Preparation of rapamycin photosensitive nanodiscs and evaluation of their in vitro antitumor activity

Acta Universitatis Medicinalis Anhui     font:big middle small

Fund programs: Natural Science Foundation of Shanghai (No. 23ZR1477500)

Authors:Zhang Kuizhi1,2,3, Lu Guangzhao4, Lu Ying4, Yu Shidan5, Zhang Li1,2,3

Keywords:rapamycin; photosensitive; nanodisc; high performance liquid chromatography; ovarian cancer; antitumor;

DOI:专辑:工程科技Ⅰ辑;医药卫生科技

〔Abstract〕 Objective To prepare photosensitive nanodiscs loaded with rapamycin and evaluate their in vitro antitumor activity against ovarian cancer. Methods Nanodiscs were prepared by the thin-film hydration method, and their particle size, potential and morphology were characterized by dynamic light scattering and transmission electron microscopy. High performance liquid chromatography was established for the determination of rapamycin content, and the specificity, linearity, precision, repeatability, stability, and recovery rate of the method were verified. The singlet oxygen generation and light-controlled drug release properties of nanodiscs under near-infrared light were evaluated respectively by singlet oxygen detection probe and reverse dialysis method. The cytotoxicity of the nanodiscs against human ovarian cancer cells (OVCAR-8) was evaluated by detecting cell metabolic activity. Confocal microscopy and flow cytometry were used to investigate the cellular uptake and endocytosis mechanisms of the nanodiscs. Results The nanodiscs exhibited a hydrodynamic diameter of (63.66±0.27) nm, a zeta potential of (-18.2 ± 2.4) mV, and demonstrated good stability. The results from transmission electron microscopy revealed that the nanodiscs exhibited spherical and short rod-like morphologies. The peak area of rapamycin showed good linearity in the concentration range of 0.2~40 μg/mL (R=0.999 9), and the relative standard deviations (RSDs) of precision, repeatability and recovery were all less than 5%. Under near-infrared light irradiation, the nanodiscs could effectively produce singlet oxygen. At the same time, the singlet oxygen generated could induce lipid membrane oxidation, which significantly promoted the responsive release of rapamycin (P<0.001). Nanodiscs had no obvious cytotoxicity, but the cytotoxicity to ovarian cancer cells was significantly enhanced after near-infrared irradiation. Cellular uptake experiments confirmed that the nanodiscs mainly entered cells through clathrin-mediated, energy-dependent endocytosis (P<0.001), with drug release triggered by light exposure. Conclusion Rapamycin photosensitive nanodiscs were successfully prepared, which showed significant light-controlled release properties and enhanced anti-ovarian cancer activity in vitro.