Biofunctional polymers prepared in supercritical fluid

A process for the preparation of a composition comprising a solid admixture of a biofunctional polymer substrate and a biofunctional material substrate for use in or in association with the human or animal body, cultivated or uncultivated living matter, which process comprises mixing the biofunctional material substrate in solid or liquid phase into the biofunctional polymer substrate in fluid phase or solid phase and a supercritical fluid in fluid phase under supercritical conditions of reduced viscosity to plasticize and swell the biofunctional polymer substrate and under conditions of physical blending to distribute the biofunctional material substrate throughout the biofunctional polymer substrate, and releasing the fluid under supercritical conditions, in situ, by depressurizing a pressure vessel to obtain a monolithic block of the biofunctional polymer substrate, wherein a biofunctional polymer substrate consistency, which retains a foamed state on releasing supercritical fluid is selected or less viscous biofunctional polymer substrate consistency which relaxes on releasing the supercritical fluid is selected.