共载依克立达和阿霉素的PBM-Hz-PEG纳米粒制备与性能研究

Preparation and Properties of PBM-Hz-PEG Nanoparticles Co-loaded with Elacridar and Doxorubicin

目的:研究不同比例依克立达(ELC)和阿霉素(DOX)的联合抗肿瘤效果,确定最佳联用比例。以生物可降解材料聚苹果酸苄基酯(PBM)为载体包封两种药物,得到一种酸敏感纳米胶束。方法:以L-天冬氨酸为原料通过内酯开环法制备PBM,并以酸敏感的腙键(Hz)连接PEG,得到嵌段聚合物PBM-Hz-PEG,红外光谱和核磁氢谱对其结构进行表征。动态透析法制备纳米胶束,测定纳米胶束的粒度、分散系数(PDI)、临界胶束浓度(CMC)及其载药量(DL)、包封率(EE)。动态透析法模拟胶束的体外释药性能,采用三阴性乳腺癌MDA-MB-231细胞系考察载药纳米胶束的体外细胞毒性。结果:①ELC能够增敏DOX,二者摩尔比为1:3时有最强肿瘤抑制作用。②经红外光谱和核磁共振氢谱表征,嵌段共聚物PBM-Hz-PEG成功合成。③空白纳米胶束的粒径为69.67±11.55 nm,PDI为0.245±0.026,CMC值为3.9μg·mL^(-1);载药纳米胶束粒径略大,粒径在96.92~113.47 nm之间,ELC和DOX的载药量与投料比一致。④载药纳米胶束在pH 7.4和pH 6.0时的药物释放率曲线和体外细胞毒性试验证实载药胶束具有良好的酸敏特性。结论:ELC和DOX联用有较强的肿瘤抑制作用,PBM是二者的优良载体。该PBM-Hz-PEG纳米胶束载药率高,其特有的酸敏性能够有效降低药物对正常组织的毒副作用,具有肿瘤组织富集释放特性,有望成为一种新型智能释药平台。

Objective: To study the anti-tumor effect of different proportions of elacridar(ELC) and doxorubicin(DOX), and determine the best combination ratio. Preparing a new type of acid-sensitive nanoparticles co-loaded with ELC and DOX using poly(benzyl malate)(PBM) as a carrier. Methods: PBM was prepared from L-aspartic acid by lactone ring opening method, then PEG was linked with acid sensitive hydrazone bond(Hz). The block polymer PBM-Hz-PEG was obtained and characterized by IR and 1H NMR.The nano micelles were prepared by dynamic dialysis. The particle size, polydispersity index(PDI), critical micelle concentration(CMC),drug loading capacity(DL) and entrapment efficiency(EE) of nano micelles were determined. Dynamic dialysis method was used to simulate the drug release performance in vitro for the drug loaded nano micelles. The cytotoxicity of the drug loaded nano micelles was evaluated by triple negative breast cancer MDA-MB-231 cell line in vitro. Results:(1) ELC can enhance the sensitivity of DOX. They have the strongest antitumor effect when the molar ratio of ELC and DOX is 1:3.(2)The results of IR and 1H NMR showed that the block copolymer PBM-Hz-PEG was successfully synthesized.(3) The particle size of the blank micelles was 69.67 ±11.55 nm, the PDI was 0.245±0.026, and the CMC value was 3.9 μg·mL-1. The particle size of drug loaded nano micelles was slightly larger, ranging from 96.92 nm to 113.47 nm. The drug loading of ELC and DOX was consistent with the feed ratio.(4)The drug release rate curves and cytotoxicity tests in vitro of drug loaded micelles at pH 7.4 and pH 6.0 confirmed that the drug loaded micelles had good acid sensitivity.Conclusions: The combination of ELC and DOX has strong antitumor effect, and the PBM is an excellent carrier for both. The PBM-Hz-PEG nanomicelles have high drug loading rate, and their unique acid sensitivity can effectively reduce the toxicity of drugs on normal tissues and significantly increase the release of tumor tissues, which is expected to become a new intelligent drug delivery platform.