The invention relates to a method for producing a porous material from aliquidsolution including a biocompatible polymer. Incertain embodiments of themethods, the biocompatible polymer solution is optionally gelled, then frozenin acontrolled fashion. The freezing optionally comprises steps that include:rapidly dropping the temperature to between -10°C and -50°C, soasto form a thin layer of frozen biocompatible polymer gel/solution onthe thermally conducting surface；(ii) rapidly raising the temperature of the cooling device, to atemperature below sample Tm；(iii) lowering the temperature of the cooling device so as to induce aconstant unidirectional growth rate of ice-crystals, then freeze dryingthe product.
