常用的蛋白质保护剂对NGF-PLGA微球性质的影响

目的研究常用的蛋白质保护剂对微球性质的影响特点。方法复乳化溶剂挥发法制备NGF-PLGA微球，分别添加葡萄糖，聚乙二醇，卵清蛋白作保护剂，观察微球的形态，载药量、包封率及体外释放特点，研究保护剂的作用特点。结果保护剂对微球的粒径、包封率和载药量影响不明显，粒径集中分布在10-40μm，载药量0．0007％-0．0011％，包封率7％～11％。保护剂主要影响微球的形态和体外释放。添加不同的保护剂，微球表面的光滑度和孔隙差别较大；体外释放的突释较小，存在明显的缓慢释放期，进入快速释放期的起始时间和释药速度受保护剂影响显著，一个月内的累积释放药量达到80％以上。结论保护剂的分子量可能是微球形态和释放不同的原因，添加分子量大的保护剂形成的微球的表面比添加分子量小的保护剂时致密光滑，体外的缓慢释放期长。

Effect of Protective Additives on the Characteristics of NGF-PLGA Microspheres

Aim To study the effect of some protective additives on quality of NGF-PLGA microspheres. Methods The NGF-PLGA microspheres were prepared by W/O/W emulsion-solvent evaporation technique. The effects of protective additives were studied by comparing the difference in microphere quality, including morphology, drug loading, incorporation efficiency, and in vitro release profile. Results Loading different protective additives had no noticeabe effect on the particle size, drug loading and encapsulation efficiency. The particle size of most microspheres ranged from 10 to 40μm with drug loading 0. 000 7% -0. 001 1% and incorporation efficiency 7% - 11%. The protective additives mainly affected the morphology of microspheres and in vitro release profile. The slippy and hollow extent of surface had some feature respectively. NGF-PLGA had a smaller burst release within the first day and then slowly released other days. The time and speed of fast release depended on the sort of protective additives. Within one month, the NGF-PLGA slowly released an approximate total of 80% of the labeled protein. Conclusions The molecular weight of protective additives is possibly the cause of differences in the morphology of microspheres and in vitro release profile When macromolecule was added as protective additives, the surface of microspheres is slippier and compacter, the phase of slow release is longer than that of microspheres that were added micromolecule.