Physical and chemical processing for a human dura mater substitute

Object: Allogenic human fascia lata used in neurosurgery, as dura mater substitute, can be associated with a risk of viral and bacterial transmission. Chemical and physical procedures, developed to inactivate virus and bacteria, have been applied to fascia lata. The aim of this study consists in the evaluation of the biological properties of this treated graft. Methods: Grafts were treated with solvent detergents, freeze-dried for conservation and gamma irradiated (25,000 Gy) for sterilization. The indirect toxicity evaluation was performed by extraction method, according to the International Standard Organization (ISO). First, the cytotoxic effect of each extracts incubated in the presence of human fibroblasts (WI38) was quantitatively assessed by measuring the cell growth, the viability (succinate dehydrogenase activity, MTT), the membrane integrity (uptake of the neutral red by viable cells, NR) as well as the release of lactate dehydrogenase in the culture medium. Second, confocal laser scanning microscopy (CLSM) was used to assess the direct contact between human primary fibroblasts and graft. CLSM was performed at days 3 and 7 after cells loading. Results: No acute cytotoxicity was observed for chemically processed allografts. Cells loaded on the graft have demonstrated a good growth and spreading. Conclusions: Human fascia lata secured against conventional and non-conventional agents is a fully biocompatible alternative to the available dural graft materials.