The Impact of Stirring Rate on the Crystallinity and Bioactivity of 58S Bioactive Glass

2011 ◽  
Vol 493-494 ◽  
pp. 43-48 ◽  
Author(s):  
Ourania Menti Goudouri ◽  
Maria Perissi ◽  
Eleni Theodosoglou ◽  
Lambrini Papadopoulou ◽  
Xanthippi Chatzistavrou ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Sol Gel ◽  
Apatite Formation ◽  
Reinforcing Agent ◽  
Main Crystalline Phase ◽  
Before And After ◽  
Amorphous Glass ◽  
Sbf Solution ◽  
The Impact

In most biphasic composite systems consisting of sol-gel derived bioactive glass and a second system that is usually used as a reinforcing agent, thorough stirring is necessary to prevent the precipitation of the grains of the second system. Consequently, the aim of this work is to investigate the impact of various stirring rates on the crystallinity and bioactivity of a bioactive glass in the system 58S. Sol-gel-derived bioactive glass (58S) was produced as described in literature. During the gelation, stirring rates of 0, 200, 400, 600 and 800 rpms were applied producing, respectively, the corresponding glass powders. The in vitro bioactivity of the powders was tested in Simulated Body Fluid (SBF) for various immersion times, while the solution was renewed after 6h, 24h and then every 2 days. Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-ray Diffractometry (XRD) were used to characterize all materials before and after immersion in SBF solution. FTIR and XRD measurements of all powders revealed mainly the formation of an amorphous glass, while the main crystalline phase was identified to be Ca2SiO4. After immersion in SBF solution for 12h, SEM microphotographs revealed apatite formation on the surface of all samples, while FTIR and XRD confirmed the aforementioned findings. Furthermore, since EDS analysis proved a mean molar Ca/P ratio of about1.7 after 6 days of immersion of all samples- besides those stirred at 400 and 600rpm- it can be assumed that a thick apatite layer was formed covering the whole surface.

scholarly journals In vitro bioactivity of Polyurethane/85S Bioglass composite scaffolds

2013 ◽  
Vol 11 (9) ◽  
pp. 1439-1446 ◽  
Author(s):  
Lachezar Radev ◽  
Darina Zheleva ◽  
Irena Michailova
Keyword(s):  
Sol Gel ◽  
Spherical Particles ◽  
Polymerization Reaction ◽  
In Vitro Test ◽  
In Vitro Bioactivity ◽  
Before And After ◽  
Vitro Test ◽  
Sbf Solution ◽  
Static Conditions

AbstractIn the present work Polyurethane (PU)/Bioglass (BG) composite materials were synthesized with different content of BG (10 and 20 mol.%) as filler. The 85S Bioglass was synthesized via polystep sol-gel method. The chemical composition of BG is 85SiO2-10CaO-5P2O5 (wt.%). The synthesis of PU was carried out by a two-step polyaddition reaction. The 85S BG was added in situ during the polymerization reaction. In vitro bioactivity of the prepared composites was examined in the presence of 1.5 SBF for 7 days in static conditions. The structure of synthesized PU/BG composites before and after in vitro test was determined by XRD, FTIR and SEM. XRD of the samples before in vitro test proved that the phase of γCa2P2O7 in the PU/20BG is visible. FTIR revealed the presence of urethane bond between OH-(from BG) and NCO groups (from PU). Based on FTIR results after in vitro test in 1.5 SBF solutions, A/B-carbonate containing hydroxyapatite (CO3HA) was formed. XRD proved that HA was formed on the surface of the samples, but Ca2P2O7 does not undergo any changes in the 1.5 SBF solution. SEM depicted the nano-HA agglomerated in spherical particles after immersion in 1.5 SBF for 7 days.

scholarly journals Characterization of Bioactive Glass Synthesized by Sol-Gel Process in Hot Water

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 529 ◽  
Author(s):  
Tan Hiep Dang ◽  
Thi Hoa Bui ◽  
Elena V. Guseva ◽  
Anh Tuan Ta ◽  
Anh Tien Nguyen ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Sol Gel ◽  
Acid Catalyst ◽  
Mesoporous Structure ◽  
Hot Water ◽  
Spherical Particles ◽  
Average Pore ◽  
Amorphous Glass ◽  
Adsorption Desorption

Bioactive glass 70SiO2-30CaO (mol.%) was successfully synthesized by modified sol–gel in hot water without using an acid catalyst. TG-DSC analysis showed that the amorphous glass could be synthesized by sintering the sample at 700 °C for three hours. The N2 adsorption/desorption and TEM investigations highlighted that the synthetic glass had a mesoporous structure, consisting of spherical particles with sizes in the range of 11–20 nm. The specific surface area, pore volume, and average pore diameter of synthetic glass were 150.13 m2/g, 0.37 cm3/g, and 11.84 nm, respectively. Moreover, synthetic bioactive glass presented interesting bioactivity and good biocompatibility after in vitro experiments in simulated body fluid (SBF) and in cellular medium.

