中文摘要：

制备了聚乙烯吡咯烷酮（Polyvinylpyrrolidone，PVP）修饰的脂质体，采用激光粒度仪检测了脂质体的粒径分布，采用原子力显微镜及力曲线测量技术研究了脂质体的形貌变化和纳米力学特性．实验数据表明，与未修饰的脂质体囊泡相比，经PVP修饰后脂质体囊泡之间聚集的程度明显降低，形状更为规则，在云母表面更加稳定．力曲线实验中针尖接近脂质体过程的弹性力和撤离过程中的黏附力数值变大，且针尖与样品间的静电作用引起的滞留现象消除．实验表明，PVP修饰脂质体能提高其在体内环境的稳定性，降低被免疫系统吞噬的数量，极大地提高脂质体的功效．

英文摘要：

The stability and mechanics character of liposome are very important in the chemical biology and biomedical field as a carrier of drug and gene. The liposome modified by polyvinylpyrrolidone（PVP） was prepared by sonication method, and the size ranges were examined by dynamic light scattering（DLS）. The morphology and nanometer mechanics character were studied by atomic force microscopy（AFM） and force curves respectively. The results showed that compared with normal liposome, the degree of aggregation of PVP-modifled lipsome was obviously lower and its structure became more stable and regular. In the force curve （FC） ex- periments, the elastic force in the approaching process and the adhesion force in the retracting process increased. The hysteretic case disappeared due to the interaction between tip and samples. PVP-modification could improve the stability of the nano-liposome in inner environment, reduce the number of lipsome that phagocytosed by the immune system and greatly enhance the therapy function.