In vitro degradation behavior of freeze-dried carboxymethyl-chitin sponges processed by vacuum-heating and gamma irradiation

摘要

Freeze-dried carboxymethyl-chitin (CM-chitin) sponges were processed by heat-treatment in a vacuum at 120-160 degreesC to endow biological stability for use as biomaterials. The sponges were also sterilized by gamma-irradiation (25 kGy). The in vitro degradation behavior of these sponges was evaluated in phosphate-buffered saline (PBS) or 10 mug/ml of lysozyme in PBS at 37 degreesC. Stability to enzymatic hydrolysis of the sponges was increased with increasing temperature in processing, whereas gamma irradiation increased the degradation ratio of sponges. The results of X-ray diffraction (XRD) for constructs and gel permeation chromatography (GPC) for extracts of the sponges suggested that the stabilities of the CM-chitin sponges basically depended not on crystallinity but on three-dimensional crosslinkage of CM-chitin molecules. These findings indicated that the biodegradability properties of CM-chitin sponge could be controlled by post-molding treatment involving vacuum-heating and gamma irradiation. (C) 2003 Elsevier Science Ltd. All rights reserved. [References: 22]