目的 为了改善紫杉醇（paclitaxel，PTX）的抗乳腺癌疗效，以枸杞多糖（Lycium barbarum polysaccharides，LBP）为载体构建紫杉醇纳米粒（PTX/LBP nanoparticles，PTX/LBP NPs）。方法 采用反溶剂沉淀法构建PTX/LBP NPs并与常规载体mPEG_2K-PDLLA_2K构建的纳米粒PTX/mPEG_2K-PDLLA_2K NPs进行比较，动态光散射法测定其平均粒径、多分散指数（polydispersity index，PDI）及ζ电位，HPLC法测定其载药量和包封率，透射电子显微镜（transmission electron microscope，TEM）观察其外观形态，同时考察纳米粒在不同生理介质中的粒径变化及在室温下放置稳定性以及纳米粒的体外释放情况；采用MTT法考察纳米粒对4T1细胞的体外毒性，4T1荷瘤小鼠模型考察纳米粒的体内抗肿瘤作用。结果 PTX/LBP NPs的粒径为（217.8±3.2）nm，PDI为0.192±0.039，ζ电位为（−14.6±0.1）mV；载药量和包封率分别为13.44%和93.53%；PTX/mPEG_2K-PDLLA_2K NPs的粒径为（221.5±2.4）nm，PDI为0.219±0.012，ζ电位为（−3.6±0.1）mV，载药量和包封率分别为13.02%和93.61%；2种纳米粒均呈圆球形且在生理盐水、5%葡萄糖、PBS和血浆中粒径均无明显变化，室温下放置7 d仍稳定；体外释放结果表明，以LBP为载体制备的紫杉醇纳米粒表现出良好的缓释效果；体外细胞毒性实验表明，PTX/LBP NPs对4T1细胞的生长抑制作用比同质量浓度PTX/mPEG_2K-PDLLA_2K NPs的更强[半数抑制浓度（half maximal inhibitory concentration，IC₅₀）：0.21 vs 0.30 μg/mL]；体内抗肿瘤实验表明，PTX/LBP NPs对荷瘤小鼠的抗肿瘤效果明显优于PTX/ mPEG_2K-PDLLA_2K NPs（抑瘤率：70.16% vs 49.93%，P＜0.05），且小鼠体质量、脏器指数无明显下降。结论 以LBP为载体构建紫杉醇纳米给药系统，与常规载体相比，不仅可以显著增强紫杉醇的抗肿瘤疗效，还能降低紫杉醇治疗过程中的毒性，为多糖纳米载体的应用提供基础。

Objective To improve the anti-breast cancer effect of paclitaxel (PTX), Lycium barbarum polysaccharide (LBP) was used as a carrier to construct PTX/LBP nanoparticles (PTX/LBP NPs). Methods Antisolvent precipitation method was used to construct the PTX/LBP NPs and compared with conventional carrier mPEG_2K-PDLLA_2K build nanoparticles PTX/mPEG_2K-PDLLA_2K NPs, dynamic light scattering method to determine the average particle size and dispersion index (PDI) and ζ potential, The drug loading and encapsulation efficiency of the nanoparticles were determined by HPLC, and the morphology of the nanoparticles was observed by transmission electron microscopy. The particle size changes in different physiological media, the stability of the nanoparticles at room temperature, and the release of the nanoparticles in vitro were investigated. MTT assay was used to evaluate the toxicity of the nanoparticles on 4T1 cells in vitro, and the anti-tumor effect of the nanoparticles in vivo was evaluated in 4T1 tumor-bearing mice model. Results The size of PTX/LBP NPs was (217.8 ± 3.2) nm, PDI was 0.192 ± 0.039, ζ potential was (−14.6 ± 0.1) mV, drug loading and encapsulation rate were 13.44% and 93.53%. The particle size of PTX/mPEG_2K-PDLLA_2K NPs was (221.5 ± 2.4) nm, PDI was 0.219 ± 0.012, ζ potential was (−3.6 ± 0.1) mV, drug loading and encapsulation rate were 13.02% and 93.61%, respectively. Both nanoparticles were spherical in shape and showed no significant changes in size in saline, 5% glucose, PBS and plasma, and remained stable for 7 d at room temperature. The in vitro release results showed that the paclitaxel nanoparticles prepared with LBP showed a good sustained release effect. In vitro cytotoxicity experiments showed that PTX/LBP NPs had a stronger inhibitory effect on the growth of 4T1 cells than PTX/mPEG_2K-PDLLA_2K NPs at the same concentration (half maximal inhibitory concentration, IC₅₀: 0.21 vs 0.30 μg/mL). In vivo anti-tumor experiments showed that the anti-tumor effect of PTX/LBP NPs on breast cancer was significantly better than that of PTX/mPEG_2K-PDLLA_2K NPs (tumor inhibition rate: 70.16% vs 49.93%, P < 0.05), in addition, the body weight and viscera index of mice did not decrease significantly. Conclusion The construction of a paclitaxel nanodrug delivery system used LBP as carrier for the treatment of breast cancer, which not only significantly enhanced the anti-tumor efficacy of paclitaxel, but also reduced the systemic toxicity during the treatment of paclitaxel, providing a theoretical basis for the application of polysaccharide nanocarriers.

R283.6

中国医学科学院医学与健康创新工程（2021-I2M-1-071）