Characterizing PEGylated chitosan nanoparticles in terms of size and zeta potential for gene delivery applications
M. Malhotra, A. Kulamarva, A. Paul, S. Prakash
McGill University, CA
Keywords: nanoparticles, gene delivery
Abstract:Gene delivery using cationic polymers like chitosan has proved to be an efficient system due to its biocompatibility and low toxicity. The cationic nanoparticles can be conveniently surface functionalized with various drugs, proteins or peptides in order to be more target specific. Chitosan nanoparticles of size less than 100 nm were prepared using ionic gelation mechanism and further functionalized with polyethylene glycol (PEG5000) in 1:1 (w/w) ratio with chitosan. It was observed that surface coating of chitosan nanoparticles with PEG enhanced hydrophilicity, stability and monodispersity of nanoparticles. The degree of substitution of PEG onto primary amines of chitosan was determined by performing TNBS assay in order to quantify the number of free amine groups present before and after surface coating chitosan nanoparticles with PEG. The particle characterization in terms of size, surface charge and morphology was performed using Brookhaven BI-90 Particle Nanosizer and Malvern Zeta sizer and Transmission Electron Microscope at a magnification of 100K using JEOL JEM 2000FX Electron Microscope. Results obtained confirm the modification of chitosan nanoparticles with PEG and appeared to highly monodispersed. The particle size significantly increased to approximately 150±20nm. Also there was a significant reduction of the zeta potential of the nanoparticles from 16mV±2mV to 0mV±3 mV. We are currently engaged in analyzing the transfection efficiency of these nanoparticles in-vitro for gene delivery applications.