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Abstract

Soluble glasses are considered to be of potential clinical value in orthopaedic and dental surgery. However, the biological response to these materials is not well understood. To determine the effects of these glasses, two human osteoblast cell lines, MG63 and HOS (TE85), were incubated in vitro in the presence of increasing concentrations of extracts of the glasses. The effects of the extracts on cell growth was measured using the MTT assay and an ELISA assay was used to measure the expression of bone sialoprotein (BSP), osteonectin (ON) and fibronectin (FN), antigens which play a fundamental part in the integrity and function of hard connective tissue. The results showed that the proliferation of the cells was adversely affected only by the more soluble glasses, which also down-regulated the expression of the bone-associated proteins. In contrast, the extract of the glass with the lowest dissolution rate, which contains relatively elevated levels of Ca2+, was found to enhance bone cell growth and antigen expression. These findings suggest that the compositions of these glasses at least partly determine the response of cells and thus, that the glasses could be modified to elicit a more optimal biological response and clinical efficacy.

Titanium-containing bioactive phosphate glasses

“…The correlation experiments work on both crystalline and glassy systems so they can separate these phases and provide information on the connectivity in both. In the crystallized titanium composition examined ((P 2 O 5 ) 50 (CaO) 30 (Na 2 O) 10 (TiO 2 ) 10 ), three crystalline phases were identified by a combination of X-ray diffraction and 31 P one-dimensional and two-dimensional INADEQUATE NMR [68]. Figure 3 shows the NMR data.…”

Doping of a high calcium oxide metaphosphate glass with titanium dioxide

“…The degradation can also be reduced by an increase of the cross-linkage or the introduction of highly insoluble ions, which makes the glass structure less susceptible to solution attack [8]. Reducing the degradation in turn has led to better biocompatibility [9], for instance, an enhanced bone cell growth together with an up regulation of antigen expression has been observed [10]; in addition, a minimal inflammatory response was also induced by the extracts of low soluble glasses [11,12].…”

“…Therefore, it was assumed that TiO 2 -containing glasses that maintain the TiO 2 at 1, 3, and 5 mol% and increasing the CaO content (to 40 mol%) could further improve the cellular response by introducing further control of their degradation. Metaphosphate glasses with high calcium content have already been shown to be better for cellular proliferation than those with low calcium content [9]. Hence, the aims of this study were; (a) to prepare glasses of the general formula (CaO) 40 (Na 2 O) 10Àx (P 2 O 5 ) 50 (TiO 2 ) x , where x = 0, 1, 3 and 5, (b) analyze the thermal and structural properties of these glasses using differential scanning calorimetry (DSC), differential thermal analysis (DTA), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), nuclear magnetic resonance, and FTIR spectroscopy (c) conduct in vitro studies on glass degradation, ion release, and pH changes of the degrading medium and (d) to correlate these results to surface properties; roughness, wettability and surface free energy of the glasses.…”

An Ab Initio Molecular Dynamics Study of Bioactive Phosphate Glasses

“…[2] One commercially available bioactive glass is Bioglass, composed of 45.0 wt% SiO 2 , 24.5 wt% CaO, 24.5 wt% Na 2 O, and 6.0 wt% P 2 O 5 , [3,4] which has been remarkably successful in many clinical applications, especially in dental and orthopedic fields. However, questions relating to the long term effect of silica, [5] and the slow degradation of these glasses, taking one to 2 years to disappear from the body, [6] have prompted a search for more benign materials.…”