Plasma surface modification effects on biodegradability and protein adsorption properties of chitosan films

This study investigates how plasma surface modification influences chitosan film biodegradability and protein adsorption properties. Plasma-modified chitosan films exhibit significantly more hydroxyl and carboxylic acid absorption bands in infrared spectra, and therefore exhibit superior hydrophilicity to that of unmodified chitosan films. The plasma-modified chitosan films exhibit rougher surface morphologies and higher swelling ratios in comparison to unmodified chitosan films. The plasma-modified chitosan films possess enhanced biodegradability in comparison to unmodified chitosan films, because more hydroxyl and carboxylic acid groups are metabolized during biodegradation. The plasma-modified chitosan films exhibit less bovine serum albumin (BSA) adsorption in bicinchoninic acid protein assays because the carboxylic acid group in bovine serum albumin is charge-charge repulsed from the abundant carboxylic acid group on the film surface. The 120 s plasma-modified chitosan film possesses optimal hydrophilicity, swelling property, biodegradability, and the lowest BSA protein adsorption, because prolonged plasma treatment time may cause films surface damage.