P10. The bioabsorption of the novel porous calcium particles in the back skin of rats

• Published in: Journal of the Japanese Association of Regenerative Dentistry Vol. 6; no. 1; p. 58
• Main Authors: Tetsunari NISHIKAWA, Kazuya MASUNO, Kazuya TOMINAGA, Tomoharu OKAMURA, Ayako KAWANAKA, Masahiro WATO, Shinichi NAKAMURA, Akio TANAKA
• Format: Journal Article
• Language: Japanese
• Published: Japanese Association of Regenerative Dentistry 2008
• ISSN: 1348-9615

Objects： The bone graft materials are desirable which are biodegradable and absorbable. We examined how the various-sized porous calcium particles are absorbed in vivo to find novel bone graft materials. Materials and methods： Three different kinds of porous calcium particles (10μm-sized Ca3(PO4)2, 30μ m-sized Ca3(PO4)2 and CaCO3, 60μm-sized CaCO3) and autogenous rat crushed femoral bone and heterogenous mouse crushed femoral bone were mixed with propylene glycol each to make injectable materials. Each material was subcutaneously transplanted into the rat back. Following transplantation, at 2, 4, 6 and 8 weeks, the tissues were resected, fixed in neutral formalin and processed into the paraffin sections for a light microscopy. As a control, only propylene glycol was injected in the rats. Results： After 2 weeks, although all porous calcium particles and autogenous and heterogenous crushed bones were discernible in the tissue, to some extent 10 μm-sized Ca3(PO4)2 and autogenous crushed bones were absorbed after 4 weeks. Lymphocytes and foreign body giant cells after 4 weeks were increased in number compared to those after 2 weeks. Aftert 6 weeks, much materials were phagocyted by foreign body giant cells, whereas lymphocytes were decreased in number except the heterogenous mouse material. At 8 weeks, the heterogenous mouse materials were phagocyted by foreign body giant cells. On the other hand, injected calcium particle and rat autogenous crushed bone were absorpted, with little infiltration of lymphocytes and foreign body giant cells. Discussions： Since porous calcium particles remained at least one month in the tissue, they might use as slow release scaffolds of anticancer agents or various growth factors.