The use of synthetic implants for bone restoration is associated with the risk of bacterial colonization, resulting in implant failure. Bioactive glasses (BG) are among the most used materials in bone regeneration applications. However, this material does not have an effective antibacterial activity capable of maintaining an infection-free wound for long. A material that could respond to this need is tantalum (Ta), as it is biocompatible, has antibacterial properties, promotes osseointegration, and has hemostatic capacity. This work aims to improve the performance of BG-coated implants by doping BG with metal ions known for their excellent anti-microbiological activity. To achieve this goal, 45S5 Bioglass™ was doped with Ta, prepared using the melt quenching technique, and then characterized both physically and biologically. The biological analysis focuses on cell responses and microbiological assays. Cell responses were analyzed by cytotoxicity assays, using both osteoblasts and macrophages, and macrophage polarization. The microbiological assays allow minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determination. The incorporation of Ta ions does not show a significant change in the glass structure at low concentrations; however, for the highest Ta concentration, Ta-doped BG presented characteristic peaks of the Ta2O5 crystal. Furthermore, an increase of Ta in BG led to an increase in cell viability for both types of cells tested (Saos2 and THP-1). In what concerns the anti-bacterial activity, the effect of incorporating 4 mol% Ta in BG led to an effective bactericidal activity against both Gram-negative (Escherichia coli) and Gram-positive bacteria (methicillin-resistant Staphylococcus aureus). These results show that Ta-doped BG is a promising material for accelerating tissue regeneration and preventing bacterial infections.
Author Contributions
Conceptualization, A.S.P., M.P.F.G. and J.C.S.; methodology, A.S.P. and S.R.G.; validation, M.P.F.G., I.S.-N. and J.C.S.; formal analysis, A.S.P.; investigation, A.S.P. and S.R.G.; resources, M.P.F.G., I.S.-N. and J.C.S.; data curation, A.S.P.; writing—original draft preparation, A.S.P.; writing—review and editing, M.P.F.G. and J.C.S.; supervision, M.P.F.G., I.S.-N. and J.C.S. All authors have read and agreed to the published version of the manuscript.
Funding
This work was funded by FCT—Portuguese Foundation for Science and Technology (UI/BD/151287/2021), CENIMAT/i3N (UID/CTM/50025), UCIBIO (UIDP/04378/2020 and UIDB/04378/2020) and Associate Laboratory i4HB (LA/P/0140/2020).
Institutional Review Board Statement
Not applicable.
Informed Consent Statement
Not applicable.
Data Availability Statement
Data may be obtained from authors upon reasonable request.
Conflicts of Interest
The authors declare no conflict of interest.
| Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. |
© 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
, 
