College of Pharmacy, Chung-ang University , Seoul, Korea.
College of Medicine, Chung-ang University , Seoul, Korea.
Int J Nanomedicine. 2019 Aug 5;14:6249-6268. doi: 10.2147/IJN.S216432. eCollection 2019.
To develop an intravesical instillation system for the treatment of bladder cancer, rapamycin (Rap) was encapsulated into liposomes and then homogeneously dispersed throughout a poloxamer 407 (P407)-based hydrogel.
Rap-loaded conventional liposomes (R-CL) and folate-modified liposomes (R-FL) were prepared using a film hydration method and pre-loading technique, and characterized by particle size, drug entrapment efficiency, and drug loading. The cellular uptake behavior in folate receptor-expressing bladder cancer cells was observed by flow cytometry and confocal laser scanning microscopy using a fluorescent probe. In vitro cytotoxic effects were evaluated using MTT assay, colony forming assay, and Western blot. For in vivo intravesical instillation, Rap-loaded liposomes were dispersed in P407-gel, generating R-CL/P407 and R-FL/P407. Gel-forming capacities and drug release were evaluated. Using the MBT2/Luc orthotopic bladder cancer mouse model, in vivo antitumor efficacy was evaluated according to regions of interest (ROI) measurement.
R-CL and R-FL were successfully prepared, at approximately <160 nm, 42% entrapment efficiency, and 57 μg/mg drug loading. FL cellular uptake was enhanced over 2-fold than that of CL; folate receptor-mediated endocytosis was confirmed using a competitive assay with folic acid pretreatment. In vitro cytotoxic effects increased dose-dependently. Rap-loaded liposomes inhibited mTOR signaling and induced autophagy in urothelial carcinoma cells. With gelation time of <30 seconds and gel duration of >12 hrs, both R-CL/P407 and R-FL/P407 preparations transformed into gel immediately after instillation into the mouse bladder. Drug release from the liposomal gel was erosion controlled. In orthotopic bladder cancer mouse model, statistically significant differences in ROI values were found between R-CL/P407 and R-FL/P407 groups at day 11 (=0.0273) and day 14 (=0.0088), indicating the highest tumor growth inhibition by R-FL/P407.
Intravesical instillation of R-FL/P407 might represent a good candidate for bladder cancer treatment, owing to its enhanced retention and FR-targeting.
为了治疗膀胱癌，我们开发了一种膀胱内灌注系统，将雷帕霉素（Rap）包封在脂质体中，然后均匀分散在泊洛沙姆 407（P407）水凝胶中。
采用薄膜水化法和预载技术制备载雷帕霉素的普通脂质体（R-CL）和叶酸修饰的脂质体（R-FL），并通过粒径、药物包封率和药物载量进行表征。使用荧光探针通过流式细胞术和共聚焦激光扫描显微镜观察叶酸受体表达的膀胱癌细胞中的细胞摄取行为。采用 MTT 法、集落形成实验和 Western blot 法评价体外细胞毒性作用。对于体内膀胱内灌注，将载雷帕霉素的脂质体分散在 P407 凝胶中，生成 R-CL/P407 和 R-FL/P407。评估凝胶形成能力和药物释放。使用 MBT2/Luc 原位膀胱癌小鼠模型，根据感兴趣区域（ROI）测量评估体内抗肿瘤疗效。
成功制备了 R-CL 和 R-FL，粒径约为<160nm，包封率为 42%，药物载量为 57μg/mg。与 CL 相比，FL 的细胞摄取增加了 2 倍以上；通过用叶酸预处理进行竞争性测定，证实了叶酸受体介导的内吞作用。体外细胞毒性作用呈剂量依赖性增加。载雷帕霉素的脂质体抑制了尿路上皮癌细胞中的 mTOR 信号通路并诱导自噬。R-CL/P407 和 R-FL/P407 制剂在注入小鼠膀胱后立即转变为凝胶，凝胶形成时间<30 秒，凝胶持续时间>12 小时。脂质体凝胶中的药物释放为侵蚀控制。在原位膀胱癌小鼠模型中，在第 11 天（=0.0273）和第 14 天（=0.0088），R-CL/P407 和 R-FL/P407 组之间的 ROI 值存在统计学差异，表明 R-FL/P407 对肿瘤生长的抑制作用最强。
由于其增强的保留和 FR 靶向性，膀胱内灌注 R-FL/P407 可能成为膀胱癌治疗的一个很好的候选药物。
Zotero 插件