Abstract: 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-modified lipsome was obviously lower and its structure became more stable and regular. In the force curve(FC) experiments, 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.

Key words: Liposome, Polyvinylpyrrolidone(PVP), Morphology, Force curve