Biocompatibility of Calcium Phosphate Ceramics Synthesized from Eggshell

The aim of this paper was the HA and β-TCP powers were synthesized by a new wetchemical method using eggshell and phosphoric acid. The biocompatibility of synthesized natural HA, HA/β-TCP(50:50) and β-TCP derived from eggshell was compared with those of as commercial chemical powder with mesenchymal stem cells derived from human bone marrow. Development of crystalline phases of the mixtures was studied as functions of mixing ratio and temperature using X-ray diffractometer. The morphological characteristics of the calcined eggshell and synthesized powders were examined by scaning electron microscopy. The in-vitro cytotoxicity and cell attachment of sintered disks were examined using human bone marrowderived multipotent stem cells(hBMSCs). Cell response was characterized by MTT assay , Alkaline phosphatase stain and RT-PCR analysis. Pure HA was synthesized in the mixing ratio of 1:1.1 wt% at 900℃ for 1h. the crystallization of HA was started at 800℃ in the 1:1.1 mixing ratio, ant the HA phase was continued up to the high temperatures. In the ratio of 1:1.3 and 1:1.5 wt%, β-TCP was effectively synthesized at 900℃. In the 1:1.5 ratio, β-TCP phase was detected at 700℃, and complete crystallized β-TCP was observed above 900℃. At the higher temperature than 1000℃, the β-TCP was gradually decreased and α-TCP was observed. The HA and β-TCP disk does not exert cytotoxic effect on the hBMSCs undergoing osteoblastic differentiation. In addition, the hBMSCs are adhered on the surface of synthesized natural HA and β-TCP disk as successfully as on the culture plate or as commercial chemical HA and β-TCP disk. The hBMSCs adhered on either synthesized natural HA, β-TCP or as commercial chemical HA, β-TCP disk displays undistinguishable actin arrangement and cellular phenotypes, indicating that synthesized natural HA, β-TCP does not disrupt normal cellular responses. Analysis of differentiation of the hBMSCs cultured on culture plate, synthesized natural HA, β-TCP and as commercial chemichal HA, β-TCP disk shows that three matrices are able to support osteoblastic differentiation of the hBMSCs as accessed by alkaline phosphatase staining.