载端粒酶反义核酸PLGA纳米粒的表征及生物学效应

Study on physiochemical characteristics of PLGA nanoparticles carrying telomerase antisensenucleic acids

目的检测载端粒酶反义核酸聚乳酸-乙醇酸共聚物(PLGA)纳米粒的表征及生物学效应,分析其粒径范围、载药量及生物相容性。方法以激光粒度分析仪测定纳米粒的粒径分布及平均粒径,紫外分光光度法测定反义核酸装载量,双室扩散法研究纳米粒的体外释药特性,核酸酶解法检测纳米粒对反义核酸的保护作用,MTT法研究纳米粒的细胞毒性。结果纳米粒的平均粒度为201nm;包封率为67.3%,载药量为3.66%。纳米粒体外释放开始阶段存在突释期,5d后释放量开始稳定,15d后仍有核酸释放。纳米粒中的核酸在37℃,经核酸酶消化1h后,仍然保持结构的完整、未被降解,而裸核酸在同样条件下30min即被完全降解。纳米粒对细胞的生长抑制与空白对照差异无显著性。结论制备的端粒酶反义核酸-PLGA纳米粒稳定性、生物相容性好,以PLGA纳米粒作为载体可保护反义核酸免受核酸酶的降解。但PLGA纳米粒的反义端粒酶核酸载药量偏低,需进一步改进制备方法,提高载药量。

[Objective] To detect superficial syndrome and biological effect of telomerase antisensenucleic acids polylactic acid-glycolic acid copolymer（PLGA） nanoparticles, and to analyze particle diameter, loaded dosage, biocompatibility of nanoparticles. [Methods] We determined particle diameter distribution and mean diameter of nanoparticles by laser particle size analysator, determined load of antisensenucleic acids through ultraviolet spectrophotometry, tested in vitro releasing character of nanoparticles with the method of double-room diffusion method, determined the protection of nanoparticles to antisensenucleic acids, analyzed cytotoxicity of nanoparticles with the method of MTT. [Result] Mean diameter of nanoparticles is 201 nm; envelopment ratio is 67.3%, loaded dosage was 3.66%. There was a outbreak release in the early stage of nanoparticles in vitro release, and the releasing amount became steady after 5 days, nucleic acids release not disappeared after 15 days. Nucleic acids of nanoparticles still kept Integrity and un-degradation through one hour nuclease digestion in 37℃. Growth inhibiting effect of nanoparticles had no significant difference with blank group. [ Conclusion] loaded telomerase antisensenucleic acids polylactic acid-glycolic acid copolymer （PLGA） nanoparticles had good stability and biocompatibility, PLGA dad the ability to protect antisensenucleic acids from degradation of nuclease. But the telomerase antisensenucleic acids loaded amount was so low. Preparative method required been improved, to increase the load.