSpace

Diabetes is a chronic medical condition that may induce complications such as poor wound healing. Stem cell therapies have shown promise in treating diabetic wounds with pre-clinical and clinical studies. However, little bibliometric analysis has been carried out on stem cells in the treatment of diabetic wounds. In this study, we retrieved relevant papers published from January 1, 2003, to December 31, 2023, from Chinese and English databases. CiteSpace software was used to analyze the authors, institutions, and keywords by standard bibliometric indicators. Our analysis findings indicated that publications on stem cells in the treatment of diabetic wounds kept increasing. The most prolific author was Qian Cai (n = 7) and Mohammad Bayat (n = 16) in Chinese and English databases, respectively. Institutions distribution analysis showed that Chinese institutions conducted most publications, and the most prolific institution was the Chinese People's Liberation Army General Hospital (n = 9) and Shahid Beheshti University of Medical Sciences (n = 17) in Chinese and English databases, respectively. The highest centrality keyword in Chinese and English databases was "wound healing" (0.54) and "in vitro" (0.13), respectively. There were 8 and 11 efficient and convincing keyword clusters produced by a log-likelihood ratio in the Chinese and English databases, respectively. The strongest burst keyword was "exosome" (strength 3.57) and "endothelial progenitor cells" (strength 7.87) in the Chinese and English databases, respectively. These findings indicated a direction for future therapies and research on stem cells in the treatment of diabetic wounds.

A review of diabetic wound models-Novel insights into diabetic foot ulcer

Diabetic foot ulcer (DFU) is a major debilitating complication of diabetes. Many research investigations have been conducted with the aims to uncover the diabetic wound healing mechanisms, develop novel therapeutics, and screen bioactive wound dressings in order to improve the current management of DFU. These would have not been possible without the utilization of an appropriate wound model, especially in a diabetic wound context. This review focuses on the different in vitro research models used in DFU investigations such as the 2D scratch wound assay, 3D skin model, and 3D angiogenesis model as well as their limitations. The current efforts and challenges to apply the 2D and 3D in vitro models in a hyperglycemic context to provide insights into DFU modeling will be reviewed. Perspectives of utilizing 3D bioprinting and skin-on-the-chip model as a diabetic wound model in the future will also be highlighted. By leveraging knowledge from past experiences and current research, an improved experimental model for DFU is anticipated to be established in near future.

Toward Developing Immunocompetent Diabetic Foot Ulcer-on-a-Chip Models for Drug Testing

Bioengineering of skin has been significantly explored, ranging from the use of traditional cell culture systems to the most recent organ-on-a-chip (OoC) technology that permits skin modeling on physiological scales among other benefits. This article presents key considerations for developing physiologically relevant immunocompetent diabetic foot ulcer (DFU) models. Diabetic foot ulceration affects hundreds of millions of individuals globally, especially the elderly, and constitutes a major socioeconomic burden. When DFUs are not treated and managed in a timely manner, 15-50% of patients tend to undergo partial or complete amputation of the affected limb. Consequently, at least 40% of such patients die within 5 years postamputation. Currently, therapeutic strategies are actively sought and developed. However, present-day preclinical platforms (animals and in vitro models) are not robust enough to provide reliable data for clinical trials. Insights from published works on immunocompetent skin-on-a-chip models and bioengineering considerations, presented in this article, can inform researchers on how to develop robust OoC models for testing topical therapies such as growth factor-based therapies for DFUs. We propose that immunocompetent DFU-on-a-chip models should be bioengineered using diseased cells derived from individuals; in particular, the pathophysiological contribution of macrophages in diabetic wound healing, along with the typical fibroblasts and keratinocytes, needs to be recapitulated. The ideal model should consist of the following components: diseased cells embedded in reproducible scaffolds, which permit endogenous "diseased" extracellular matrix deposition, and the integration of the derived immunocompetent DFU model onto a microfluidic platform. The proposed DFU platforms will eventually facilitate reliable and robust drug testing of wound healing therapeutics, coupled with reduced clinical trial failure rates. Impact statement Current animal and cell-based systems are not physiologically relevant enough to retrieve reliable results for clinical translation of diabetic foot ulcer (DFU) therapies. Organ-on-a-chip (OoC) technology offers desirable features that could finally enable the vision of modeling DFU for pathophysiological studies and drug testing at a microscale. This article brings together the significant recent findings relevant to developing a minimally functional immunocompetent DFU-on-a-chip model, as wound healing cannot occur without a proper functioning immune response. It looks feasible in the future to recapitulate the stagnant inflammation in DFU (thought to impede wound healing) using OoC, diseased cells, and an endogenously produced extracellular matrix.

Effects of Dendrobium Polysaccharides on the Functions of Human Skin Fibroblasts and Expression of Matrix Metalloproteinase-2 under High-Glucose Conditions

The effects of Dendrobium polysaccharides (PDC) on the functions of human skin fibroblasts (HSFs) and expression of matrix metalloproteinase-2 under high-glucose conditions and exploration of the underlying mechanism remain unclear. We used the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) analysis and flow cytometry to evaluate the cell viability and apoptosis. The collagen levels were determined by the Sircol™ Collagen Assay. Real-time quantitative polymerase chain reaction (RT-PCR) was used to detect the expression of matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase inhibitor (TIMP-2) mRNA. We found the following: (1) under the high-glucose condition, the HSF cell viability, the expression of TIMP-2 mRNA, and the collagen levels were reduced, while the apoptosis rate and the expression of MMP-2 mRNA increased (P < 0.05). (2) In the high-glucose + PDC group, the PDC reversed the changes in the collagen level, viability, and apoptosis rate of the HSF cells caused by high glucose, with the expression of protein and TIMP-2 mRNA increased and the level of MMP-2 mRNA decreased (P < 0.05). This is the first time attempting to reveal that PDC can exhibit protective effects on HSF under high-glucose conditions, which may be related to the upregulation of the TIMP-2 expression and inhibition of the MMP-2 expression.

Therapeutic angiogenesis using stem cell-derived extracellular vesicles: an emerging approach for treatment of ischemic diseases

Ischemic diseases, which are caused by a reduction of blood supply that results in reduced oxygen transfer and nutrient uptake, are becoming the leading cause of disabilities and deaths. Therapeutic angiogenesis is key for the treatment of these diseases. Stem cells have been used in animal models and clinical trials to treat various ischemic diseases. Recently, the efficacy of stem cell therapy has increasingly been attributed to exocrine functions, particularly extracellular vesicles. Extracellular vesicles are thought to act as intercellular communication vehicles to transport informational molecules including proteins, mRNA, microRNAs, DNA fragments, and lipids. Studies have demonstrated that extracellular vesicles promote angiogenesis in cellular experiments and animal models. Herein, recent reports on the use of extracellular vesicles for therapeutic angiogenesis during ischemic diseases are presented and discussed. We believe that extracellular vesicles-based therapeutics will be an ideal treatment method for patients with ischemic diseases.