Zwitterionic polymers have emerged as an important class of biomaterials to construct wound dressings and antifouling coatings over the past decade due to their excellent hydrophilicity. However, all the reported zwitterionic polymers as wound dressings are nondegradable because of noncleavable carbon─carbon bonding backbones, and must be removed periodically after treatment to avoid hypoxia in the wound, thus leading to potential secondary injury. In this work, a biodegradable polyzwitterion patch is fabricated for the first time by ring-opening polymerization of carboxybetaine dithiolane (CBDS), which is self-crosslinked via inter-amide hydrogen bonds and zwitterionic dipole–dipole interactions on the side chains. The unprecedented polyCBDS (PCBDS) patch demonstrates enough ductility owing to the intermolecular physical interactions to fully cover irregular wounds, also showing excellent biodegradability and antifouling performance resulted from the existence of disulfide bonds and carboxybetaine groups. Besides, the PCBDS degradation-induced released CBDS owns potent antioxidant and antibacterial activities. This PCBDS patch is used as a diabetic wound dressing, inhibiting bacterial adhesion on the external surface, and its degradation products can exactly kill bacteria and scavenge excessive reactive oxygen species (ROS) at the wound site to regulate local microenvironment, including regulation of cytokine express and macrophage polarization, accelerating infected diabetic wound repair, and also avoiding the potential secondary injury.

中文翻译：

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前所未有的可生物降解的多两性离子：一种无需移除的贴剂，可加速感染的糖尿病伤口愈合


在过去的十年中，两性离子聚合物由于其优异的亲水性，已成为构建伤口敷料和防污涂层的一类重要的生物材料。然而，所有报道的作为伤口敷料的两性离子聚合物由于碳－碳键主链不可裂解，都是不可降解的，并且在治疗后必须定期去除，以避免伤口缺氧，从而导致潜在的二次损伤。在这项工作中，首次通过羧基甜菜碱二硫戊环（CBDS）的开环聚合制备了可生物降解的聚两性离子贴剂，CBDS通过酰胺间氢键和侧链上的两性离子偶极-偶极相互作用进行自交联。前所未有的聚CBDS（PCBDS）贴片由于分子间的物理相互作用而表现出足够的延展性，可以完全覆盖不规则伤口，同时由于二硫键和羧基甜菜碱基团的存在而表现出优异的生物降解性和防污性能。此外，PCBDS降解诱导释放的CBDS具有有效的抗氧化和抗菌活性。该PCBDS贴片用作糖尿病伤口敷料，抑制外表面细菌粘附，其降解产物能够准确杀灭细菌并清除伤口部位过量的活性氧（ROS），调节局部微环境，包括调节细胞因子的表达巨噬细胞极化，加速感染糖尿病伤口的修复，同时避免潜在的继发损伤。