Optimization of thickness, pore size and mechanical properties of a biomaterial designed for deep burn coverage.

A collagen and chondroitins 4-, 6-sulphate biomaterial designed for the coverage of severe burns was optimized in terms of mechanical strength by addition of 20% (wt/vol) of chitosan to the starting material. Chitosan should create ionic bonds with collagen and thus increase the tensile strength and Young's modulus of the sponge. On the other hand, sterilization by h-irradiation of the biomaterial induced a decrease in its mechanical properties that could be avoided by sterilization using beta-irradiation. The thickness, pore size and morphology of the biomaterial were optimized before freeze-drying by freezing the mixture at -60 degrees C at a weight/volume concentration of 1.25% and a volume of 270 mul/cm2. The biomaterial obtained under these conditions may further the vascularization and cellular colonization of the porous structure by the host cells of the wound bed and therefore may accelerate the regeneration of a new dermis.