Characterization and cytocompatibility of biphasic calcium phosphate/polyamide 6 scaffolds for bone regeneration

Porous scaffolds of biphasic calcium phosphate (BCP)/polyamide 6 (PA6) with weight ratios of 30/70, 45/55, and 55/45 have been fabricated through a modified thermally induced phase separation technique. The chemical structure properties, macrostructure, and mechanical strength of the scaffolds were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy, and mechanical testing. The results indicated that the BCP/PA6 scaffolds had an interconnected porous structure with a pore size mainly ranging from 100 to 900 μm and many micropores on the rough pore walls. The mechanical property of the scaffold was significantly enhanced by the addition of BCP inorganic fillers. The 55/45 BCP/PA6 composite scaffold with 76.5% ± 2.1% porosity attained a compressive strength of 1.86 ± 0.14 MPa. Moreover, the BCP/PA6 porous scaffold was cultured with rat calvarial osteoblasts to investigate the cell proliferation, viability, and differentiation function (alkaline phosphatase). The type I collagen expression was also used to characterize the differentiation of rat calvarial osteoblasts on BCP/PA6 composite scaffold by immunocytochemistry. The in vitro cytocompatibility evaluation demonstrated that the BCP/PA6 scaffold acted as a good template for the cells adhesion, spreading, growth, and differentiation. These results suggest that the BCP/PA6 porous composite could be a candidate as an excellent substitute for damaged or defect bone.