A novel biodegradable amphiphilic triblock copolymer, polyphosphate, polyethylene glycol, and polylactic acid (PAEEP-PEG-PLLA), was synthesized by twice ring-opening polymerization and triphenylphosphine (TPP) was grafted onto the block copolymer to synthesize a carrier material TPP-PAEEP-PEG-PLLA, which was identified by ¹H-nuclear magnetic resonance (¹H-NMR) spectroscopy. The TPP-PAEEP-PEG-PLLA nanoparticles encapsulated with ursolic acid (UA) were prepared by the emulsion-solvent evaporation method and characterized by dynamic light scattering. The mitochondrial targeting ability of fluorescently labeled nanoparticles was evaluated by laser confocal microscopy. The average particle size and surface charge of the UA -loaded nanoparticle solution were 180.07 ± 1.67 nm and +15.57 ± 1.33 mV, respectively. The biocompatibility of nanoparticles was briefly evaluated by erythrocyte hemolysis assay. In vitro cell proliferation assay and scratch migration assay were performed to compare the difference in anti-tumor effect between UA and UA nanoparticles. The results showed that TPP-modified triblock copolymers had good mitochondrial targeting and improved the low bioavailability of UA, and UA nanoparticles exhibited more pronounced anti-tumor capabilities. In summary, the results suggested that our UA nanoparticles were a promising drug-targeted delivery system for the treatment of tumors.

中文翻译：

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基于三苯基膦的负载熊果酸的三嵌段共聚物纳米颗粒用于线粒体靶向癌症治疗

通过两次开环聚合合成了一种新型可生物降解的两亲性三嵌段共聚物聚磷酸盐、聚乙二醇和聚乳酸（PAEEP-PEG-PLLA），并将三苯基膦（TPP）接枝到该嵌段共聚物上，合成了载体材料TPP-PAEEP -PEG-PLLA，通过¹ H-核磁共振（¹ H-NMR）光谱鉴定。采用乳液-溶剂蒸发法制备了熊果酸（UA）包裹的TPP-PAEEP-PEG-PLLA纳米粒子，并通过动态光散射对其进行了表征。通过激光共聚焦显微镜评估荧光标记纳米颗粒的线粒体靶向能力。负载UA的纳米粒子溶液的平均粒径和表面电荷分别为180.07±1.67nm和+15.57±1.33mV。通过红细胞溶血试验简要评估了纳米颗粒的生物相容性。体外通过细胞增殖实验和划痕迁移实验比较UA和UA纳米颗粒抗肿瘤效果的差异。结果表明，TPP修饰的三嵌段共聚物具有良好的线粒体靶向性，改善了UA生物利用度低的问题，UA纳米粒表现出更明显的抗肿瘤能力。总之，结果表明我们的 UA 纳米颗粒是一种有前途的肿瘤治疗药物靶向递送系统。