dCas9-Based PDGFR-β Activation ADSCs Accelerate Wound Healing in Diabetic Mice through Angiogenesis and ECM Remodeling

α-ketoglutarate preconditioning extends the survival of engrafted adipose-derived mesenchymal stem cells to accelerate healing of burn wounds

The application of adipose-derived stem cells (ADSCs) in treating hard-to-heal wounds has been widely accepted, while the short-term survival rate remains an obstacle in stem cell therapy. The aim of this study is to investigate the effect of preconditioning ADSCs with α-ketoglutarate (α-KG) on the healing of acid burn wounds and cell survival within wounds. Preconditioning of ADSCs was performed by treating cells at passage 3 with 3.5 mM DM-αKG for 24 h. Proliferation and migration of ADSCs was examined. An acid burn wound was created on the dorsal skin of mice. Cell suspension of ADSCs (2 × 106 cells/ml), either pre-treated with α-KG or not, was injected subcutaneously around the margin of wound. At 1,4,7,10,14 days after injection, the percentage of wound closure was evaluated. Expression of pro-angiogenic factors, matrix molecules and HIF1-α in pretreated ADSCs or in wounds was evaluated by qRT-PCR and immunohistochemistry staining, respectively. The survival rate of DiO-labelled ADSCs was determined with the in vivo bioluminescent imaging system. Treating with α-KG induced an enhancement in migration of ADSCs, while their proliferation was not affected. Expression of Vegf and Fgf-2 was significantly increased. With injection of pretreated ADSCs, healing of wounds was remarkably accelerated, along with increased ECM deposition and microvessel density. Moreover, pretreatment with α-KG resulted a prolonged survival of engrafted ADSCs was observed. Expression of HIF-1α was significantly increased in ADSCs treated with α-KG and in wounds injected with preconditioned ADSCs. Our results revealed that healing of acid burn wound was accelerated with administration of ADSCs pretreated with α-KG, which induced elevated expression of HIF-1α and prolonged survival of engrafted stem cells.

Development of pro-angiogenic skin substitutes for wound healing

Wounds pose significant challenges to public health, primarily due to the loss of the mechanical integrity and barrier function of the skin and impaired angiogenesis, causing physical morbidities and psychological trauma to affect patients. Reconstructing the vasculature of the wound bed is crucial for promoting wound healing, reducing scar formation and enhancing the quality of life for patients. The development of pro-angiogenic skin substitutes has emerged as a promising strategy to facilitate vascularization and expedite the healing process of burn wounds. This review provides an overview of the various types of skin substitutes employed in wound healing, explicitly emphasising those designed to enhance angiogenesis. Synthetic scaffolds, biological matrices and tissue-engineered constructs incorporating stem cells and primary cells, cell-derived extracellular vesicles (EVs), pro-angiogenic growth factors and peptides, as well as gene therapy-based skin substitutes are thoroughly examined. The review summarises the existing challenges, future directions and potential innovations in pro-angiogenic dressing for skin substitutes. It highlights the need for continued research to develop new technologies and combine multiple strategies and factors, and to overcome obstacles and advance the field, ultimately leading to improved outcomes for wound patients.

Platelet-derived extracellular vesicles: a new-generation nanostructured tool for chronic wound healing

Chronic nonhealing wounds pose a serious challenge to regaining skin function and integrity. Platelet-derived extracellular vesicles (PEVs) are nanostructured particles with the potential to promote wound healing since they can enhance neovascularization and cell migration and reduce inflammation and scarring. This work provides an innovative overview of the technical laboratory issues in PEV production, PEVs' role in chronic wound healing and the benefits and challenges in its clinical translation. The article also explores the challenges of proper sourcing, extraction techniques and storage conditions, and discusses the necessity of further evaluations and combinational therapeutics, including dressing biomaterials, M2-derived exosomes, mesenchymal stem cells-derived extracellular vesicles and microneedle technology, to boost their therapeutic efficacy as advanced strategies for wound healing.

Adipose tissue-derived stem cells, in vivo and in vitro models for metabolic diseases

The primary role of adipose tissue stem cells (ADSCs) is to support the function and homeostasis of adipose tissue in physiological and pathophysiological conditions. However, when ADSCs become dysfunctional in diseases such as obesity and cancer, they become impaired, undergo signalling changes, and their epigenome is altered, which can have a dramatic effect on human health. In more recent years, the therapeutic potential of ADSCs in regenerative medicine, wound healing, and for treating conditions such as cancer and metabolic diseases has been extensively investigated with very promising results. ADSCs have also been used to generate two-dimensional (2D) and three-dimensional (3D) cellular and in vivo models to study adipose tissue biology and function as well as intracellular communication. Characterising the biology and function of ADSCs, how it is altered in health and disease, and its therapeutic potential and uses in cellular models is key for designing intervention strategies for complex metabolic diseases and cancer.