The Impact of Sintering Temperature on the Bioactive Glass-Dental Porcelain Composite Material

2011 ◽  
Vol 493-494 ◽  
pp. 80-84
Author(s):  
M. Manda ◽  
Ourania Menti Goudouri ◽  
Lambrini Papadopoulou ◽  
Nikolaos Kantiranis ◽  
T. Zorba ◽  
...  
Keyword(s):  
Composite Material ◽  
Bioactive Glass ◽  
Sol Gel ◽  
Apatite Layer ◽  
Firing Cycle ◽  
Sintering Process ◽  
Dental Porcelain ◽  
Increased Temperature ◽  
The Impact

End temperature of the firing cycle, during processing of dental ceramics, directs the interaction of both sintering and crystallization pathways, tailoring physicochemical properties and bioactivity. Thus, the purpose of the present study was to investigate the influence of end temperature over the structural properties and composition, along with the bioactive behavior of dental porcelain, modified by bioactive glass. Sol-gel derived specimens of bioactive glass (58S)- commercial dental porcelain composites synthesized (BP) and underwent firing cycles at the crystallization temperature (Tc=1040oC) and the temperature just below the melting range (Tm=1080oC), as the composite material. The recommended temperature for the commercial porcelain (Ta=930oC) was examined, too. All specimens were characterized using X-ray diffraction (XRD), Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM). The assessment of bioactivity was performed in vitro, via the detection of apatite layer development. The well-defined particles, observed by SEM, at 930oC, developed contact formation during the stage of neck growth at 1040oC and 1080oC, indicating the initiation of sintering process. Increasing temperature, the complex porei network became smoother, while spherical and closed porei were evident. FTIR revealed the predominance of wollastonite at the increased temperatures, along with the appearance of cristobalite, while XRD confirmed the results. Finally, the in vitro tests evidenced the bioactivity of the specimens independently of the final temperature, though the increased temperature caused delayed apatite layer formation on their surface. The, microstructural and chemical evolution of the studied composite is temperature-dependent. Increased temperature favored the sintering process initiation, along with the surface crystallization, which delays bioactivity.

scholarly journals Quenched/unquenched nano bioactive glass-ceramics: Synthesis and in vitro bioactivity evaluation in Ringer’s solution with BSA

2013 ◽  
Vol 19 (2) ◽  
pp. 231-239 ◽  
Author(s):  
Nima Nabian ◽  
Maedeh Delavar ◽  
Mahmood Rabiee ◽  
Mohsen Jahanshahi
Keyword(s):  
Electron Microscope ◽  
Bioactive Glass ◽  
Glass Ceramic ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Apatite Formation ◽  
In Vitro Bioactivity ◽  
Sem Images ◽  
Transmission Electron

The paper reports the first attempt at changing cooling treatment of synthesizing method in order to investigate its effect on the physical properties of sol-gel derived nano bioactive glass-ceramic in the system 58SiO2-33CaO-9P2O5 (wt.%). We hypothesized that the method of cooling may affect the properties of nano bioactive glass-ceramic. To test this hypothesis, two different method of cooling treatment was applied after calcinations in synthesizing method. Both quenched and unquenched nano bioactive glass-ceramics were soaked in Ringer?s solution with bovine serum albumin (BSA) for bioactivity evaluation. The obtained samples were analyzed for their composition, crystalinity and morphology through X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), surface electron microscope (SEM) and transmission electron microscope (TEM). The SEM images showed that the morphology of nano bioactive glass-ceramics was completely changed by quenching process. Results of in vitro bioactivity evaluation revealed that the unquenched attains faster apatite formation ability than the quenched sample. Other properties of these two morphologically different nano bioactive glass-ceramics were strongly discussed.

