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Surface engineering of poly(D,L-lactic acid) by entrapment of chitosan-based derivatives for the promotion of chondrogenesis



Chitosan and chitosan–amino acid derivatives were explored to engineer poly(D,L-lactic acid) (PDL-LA) as an extracellular matrix-like surface to promote cell adhesion and growth. Four kinds of chitosan–amino acid derivatives were prepared to mimic the carbohydrate moieties of cell matrix glycoprotein. The chitosan–amino acid derivatives were characterized by using Fourier transform infrared and ultraviolet spectra. The amino acid content on chitosan–amino acid derivatives was determined by using a ninhydrin-ultraviolet method. A new strategy, entrapment, was therefore used to modify the PDL-LA membrane with chitosan and chitosan–amino acid derivatives. The results of X-ray photoelectron spectroscopy, attenuated total reflectance–Fourier transform infrared, and contact angle confirmed that a stable thin film of chitosan and its derivatives can be entrapped on the surface of the PDL-LA membrane. From the results of chondrocyte cytocompatibility, MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assays, and cell morphology, the chitosan–amino acid derivative modified PDL-LA membranes were shown to promote chondrogenesis. The novel surface treatment method combines the good mechanical property of PDL-LA with the good cytocompatibility of chitosan derivatives, which may have potential for tissue engineering. © 2002 Wiley Periodicals, Inc. J Biomed Mater Res 62: 532–539, 2002