采用改良沉淀法制备了聚乳酸(PLA)纳米颗粒，采用响应面分析法建立数学模型对工艺条件进行优化. 结果表明，影响PLA颗粒制备的主要因素有PLA质量、油相中乙醇含量和油相体积，以平均粒径最小为目标，得到最优工艺条件为：聚乳酸质量76.82 mg，油相中乙醇含量40%(j)，油相体积19.49 mL. 按最优工艺条件所制PLA颗粒的粒径为109.1 nm，多分散系数PDI值为0.084，与预测值偏差较小. PLA纳米颗粒为球形实心颗粒，分散性良好且粒径均一. PLA纳米颗粒能被巨噬细胞摄取，有望作为免疫佐剂.

A modified precipitation method was used to prepare poly(lactic acid) (PLA) nanoparticles, and the response surface method applied to optimize the preparation parameters. The results showed that there were three main factors affecting the formation of nanoparticles in the preparation process, amount of PLA, volume fraction of ethanol in oil phase and total volume of oil phase. The mathematical model was established using the response surface methodology, and the optimal conditions were obtained with the aim of minimum average particle size, which were the amount of PLA at 76.82 mg, volume fraction of ethanol in oil phase 40%, and oil phase volume 19.49 mL. The size of PLA nanoparticles prepared under the optimal conditions was 109.1 nm and the PDI value 0.084, which was closer to the predicted value. The PLA nanoparticles were spherical solid particles with good dispersibility and uniform size distribution. The PLA nanoparticles could be phagocytosed by macrophage, and used in later immune experiments.