||Nishikawa T, Masuno K, Okamura T, Tominaga K, Wato M, Kokubu M, Imai K, Takeda S, Taguchi Y, Ueda M, Tanaka A
||Objectives: In order to histopathologically investigate biological reactions to materials used for scaffolds, we examined the cytotoxicity to calcium particles in vitro and bioabsorption in vivo. Materials and methods: Calcium phosphate-coated calcium carbonate particles 30µm in diameter (calcium particles) were used for the materials. In vitro; Normal human dermal fibroblasts (NHDF) and human umbilical vein endothelial cells were co-cultured and seed with calcium particles. In vivo; The calcium particles were used as the experimental group, and rat bone, mouse bone and propylene glycol alone serving as the control group were implanted under the dorsal skin of rats. Following transplantation at 2, 4, 6 and 8 weeks, the skins were resected. The sections stained with HE, DAPI, anti-rat CD3, anti-immunoglobulin, and anti-rat macrophage, were observed histopathologically. Results: The co-cultured cells grew densely around the calcium particles, and the latter were assimilated by granulation tissue comprised of CD3 dominant lymphocytes, macrophages, and foreign-body giant cells. The particles were phago-cytosed by foreign-body giant cells with 10-20 nuclei. The bioabsorption of the calcium particles was similar to that of rat bone, but different from that of mouse bone.