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目的:构建酸敏释药胶束并考查其酸敏释药特性。方法:用亚胺键连接PEG和苯棕榈酸脂肪链,用透析法制备载阿霉素胶束,对其粒径,载药量和包封率进行考察,用紫外分光光度法测定载药胶束在不同pH值条件下的释放。结果:载药胶束粒径为60~70 nm,PEG相对分子质量为2 000 Da的胶束载药量和包封率分别为(12.7±1.1)%和(49.8±2.2)%,PEG相对分子质量为5 000 Da的胶束载药量和包封率分别为(10.7±0.3)%和(39.9±2.1)%。体外释放研究表明酸敏释药胶束在pH6.5时的累积释放率比pH7.4时大,但在pH5.0条件下其累积释放较pH7.4时还要小,可能原因是胶束解聚太快致药物与材料形成复合物沉淀所致。结论:以酸敏感亚胺键连接的两亲材料载药胶束具有一定的酸敏释药特性。
OBJECTIVE: To construct acid sensitive drug-releasing micelles and investigate its acid sensitive drug-releasing properties. Methods: PEG and palmitic acid palmitate chains were connected by imine bond, and doxorubicin micelles were prepared by dialysis method. The size, drug loading and entrapment efficiency were investigated. The drug-loaded gels were determined by UV spectrophotometry Beam release under different pH conditions. Results: The drug loading and entrapment efficiency of micelles with drug-loaded micelles of 60-70 nm and PEG molecular weight of 2 000 Da were (12.7 ± 1.1)% and (49.8 ± 2.2)%, respectively The drug loading and entrapment efficiency of the micelles with a molecular mass of 5 000 Da were (10.7 ± 0.3)% and (39.9 ± 2.1)%, respectively. In vitro release studies showed that the cumulative release rate of acid sensitive drug-releasing micelles at pH 6.5 was greater than that at pH 7.4, but its cumulative release was still lower at pH 5.0 than at pH 7.4, probably due to micelles Disaggregation caused by the formation of complex precipitated drugs and materials too fast. CONCLUSION: Amphiphilic drug-loaded micelles with acid-sensitive imine linkages have certain acid sensitive and drug-releasing properties.