The bioactivity and ion release of titanium-containing glass polyalkenoate cements for medical applications

The ion release profiles and bioactivity of a series of Ti containing glass polyalkenoate cements (GPCs). Characterization revealed each material to be amorphous with a Tg in the region of 650-660ºC. The network connectivity decreased (1.83-1.35) with the addition of TiO2 which was also evident with analysis by X-ray Photoelectron Spectroscopy (XPS). Ion release from cements were determined using Atomic Absorption Spectroscopy (AAS) for zinc (Zn2+), calcium (Ca2+), strontium (Sr2+), Silica (Si4+) and titanium (Ti4+). Ions such as Zn2+ (0.1-2.0 mg/L), Ca2+ (2.0-8.3 mg/L,) Sr2+ (0.1-3.9 mg/L), and Si4+ (14-90 mg/L) were tested over 1-30 days. No Ti4+ release was detected. Simulated body fluid (SBF) revealed a CaP surface layer on each cement while cell culture testing of cement liquid extracts with TW-Z (5 mol% TiO2) produced the highest cell viability (161%) after 30 days. Direct contact testing of discs resulted in a decrease in cell viability of each cement tested.