IN SITU MONITORING OF OSTEOSARCOMA CELLS ON SURFACE-MODULATED SILICON NITRIDE AND TITANIUM BIOMATERIALS

IntroductionDue to its remarkable stoichiometric flexibility and surface chemistry, hydroxyapatite (HAp) is the fundamental structural material in all vertebrates. Natural HAp's properties inspired an investigation into silicon nitride (Si3N4) to see if similar functionality could be engineered into this bioceramic. Biological and in situ spectroscopic analyses were used to monitor the response of osteosarcoma cells (SaOS-2) to surface-modulated Si3N4 and a titanium alloy after long-term in vitro exposure.Materials and MethodsFour groups of Si3N4 discs, O12.7×1.0mm, (Amedica Corporation, Salt Lake City, UT USA) were subjected to surface treatments: (i) “As-fired;” (ii) HF-etched (5% HF solution for 45 s); (iii) Oxidized (1070°C for 7 h); and (iv) Nitrogen-annealed (1400°C for 30 min, 1.1 bar N2 gas).1 Titanium alloy discs (Ti6Al4V, ASTM F136) were used as a control group. SaOS-2 cells cultured for 24 h at 37°C were deposited (5×105 cells/ml) and incubated on the UV sterilized discs in an osteogenic medium...