Multi-channelled collagen-calcium phosphate scaffolds: their physical properties and human cell response

An ideal collagen scaffold for bone tissue engineering should possess micro- and macro-porosity to promote tissue ingrowth within the scaffold. The introduction of this pore structure should not compromise the mechanical strength of the scaffold. A multi-channelled collagen-calcium phosphate scaffold was designed by complexing collagen solution with calcium phosphate and then introducing macro pores using a forging technique. Synthetic hydroxyapatite formed in the presence of collagen was confirmed using X-ray diffraction, whereas Fourier transform infrared showed the interaction between the synthetic and organic components. The porosity of the resulting scaffold increased more than 25% as determined using micro-computed tomography. There was no significant change in compression properties (p < 0.05) tested using American Society for Testing and Materials standard F451-95. The presence of macro pore channels facilitated human osteosarcoma cell infiltration into pores and maintained cellular viability and ability to differentiate. Cell surface morphology and gene expression for osteocalcin, alkaline phosphatase, and collagen type I were also preserved. In conclusion, a multi-channel collagen-calcium phosphate scaffold was designed to encourage cellular infiltration in vitro without weakening the mechanical strength of the composite.