Comparison of drying methods in the fabrication of collagen scaffold via indirect rapid prototyping

Porous collagen scaffolds with predefined 3-dimesional (3-D) networks of internal channels are fabricated via an indirect rapid prototyping technique. To obtain the scaffolds, two drying methods, namely critical point drying and freeze-drying were investigated. The latter was found to he a more suitable process as it induced less shrinkage and reproduced the design morphology accurately. The resulting scaffold contained internal hollow channels with porous foam-like structure occupying the surrounding volume. The mean diameter of the pores was 180 +/- 60 mu m and the channels diameter obtained was measured as 437 +/- 100 mu m. The channels were defined and strengthened by a layer of skin due to the process of freeze-drying. These networks of internal channels serve to enhance the mass transport rate through the scaffold and help to increase the depth of cells penetration in the scaffold. (c) 2006 Wiley Periodicals, Inc.