Characterization of silica-based and borate-based, titanium-containing bioactive glasses for coating metallic implants

Titanium addition influences antibacterial activity of bioactive glass coatings on metallic implants

“…For the silica-based glasses, at 30 days, decreasing solubility with increasing TiO 2 content to up to 15 mol% can be observed, whereas for the borate-based glasses this trend is observed only up to 10 mol% TiO 2 . BRT3 exhibited degradation behavior comparable to that of the control BRT0, which may be attributed to TiO 2 in BRT3 partially existing as a separate phase from the glass phase [45] , which may explain the increased solubility of these particular glass samples. In terms of overall solubility, the borate-based glasses exhibited higher solubility compared to the silica-based glasses, which was expected since borate-based glasses have been shown to degrade faster than their silica-based counterparts due to their lower chemical durability [ 48 , 49 , 47 ], making them a suitable option in applications where faster dissolution of the coating is required.…”

“…In terms of incubation time, a significant increase in Zn 2+ is observed for both glass series at all incubation times, except for SRT2 between 1 and 7 days. With respect to Ti 4+ release, for the SRT series an increase in release is observed with an increase in the TiO 2 content, which may be associated with a decrease in crystallinity for this series as TiO 2 is increased (SRT3 is amorphous, while SRT1 and SRT2 exhibit crystallinity) [45] ; Ti 4+ release in the BRT glasses increased with TiO 2 content incorporated into the glass, with a decrease observed for BRT3, glass which exhibited a secondary crystal phase of TiO 2 in XRD [45] explaining the decrease in Ti 4+ release. As a function of incubation time, all glasses exhibited statistically different Ti 4+ concentrations at each time.…”

“…As an antibacterial agent, the amounts of Zn 2+ measured through AAS at day 1 are linked to the larger bacterial inhibition zones in BRT0 and BRT3 in the BRT series and SRT0 in the SRT series for Gram-positive bacteria S. epidermidis , with the BRT series significantly outranking the SRT series. The reduction in solubility due to the addition of TiO 2 translated into a reduction in release of Zn 2+ , and therefore the lack of antibacterial behavior of glasses BRT1 and BRT2, with the sudden increase in antibacterial behavior observed in BRT3 attributed to the occurrence of TiO 2 as a separate phase [45] . Additionally, the SRT glasses that exhibited antibacterial behavior also showed signs of bacterial recolonization, evidencing the weak antibacterial nature of these glasses.…”

“…Silica-based and borate-based glasses ( Table 1 ) in this study were previously synthesized, and characterized structurally and mechanically as bulk and coating material [ 45 , 46 ]. TiO 2 was added at the expense of SiO 2 for the SRT series and at the expense of B 2 O 3 for the BRT series.…”

Silica-Based and Borate-Based, Titania-Containing Bioactive Coatings Characterization: Critical Strain Energy Release Rate, Residual Stresses, Hardness, and Thermal Expansion

“…Silica-based and borate-based glasses in this study were synthesized (compositions and nomenclature are reported in Table 1) and characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR), among other techniques [55]. TiO 2 was added at the expense of SiO 2 for the SRT series and at the expense of B 2 O 3 for the BRT series.…”