A porous polymeric matrix containing at least one natural polymer and at least one synthetic polymer and optionally at least one cation. Furthermore, a method of making a porous polymeric matrix involving mixing at least one natural polymer and inorganic salts with a solution comprising at least one solvent and at least one synthetic polymer to form a slurry, casting the slurry in a mold and removing the solvent to form solid matrices, immersing the solid matrices in deionized water to allow natural polymer cross-linking and pore creation to occur simultaneously, and drying the matrices to create a porous polymeric matrix; wherein the matrix contains a cation. Also, a method of making a porous polymeric matrix, involving mixing at least one natural polymer in an aqueous solvent and mixing at least one synthetic polymer in an organic solvent, combining the mixtures and casting in a mold, and separately removing said aqueous solvent and said organic solvent to form a porous polymeric matrix; wherein the porous polymeric matrix does not contain a cation.