Hydrolysis, setting properties and in vitro characterization of wollastonite/newberyite bone cement mixtures

Bone cements based on magnesium phosphates such as newberyite (N; MgHPO4.3H2O) have been shown as potential bone substitutes due to their biocompatibility, biodegradability and ability to support osteoblast differentiation and proliferation. Newberyite can hydrolyze to hydrated magnesium phosphate compounds (e.g. bobierite (Mg3(PO4)2.8H2O)) at alkaline conditions. In this study, 25 and 50 wt% of crystalline β -wollastonite (woll; CaSiO3) was admixed to newberyite powder in order to both enhance the acid-base hydrolysis of newberyite and to produce a functional bone cement. The setting process of wollastonite/newberyite cement mixtures started with the hydrolysis of the wollastonite with further transformation of newberyite into bobierite and the formation of magnesium silicate phase. The results demonstrated that 25 wollastonite/newberyite and 50 wollastonite/newberyite cement pastes at optimal powder/liquid ratios had final setting times of ∼34 and 25 min and compressive strength values of 18 and 32 MPa ...