A multi-layer scaffold that incorporates bioglass, phosphatidylserine and steroidal saponins loaded collagen microparticles was prepared in this study. Combinatorial processing techniques involving porogen leaching protocol and freeze-drying were used. Drug distribution and microstructure could be controlled mainly by the concentrations of drug-loaded collagen microparticles and porogen as well as freezing temperature for different layers of the scaffolds. Morphological observation, measurement of swelling properties, examination of drug release kinetics, and analysis of cell bioactivity showed that the resultant scaffolds had highly interconnected pores, gradient drug distribution and graded porous micro-architecture, similar swelling ratio for different layers, better drug release kinetics in view of lower initial release and slower average release rate compared to the scaffolds with homogeneous structure, as well as approving support of cell ingrowth. This study suggests that the optimized scaffolds have promising potential for applications in bone tissue engineering.
Keywords:
multi-layer scaffold; microstructure; drug distribution
