Enhancing gene delivery efficiency with amphiphilic chitosan modified by myristic acid and tertiary amino groups

The aim of this study is to synthesize new amphiphilic chitosan containing myristic acid as the hydrophobic tail and tertiary amine groups as the hydrophilic head and to evaluate the gene delivery efficiency. In this context, the primary amine groups of chitosan were first modified with myristic acid (Chi-M), followed by the modification of the methylol groups with 3-dimethylamino-1-propyl chloride hydrochloride. The chemical characterization of this chitosan formulation (Chi-MA) was determined using nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FTIR) analysis and gel permeation chromatography-size exclusion chromatography. Chi-MA nanoparticles were prepared via ionic gelation, and particle size, polydispersity and zeta potential were determined. The nanoparticles were evaluated for their proton buffering capacity and gene complexing capacity. Additionally, the cytotoxicity of Chi-MA on HEK293 cells was determined via MTT assay, and the transfection efficiency of Chi-MA was analyzed by a flow cytometer. The results indicate a significant increase in gene complexing capacity (8-fold) and nanoparticle formation ability of Chi-MA compared to other chitosan formulations. Chi-MA nanoparticles showed no toxicity against HEK293 cells and exhibited the highest transfection efficiency with significantly lower nanoparticle: gene ratios compared to previous studies. These findings demonstrate the effective use of amphiphilic Chi-MA as a gene carrier.