Lipopolysaccharides priming mesenchymal stem cells accelerate diabetic wound healing viaexosomes

Objective To study the therapeutic effect of exosome derived from lipopolysaccharides (LPS) priming mesenchymal stem cells (MSCs) for diabetic wound healing. Methods Human umbilical cord MSCs were treated with LPS (100ng/ml) for 2 days, the supernatant were then collected, and exosomes were harvested by density gradient centrifugation and identified. Diabetic cutaneous wounds were prepared and the animals were divided into the following three groups: control group, untreated MSCs derived exosome (un-exosome) treatment group and LPS primed MSCs derived exosome (LPS-exosome) treatment group. Exosomes (60μg) were injected dispersively into the wound edge daily for 10 days. After treatment, the therapeutic results were evaluated by gross observation of the wounds, the expression levels of inflammation related factors and macrophage subtype markers in the injured sites were detected by qRT-PCR at day 3, 7 and 14 after treatment. Results Compared with control group, the diabetic wound healing was obviously improved in LPS-exosome treatment group after treatment for 7 and 14 days, with faster wound close, depressed expression of pro-inflammatory factors IL -1, IL -12 and M1 macrophage surface marker iNOS, and up-regulation of anti-inflammatory factors IL-10, TGF-βand M2 macrophage surface marker CD163, the differences were significant (P