In vitro investigation of the growth of hydroxyapatite and proliferation of human cell lines on the sol gel derived diopside co-substituted tricalcium phosphate bioceramics

Abstract

Sol-gel derived bioceramic samples with the composition formula x(CaO.MgO.2SiO2).(100-x)3CaO.P2O5 where x = 0, 10, 20, 30 and 40 mass% have been prepared in the laboratory. Diopside (CaO.MgO.2SiO2) co-substituted tricalcium phosphate (3CaO.P2O5) bioceramics are speculated to be successful bone repair materials for clinical applications due to improved bone bonding ability and bioresorbability properties. Authors have employed x-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy along with energy dispersive spectroscopy, hardness testing and cell culture studies during the investigations. X-ray diffraction spectra demonstrated the formation of crystalline phases of diopside, merwinite and whitlockite in the samples and Raman spectra shows the presence of phosphate species in the orthophosphate environment. In vitro hydroxyapatite forming ability in simulated body fluid has been investigated by x-ray diffraction, Raman and field emission scanning electron microscopy techniques for time durations varying between day 1 to day 12 and results demonstrated that hydroxyapatite layer has developed from day 1 in sample with composition 40 mass% tricalcium phosphate and 60 mass% diopside. Pure diopside has shown the best hardness value. Although, 10 mass% tricalcium phosphate and 90 mass% diopside composition has shown the slower rate for growth of hydroxyapatite but it has shown the best cell viability values for human cell line. Results indicate that growth rate of hydroxyapatite is composition as well as sample synthesis technique dependent.