Strontium Substituted β-Tricalcium Phosphate Ceramics: Physiochemical Properties and Cytocompatibility

Sr2+-substituted beta-tricalcium phosphate (beta-TCP) powders were synthesized using the mechano-chemical activation method with subsequent pressing and sintering to obtain ceramics. The concentration of Sr2+ in the samples was 0 (non-substituted TCP, as a reference), 3.33 (0.1SrTCP), and 16.67 (0.5SrTCP) mol.% with the expected Ca-3(PO4)(2), Ca2.9Sr0.1(PO4)(2), and Ca2.5Sr0.5(PO4)(2) formulas, respectively. The chemical compositions were confirmed by the energy-dispersive X-ray spectrometry (EDX) and the inductively coupled plasma optical emission spectroscopy (ICP-OES) methods. The study of the phase composition of the synthesized powders and ceramics by the powder X-ray diffraction (PXRD) method revealed that beta-TCP is the main phase in all compounds except 0.1SrTCP, in which the apatite (Ap)-type phase was predominant. TCP and 0.5SrTCP ceramics were soaked in the standard saline solution for 21 days, and the phase analysis revealed the partial dissolution of the initial beta-TCP phase with the formation of the Ap-type phase and changes in the microstructure of the ceramics. The Sr2+ ion release from the ceramic was measured by the ICP-OES. The human osteosarcoma MG-63 cell line was used for viability, adhesion, spreading, and cytocompatibility studies. The results show that the introduction of Sr2+ ions into the beta-TCP improved cell adhesion, proliferation, and cytocompatibility of the prepared samples. The obtained results provide a base for the application of the Sr2+-substituted ceramics in model experiments in vivo.

Automated summary

In this study, Sr2+-substituted beta-tricalcium phosphate ceramics were synthesized and their physicochemical properties and biocompatibility were investigated. The results showed that the introduction of Sr2+ ions significantly improved cell adhesion, proliferation, and cytocompatibility of the samples.