Biological characterization of EDC-crosslinked collagen-hyaluronic acid matrix in dermal tissue restoration

Porous collagen matrices crosslinked with various amounts of hyaluronic acid (HA) by 1-ethyl-3-(3-dimethyl aminopropyl)carbodiimide (EDC) were developed as scaffolds for dermal tissue regeneration. The effect of HA on cells in accordance with HA concentrations in the collagenous matrices was investigated using cultures of fetal human dermal fibroblasts, and the effect of EDC-crosslinked collagen-HA matrix on wound size reduction was also evaluated in vivo. Scanning electron microscopic views of the matrices demonstrated that all of the collagen-HA matrices had interconnected pores with mean diameters of 150-250 microm. An HA matrix retention test showed that the concentration of HA decreased slowly after an initial rapid decrease over 24h. Fetal human dermal fibroblasts adhered well to all of the collagen-based matrices as compared with the Porous polyurethane matrix used as a control. An 3-(4,5-dimethylthiazolyl)-2,5-diphenyltetrazolium bromide based proliferation test and the hematoxylin and eosin staining of a 2 week cultured matrix showed that the proliferation of fibroblasts was enhanced on a 9.6% HA contained collagen matrix. No significant difference was in terms of fibroblast migration into the various types of scaffolds as HA content was increased. In vivo testing showed that dermis treated with collagen or collagen-HA matrix was thicker than the control, and epithelial regeneration was accelerated, and collagen synthesis increased. However, no significant effect of HA on wound size reduction was found.