Glass - Back to the Future!

Presenting Author:
Aldo Boccaccini

article posted 21 March 2016

Aldo R. Boccaccini is Professor of Biomaterials and Head of the Institute of Biomaterials at the University of Erlangen-Nuremberg, Germany. He is also visiting Professor at Imperial College London, UK. He holds an engineering degree from Instituto Balseiro (Argentina), Dr-Ing. from RWTH Aachen University (Germany) and Habilitation from TU Ilmenau (Germany). The research activities of Prof. Boccaccini are in the field of glasses, ceramics and composites for biomedical, functional and/or structural applications. He is the author or co-author of more than 600 scientific papers and 15 book chapters. His work has been cited more than 20,000 times and he was named in the 2014 Thomson Reuters Highly Cited Researcher list. Boccaccini has been a visiting professor at different universities around the world, including Japan, Italy, Spain, Slovenia, Netherlands, Singapore, Germany, Argentina and Poland. His achievements have been recognized with several awards including, most recently, the Materials Prize of the German Materials Society (DGM) in 2015. Boccaccini is the editor-in-chief of the journal Materials Letters and serves in the editorial board of more than 10 international journals. In 2015 he was elected member of the Council of the European Society for Biomaterials (ESB) and member of the World Academy of Ceramics. He also serves in the Review Panel of the German Science Foundation (DFG) and is an international advisor to the Ministry of Science and Technology of Argentina. He has been member of the Basic Science and Technology Division of the Society of Glass Technology for almost 10 years.

Development and characterization of niobium ion releasing silicate bioactive glasses

V. Miguez-Pacheco1, D. de Ligny2 & A. R. Boccaccini1*
1 Institute of Biomaterials, University of Erlangen-Nuremberg, 91058, Erlangen, Germany
2 Institute of Glass and Ceramics, University of Erlangen-Nuremberg, 91058, Erlangen, Germany

Metallic ions have been incorporated into different glass compositions to stimulate healthy bone formation by improving the biochemical properties of bioactive glasses (BGs) for bone tissue engineering applications [1]. In this study, Nb2O5 was substituted for P2O5 in the 45S5 formulation to obtain niobium-containing bioactive glasses (Nb-BGs) at 1.3 and 2.6 mol% Nb2O5 via the melt-derived route. The as-melted Nb-BGs were milled into fine powders.
Niobium was chosen as a dopant because it has been demonstrated to enhance the mineralization and differentiation of osteogenic cells [2]. To further investigate these effects, Nb-BG granules were prepared and then subjected to simulated body fluid (SBF) studies to ascertain their bioactivity. Briefly, the granules were made by preparing a slurry for each composition, pouring it into molds, drying, sintering, crushing and sieving them to the desired size range (0.5–0.85 mm). The formation of apatite-like crystals on the glass surface was a strong indication of their bioactivity, observed in SEM images (see Fig. 1). Structural characterization of the glasses was carried out using FTIR and XRD techniques. The biocompatibility of the novel BGs was tested by indirect culture of fibroblast-like mouse derived ST-2 cells with BG granules. This assay also allowed to detect the angiogenic potential of the Nb-BGs by measuring the secretion of vascular endothelial growth factor (VEGF) by fibroblasts over a 48h period. Release of relevant ions into SBF was measured using ICP-OES to ascertain their effects on cell viability, proliferation and metabolism.

Figure 1- Nb-BG granules prior to (L) and after 7 days (R) SBF treatment showing change of morphology ascribed to the granules’ surface reactivity and deposition of hydroxyapatite crystals
Acknowledgement: This project was funded by the European Commission under the 7th Framework Programme (Marie Curie Initial Training Networks; grant number: 289958, Bioceramics for bone repair).
[1] Hoppe, A., et al., Biomaterials 2011;32 (11):2757–2774
[2] Obata A, et al., ACS Appl Mater Interfaces. 2012;4(10):5684–90.