Biomimetic modification of chitosan with covalently grafted lactose and blended heparin for improvement of in vitro cellular interaction

Lactose- and heparin-modified chitosan films were prepared and their physical and biological properties were compared with chitosan, chitosan-g-heparin, and chitosan-g-lactose films. Atomic force microscopy (AFM) measurement showed that all these films in the dry state were rather flat with a roughness smaller than 20 nm. While the chitosan-g-lactose/heparin and chitosan-g-lactose films have the highest swelling and weight loss ratios, the chitosan and chitosan-g-heparin films have the lowest. The chitosan-g-lactose/heparin film showed stronger ability to induce chondrocyte attachment, proliferation, viability, and glycosaminoglycan (GAG) secretion than that of the chitosan, chitosan-g-heparin, and chitosan-g-lactose films. Chondrocyte aggregates and nodules were observed on the chitosan-g-lactose/heparin and chitosan-g-lactose films, which still preserved viable metabolic ability. These results show that the lactose-modified and heparin-incorporated chitosan film can enhance the cell-biomaterial interaction synchronously. The resulting chitosan-g-lactose/heparin material is more bioactive that might be applicable as promising scaffold for chondrogenesis. Copyright (C) 2007 John Wiley & Sons, Ltd.