Synthesis Of Multi-Functional Quaternized Chitosan Drug Loaded Nanoparticles

Novel amphiphilic octadecyl quaternized carboxymethyl chitonsan (OQCMC) was systhesized through carboxymethl chitonsan gtafting with glycidyl octadecyl dimethylammonium chloride. Structural characteristics of these products were investigated using FT-IR, 1H-NMR, XRD and Zeta potential.Three kinds of drug-loaded nanoparticles formed by the microemulsion of the amphiphiles obtained forward were prepared in the aqueous solution. Transmission electronic microscope (TEM), laser particles size analyzer, and Zeta potential analyzer were employed to investigate the properties of the nanoparticles. The results indicated that the nanoparticles formed by the amphiphiles had small size(≈20nm)and were suitable drug-carrier for hydrophilic drug -Vincristine and hydrophabic drug-indomethacin. The maximal drug loading efficiency of Vincristine nanoparticles was 22.7%, the indomethacin nanoparticles was 20.1%, and the co-delivery nanoparticles of Vincristine and indomethacin were 12.2% and 10.0% respectively. All of the nanoparticles exhibited slow steady release at 37℃in PBS solution (pH=7.4).Novel magnetic cation polymeric liposomes formed from OQCMC/cholesterol and Fe3O4 nanoparticles were prepared by thin film method or Reverse-phase evaporation method. The structure and properties of all samples were characterized by TEM,VSM and Zeta potential. The results show that the superparamagnetic cation polymeric liposomes were prepared successfully. It was stable in aqueous phase with small size (25nm) , had a high Zeta potential of 41.20mV and its saturation magnetization was 39.96 emu/g. Indomethacin encapsulation efficiency of magenetic cationic polymeric liposomes was 83% and it exhibited slow steady release at 37℃in PBS solution (pH=7.4).Novel magnetic cation polymeric liposomes, which have positive charge, can bind with the WTp53 to construct the target gene-carrier nano-delivery system. The stable complexes of vectors and plasmid at different mass ratios were investigated via agarose gel electrophoresis, and the result show that under the neutral pH and quality ratios of 1∶0.6, the WTp53 can totally combine with nanoparticles. There combination efficacy can nearly be up to 100%. The complexes could protect plasmid from digested by DNase-I. Release time of the delivery system was about 9 days. The results will establish an indispensable prophase foundation to the future cell and animal experiment.