Ex vivo tolerization and M2 polarization of macrophages dampens both pro- and anti-inflammatory cytokine production in response to diabetic wound fluid stimulation

Advances in stem cell therapy for diabetic foot

Diabetic Foot Ulcers (DFU) represent a grave complication often encountered in the advanced stages of diabetes mellitus. They frequently lead to recurrent hospitalizations and, in severe cases, can result in life-threatening conditions such as infections, gangrene, and even amputation Diabetic foot ulcers (DFU), as a serious complication in the late stage of diabetes mellitus, are prone to lead to repeated hospitalization, and in severe cases, infection, gangrene, and even amputation. Although there are many methods for treating diabetic foot, there is no clear and effective method to reduce the amputation rate of diabetic foot patients. In recent years, advancements in the understanding of stem cell therapy for the treatment of DFU have shed light on its potential as a novel therapeutic approach. In recent years, as the research on stem cell therapy for diabetic foot is gradually deepening, stem cells are expected to become a new therapeutic method for treating DFU in the future. Their therapeutic effects are through promoting angiogenesis, secreting paracrine factors, controlling inflammation, promoting collagen deposition, and regulating immunity, etc. Despite numerous studies confirming the efficacy of stem cell therapy in treating DFU, there is still a need for the establishment of standardized treatment protocols. Although numerous studies have shown that stem cell therapy for DFU is real and effective, there has not yet been a standardized treatment protocol. This article reviews studies related to stem cell therapy for DFU, looking at the mechanism of action, types of stem cells, and modes of administration.

Spermidine-Functionalized Injectable Hydrogel Reduces Inflammation and Enhances Healing of Acute and Diabetic Wounds In Situ

The inflammatory response is a key factor affecting tissue regeneration. Inspired by the immunomodulatory role of spermidine, an injectable double network hydrogel functionalized with spermidine (DN-SPD) is developed, where the first and second networks are formed by dynamic imine bonds and non-dynamic photo-crosslinked bonds respectively. The single network hydrogel before photo-crosslinking exhibits excellent injectability and thus can be printed and photo-crosslinked in situ to form double network hydrogels. DN-SPD hydrogel has demonstrated desirable mechanical properties and tissue adhesion. More importantly, an "operando" comparison of hydrogels loaded with spermidine or diethylenetriamine (DETA), a sham molecule resembling spermidine, has shown similar physical properties, but quite different biological functions. Specifically, the outcomes of 3 sets of in vivo animal experiments demonstrate that DN-SPD hydrogel can not only reduce inflammation caused by implanted exogenous biomaterials and reactive oxygen species but also promote the polarization of macrophages toward regenerative M2 phenotype, in comparison with DN-DETA hydrogel. Moreover, the immunoregulation by spermidine can also translate into faster and more natural healing of both acute wounds and diabetic wounds. Hence, the local administration of spermidine affords a simple but elegant approach to attenuate foreign body reactions induced by exogenous biomaterials to treat chronic refractory wounds.

Mesenchymal stem cell therapy for non-healing diabetic foot ulcer infection: New insight

Diabetic foot ulcer (DFU) is considered the most catastrophic complication of diabetes mellitus (DM), leading to repeated hospitalizations, infection, gangrene, and finally amputation of the limb. In patients suffering from diabetes mellitus, the wound-healing process is impaired due to various factors such as endothelial dysfunction and synthesis of advanced glycation end-products, hence, conventional therapeutic interventions might not be effective. With increasing therapeutic applications of mesenchymal stem cells (MSCs) in recent years, their potential as a method for improving the wound-healing process has gained remarkable attention. In this field, mesenchymal stem cells exert their beneficial effects through immunomodulation, differentiation into the essential cells at the site of ulcers, and promoting angiogenesis, among others. In this article, we review cellular and molecular pathways through which mesenchymal stem cell therapy reinforces the healing process in non-healing Diabetic foot ulcers.