Synthesis, biodegradability and cytotoxicity of water-soluble isobutylchitosan

The objective of the present study was to improve the solubility of chitosan at neutral aqueous solution without altering its bioactivity. Through an alkylation reaction under mild conditions, isobutyl was introduced to chitosan to form isobutylchitosan, which showed a good solubility in neutral aqueous media resulting from the reduced crystallinity of the product. The structure of isobutylchitosan was characterized by IR, 1H NMR spectroscopy, and X-ray diffraction. The degradation of the product was evaluated in vivo using a mouse model, and the cytotoxicity of the product in L929 mouse fibroblasts was monitored using the MTT assay and the release of the cytosolic enzyme lactate dehydrogenase (LDH). It was found that the product exhibited the properties of improved biodegradability, increased MTT values and decreased LDH release. The results suggested that isobutylchitosan might be one of promising and safe biomaterial with potential applications.