Effect of solution condition on hydroxyapatite formation in evaluating bioactivity of B2O3 containing 45S5 bioactive glasses

Abstract

The effects of testing solutions and conditions on hydroxyapatite (HAp) formation as a means of in vitro bioactivity evaluation of B 2 O 3 containing 45S5 bioactive glasses were systematically investigated. Four glass samples prepared by the traditional melt and quench process, where SiO 2 in 45S5 was gradually replaced by B 2 O 3 (up to 30%), were studied. Two solutions: the simulated body fluid (SBF) and K 2 HPO 4 solutions were used as the medium for evaluating in vitro bioactivity through the formation of HAp on glass surface as a function of time. It was found that addition of boron oxide delayed the HAp formation in both SBF and K 2 HPO 4 solutions, while the reaction between glass and the K 2 HPO 4 solution is much faster as compared to SBF. In addition to the composition and medium effects, we also studied whether the solution treatments (e.g., adjusting to maintain a pH of 7.4, refreshing solution at certain time interval, and no disturbance during immersion) affect HAp formation. Fourier transform infrared spectrometer (FTIR) equipped with an attenuated total reflection (ATR) sampling technique and scanning electron microscopy (SEM) were conducted to identify HAp formation on glass powder surfaces and to observe HAp morphologies, respectively. The results show that refreshing solution every 24 h produced the fastest HAp formation for low boron-containing samples when SBF was used as testing solution, while no significant differences were observed when K 2 HPO 4 solution was used. This study thus suggests the testing solutions and conditions play an important role on the in vitro bioactivity testing results and should be carefully considered when study materials with varying bioactivities.

Synthesis and Characterization of ZnO(MgO)-CaO-SiO2-P2O5 Bioglass Obtained by Sol-Gel Method in Presence of Surfactant Agent

“…Scanning electron microscopy images on masses immersed for 14 days in SBF at 37 °C— Figure 6 , clearly show an interaction between them by: (i) breaking the existing bridges between particles; (ii) modification of the surface characteristics of the powders; for M2 mass, the presence of platelet crystals is highlighted, agglomerated as spherical aggregates which, according to the literature data, corresponds to the morphology of hydroxyapatite [ 26 , 27 , 28 ].…”

Multifunctional zinc ion doped sol – gel derived mesoporous bioactive glass nanoparticles for biomedical applications

“…Also, the solution conditions selected for bioactivity test significantly affected HCAp formation. Conditions such as pH adjustment and refreshment of SBF could lead to different rates of HCAp formation [44].…”

Bioactive Glass Applications in Dentistry

“…This material turned out to be a glass that precipitated hydroxyapatite in aqueous solutions, with the ability of bonding to hard and soft tissues without rejection. The bioactive properties of BAG have caused a revolution in healthcare and apply to several clinical applications involving the regeneration of hard tissues in medicine and dentistry [5,6]. The application of nanotechnology help to synthesize BAG in the nano scale, this aids in coating the dental implant surfaces, orthopedic, and spinal implants [7,8].…”