目的 制备包载As₂O₃的聚乙二醇-聚己内酯-聚乙烯亚胺（PEG-PCL-PEI，PPP）纳米粒（As₂O₃-PPP-NPs），并进行体外评价。方法 以PPP三嵌段聚合物为载体材料，通过静电载药原理一步制备As₂O₃-PPP-NPs；电感耦合等离子体发射光谱仪（ICP-OES）测定纳米药物的载药量与包封率，透析袋法考察其体外释药特性；紫外分光光度法测定As₂O₃-PPP-NPs的溶血毒性；噻唑蓝（MTT）法考察As₂O₃-PPP-NPs对人宫颈癌细胞HeLa和人肝癌细胞HepG2的细胞毒性；采用ICP-OES以及共聚焦显微镜考察HepG2细胞对As₂O₃-PPP-NPs的摄取效率以及摄取机制。结果 所制备的As₂O₃-PPP-NPs呈类球形，分散良好，粒径约为88.7 nm，包封率和载药量分别为（92.75±3.83）%和（4.39±0.26）%。体外释放研究表明，As₂O₃-PPP-NPs具有缓释以及低pH响应释药的特征，能够实现肿瘤环境的特异性释药。溶血实验表明，As₂O₃的负载中和了PPP材料的正电性，从而降低了溶血毒性。细胞毒性试验表明As₂O₃-PPP-NPs对HeLa细胞和HepG2细胞的半数抑制浓度（IC₅₀值）分别为6.24、5.85 μmol/L，具有较理想的抑制肿瘤细胞生长的作用。细胞摄取研究表明，As₂O₃-PPP-NPs因表面荷正电，容易被细胞摄取迅速，并具备溶酶体逃逸的特性，能实现As₂O₃在细胞浆中释放从而发挥药效。结论 As₂O₃-PPP-NPs展现出显著的缓释以及低pH响应释药的特性，并具有溶酶体逃逸的特征，是一种有潜在价值的抗实体瘤纳米递药体系。

Objective To prepare and evaluate As₂O₃ loaded polyethylene glycol-polycaprolactone-polyethyleneimine (PEG-PCL-PEI, PPP) nanoparticles (As₂O₃-PPP-NPs) in vitro. Methods As₂O₃-PPP-NPs was prepared by one-step electrostatic loading method using PPP triblock polymer as carrier. The drug loading and entrapment efficiency of the nano-drug were determined by ICP-OES. In vitro drug release property was studied by the dialysis bag method. Hemolytic toxicity of As₂O₃-PPP-NPs was investigated by UV spectrophotometry. Cytotoxicity of As₂O₃-PPP-NPs on human cervical cancer (HeLa) and human hepatocellular carcinoma cells (HepG2) was evaluated by MTT assay. Finally, ICP-OES and confocal microscopy was used to investigate the uptake efficiency and uptake mechanism of As₂O₃-PPP-NPs by HepG2 cells. Results The prepared nano-formulations were spherical and well-dispersed with particle size of 88.7 nm. The encapsulation efficiency and the drug loading rate were (92.75 ±3.83)% and (4.39 ±0.26)%, respectively. In vitro release studies showed that As₂O₃-PPP-NPs had the characteristics of sustained release and low pH responsive drug release, which could achieve specific drug release in the tumor environment. The loading of As₂O₃ neutralized the positive charge of PPP, and the hemolytic toxicity of the material was reduced. MTT assay showed that the median lethal concentrations (IC₅₀ values) of As₂O₃-PPP-NPs to HeLa and HepG2 cells were 6.24 μmol/L and 5.85 μmol/L, respectively, which showed strong inhibiting effect on tumor cells. Cellular uptake studies showed that As₂O₃-PPP-NPs was rapidly taken up by cells due to positively charged surface and featured the lysosomal escaping ability, so the drug could be released in the cytoplasm and exert its anti-tumor effect. Conclusion As₂O₃-PPP-NPs exhibits significantly sustained and low pH responsive release characteristics, and has the ability to escape from lysosomes. As₂O₃-PPP-NPs is a potential drug delivery system against solid tumor.

国家自然科学基金资助项目（81673607，81603125）；浙江省药学会医院药学专项科研资助项目（2018ZYY04）