scholarly journals Effect of Calcium Precursor on the Bioactivity and Biocompatibility of Sol-Gel-Derived Glasses

2019 ◽  
Vol 10 (1) ◽  
pp. 13 ◽  
Author(s):  
Alejandra Ruiz-Clavijo ◽  
Andrew Hurt ◽  
Arun Kotha ◽  
Nichola Coleman
Keyword(s):  
Sol Gel ◽  
Calcium Nitrate ◽  
Pure Silica ◽  
Stöber Particles ◽  
Incomplete Removal ◽  
Soluble Silica ◽  
Doped Glasses ◽  
Calcium Doped ◽  
The Impact

This study investigated the impact of different calcium reagents on the morphology, composition, bioactivity and biocompatibility of two-component (CaO-SiO2) glasses produced by the Stöber process with respect to their potential application in guided tissue regeneration (GTR) membranes for periodontal repair. The properties of the binary glasses were compared with those of pure silica Stöber particles. The direct addition of calcium chloride (CC), calcium nitrate (CN), calcium methoxide (CM) or calcium ethoxide (CE) at 5 mol % with respect to tetraethyl orthosilicate in the reagent mixture gave rise to textured, micron-sized aggregates rather than monodispersed ~500 nm spheres obtained from the pure silica Stöber synthesis. The broadening of the Si-O-Si band at ~1100 cm−1 in the infrared spectra of the calcium-doped glasses indicated that the silicate network was depolymerised by the incorporation of Ca2+ ions and energy dispersive X-ray analysis revealed that, in all cases, the Ca:Si ratios were significantly lower than the nominal value of 0.05. The distribution of Ca2+ ions was also found to be highly inhomogeneous in the methoxide-derived glass. All samples released soluble silica species on exposure to simulated body fluid, although only calcium-doped glasses exhibited in vitro bioactivity via the formation of hydroxyapatite. The biocompatibilities of model chitosan-glass GTR membranes were assessed using human MG63 osteosarcoma cells and were found to be of the order: CN < pure silica ≈ CC << CM ≈ CE. Calcium nitrate is the most commonly reported precursor for the sol-gel synthesis of bioactive glasses; however, the incomplete removal of nitrate ions during washing compromised the cytocompatibility of the resulting glass. The superior bioactivity and biocompatibility of the alkoxide-derived glasses is attributed to their ease of dissolution and lack of residual toxic anions. Overall, calcium ethoxide was found to be the preferred precursor with respect to extent of calcium-incorporation, homogeneity, bioactivity and biocompatibility.

Low temperature synthesis of wollastonite using sol–gel combustion method: In vitro bioactivity evaluation

2019 ◽  
Vol 33 (10) ◽  
pp. 1950081 ◽  
Author(s):  
Madeeha Riaz ◽  
Rehana Zia ◽  
Snudia Aslam ◽  
Alliya Qamar ◽  
Tousif Hussain ◽  
...  
Keyword(s):  
Low Temperature ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Combustion Method ◽  
Calcium Nitrate Tetrahydrate ◽  
In Vitro Bioactivity ◽  
Nitrate Tetrahydrate ◽  
Gel Combustion ◽  
Gel Combustion Method

In this paper, low temperature, economical sol–gel combustion method was adopted to synthesize wollastonite ceramic. Calcium nitrate tetrahydrate and tetraethyl orthosilicate were taken as source for Ca and Si, while citric acid and nitric acid were used as chelating/combustion agents. The yielded powder calcined at 600[Formula: see text]C for 4 h was characterized by FTIR, XRD and SEM techniques. Results showed that the citrate combustion method was the most efficient method to prepare wollastonite at low temperature. Moreover, in vitro bioactivity test performed in simulated body fluid (SBF) showed good bioactivity of synthesized wollastonite ceramics.

Apatite Formation on PDMS-Modified SiO2-CaO-P2O5 Hybrids Prepared with Different P2O5 Content by Sol-Gel Method

2004 ◽  
Vol 449-452 ◽  
pp. 1121-1124 ◽  
Author(s):  
Do Won Seo ◽  
J.G. Kim ◽  
Yun Hae Kim ◽  
Chin Myung Whang
Keyword(s):  
Sol Gel ◽  
Calcium Nitrate ◽  
Apatite Formation ◽  
Calcium Nitrate Tetrahydrate ◽  
X Ray Diffraction ◽  
Phosphate Ions ◽  
P2o5 Content ◽  
Sol Gel Process ◽  
Nitrate Tetrahydrate

Bioactive ORMOSILS (organically modified silicate), PDMS-CaO-SiO2-P2O5 with five different P2O5 content (0, 0.01, 0.03, 0.06, 0.09 mol%) have successfully been synthesized by sol-gel process. The hybrids have been prepared with polydimethylsiloxane (PDMS), tetraethoxysilane (TEOS), calcium nitrate tetrahydrate [Ca(NO3)2 4H2O] and triethyl phosphate (TEP) as starting materials and subsequently soaked into the simulated body fluid (SBF) for different period of time and the bioactivity of hybrids was determined by examining the apatite formation on the surface of the specimen by FT-IR, Thin-Film X-ray Diffraction, and Scanning Electron Microscopy (SEM). All of the prepared samples with different P2O5 content showed in vitro bioactivity. It was observed that the increase in P2O5 content up to 0.03 mole % increases the apatite formation compared to P2O5- free hybrids. However, further increase in P2O5 concentration slows down the formation of the apatite layer most probably due to the decrease of pH of SBF by dissolution of a large amount of phosphate ions.

scholarly journals Synthesis of poly(vinyl alcohol) — hydroxyapatite composites and characterization of their bioactivity

2013 ◽  
Vol 11 (9) ◽  
pp. 1403-1411 ◽  
Author(s):  
Zuzana Balgová ◽  
Martin Palou ◽  
Jaromír Wasserbauer ◽  
Jana Kozánková
Keyword(s):  
Vinyl Alcohol ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Weight Percent ◽  
Poly Vinyl Alcohol ◽  
Aqueous Environment ◽  
Calcium Nitrate Tetrahydrate ◽  
In Vitro Bioactivity ◽  
Before And After

AbstractAbstract A series of poly(vinyl alcohol) membranes reinforced with hydroxyapatite in various weight percent — 0%, 10%, 20%, 30%, 40% and 50% were prepared. Hydroxyapatite was prepared by a sol-gel procedure using diammonium hydrogen phosphate and calcium nitrate tetrahydrate as starting materials in an alkaline aqueous environment and then mixed with a solution of poly(vinyl alcohol), which was prepared by dissolving it in water at 85°C. The different mixtures were cast in a mould and evaporated for 7 days at a temperature of 30°C to obtain 1 mm thin membranes. FTIR spectroscopy was used to identify the different functional groups in the composites. The surface morphology was examined using a scanning electron microscope. In vitro bioactivity tests in Simulated Blood Fluid were performed for up to 28 days, especially for the membrane containing 50 wt.% HA. SEM was used to characterise the surface microstructure of biocomposite membranes before and after soaking in SBF. It was observed that the formation of clusters in membranes increases with increasing amount of HA. The clusters are formed due to agglomeration and crystal growth of HA particles during drying of the membranes. The in vitro bioactivity was found to increase with soaking time of biocomposite materials in simulated blood fluid. