Abstract
We have been trying to optimize the microstructures of the HAp/collagen composite fibers, in order to enable the creation of the artificial bone mimicking the bone microstructures. Previously, we evaluated the effects of the cross-linking and HAp deposition condition on the tensile strength of the HAp/collagen composite fibers. In this study, we tried to optimize the amount of the cross-linking agent, the adhesive protein and deposited HAps. The collagen fibers were prepared by the bio-inspired method, where the fibrosis and the cross-linking are generated at the same time. The HAp particles were deposited on the collagen fibers by the biomimetic deposition method, where the collagen fibers are dipped into the pseudo body fluid alternatively. The HAp/collagen composite fibers were coated with osteonectin as the adhesive protein before the HAp deposition process. As a result, the tensile strength of the HAp/collagen composite fibers increased and then decreased with the increase of the cross-linking agent concentration, the adhesive protein concentration and the HAp deposition time. In addition, the tensile strength of the HAp/collagen composite fibers with the osteonectin coating was maximized under the moderately low EDC concentration, the intermediate adhesive protein concentration and the moderately short HAp deposition time. It is considered that the osteonecitn used as the adhesive protein would act as the additional bonding factor between the collagen fibers and HAp crystals, and would decrease the tensile strength of the HAp/collagen composite fibers in the case of the excessive interfacial bonding.
