Macroporous hydrogels for biomedical applications: methodology and morphology.

Macroporous hydrogel membranes have been fabricated using two complementary techniques, both involving the polymerization of a solution of monomers around a crystalline matrix which is subsequently removed. The first of these is the freeze-thaw technique, in which aqueous systems are used to form ice-based crystalline matrices. Whereas in the second, the porosigen technique, a crystalline compound (e.g. sucrose) is dispersed in the monomer solution prior to polymerization. Both copolymer composition and the polymerization conditions were found to influence membrane morphology and the limitations in the range of morphologies attainable using each technique are discussed. Careful choice of technique and polymerization conditions enables macroporous hydrogels with a wide range of morphologies to be fabricated, which are potentially valuable in a variety of biomedical applications. The suitability of these techniques described for the production of materials for use in affinity chromatography, as cell separation substrates and as synthetic articular cartilage as well as more general areas of biomedicine, is discussed.