Fig. 4.

Cytotoxicity analysis of human dermal fibroblasts cultured on chemically crosslinked collagen films. (a) The supernatant of cells cultured on the crosslinked films over a 7 day period was analysed using the LDH metabolic activity assay. A * indicates p $<$ 0.05 with respect to the non-crosslinked condition whereas ^ indicates p $<$ 0.05 with respect to the ethanol treated conditions. Values outside brackets represent crosslinker concentration whereas values in brackets represent the ‘degree of crosslinking’ as determined by the ninhydrin free amine assay for a given condition.