The 1100 C Thermoluminescence Peak as a Probe in Bioactivity Study of the 58S Sol-Gel Bioactive Glass

2011 ◽  
Vol 493-494 ◽  
pp. 49-54 ◽  
Author(s):  
George S. Polymeris ◽  
Ourania Menti Goudouri ◽  
Konstantinos M. Paraskevopoulos ◽  
George Kitis
Keyword(s):  
Bioactive Glass ◽  
Time Scale ◽  
Immersion Time ◽  
Sol Gel ◽  
Glow Peak ◽  
In Vitro Bioactivity ◽  
Effective Application ◽  
Peak Intensity ◽  
Sbf Solution

Results of the present study provide strong indications towards the effective application of the 110oC Thermoluminescence (TL) peak in discriminating between different bioactive responses for the case of the 58S bioactive glass. The in vitro bioactivity of this glass in the form of powder in SBF solution was tested for various immersion times, ranging between 0 and 6 days. This TL peak is ubiquitously present in all 58S samples, for all immersion times. The intensity of the110oC TL peak was proven to be very sensitive to the different bioactive responses, indicating a strongly decreasing pattern with increasing immersion time in SBF, easily identifying thus the loss of silica. This loss is reflected to the decrease of the 110oC TL peak intensity, which appears to be fast even for the shorter immersion times. The 110oC TL glow peak intensity and sensitization could also be yielding a time scale regarding the beginning of some among the several stages included in the bioactivity sequence.

scholarly journals The Influence of Na and Ti on theIn VitroDegradation and Bioactivity in 58S Sol-Gel Bioactive Glass

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Shirong Ni ◽  
Ruilin Du ◽  
Siyu Ni
Keyword(s):  
Activation Energy ◽  
Bioactive Glass ◽  
Body Fluid ◽  
Sol Gel ◽  
Apatite Formation ◽  
Ion Release ◽  
Buffer Solution ◽  
Bioactive Glasses ◽  
Initial Stage

The aim of this study was to investigate the effect of Na and Ti on thein vitrodegradation and bioactivity in the 58S bioactive glass. The degradation was evaluated through the activation energy of Si ion release from bioactive glasses and the weight loss of bioactive glasses in Tris-HCl buffer solution. Thein vitrobioactivity of the bioactive glasses was investigated by analysis of apatite-formation ability in the simulated body fluid (SBF). The results showed that Na in the 58S glass accelerated the dissolution rate of the glass, whereas Ti in the 58S glass slowed down the rate of glass solubility. Bioactivity tests showed that Na in glass increased the apatite-forming ability in SBF. In contrast, Ti in glass retards the apatite formation at the initial stage of SBF soaking but does not affect the growth of apatite after long periods of soaking.

New Composite Membranes Containing Bioactive Glass-Ceramic Nanoparticles and Chitosan for Biomedical Applications

2010 ◽  
Vol 636-637 ◽  
pp. 31-35 ◽  
Author(s):  
Gisela M. Luz ◽  
João F. Mano
Keyword(s):  
Simulated Body Fluid ◽  
Bioactive Glass ◽  
Glass Ceramic ◽  
Body Fluid ◽  
Biomedical Applications ◽  
Sol Gel ◽  
Composite Membranes ◽  
Apatite Formation ◽  
Free System

In this study a new P-free system applied to the production of Bioactive Glass Nanoparticles (BG-NPs) is proposed, in order to evaluate the effect of suppressing this component, in the bioactivity capability of the materials. The BG-NPs, based on both ternary (SiO2-CaO-P2O5) and binary (SiO2-CaO) systems, were prepared via a sol-gel method. The morphology and composition of the BG-NPs were studied using FTIR and SEM. New composite membranes were produced combining chitosan and the BG-NPs. The bioactive character of the prepared biodegradable membranes was accessed in vitro by analyzing the capability for apatite formation onto the surface after being immersed in simulated body fluid (SBF). EDX and SEM were used to confirm the bioactivity of the materials.

