Cross-linking by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) of acollagen/elastin membrane meant to be used as a dermal substitute: effectson physical, biochemical and biological features in vitro

Next to in vitro-cultured autogeneic keratinocytes for the restoration of e pidermis, a suitable dermal matrix is a mandatory component of an artificia l skin substitute for the permanent covering of full thickness skin defects . In our model a xenogeneic membrane, consisting of processed native collag en and elastin of porcine origin is meant to serve as a template for the fo rmation of a neo-dermis. In order to improve the resistance of this matrix against enzymatical degradation, we cross-linked it by using the carbodiimi de 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) together with N-hyd roxysuccinimide. Chemical cross-linking by these agents at two different de grees (shrinkage temperatures 63 degreesC and 81 degreesC) had no relevant effect on mechanical features or water-uptake capacity. The time needed for enzymatic digestion was increased by cross-linking. Concerning growth and spreading of fibroblasts and keratinocytes on and within the structure of t his membrane, we did not observe a difference between cross-linked and non- cross-linked material (shrinkage temperature 48 degreesC). We therefore exp ect that cross-linking by EDC is an effective means to control the degradat ion of the collagen/elastin membranes in vivo without a significant influen ce on their biocompatibility. (C) 2001 Kluwer Academic Publishers.