Structural Investigation of the Surface of Bioglass 45S5 Enriched with Calcium Ions

Abstract

In this article the changes on the surface of the 45S5 bioglass submitted to an enrichment with calcium ions were investigated. The method employed was the immersion of bioglass in calcium molten salt bath at 450°C. Changes in composition were probed by different techniques of chemical analysis. The use of SEM‐EDS allowed estimating the thickness modified, as being about 10 μm. X‐ray photoelectron spectroscopy enabled to infer over the structural changes on the surface of 45S5 bioactive glass. The entry of calcium in the vitreous network promoted the phase separation of microdomains rich in silica and phosphate on the surface of the glass. The formation of immiscibility region was attributed a depolymerization of silica network and also, to a possible migration of phosphate species from the bulk. The results of this study indicate a great change in the surface properties of this biomaterial. In addition, the method proposed in this study proved to be very promising in the possibility of designing the surface of bioactive glasses, to modulate the desired properties, keeping the bulk unchanged.

Effect of Niobium Oxide on the Structure and Properties of Melt‐Derived Bioactive Glasses

“…The glass compositions were prepared using a traditional melt-quenching technique. 30 The chemical composition of BG45S5 (46.1 mol% SiO 2 , 26.9 mol% CaO, 24.4 mol% Na 2 O, and 2.6 mol% P 2 O 5 ) was modified by replacing 1.3 and 2.6% of P 2 O 5 with Nb 2 O 5 and 1%, 2.5%, and 5% of SiO 2 with Nb 2 O 5 , generating series (I) and (II), respectively. Toward this purpose, high purity SiO 2 , Na 2 CO 3 , CaCO 3 , and P 2 O 5 powders (>99.9%) were weighed to obtain the glass compositions depicted in Table I.…”

Evaluation of effectiveness of 45S5 bioglass doped with niobium for repairing critical‐sized bone defect in in vitro and in vivo models

“…These ions then precipitate to form an amorphous calcium phosphorous layer that then crystalizes to form a layer of hydroxyl carbonate apatite (Ca 5 [PO 4 ] 3 OH) (HCA) on its surface (Jones, 2013;Martin, Twyman, Qiu, Knowles, & Newport, 2009). Many variations of the original Bioglass 45S5 composition have been designed and investigated in the hope of improving the biological properties (Jones, 2013;Lopes et al, 2013;Lopes et al, 2017;Souza et al, 2018). Many variations of the original Bioglass 45S5 composition have been designed and investigated in the hope of improving the biological properties (Jones, 2013;Lopes et al, 2013;Lopes et al, 2017;Souza et al, 2018).…”

“…In 1971, Larry Hench developed the first bioactive material, the Bioglass 45S5 (Hench, Splinter, Allen, & Greenlee, 1971). This material is a glass composed of 46.1 mol% SiO 2 , 24.4 mol% Na 2 O, 26.9 mol% CaO and 2.6 mol% P 2 O 5 (Hench, Polak, Xynos, & Buttery, 2000;Lopes, Mazali, Landers, & Bertran, 2013). Under physiological conditions the glass slowly dissolves releasing calcium and phosphorous ions into solution.…”

In vitro and in vivo osteogenic potential of niobium‐doped 45S5 bioactive glass: A comparative study

“…Both allografts and xenografts possess potential risk of disease transmission, unpredictable resorption rate, and graft rejection. To overcome these challenges, synthetic materials have been developed, and bioactive glass–ceramics are therefore of great importance (Kushwaha et al, ; Lopes et al, ; Lopes, Bueno, Mazali, & Bertran, ; Lopes, Magalhaes, Gouveia, et al, ; Lopes, Mazali, Landers, & Bertran, ).…”

“…These effects on living tissues are determined by the chemical composition of the glass. Hence, several researchers have been designing variations of the original Bioglass 45S5 in order to improve its mechanical and biological performance (Cacciotti, Lehmann, Camaioni, & Bianco, ; De Bonis, Curcio, Fosca, et al, ; Denry, Holloway, Nakkula, et al, ; Hench & Jones, ; Jones, ; Lopes et al, ; Lopes et al, ; Lopes, Magalhães, Mazali, & Bertran, ; Obata et al, ).…”