Development and Characterisation of Radiopaque Bismuth Containing Bioactive Glasses
CLAVIJO G. 1, MICHÁLEK M. 1, GALUSEK D. 1,2, ÜNALAN I. 3, BOCCACCINI A. 3
1 Centre for Functional and Surface Functionalized Glass FunGlass, A. Dub?ek University of Tren?ín, Študentská 2, 911 50 Tren?ín, Slovakia, Tren?ín, Slovakia; 2 Joint Glass Centre of the IIC SAS, TnUAD, FChPT STU, Študentská 2, 911 50 Tren?ín, Slovakia, Tren?ín, Slovakia; 3 Institute of Biomaterials, Department of Material Science and Engineering, University of Erlangen-Nuremberg, 91058 Erlangen, Germany, Erlangen , Germany
The current advances and numerous scientific contributions to the engineering of new materials based on the bioactive glass 45S5 have led to bioglasses with a combination of a variety of desired features. Highly bioactive 45S5-based glasses (BG) with antibacterial properties, drug-release capabilities, or enhanced biocompatibility, among others, were developed and used in various biomedical applications. As an implantable material, the radiopacity of BG or its contrast in x-ray radiographs and the accuracy of evaluation of the integration of implanted BG into hard tissues is an attractive property to improve. A desired radiopacity and biocompatibility have been achieved by the incorporation of heavy element oxides into the bioactive glasses, such as Bi2O3.
The present contribution shows the results of the study of the biological performance of the 45S5 BG with enhanced radiopacity by the progressive additions of Bi2O3. The Bi2O3 was added in amounts of up to 15 wt. % and the BG was prepared by a conventional melt-quenching method. The glass bioactivity, biocompatibility, and antibacterial properties were evaluated by monitoring the apatite formation after immersion in simulated body fluid (SBF) for up to 21 days. The osteoblasts and bacterial viability after the direct and indirect exposition were evaluated. Complementary information regarding the glass's radiopacity, structure, chemical composition, and thermal properties were obtained by radiopacity ISO standard, XRD, XRF, and TG/DTA measurements.
The results show that glass radiopacity was enhanced up to 3.6 times compared to undoped bioactive glass, with a 10 wt.% addition of Bi2O3. A higher antibacterial effect against S.aureus as a gram-positive and E.coli as a gram-negative bacteria was detected both in direct and indirect exposition compared to undoped BG. Although the glass bioactivity was reduced after increasing the bismuth content, the rate of formation of apatite remained high. In addition, all studied compositions directly and indirectly exposed to MG-63 cells showed viability comparable with the positive control. The current results demonstrate that the addition of Bi2O3 into the BG improves the radiopacity and antibacterial properties while keeping the bioactivity and biocompatibility comparable to other bioceramics or bioactive glasses.