Papers by Author: J.H. Lim

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: Osteogenic repair is highly dependant upon the substrate carrier or matrix. As a part of the effort to develop a suitable scaffold optimizing bone regeneration, we evaluated the efficiency of bovine bone ash particles, prepared by ashing at 600 °C for 8 hrs and pulverizing to 150-250 µm size particles, as a scaffold for bone tissue regeneration. The non-cytotoxic bovine bone ash particles, evaluated by Agar over lay test, showed no disturbance in cellular proliferation and osteogenic differentiation in an in vitro cell culture system. Furthermore, the implanted bone ash particles in artificial bone defects on rat mandible revealed favorable biocompatibility and regeneration of bone and dentin associated with bone ash particles. The new bone and reparative dentin were well integrated with bone ash particles. These findings suggest that allogenic bone ash particles composed mainly of hydroxyapatite are applicable for repair of tooth related bone defects as well as pulp damaged tooth repair.