Evaluation of Collagen-hydroxyapatite Scaffold for Bone Tissue Engineering

The regeneration of diseased or fractured bones is the challenge faced by current technologies in tissue engineering. Tissue engineering is a new and exciting technique which has the potential to create tissues and organs de novo. It involves the in vitro seeding and attachment of human cells onto a scaffold. These cells then proliferate, migrate and differentiate into the specific tissue while secreting the extracellular matrix components required to create the desired tissue. Hydroxyapatite and collagen composites (Col-HA) have the potential in mimicking and replacing skeletal bones. In this study, Type I collagen isolated from animal tendons and synthesized Hydroxyapatite were used in different proportions. SDS-PAGE characterization results of protein extracted and purified has showed that bovine type I collagen was successfully obtained. Scaffolds were prepared by controlled freezing and lyophylization of corresponding composite solutions and cross linked using glutaraldehyde (0.3%). The properties of collagen and its composite scaffolds, such as microstructure, chemical, physical, swelling mechanical and degradable properties were studied. Compared to a single component scaffold, the addition of hydroxyapatite to collagen decreased the mean aperture but increased the swelling ability,mechanical stability,biodegradability In enzymatic degradation test, crosslinked scaffolds showed significant enhancement of the resistance to collagenase activity in comparison with non-crosslinked scaffolds. Hydroxyapatite could significantly prolong the biodegradation of collagen-HA scaffolds. FT-IR indicated the presence of bonds between Ca2+ ions of HA and R-NH2 ions of collagen in the composite scaffolds The FTIR spectra result shows that addition of HA in the scaffolds does not alter the structure of collagen. Hence, the novel developed biocomposites have high potential to be used for rebuilding small lesions in bone tissue engineering.