Bioactivity of Na2O·CaO·SiO2·P2O5·Nb2O5-based glasses: in vitro evaluation
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1
University of Campinas – UNICAMP, Institute of Chemistry, Brazil
The bioglasses emerged in the 70's and stood out initially by the ability to form a layer of carbonated hydroxyapatite (HCA) on their surface; phase chemical responsible for forming a strong bond with the hard and soft tissues. Recently, some bioactive glasses containing Nb2O5 has been generating significant interest for biomedical applications. Several studies indicate that the presence of niobium oxide in vitreous compositions improves the biocompatibility and promotes bioactivity.[1] In this study, the structure and in vitro behavior of two series of bioglasses derived from the 45S5 with varying Nb2O5 contents were investigated. Bioglasses were prepared by melt-quenching technique (Table 1).[2][3] The melts were quenched in air by pouring it into a graphite mold, which were annealed at 50 °C below of Tg for 12 h. Monoliths obtained were cut into discs 1 mm thick and 5 mm diameter and after polishing to a mirror finish were characterized by FTIR spectroscopy. In additional, the same discs were used in the glass solubility studies and cell culture tests. Glasses were placed on a 96-well plate and seeded with mouse osteoblast-like cells with a density of 10000 cells/well and were then incubated at 37 °C. Cell adhesion was evaluated at 1, 7, and 14 days. In vitro assessment was carried out by immersion of 2 grs glass particles in 200 mL of HEPES solution (50.69 mmolL-1) at pH 7.4 and 37 °C. After set times, 10 mL of the solution were removed with a syringe and filtered. The powders remaining on the filter were employed for the FTIR experiments and liquid was analyzed by ICP. In vitro assessment was performed assuming that the reactivity of glass is related with the rate at which the silica-gel layer is formed in the early stages, which is of paramount importance for the nucleation of calcium phosphate layer in the early stages of biomineralization. The comparison between ICP measurements of species in solution and surface modifications with FTIR technique showed that a rapid silica-gel layer formation, less than 30 minutes. In addition, it was observed that for the samples; BGSN1 and BGPN1.3 a similar reactivity to BG45S5, whereas for BGP2.6, BGSN2.5 and BGSN5 the formation of silica gel is significantly slower. The cell viability assay showed that all prepared bioactive glasses allow cell adhesion and proliferation and they are not toxic to cells. In addition, the BGPN2.6 showed a better performance on essays of cell viability compared with the other compositions vitreous, showing great potential for application as biomaterial.
he authors are grateful to Institute of Chemistry at the University of Campinas and SpinLab are acknowledged. This work was carried out with the support of the FAEPEX and PETROBRAS.
References:
[1] Obata A, et al., ACS Appl. Mater. Interfaces 2012, 4, 5684.
[2] FitzGerald V, et al Adv. Funct. Mater. 2007, 17, 3746.
[3] Lopes JH, et al., J. Am. Ceram. Soc. 2013, 96, 1464.
Keywords:
hierarchy,
Bioactivity,
Bone repair,
bioactive interface
Conference:
10th World Biomaterials Congress, Montréal, Canada, 17 May - 22 May, 2016.
Presentation Type:
Poster
Topic:
Biomaterials to modulate biological processes involved in host response
Citation:
Lopes
J,
Bertran
C and
Mazali
I
(2016). Bioactivity of Na2O·CaO·SiO2·P2O5·Nb2O5-based glasses: in vitro evaluation.
Front. Bioeng. Biotechnol.
Conference Abstract:
10th World Biomaterials Congress.
doi: 10.3389/conf.FBIOE.2016.01.00614
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Received:
27 Mar 2016;
Published Online:
30 Mar 2016.