Papers by Keyword: Bioactive Glass

Abstract: Bioactive glass (BG) is characteristic of its great biocompatibility as well as osteoconductivity. Application of BG after surgery (e.g., tumor resection) aids rehabilitation of previously traumatized area, promotes bone regeneration, and prevents aggravation of wounds. In this in vitro study, bioglass nanoparticles (BGN) were successfully produced via sol-gel method. We observed the morphology of BGN through Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Particle size was measured by Dynamic Light Scattering (DLS): 182.9 nm ± 37.7 nm in diameter, which corresponds to images obtained by SEM and TEM. We then synthesized BGs containing different proportions of Ca and P ions. Under different pH values, gels with various morphologies were formed.

Abstract: Bone infections are challenging due to their difficult and prolonged treatment, considerable possibility of relapse and strong negative physical and emotional impact. Since their treatment require thorough excisions, bone substitutes have been studied for restoring bone continuity, but with limited efficacy due to the pathophysiology of bone infections; one of the classes which proved to be efficient were the BioActive Glasses [BAG], synthetic biocompatible inorganic materials with a controlled ionic release, with demonstrated properties of wound healing, osteoconduction, angiogenesis and antibacterial activity. This paper presents the clinical experience from a Level 1 Trauma Centre where post-traumatic osteitis was treated using BioActive Glasses as bone fillers, demonstrating the potential clinical impact of these materials. The outcome of the patients was favourable, with no relapse of sepsis, therefore proving the efficacy of BAG in cases with limited grafting possibilities

Abstract: Hydroxyapatite (HA) has similar constituent with natural bone mineral and is able to evoke apatite formation on the bone interface. Similarly, bioactive glass (BG) such as 45S5 has the ability to induce bone formation when exposed to physiological environment. However, both materials have drawbacks in mechanical properties such as brittleness and low compressive strength. Hence, HA-BG composite has potential for enhance properties. The current work aims to assess the effects of BG addition in HA system focusing on mechanical properties.

Abstract: In this study four types of calcium phosphate cement/bioactive glass composites has been synthesized via mixing and sol-gel method and the effect of hydroxyapatite/tricalcium phosphate ratio to its mechanical properties and setting time was investigated. The prepared samples were characterized using X-ray diffraction (XRD), foureir transform infra-red spectroscopy (FTIR), scanning electron microscopy (SEM), mechanical testing and setting time measurement. XRD analysis showed amorphous structure of the prepared bioactive glass. But the patterns of the prepared composite had sharp peaks because of their crystalline structure. FTIR analysis indicated that the composites had carbonated calcium phosphate structure. SEM micrographs illustrated amorphous calcium phosphate particles with irregular shapes. With increasing the HA/TCP ratio, Young's modulus and compressive strength of the composites increased from 179 to 453 MPa and from 20 to 38 MPa respectively. The setting time of the samples decreased with increasing the HA/TCP ratio from 22 to 18 minutes.

Abstract: Bone tissue engineering is an excellent alternative to reduce bone disorders and conditions, by inducing new functional bone regeneration starting from the synthesis of the biomaterials and then the combination of cell and factor therapy. In the present contribution, the scaffolds were made with a ratio of 80 wt.% of β-TCP and 20 wt. % of phosphate-based bioglass, in addition the phosphate-based bioglass was reinforced with zirconia in different amounts (0, 0.5 and 1.0 mol%) with the aim to reduce the dissolution rate, improve the osteoconduction and the osteogenesis of the bone tissue. The results obtained by μCT of the scaffolds containing zirconia showed a wide pore size distribution between 1.5 and 303 μm. AlamarBlue assays showed that the cell proliferation of MC3T3-E1 preosteoblasts scaffolds were sixfold increase in relation to the number of the initial cells. FE-SEM helped to observe the cauliflower structure of HA and DRX showed that crystalline phases formed after heat treatment were (NaCaPO4 and NaZr5PO4) owing both to the crystallization and combination of the bioglass and β-TCP .

Abstract: Bio-glass^® and hydroxyapatite (Ca₁₀ (PO4)₆(OH) ₂, HA) has been widely used as a bone replacement material in restorative dental and orthopedic implants. In order to analyze in vitro bioactivity bio-composite before and after exposed to simulated body fluid (SBF) solution for different time periods were investigated by fourier transform infrared (FTIR) reflectance spectrometer with measuring the pH and concentration of silicon, sodium, calcium, phosphorus and manganese ions in SBF solution. The prepared bio-composites were assessed by XRD, FTIR, mechanical properties. FTIR confirmed the presence of a rich bone like apatite layer post-immersion on the composite surface. It has been found that the new BG/HA bio-composite materials have high bioactivity properties. These bio-composite materials are promising for medical applications such as bone substitutes.

