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Protein adsorption and cytocompatibility of poly(L-lactic acid) surfaces modified with biomacromolecules



Surface modification of biomaterials has been adopted over the years in order to improve their biocompatibility. In this study, heparin, hyaluronic acid and chondroitin sulfate were used to modify the surface of poly(L-lactic acid) (PLLA) films by an entrapment method to promote its biocompatibility and to introduce natural recognition sites to the surface of PLLA films. The surface properties of PLLA films before and after modification were characterized by using water contact angle measurement, scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). Subsequently, the protein adsorption behavior of radiolabeled (125I) fibronectin (Fn) was evaluated on the modified PLLA surfaces, including adsorption kinetics, isotherm adsorption, competitive adsorption with bovine serum albumin (BSA) or serum. The cytocompatibility of the modified PLLA films was further investigated by testing osteoblasts-like compatibility, including cell attachment, cell proliferation, alkaline phosphatase activity and cell cycle. Experimental results indicated that the hydrophilicity of the modified PLLA films was improved by the enriched biomacromolecules. In the study of protein absorption, the entrapment of the biomacromolecules on PLLA surface could decrease and reduce Fn adsorption speed and capacity, while the three biomacromolecules had almost the same adsorption capacity. Addition of BSA or serum had great effect on the adsorption of Fn on the modified PLLA surfaces. Moreover, the modifications could significantly promote osteoblasts-like compatibility of PLLA films. The biomacromolecules modified PLLA films, combining their individual advantages such as good mechanical property and excellent cytocompatibility, are promising candidates for tissue engineering. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012