中国生物工程杂志

Abstracts Objective: To prepare chitosan nanoparticles carrying gene，study its transfection efficiency and immunological enhancement in mice. Methods: The nanoparticles was based on the foot and mouth disease DNA vaccine which designed by our laboratory,it was prepared by complex coacervation , and its morphology was observed by transmission electronic microscopy (TEM) . Particle size , polydispersity and zeta potential were determined by nanoparticle size analyser. The molecular localization of pDNA in the chitosan nanoparticles was determined by gel retardation assay. Transfection efficiency of pDNA-chitosan nanoparticles was determined by gene transfection experiment in vitro. Balb/c mice were immunized by pDNA- chitosan nanoparticles to test both humoral and cellular immune responses. Results: The morphology of the nanoparticles were mostly spherical. The average particle size was 150nm, and the polydispersity of particle size＜0.26,the zeta potential of the nanoprticles was 21 mV. The results of gel retardation showed chitosan could completely combine the pDNA by electronic combination and pDNA was mostly encapsulated within the nanoparticles.The gene transfection experiment in vitro showed that the pDNA-chitosan nanoparticles can transfect BHK celles , and the gene can express in these celles. Immunity test proved that the nanoparticles not only induced high cellular immunogenecity, but also induced a good humoral immunogenecity in mice. Conclusion: chitosan nanoparticles can deliver gene into cell and express in these celles. Immunity test proved that it has favourable immunological enhancement.