Synthesis and Characterization of Sol-Gel Derived SiO2-CaO Glass

2015 ◽  
Vol 754-755 ◽  
pp. 964-968 ◽  
Author(s):  
S.A. Syed Nuzul Fadzli ◽  
S. Roslinda ◽  
Firuz Zainuddin
Keyword(s):  
Sol Gel ◽  
Xrd Analysis ◽  
Infrared Analysis ◽  
Carbonate Apatite ◽  
Binary Glass ◽  
Amorphous Glass ◽  
Sbf Solution ◽  
Free Glass

A phosphate-free glass based on SiO2-CaO was synthesized by a low temperature acid catalysed sol-gel route. The obtained material was evaluated by X-ray powder diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The XRD analysis showed the sol-gel derived glass was amorphous in nature and crystallized when sintered at temperature above 900oC. The crystalline state was consisted of quartz and wollastonite phases. Meanwhile the infrared analysis showed typical transmission bands of monolith silica in the binary glass pattern. The bioactivity of the amorphous glass was investigated in vitro in simulated body fluid (SBF). The amorphous glasses were soaked in SBF for 1, 3 and 7 days. It is notable that the obtained results from FTIR, SEM and EDS analyses showed the deposition of spherical-shaped crystalline hydroxyl-carbonate-apatite (HCA) on the surface of the glass within 3 days of immersion in SBF solution. The HCA deposition was covered most of the surface after 7 days of immersion.

In Vitro Bioactivity of Potassium Titanate Whiskers

2008 ◽  
Vol 47-50 ◽  
pp. 1351-1354 ◽  
Author(s):  
Yan Bao Li ◽  
Qing Lin ◽  
Jun Sheng Chen ◽  
Xiang Hui Lan ◽  
Chun Hua Lu ◽  
...  
Keyword(s):  
Potential Candidate ◽  
In Vitro Bioactivity ◽  
Oh Groups ◽  
Potassium Titanate ◽  
Reinforcing Agent ◽  
Before And After ◽  
Good Biocompatibility ◽  
Simulated Body Fluids ◽  
Sbf Solution

The bioactivity of potassium titanate whiskers (PTW) was evaluated by soaking in simulated body fluids (SBF, Kokubo solution). At first, PTW was chemically treated by 1 M HCl and 1 M NaOH solutions at 60 oC for 48 h, respectively. Then PTW before and after treated were soaked in SBF solution and cultured at 37 oC for different times. The apatite deposit on PTW was examined by FTIR and SEM/EDX. The results showed that there was not apatite deposit on the raw PTW even after soaked for 14 days while apatite appeared on the treated PTW after soaked for only 7 days. This implies that treatment by HCl/NaOH solutions can improve the in vitro bioactivity of PTW. The possible mechanism is that more Ti–OH groups occur after treatment and induce Ca2+ and PO4 3- aggregate and accelerate to deposit of apatite. The bioactive PTW with good biocompatibility is a potential candidate as reinforcing agent to improve the mechanical properties of calcium phosphate ceramics or cements.

scholarly journals A Comparative Study on the Properties of Potentially Bioactive Glasses Obtained by Sol-Gel Technique and by Melting Mixtures of Oxides

2017 ◽  
Vol 15 (13) ◽  
pp. 18-24
Author(s):  
Daniela Avram ◽  
Dan Ungureanu ◽  
Nicolae Angelescu ◽  
José Barroso de Aguiar
Keyword(s):  
Mechanical Energy ◽  
Sol Gel ◽  
Diffraction Method ◽  
Sem Analysis ◽  
Thin Layers ◽  
Apatite Formation ◽  
Before And After ◽  
Gel Technique ◽  
The Fourier Transform

AbstractPhosphocalcic glasses, based on ternary system SiO2 - CaO- P2O5 and those doped with copper (SiO2 – CaO - P2O5 - Cu2O) can be obtained by the traditional method of sub-cooling melts or modern methods such as process that uses mechanical energy, neutrons action, deposition in thin layers or by sol-gel technique. This paper shows the experimental results of three compositional phosphocalcic glasses: 50% SiO2 - 43% CaO - 7% P2O5, 50% SiO2 - 38% CaO - 7% P2O5 - 5% Cu2O obtained through sol-gel method and 45% SiO2 - 22.5% CaO - 22.5 Na2O - 5% P2O5 - 5% Cu2O obtained by melting. In order to study their bioactivity, the three compositions were structural analyzed by X-ray diffraction method. In this case the apatite formation was highlighted after soaked in simulated body fluid, but also other compounds (CaCO3 and CuO) resulting from the same process were observed. In case of the melting glass apatite formation has not been highlighted. The functional groups present in the structure of glasses before and after soaking (PO43−, CO32− and HO−) were highlighted by the Fourier Transform Infrared Spectroscopy (FTIR). The elemental chemical composition was confirmed by elemental analysis WD-XRF. The morphology of sol-gel glass powders was revealed by SEM analysis. All glass compositions were tested in terms of antibacterial activity in vitro.

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