Benefits and drawbacks of zinc in glass ionomer bone cements

Abstract

Glass polyalkenoate (ionomer) cements (GPCs) based on poly(acrylic acid) and fluoro-alumino-silicate glasses are successfully used in a variety of orthopaedic and dental applications; however, they release small amounts of aluminium, which is a neurotoxin and inhibits bone mineralization in vivo. Therefore there has been significant interest in developing aluminium-free glasses containing zinc for forming GPCs because zinc can play a similar structural role in the glass, allowing for glass degradation and subsequent cement setting, and is reported to have beneficial effects on bone formation. We created zinc-containing GPCs and characterized their mechanical properties and biocompatibility. Zinc-containing cements showed adhesion to bone close to 1 MPa, which was significantly greater than that of zinc-free cements (<0.05 MPa) and other currently approved biological adhesives. However, zinc-containing cements produced significantly lower metabolic activity in mouse osteoblasts exposed to cell culture medium conditioned with the cements than controls. Results show that although low levels of zinc may be beneficial to cells, zinc concentrations of 400 µM Zn(2+) or more resulted in cell death. In summary, we demonstrate that while zinc-containing GPCs possess excellent mechanical properties, they fail basic biocompatibility tests, produce an acute cytotoxic response in vitro, which may preclude their use in vivo.

Bactericidal strontium-releasing injectable bone cements based on bioactive glasses

“…Efforts have been made to replace aluminium with iron [24] or zinc [25]; however, these also have drawbacks and particularly too high a zinc release has been shown to result in cytotoxic reactions [26]. Materials based on magnesium-containing BG can therefore provide a promising alternative.…”

Therapeutic Ion-Releasing Bioactive Glass Ionomer Cements with Improved Mechanical Strength and Radiopacity

“…Efforts have been made to replace aluminum with iron (Hurrell-Gillingham et al, 2006) or zinc (Darling and Hill, 1994); however, these also have drawbacks and particularly too high a zinc release has been shown to result in cytotoxic reactions (Brauer et al, 2011a). Materials based on magnesium-containing BG can therefore provide a promising alternative.…”

“…In previous studies, GIC based on magnesium-containing BG and PAA have been shown to be promising candidates for use as bone cements (Brauer et al, 2011a and to show antibacterial properties . However, their mechanical properties and hydrolytic stability were poor compared to GIC using aluminum-or zinc-containing glasses (Brauer et al, 2011a).…”

The effect of TiO2thin film thickness on self-cleaning glass properties

“…The use of glass remains to be a choice for buildings in the 21 st century [1]. Besides the improved knowledge on the properties of transparent materials, glass also beautifies the property and becomes an alternative to save energy [2] due to its benefits in regard with the room lighting and heating of a building.…”