Effect of microstructure characteristics on tetracalcium phosphate–nanomonetite cement in vitro cytotoxicity

MC3T3E1 murine pre-osteoblastic cells were used to evaluate the cytotoxicity of tetracalcium phosphate (TTCP)-nanomonetite (DCPA) cement. The starting cement powder mixture was prepared by the in situ reaction between TTCP and a diluted solution of orthophosphoric acid in a planetary ball mill. The cements in the form of pressed cement powder mixture discs differ from each other by the method of pre-treatment and degree of the transformation of cement components in phosphate-buffered saline (PBS). For the evaluation of TTCP-DCPA cement to be non-cytotoxic, it was sufficient to apply the short-time soaking in PBS solution, regardless of whether the cement components were completely transformed or not. If the texture motif and hydroxyapatite particle morphology were properly developed during the initial stage of hardening, the cement cytotoxicity or osteoblast proliferation were insignificantly influenced by the soaking time or the texture stability during cell cultivation, but the lattice ordering enhanced cell proliferation. Results showed that the surface texture and the hydroxyapatite particle morphology are crucial for in vitro cement cytotoxicity evaluation.