Characterization of porous collagen/hyaluronic acid scaffold modified by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide cross-linking

In order to develop a scaffolding material for tissue regeneration, porous matrices containing collagen and hyaluronic acid were fabricated by freeze drying at -20 degreesC, -70 degreesC or -196 degreesC. The fabricated porous membranes were cross-linked using 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) in a range of 1-100mM. concentrations for enhancing mechanical stability of the composite matrix. Scanning electron microscope (SEM) views of the matrices demonstrated that the matrices obtained before crosslinking process had interconnected pores with mean diameters of 40, 90 or 230 mum and porosity of 58-66% according to the freezing temperature, and also the porous structures after cross-linking process were retained. The swelling test and IR spectroscopic measurement of different cross-linked membranes were carried out as a measure of the extent of cross-linking. The swelling behavior of cross-linked membranes showed no significant differences as cross-linking degree increased. FT-IR spectra showed the increase of the intensity of the absorbencies at amide bonds (1655, 1546, 1458 cm(-1)) compared to that of CH bond (2930cm(-1)). In enzymatic degradation test, EDC treated membranes showed significant enhancement of the resistance to collagenase activity in comparison with 0.625% glutaraldehyde treated membranes. In cytotoxicity test using L929 fibroblastic cells, the EDC-cross-linked membranes demonstrated no significant toxicity. (C) 2001 Elsevier Science Ltd. All rights reserved.