Sol–gel derived bioactive glasses with low tendency to crystallize: Synthesis, post-sintering bioactivity and possible application for the production of porous scaffolds

Abstract

A new sol-gel (SG) method is proposed to produce special bioactive glasses (BG_Ca family) characterized by a low tendency to devitrify. These formulations, derived from 45S5 Bioglass®, are characterized by a high content of CaO (45.6 mol%) and by a partial or complete substitution of sodium oxide with potassium oxide (total amount of alkaline oxides: 4.6 mol%), which increases the crystallization temperature up to 900°C. In this way, it is possible to produce them by SG preserving their amorphous nature, in spite of the calcination at 850°C. The sintering behavior of the obtained SG powders is thoroughly investigated and the properties of the sintered bodies are compared to those of the melt-derived (M) counterparts. Furthermore, the SG glass powders are successfully used to produce scaffolds by means of a modified replication technique based on the combined use of polyurethane sponges and polyethylene particles. Finally, in the view of a potential application for bone tissue engineering, the cytotoxicity of the produced materials is evaluated in vitro.

Bioglass and bioceramic composites processed by Spark Plasma Sintering (SPS): biological evaluation Versus SBF test

“…Here, for the first time, the biocompatibility of a set of pure HA, pure BGCaMIX and HA/BGCaMIX composites produced by SPS was evaluated with respect to murine long bone osteocytes by means of both direct (NR uptake) and indirect test (XTT and BrdU). It should be noted that, although previous works [24,37] confirmed the biocompatibility of both BGCaMIX and HA/BGCaMIX composites produced by conventional sintering, analogous investigations regarding bioglasses and bioglass-based composites sintered by SPS are lacking in the literature.…”

“…4. Finally, the biocompatibility of BGCaMIX and of HA/BGCaMIX composites with different HA to glass ratio, produced by conventional sintering, has been successfully tested with respect to murine osteocytes and/or fibroblasts [24,37].…”

Biomaterials Obtained by Gelation

“…For this purpose, samples of the material can be immersed in a simulated body fluid (SBF), which is a saturated solution in equilibrium with apatite at 37 C and with pH and chemical composition similar to the human blood plasma (Kokubo et al 1990;Kokubo and Takadama 2006;Bohner and Lemaitre 2009;Bui et al 2013;Bellucci et al 2014). Several different SBF solutions were proposed in the past, each depending on the human plasma characteristics taken in consideration (e.g., the Fig.…”

Effect of the Chemical Composition of Simulated Body Fluids on Aerogel-Based Bioactive Composites

“…The most widely used ones are bioactive glasses [11][12][13][14][15], calcium phosphate-based cement and ceramics, biodegradable polymer-based composites, and special alloys (Ti, Zr) etc. [16][17][18][19][20][21].…”