Papers by Author: Hae Jung Kim

Abstract: A edible cuttlefish(Zoological name : Sepia esculenta) bone has a porous structure with all pores interconnected The purpose of this research is to develop porous hydroxyapatite prepared by hydrothermal treatment from cuttlefish bone and evaluate the biocompatibility using undecalcified materials through the in-vivo test of rabbits. In this study, the phase and substructure of a porous hydroxyapatite, prepared by hydrothermal treatment using edible cuttlefish bone as a calcium source, has been confirmed by X-ray diffractometer and scanning electronic microscope. After preparing the specimens with 5mm diameter and 7mm length, the specimens were implanted into the femoral condyles of rabbits. Each rabbits were sacrificed at each time period of 1, 2, 3, 4 weeks after operation, respectively and the stained section was examined by a transmission light microscope. The X-ray diffraction patterns of the edible cuttlefish bone was confirm for aragonite phase and of the sample after hydrothermal treatment showed mostly into hydroxyapatite phase. There was more bone density increase in porous HA rod around implant site than natural edible cuttlefish bone. Because the edible cuttlefish bone is a very pure and good calcium source, porous hydroxyapatite developed from this study is expected to be a biomaterial having a good biocompatibility to be used as a suitable bone substitute.

Abstract: A porous silicon-containing hydroxyapatite has been prepared using natural coral as a calcium source to obtain a biomaterial having an improved biocompatibility. From the XRD analysis, it was confirmed that the single-phase hydroxyapatite containing silicon has formed without revealing the presence of extra phases related to silicon dioxide or other calcium phosphate species. Silicon content is ranged from 0.5wt% to 1wt% by weight. The porous silicon-containing hydroxyapatite blocks were inserted into the 5mm diameter of drill holes made through the lateral femoral condyles of New Zealand white rabbits. The new bony formation did not begin after 1 week. At 3 week, bony ongrowth to the inserted porous silicon-containing hydroxyapatite block could be found, and the new bone surrounded the inserted block entirely after 24weeks. Based on in-vivo test, Si-containing porous hydroxyapatite derived from coral possesses high biodegradability and can be considered a useful material for bone implants.

Abstract: An appropriate scaffold, which provides structural support for transplanted cells and acts as a vehicle for the delivery of biologically active molecules, is critical for tissue engineering. We developed a fully interconnected globular porous biphasic calcium phosphate ceramic scaffold by adopting a foaming method, and evaluated its efficiency as a bone substitute and a scaffold for bone tissue engineering by in vitro and in vivo biocompatible analysis and its osteogenic healing capacity in rat tibial bone defects. They have spherical pores averaging 400um in diameter and interconnecting interpores averaging 70um in diameter with average 85% porosity. They elicited no cytotoxicity and noxious effect on cellular proliferation and osteoblastic differentiation during the cell-scaffold construct formation. Also the bone defects grafted with fully interconnected globular porous biphasic calcium phosphate ceramic blocks revealed excellent bone healing within 3 weeks. These findings suggest that the fully interconnected porous biphasic calcium phosphate scaffold formed by the foaming method can be a promising bone substitute and a scaffold for bone tissue engineering.

Abstract: Porous hydroxyapatite has been prepared using a hydrothermal hot pressing method from calcium carbonate as a starting material. SEM result shows porous hydroxyapatite block is formed of three dimensionally inter-connected pores of 100-400µm in size, similar to human cancellous bone. At the ~ 70% porosity, the compressive strength was about 4MPa, which is similar to that of the commercially available porous hydroxyapatite derived from natural coral.