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 © 2007 John Wiley & Sons, Ltd.