Drug delivery systems developed from zwitterionic polymers have intriguing antifouling properties. Combining these with stimuli-responsiveness, we fabricated a new type of zwitterionic nanogel with dual redox-labile properties by copolymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and a diselenide bond-containing crosslinker through reflux precipitation polymerization. Poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC)-based nanogels show high protein adsorption resistibility and colloidal stability at high salt concentrations. By incorporation of diselenide bonds into polymer networks, the nanogels are endowed with unique dual redox-labile properties that lead to their efficient degradation into short polymers either in a reducing environment (GSH) or in an oxidative environment (H₂O₂). Nanogels loaded with anticancer drugs (doxorubicin, DOX) display a finely controlled release behavior and low leakage of DOX under physiological conditions (15.0% in 24 h), but rapid and sufficient release under reducing conditions (88.3% in 24 h) or under oxidative conditions (82.2% in 24 h). Cell viability assays reveal that the blank nanogels have no cytotoxicity within a wide concentration range, while DOX-loaded nanogels present a significant inhibitive effect against tumor cells.

中文翻译：

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具有双重氧化还原不稳定特性的二硒化物交联的两性离子纳米凝胶可控制药物释放

由两性离子聚合物开发的药物输送系统具有令人着迷的防污性能。结合这些与刺激反应性，我们通过回流沉淀聚合通过2-甲基丙烯酰氧基乙基磷酰胆碱（MPC）和含二硒键的交联剂的共聚合，制备了具有双重氧化还原不稳定特性的新型两性离子纳米凝胶。基于聚（2-甲基丙烯酰氧基乙基磷酰胆碱）（PMPC）的纳米凝胶在高盐浓度下显示出高的蛋白质吸附抗性和胶体稳定性。通过将二硒化物键结合到聚合物网络中，纳米凝胶具有独特的双重氧化还原不稳定特性，从而使其在还原环境（GSH）或氧化环境（H ₂ O ）中有效降解为短聚合物₂）。载有抗癌药（阿霉素，DOX）的纳米凝胶在生理条件下（24小时内为15.0％）显示出良好的控制释放行为和低DOX泄漏，但在还原条件下（24小时内为88.3％）或在氧化条件下迅速而充分地释放条件（24小时内为82.2％）。细胞活力测定表明空白的纳米凝胶在宽浓度范围内均无细胞毒性，而装有DOX的纳米凝胶对肿瘤细胞具有明显的抑制作用。