In vitro biomimetic construction of hydroxyapatite-porcine acellular dermal matrix composite scaffold for MC3T3-E1 preosteoblast culture.

The application of porous hydroxyapatite-collagen (HAp-Collagen) as a bone tissue engineering scaffold is hindered by two main problems: its high cost and low initial strength. As a native 3-dimenssional collagen framework, purified porcine acellular dermal matrix (PADM) has been successfully used as a skin tissue engineering scaffold. Here we report its application as a matrix for the preparation of HAp to produce a bone tissue scaffold through a biomimetic chemical process. The HAp-PADM scaffold has two-level pore structure, with large channels (∼100 μm in diameter) inherited from the purified PADM microstructure and small pores (<100 nm in diameter) formed by self-assembled HAp on the channel surfaces. The obtained HAp-PADM scaffold (S15D) has a compressive elastic modulus as high as 600 kPa. The presence of HAp in sample S15D reduces the degradation rate of PADM in collagenase solution at 37°C. After 7 day culture of MC3T3-E1 pre-osteroblasts, MTT data show no statistically significant difference on pure PADM framework and HAp-PADM scaffold (p > 0.05). Because of its high strength and nontoxicity, its simple preparation method, and designable and tailorable properties, the HAp-PADM scaffold is expected to have great potential applications in medical treatment of bone defects.