载有蜂毒素的磷酸钙纳米粒的制备、表征和体外抑瘤活性研究

Study on the Preparation,Characterization and In Vitro Anti-tumor Activity of Melittin Loaded Calcium Phosphate Nanoparticles

目的:采用吸附法制备载有蜂毒素的磷酸钙纳米粒(MLT-CAP-NP),优化制备工艺,并对其进行表征和体外抗癌活性考察。方法:以包封率、载药量和粒径为指标,对MLT-CAP-NP制备过程中温度、pH值、药载比、载体浓度、钙离子的加入和吸附时间等进行单因素考察,并在此基础上,采用正交实验优化制备工艺。采用透析法对MLT-CAP-NP进行体外释放实验,并采用MTT法考察MLT-CAP-NP对HepG2细胞的抑制作用。结果:MLT-CAP-NP的最佳制备工艺包括:常温下,系统pH为8左右,CAP载体浓度为6 mmol.L-1,药载比为4%,吸附时间不少于0.5 h。在高离子强度和低pH值的释放介质中,MLT-CAP-NP释放度更大。MLT-CAP-NP的抑瘤活性分别为MLT水溶液和脂质体的1.77和1.45倍。结论:采用吸附法制备MLT-CAP-NP,切实可行。MLT-CAP-NP的释放机制可能是离子交换,其释放行为具有酸敏性特点,其缓释作用提高了其抑瘤活性。

Objective：To prepare melittin loaded calcium phosphate nanoparticles（MLT-CAP-NP） by the adsorption method,to optimize their preparation process and to evaluate their characterization as well as in vitro anti-tumor activity.Methods：Based on the main indexes,entrapment efficiency,drug loading and particle size,the influnces of temperature,pH value,drug-carrier ratio,carrier concentration,addition of Ca2＋ and adsorption duration in the preparation process were investigated by mono-factor tests and then the preparation process was optimized by orthogonal test.The in vitro release test for MLT-CAP-NP was conducted by dialysis method.The anti-tumor effect of MLT-CAP-NP on HepG2 cells was measured by MTT test.Results：The optimal preparation conditions were as follows：room temperature,pH 8,the carrier concentration of 6 mmol ·L-1,the drug-carrier ratio of 4% and the adsorption duration of more than 0.5 h.The release rate of MLT-CAP-NP was greater in the medium with higher ion strength and lower pH value.The anti-tumor activity of MLT-CAP-NP was as much as 1.77 and 1.45 fold over MLT-S and MLT-LIPO respectively.Conclusion：The preparation of MLT-CAP-NP by the adsorption method is practicable.The release mechanism of MLT-CAP-NP might be ion exchange.Their release behavior is characterized by acid-sensitivity.The sustained-release effect improves their anti-tumor activity.