Fabrication of porous collagen/chitosan scaffolds with controlling microstructure for dermal equivalent

Two sets of homemade apparatus have been utilized to fabricate collagen/chitosan porous membranes by quenching its acetic solution and subsequently extracting the solvent with ethanol. The influence of chitosan concentration on the surface morphology of the collagen/ chitosan membranes was studied using a quenching cold plate (apparatus 1). The pore size was enlarged along with an increase in the chitosan content, accompanied with the emergence of a sheet-like microstructure. Due to the large thermal conductivity of the membrane-forming platform (stainless steel), collagen/chitosan membranes prepared using apparatus 1 at freezing temperature between -60 to -20degreesC present similar pore size (2-4 nm) and surface morphology. However, a large difference in pore size is generated using apparatus 2 (membrane preparation in a cold ethanol bath) and using a membrane-forming platform of poor thermal conductivity (polymethylmethacrylate), e.g. similar to10 to 20 mum at freezing temperature of -60 to -40degreesC, and 265 mum at -20degreesC accompanied with the transformation from fiber- to sheet-dominated morphology. The spongy collagen/chitosan membranes with pore sizes ranging from tens to hundreds of micrometers and porosity higher than 95%, which could be used as dermal regeneration template, have thus been fabricated. Copyright (C) 2003 John Wiley Sons, Ltd.