Development of biodegradable porous scaffolds for tissue engineering

Three-dimensional biodegradable porous scaffolds play an important role in tissue engineering. A new method of preparing porous scaffolds composed of synthetic biodegradable polymers was developed by combining porogen leaching and freeze-drying techniques using preprepared ice particulates as the porogen material. The pore structures of the polymer sponges could be manipulated by controlling processing variables such as the sized and weight fraction of the ice particulates and the polymer concentration. The synthetic polymer sponges were further hybridized with collagen microsponges to prepare biodegradable hybrid porous sponges of synthetic polymer and collagen. The collagen microsponges were formed in the pores of synthetic polymer sponges. The hybrid sponges exhibited the advantages of both the synthetic polymers and collagen. Hybrid sponges of synthetic polymer, collagen, and inorganic hydroxyapatite were developed by depositing hydroxyapatite particulates on the surfaces of the collagen microsponges in the synthetic polymer-collagen sponges. The use of synthetic polymer sponge as a mechanical skeleton facilitated the formation of these hybrid sponges into desired shapes, contributed good mechanical strength and handling, while the collagen and hydroxyapatite facilitated cell seeding and promoted cell interaction. (C) 2001 Elsevier Science B.V. All rights reserved.