Abstract: This study was to examine the effects of ferric oxide contents, which is one of the components of a newly developed glass, on the color and mechanical strengths of zirconia surfaces after glass infiltration. The composition of bioactive glass contained: SiO₂–Al₂O₃–Na₂O–MgO–BaO–CaO–Nb₂O₅–TiO₂–Fe₂O₃. 84 presintered zirconia discs (diameter 15 mm, height 1.2 mm) were prepared. The experimental groups were divided into 6 groups by Fe₂O₃ contents of 0, 1, 1.5, 2.0, 2.5 and 2.9 wt%. Non-glass infiltrated zirconia was used as a control. Bioactive glass was coated on the presintered zirconia disc by a spin coating and infiltrated into zirconia by complete sintering at 1450°C for 2 hr. The color of the specimens was measured using a digital spectrophotometer and biaxial flexural strength and fracture toughness was compared. The colors of glass infiltrated zirconia were from yellow to yellowish orange according to ferric oxides contents and those were within the range of natural teeth colors. The mechanical properties of glass infiltrated zirconia were not inferior to those of zirconia. Glass infiltration with ferric oxide into zirconia can improve the color and mechanical properties of zirconia and be applicable for dental purpose.

Abstract: The objective of this study is to determine the bioactive property of compacted and crystallized glass-ceramic based on 60 (wt.)%SiO₂-40 (wt.)%CaO by immersion in simulated body fluid (SBF) for various times. The powder of this phosphate-free glasses based on binary SiO₂-CaO system was synthesized via an acid catalyzed sol-gel route prior to powder compaction for the bioactivity assessment. The main chemical precursors used for synthesis the glass powder were tetraethylorthosilicate (TEOS) and calcium nitrate tetrahydrate reagent whereas nitric acid was used as the catalyst during the sol-gel process. The obtained hydrogels were dried, heat treated and grounded into powders before being pressed into rounded shape compacts. The initial compacted glass then sintered at 1000°C for 4 hours in typical muffle furnace to obtain crystallized glass-ceramic phase. Precipitation of apatite structures on the glass-ceramic surface were observed by immersion of the compacted pellets into SBF solution from one to 21 days. All the test results obtained from X-Ray Diffraction (XRD), Fourier Transform-Infrared (FT-IR), Field Emission-Scanning Electron Microscopy (FE-SEM) and Energy Dispersive Spectroscopy (EDS) indicates that the sintered glass-ceramic showed an actively bioactivity property. Precipitation of apatite was detected on the surface of the compacted glass-ceramic within the first 24 hours after being immersed in SBF. The development of apatite structures were continuously increased and progressively growth into coral-like structure and has particularly found to crystallize into carbonated apatite (HCA) layer after 14 days of immersion in SBF.

Abstract: This work presents deformation behaviour of gellan gum and gellan gum - bioactive glass composites as novel hydrophilic materials for production of scaffolds in the field of bone-tissue engineering. According to recent studies such materials are attractive for personalized design of implants thanks to their biocompatibility and wide range of available fabrication methods. Batch of samples was subjected to uni-axial compression loading in a custom designed loading device to obtain their elastic and plastic characteristics. However the testing procedure was challenging because of very low stiffness of the material acquired results show a significant reinforcement effect of bioactive glass and its influence to the elastic modulus.

Abstract: In this study, xerogel glass based on SiO-CaO-PO₄ was synthesized by a low temperature acid catalysed sol-gel route. The in vitro evaluation of apatite forming ability for the glass was conducted in simulated body fluid (SBF) solution as the glasses were immersed for duration of 1, 7, 24 hours and 7 days. The XRD analysis showed that the glass formed semi-crystalline structure when sintered at 1000oC and consisted of Ca₂O₇P₂ and Ca₂O₄Si phases. Image captured using FESEM showed the apatite-like structures were eventually formed on the glass top surface in small numbers after the glass immersed in SBF for only an hour. The numbers of the apatite structures were continuously grown with the increase period of immersion time. The apatite structure mostly covered on top of the glass surface after 24 hours of immersion and continuously growth into bone-like apatite structure when immersed for 7 days in the SBF. The apatite layer formed on the surface of the glass was confirmed as crystalline structure of hydroxyl-carbonate-apatite (HCA) as revealed by the complimentary results of EDS, XRD and FTIR analysis.