We report the synthesis of a zwitterionic carboxybetaine disulfide cross-linker (CBX-SS) and biodegradable poly(carboxybetaine) (PCB) hydrogels and nanocages (NCs) made using this cross-linker. The structure of CBX-SS combines zwitterionic carboxybetaine to confer nonfouling properties and a disulfide linkage to facilitate degradation. The physical, mechanical, and fouling characteristics of PCB hydrogels cross-linked with CBX-SS were investigated. Then, the degradation characteristics of CBX-SS-cross-linked hydrogels were evaluated through their weight loss and release of an encapsulated protein in a reducing environment. Furthermore, CBX-SS was applied to prepare degradable PCB NCs. Results show that encapsulating the highly immunogenic enzyme uricase in degradable PCB NCs eliminates or prevents an in vivo immune response to both the protein and polymer.

中文翻译：

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基于可降解二硫化物羧基甜菜碱交联剂的两性离子水凝胶

我们报道了两性离子羧基甜菜碱二硫化物交联剂（CBX-SS）以及使用该交联剂制成的可生物降解的聚（羧基甜菜碱）（PCB）水凝胶和纳米笼（NC）的合成。CBX-SS 的结构结合了两性离子羧基甜菜碱以赋予防污性能和二硫键以促进降解。研究了与 CBX-SS 交联的 PCB 水凝胶的物理、机械和污染特性。然后，通过CBX-SS交联水凝胶在还原环境中的重量损失和封装蛋白质的释放来评估其降解特性。此外，CBX-SS 用于制备可降解 PCB NC。结果表明，将高度免疫原性的尿酸酶封装在可降解的 PCB NC 中可以消除或阻止针对蛋白质和聚合物的体内免疫反应。