Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, 3584 CG, Utrecht, The Netherlands.
Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, York Street, Dublin 2, Ireland.
Drug Deliv Transl Res. 2019 Jun;9(3):679-693. doi: 10.1007/s13346-019-00637-y.
The development of an effective and safe treatment for glioblastoma (GBM) represents a significant challenge in oncology today. Downregulation of key mediators of cell signal transduction by RNA interference is considered a promising treatment strategy but requires efficient, intracellular delivery of siRNA into GBM tumor cells. Here, we describe novel polymeric siRNA nanocarriers functionalized with cRGD peptide that mediates targeted and efficient reporter gene silencing in U87R invasive human GBM cells. The polymer was synthesized via RAFT copolymerization of N-(2-hydroxypropyl)-methacrylamide (HPMA) and N-acryloxysuccinimide (NAS), followed by post-polymerization modification with cholesterol for stabilization, cationic amines for siRNA complexation, and azides for copper-free click chemistry. The novel resultant cationic polymer harboring a terminal cholesterol group, self-assembled with siRNA to yield nanosized polyplexes (~ 40 nm) with good colloidal stability at physiological ionic strength. Post-modification of the preformed polyplexes with PEG-cRGD end-functionalized with bicyclo[6.1.0]nonyne (BCN) group resulted in enhanced cell uptake and increased luciferase gene silencing in U87R cells, compared to polyplexes lacking cRGD-targeting groups.
开发有效的和安全的胶质母细胞瘤（GBM）的治疗方法是当今肿瘤学的一个重大挑战。通过 RNA 干扰下调细胞信号转导的关键介质被认为是一种很有前途的治疗策略，但需要将 siRNA 有效地递送到 GBM 肿瘤细胞内。在这里，我们描述了一种新型的聚合物 siRNA 纳米载体，其通过 cRGD 肽进行功能化，介导 U87R 侵袭性人 GBM 细胞中报告基因的靶向和有效沉默。该聚合物通过 N-（2-羟丙基）-甲基丙烯酰胺（HPMA）和 N-丙烯酰氧基琥珀酰亚胺（NAS）的 RAFT 共聚合成，随后通过聚合后修饰用胆固醇进行稳定化、用阳离子胺进行 siRNA 复合化、以及用叠氮化物进行无铜点击化学。新型的含有末端胆固醇基团的阳离子聚合物与 siRNA 自组装，在生理离子强度下产生具有良好胶体稳定性的纳米级聚集体（~40nm）。与缺乏 cRGD 靶向基团的聚集体相比，用含有双环[6.1.0]壬炔（BCN）基团的 PEG-cRGD 对预形成的聚集体进行后修饰，导致 U87R 细胞内摄取增加，并增加了荧光素酶基因的沉默。
