Ascorbic acid prevents cellular uptake and improves biocompatibility of chitosan nanoparticles

Chitosan nanoparticles have many applications, such as gene and drug delivery, due to their biocompatibility. Chitosan nanoparticles are currently produced by dissolution in acetic acid that affects the biocompatibility at acidic pH. Here, we synthesized and characterized chitosan (CS) and ascorbate chitosan (AsCS) nanoparticles and investigated their cytotoxic effects, internalization, and distribution in the human colon carcinoma cell line using confocal laser scanning microscopy (CLSM). The CS and AsCS nanoparticles were spherical with average particle sizes of 44±8.4nm and 87±13.6nm, respectively. CS nanoparticles were taken up by the cells and showed dose-dependent cytotoxicity. By contrast, AsCS nanoparticles were not internalized and showed no cytotoxicity. Therefore, AsCS nanoparticles are more biocompatible than CS nanoparticles and may be more suitable for extracellular drug delivery. [Display omitted] •Physicochemical properties of chitosan and ascorbate chitosan nanoparticles have been investigated.•Cytotoxicity is concentration and pH dependent in case of chitosan.•Ascorbate chitosan has an excellent biocompatibility.•Ascorbate Chitosan may be used for drug delivery to extracellular spaces.