A long-term inflammatory phase of diabetic wounds is the primary cause to prevent their effective healing. Bacterial infection, excess reactive oxygen species (ROS), especially failure of M2-phenotype macrophage polarization can hinder the transition of diabetic wounds from an inflammation phase to a proliferation one. Herein, a chitosan-based hydrogel dressing with the ability of regulating M2 macrophage polarization was reported. The PAAc/CFCS-Vanillin hydrogel dressing was synthesized by one step thermal polymerization of catechol-functionalized chitosan (CFCS), acrylic acid, catechol functional methacryloyl chitosan‑silver nanoparticles (CFMC-Ag NPs) and bioactive vanillin. The PAAc/CFCS-Vanillin hydrogel possessed sufficient mechanical strength and excellent adhesion properties, which helped rapidly block bleeding of wounds. Thanks to CFCS, CFMC-Ag NPs and vanillin in the hydrogel, it displayed excellent antibacterial infection in the wounds. Vanillin helped scavenge excess ROS and regulate the levels of inflammatory factors to facilitate the polarization of macrophages into the M2 phenotype. A full-thickness skin defect diabetic wound model showed that the wounds treated by the PAAc/CFCS-Vanillin hydrogel exhibited the smallest wound area, and superior granulation tissue regeneration, remarkable collagen deposition, and angiogenesis were observed in the wound tissue. Therefore, the PAAc/CFCS-Vanillin hydrogel could hold promising potential as a dressing for the treatment of diabetic chronic wounds.

糖尿病伤口的长期炎症阶段是阻碍其有效愈合的主要原因。细菌感染、过量的活性氧 (ROS)，尤其是 M2 表型巨噬细胞极化失败，可能会阻碍糖尿病伤口从炎症阶段向增殖阶段的转变。本文报道了一种基于壳聚糖的水凝胶敷料，具有调节 M2 巨噬细胞极化的能力。 PAAc/CFCS-香草醛水凝胶敷料是通过儿茶酚功能化壳聚糖（CFCS）、丙烯酸、儿茶酚功能化甲基丙烯酰壳聚糖银纳米粒子（CFMC-Ag NPs）和生物活性香草醛一步热聚合合成的。 PAAc/CFCS-香草醛水凝胶具有足够的机械强度和优异的粘附性能，有助于快速止血伤口。由于水凝胶中含有CFCS、CFMC-Ag NPs和香草醛，它在伤口中表现出优异的抗菌感染能力。香草醛有助于清除过量的 ROS 并调节炎症因子的水平，以促进巨噬细胞极化为 M2 表型。全层皮肤缺损糖尿病伤口模型显示，PAAc/CFCS-香兰素水凝胶治疗的伤口具有最小的伤口面积，并且在伤口组织中观察到良好的肉芽组织再生、显着的胶原沉积和血管生成。因此，PAAc/CFCS-香兰素水凝胶作为治疗糖尿病慢性伤口的敷料具有广阔的潜力。