Biomaterial availability of magnesium substituted beta-tricalcium phosphate converted from sea urchin Tripneustes gratilla shell

Sea urchin Tripneustes gratilla is one of the valuable fishery products in Taiwan. The edible part of sea urchin is about 10% and the rest is regarded as waste. In this study, sea urchin shell was used here as an ingredient to synthesize magnesium substituted beta-tricalcium phosphate (β-TCMP). Shell powder of the echinoid Tripneustes gratilla was converted by hydrothermal reaction at 180°C for 24 h (referred as SU-180-24 product), and calcinated into tablet at 800°C for 4 h to form the target ingredient (SU-800-4 product). Then these products were tested for chemical composition analysis and bioassays. These products are confirmed to be rich in magnesium and constitute as β-TCMP. Results from bioassays showed that SU-180-24 and SU-800-4 products increased cell viability in human osteosarcoma cell (MG-63). Alkaline phosphatase (ALP) activity of MG-63 cell cultured with SU-800-4 tablet also showed significant increase when compared to commercial β-TCMP. It indicated that sea urchin’s β-TCMP materials including SU-180-24 and SU-800-4 products exhibited the potential for applying as the bone graft material.