Schötz Sebastian, Reisbeck Felix, Schmitt Ann-Cathrin, Dimde Mathias, Quaas Elisa, Achazi Katharina, Haag Rainer
Institute of Chemistry and Biochemistry, Freie Universität Berlin, Takustr. 3, 14195 Berlin, Germany.
Pharmaceutics. 2021 Aug 17;13(8):1276. doi: 10.3390/pharmaceutics13081276.
The sensitivity of therapeutic proteins is a challenge for their use in biomedical applications, as they are prone to degradation and opsonization, thus limiting their potential. This demands for the development of drug delivery systems shielding proteins and releasing them at the site of action. Here, we describe the synthesis of novel polyglycerol-based redox-responsive nanogels and report on their potential as nanocarrier systems for the delivery of cytochrome C (CC). This system is based on an encapsulation protocol of the therapeutic protein into the polymer network. NGs were formed via inverse nanoprecipitation using inverse electron-demand Diels-Alder cyclizations (iEDDA) between methyl tetrazines and norbornenes. Coprecipitation of CC led to high encapsulation efficiencies. Applying physiological reductive conditions of l-glutathione (GSH) led to degradation of the nanogel network, releasing 80% of the loaded CC within 48 h while maintaining protein functionality. Cytotoxicity measurements revealed high potency of CC-loaded NGs for various cancer cell lines with low IC values (up to 30 μg·mL), whereas free polymer was well tolerated up to a concentration of 1.50 mg·mL. Confocal laser scanning microscopy (CLSM) was used to monitor internalization of free and CC-loaded NGs and demonstrate the protein cargo's release into the cytosol.
治疗性蛋白质的敏感性对其在生物医学应用中的使用构成了挑战，因为它们容易降解和被调理作用，从而限制了它们的潜力。这就需要开发药物递送系统来保护蛋白质并在作用部位释放它们。在此，我们描述了新型聚甘油基氧化还原响应性纳米凝胶的合成，并报告了它们作为细胞色素C（CC）递送的纳米载体系统的潜力。该系统基于将治疗性蛋白质封装到聚合物网络中的方案。纳米凝胶通过甲基四嗪与降冰片烯之间的逆电子需求狄尔斯-阿尔德环化反应（iEDDA），采用逆纳米沉淀法形成。CC的共沉淀导致了高封装效率。应用l-谷胱甘肽（GSH）的生理还原条件导致纳米凝胶网络降解，在48小时内释放80%负载的CC，同时保持蛋白质功能。细胞毒性测量显示，负载CC的纳米凝胶对各种癌细胞系具有高效力，IC值较低（高达30μg·mL），而游离聚合物在浓度高达1.50mg·mL时具有良好的耐受性。共聚焦激光扫描显微镜（CLSM）用于监测游离和负载CC的纳米凝胶的内化，并证明蛋白质货物释放到细胞质中。
