ABSTRACT
XUEJUN XIN, A. BORZACCHIELLO *, P. A. NETTI, L. AMBROSIO and L. NICOLAIS Institute of Composite and Biomedical Materials, CNR and Interdisciplinary Research Center in Biomaterials (CRIB), University of Naples, (Federico IV, Piazzale Tecchio 80, 80125 Napoli, Italy
Received 30 October 2003; accepted 12 March 2004
Abstract-In order to enhance the mechanical performances of hyaluronic acid (HA) without compromising its biological activity, HA has been interpenetrating with a fibrillar collagen scaffold. The semi-interpenetrating materials were obtained by mixing HA with different molecular weight and a pepsin-solubilized collagen (atelocollagen) solution, and then by inducing collagen fibrillogenesis. Results indicate that molecular weight of HA significantly influences the mechanical properties of the semi-interpenetrating materials and more specifically stronger material results from the use of lowmolecular-weight (LMW) HA. According to the dynamic mechanical data the composite collagenLMW HA has a higher elastic modulus than collagen, whereas the opposite is true for the highmolecular-weight (HMW) HA. This result highlights the role of specific interactions that occur between collagen and HA during the gel formation in controlling the network mechanical stability. LMW HA may, probably, interact more strongly with collagen during the fibrillogenesis process than HMW HA due to the higher mobility of the chains and the weaker homologous interactions. Moreover, morphological observations showed that LMW HA is intimately interdispersed within the collagen network and completely coated the fibrils, which act as mechanical support.
