A bone replaceable artificial bone substitute: Morphological and physiochemical characterizations

A composite material consisting of carbonate apatite (CAp) and type I atelo collagen (AtCol) (88/12 in wt/wt%) was designed for use as an artificial bo ne substitute. CAp was synthesized at 58 degrees C by a solution-precipitat ion method and then heated at either 980 degrees C or 1,200 degrees C. In t his study, type I AtCol was purified from bovine tail skins. A CAp-AtCol mi xture was prepared by centirfugation and condensed into composite rods or d isks. The scanning electron-microscopic (SEM) characterization indicated th at the CAB synthesized at 58 degrees C displayed a crystallinity similar to that of natural bone and had a high porosity (mean pore size: about 3-10 m u m in diameter). SEM also revealed that the CAp heated at 980 degrees C wa s more porous than chat sintered at 1,200 degrees C, and the 1,200 degrees C-heated particles were more uniformly encapsulated by the AtCol fibers tha n the 980 degrees C-heated ones. A Fourier transformed-infrared spectroscop ic analysis showed that the bands characteristic of carbonate ions were cle arly observed in the 58 degrees C-synthesized CAp. To enhance the intramole cular crosslinking between the collagen molecules, CAp-AtCol composites wer e irradiated by ultraviolet (UV) ray (wave length 254 nm) for 4 hours or va cuum-dried at 150 degrees C for 2 hours. Compared to the non cross-linked c omposites, the UV-irradiated or dehydrothermally cross-linked composites sh owed significantly (p<0.05) low collagen degradation and swelling ratio. Pr eliminary mechanical data demonstrated that the compressive strengths of th e CAp-AtCol composites were higher than the values reported for bone.