摘要
Cationic lipids have been applied to siRNA delivery for tumor therapeutics. However, the excess positive charges of these nanoplexes may lead to high cytotoxicity and nonnegligible immunogenicity both in vitro and in vivo, which limited the applications of gene drugs. We constructed multi-component lipoplex to delivery 3＇,3＂-bis-peptide-siRNA conjugate （pp-siRNA） by the treatment of melanoma. Based on the previous studies that the gemini lipid （CLD） encapsulated pp-siRNA, a novel neutral cytosin-l-yl- lipid （DNCA） was considered to replace a certain ration of CLD by hydrogen bonds and ~t-n stacking for reducing the cytotoxicity. It similarly retained in both the loading efficiency and targeted mRNA inhibition when DNCA was accounted for 40% in the lipoplex, with lower toxicity. Moreover, CLD/DNCA/pp-siRNA nanoplex could be uptake in A375 cells and internalized mainly by macropinocytosis and caveolin-mediated endocytosis. Besides, 90% CLD/DNCA/pp-siRNA nanoplexes presented the highest efficient knockdown for the mutant B-RAF mRNA （-80%）. All the results demonstrated that the mixed cationic and neutral lipids could efficiently realize the delivery of pp-siRNA and had potential application for cancer therapy.
阳离子脂质递送siRNA已广泛应用于肿瘤的治疗,但该类纳米复合物的正电荷堆积可能导致体外和体内严重的细胞毒性和免疫原性,这限制了基因药物的应用。本研究构建了基于多组分脂质复合物,递送3′,3′′-双肽-siRNA缀合物(pp-siR NA)用于黑素瘤肿瘤治疗。在阳离子脂材(CLD)包载递送pp-siR NA的基础上,掺入了一种中性胞嘧啶脂材(DNCA)。当中性材料的比例提高至40%时,显示了与CLD包载相当的细胞摄取和靶m RNA抑制效果,同时材料毒性降低,且纳米复合物主要由巨胞饮和小窝蛋白介导的内吞作用摄取进入A375细胞。此外,90%的CLD/DNCA pp-siR NA纳米复合物表现出了对突变Braf的m RNA高敲除率(~80%)。结果表明,混合阳离子脂材CLD及中性脂材DNCA可以实现pp-siRNA的递送和靶基因有效沉默,在肿瘤治疗方面具有潜在的应用价值。
基金
The National Natural Science Foundation of China(Grant No.21778006 and 20932001)
the Ministry of Science and Technology of China(Grant No.2012AA022501)
