In vitro chemical and biological effects of Ag, Cu and Cu + Zn adjunction in 46S6 bioactive glasses

Abstract

Three bioactive glasses belonging to the system SiO2-CaO- Na2O-P2O5 elaborated by conventional melt-quenching techniques were doped with silver, copper and copper + zinc. They were characterized using the usual physical methods. Human osteoblast cells Saos-2 and human endothelial cells EAhy926 were used for viability assays and to assess the metallic ions, self toxicity. Human monocyte cells THP-1 were used to measure interleukins IL1β and IL6 release. Glass chemical structures did not vary much on introduction of metal ions. A layer of hydroxyapatite was observed on every glass after 30 days of SBF immersion. A proliferative action was seen on Saos-2 after 24 h of incubation, EAhy926 growth was not affected. For both cell lines, a moderate cytotoxicity was found after 72 h. Dose-dependent toxic effects of Ag, Cu and Zn ions were observed on Saos-2 and EAhy926 cells. Measured CD50 of silver against these two cell lines were 8 to 20 fold lower than copper and zinc’s. Except undoped control glass, all doped glasses tested showed anti-inflammatory properties by preventing IL1β and IL6 excretion by differentiated THP-1. In conclusion, strictly monitored adjunction of metal ions to bioglasses ensures good anti-inflammatory properties without altering their biocompatibility.