In vitro biocompatibility evaluation of canasite-calcium phosphate glass-ceramics

This research introduces a new bioactive glass-ceramic material based on canasite and calcium phosphate with different molar ratios in the range from 2 to 0.5. The glass-ceramics were obtained by controlled two-stage heat treatment of the parent glass (encoded G) at different temperatures (700, 800, 900 and 1000 degrees C, encoded C700, C800, C900 and C1000, respectively). The glass and glass-ceramics were characterized by DTA, XRD, FTIR and SEM. The four point bending strength was also measured. In vitro bioacdvity of the selected samples was investigated in SBF, and the cytotoxicity test was performed by culturing the samples with normal human lung fibroblast cells (WI-38 cells) and baby hamster kidney cell line (BHK cells). The results of XRD analyses showed that crystalline phases of frankamenite/canasite-A and fluorapatite were detected, and xonotlite crystal phase was formed at high heat-treatment temperature. The bending strength was significantly affected by the heat treatment temperature. It increased with increasing crystallization temperature. SEM micrographs showed a homogeneous microstructure of interlocked needle-and rod-like crystals. Moreover, immersion of the samples in SBF demonstrated that the samples G and C900 showed a relatively better ability than other two samples. The results of the cytotoxicity test showed that cytocompatibility behavior of the samples was varied with the type of cell line. G sample showed a significant higher viability than C900 sample with the WI-38 cell line for all sample concentrations, while, this significant viability differences were not observed at low and high sample concentrations cultured with BHK cells.