(475o) Preparation of Acellularized Bone Using Ultra High Pressure Technology for Tissue Engineering

One of key factors affecting the effective application of tissue engineering is the development of scaffolds. Previously, the synthetic biodegradable scaffolds have been studied mainly. As other approach, there are accllular tissues in which the cells and antigen molecules are removed to diminish the host tissue reaction. The acellular scaffold may have the same structure and composition as the natural tissue and be regulated by interaction with host cells.In this study, we performed the development of tissue engineered bone by novel processing of acellularization using ultra high pressure (UHP) technology. Porcine femur was isolated and the epiphysis and shaft of femur were divided. They were processed like cylinder and treated under 980MPa (10000 atm) at 25 degree for acellularization of donor cells. They were immediately washed with medium and PBS at 37 degree for several days and subjected to histological study (hematoxylin- eosin staining) by light and electron microscopy. The HE staining of acellularized cortical bone and bone marrow prepared by UHP treatment showed cell free completely. MC3T3-E1 cells and mouse, rat, porcine bone marrow cells were used. They were reseeded on acellularized bone. Reseeded cells were observed on the surface of them by SEM observation. In order to examine the biocompatibility of them, the acellularized porcine bone including bone marrow was implanted in rats. The animals were sacrificed at 1 week and 4 weeks after implantation. The explanted bones were examined histologically and biochemically. The decrease of inflammatory cells was observed around acellularized porcine bone. These results suggest the utility of acellularized bone for tissue regeneration.