Hypoxia endothelial cells-derived exosomes facilitate diabetic wound healing through improving endothelial cell function and promoting M2 macrophages polarization

It is imperative to develop and implement newer,more effective strategies to address refractory diabetic wounds.As of now,there is currently no optimal solution for these wounds.Hypoxic human umbilical vein endothelial cells(HUVECs)-derived exosomes have been postulated to promote diabetic wound healing,however,its effect and molecular mechanism need further study.In this study,we aimed to investigate whether hypoxic exosomes enhance wound healing in diabetics.Based on our high-throughput sequencing,differentially expressed lncRNAs(including 64 upregulated lncRNAs and 94 downregulated lncRNAs)were found in hypoxic exosomes compared to normoxic exosomes.Interestingly,lncHAR1B was one of the prominently upregulated lncRNAs in hypoxic exosomes,showing a notable correlation with diabetic wound healing.More specifically,hypoxic exosomes were transmitted to surrounding cells,which resulted in a significant increase in lncHAR1B level,thereby relieving the dysfunction of endothelial cells and promoting the switch from M1 to M2 macrophages under high glucose conditions.Mechanistically,lncHAR1B directly interacted with the transcription factor basic helix-loop-helix family member e23(BHLHE23),which subsequently led to its binding to the KLF transcription factor 4(KLF4)and promoted KLF4 expression.In our in vivo experiments,the use of hypoxic exosomes-loaded HGM-QCS hydrogels(Gel-H-Exos)resulted in rapid wound healing compared to that of normoxic exosomes-loaded HGM-QCS hydrogels(Gel-N-Exos)and diabetic groups.Consequently,our study provides potentially novel therapeutic approaches aimed at accelerating wound healing and developing a practical exosomes delivery platform.

Neddylation suppression by a macrophage membrane-coated nanoparticle promotes dual immunomodulatory repair of diabetic wounds

Oxidative stress,infection,and vasculopathy caused by hyperglycemia are the main barriers for the rapid repair of foot ulcers in patients with diabetes mellitus(DM).In recent times,the discovery of neddylation,a new type of post-translational modification,has been found to regulate various crucial biological processes including cell metabolism and the cell cycle.Nevertheless,its capacity to control the healing of wounds in diabetic patients remains unknown.This study shows that MLN49224,a compound that inhibits neddylation at low concentrations,enhances the healing of diabetic wounds by inhibiting the polarization of M1 macrophages and reducing the secretion of inflammatory factors.Moreover,it concurrently stimulates the growth,movement,and formation of blood vessel endothelial cells,leading to expedited healing of wounds in individuals with diabetes.The drug is loaded into biomimetic macrophage-membrane-coated PLGA nanoparticles(M-NPs/MLN4924).The membrane of macrophages shields nanoparticles from being eliminated in the reticuloendothelial system and counteracts the proinflammatory cytokines to alleviate inflammation in the surrounding area.The extended discharge of MLN4924 from M-NPs/MLN4924 stimulates the growth of endothelial cells and the formation of tubes,along with the polarization of macrophages towards the anti-inflammatory M2 phenotype.By loading M-NPs/MLN4924 into a hydrogel,the final formulation is able to meaningfully repair a diabetic wound,suggesting that M-NPs/MLN4924 is a promising engineered nanoplatform for tissue engineering.