创面老化、生长因子缺乏，和感染是慢性溃疡迁延不愈的根本原因。腺苷A2A受体和血小板整合素受体在机体自我愈合机制中起到关键作用。而寡聚脱氧核苷酸（PDRN）和聚乙酰氨基葡糖纳米纤维（sNAG）可以分别激活这两种受体，重启机体的自我愈合机制，促进VEGF、Ki67等众多细胞因子的释放，进而刺激细胞增生、血管新生，最后导致伤口愈合。而且sNAG可以促进防御素的分泌，从而抑制细菌的生长。使用自组装sNAG纳米纤维凝胶载荷PDRN治疗慢性溃疡，既能够实现PDRN的可控性释放，又可以提供软组织修复的3D外环境。本课题组拟设计：合成自组装sNAG纳米纤维凝胶，采用溶剂蒸发技术包埋PDRN，联合治疗小鼠背部软组织缺损模型。观察此纳米纤维凝胶作为基质修复材料和药物缓释系统的效果，并研究其诱导血管新生、促进伤口愈合的作用。如能获得预期结果，将为治疗创伤性感染、糖尿病溃疡、褥疮等慢性不愈创面提供更广阔的空间。

Wound aging, lack of growth factors and infection are the basic causes of the unhealing chronic ulcer. A2A adenosine receptors and platelet integrin receptor play a key role in the self-healing mechanism of the body. Polydeoxyribonucleotide (PDRN) and short poly-N-acetyl glucosamine nanofibers (sNAG) can activate the two receptors respectively, restart the self-healing mechanism to promote the release of cell factors such as VEGF, Ki67, and then stimulate cell proliferation, angiogenesis, finally lead to the wound healing. Moreover, sNAG can promote the secretion of defensins to inhibit the growth of the bacteria. Using self-assembly sNAG nanofiber gel loading with PDRN to treat chronic ulcer, which can achieve the controlled release PDRN and provide the soft tissue repairing 3D environment. Our study is to design self-assembly synthetic sNAG nanofiber gel combining with PDRN using solvent evaporation technology embedding to treat the mice back tissue defect model, in order to investigate the effect of nano fiber gel as matrix repairing material and drug release system, and to study its induction of angiogenesis and accelerating wound healing effect. If we can get the the expected results, this study will provide a wider space for the cure of the unhealing wound in trauma infection，diabetes, chronic ulcer and bedsore.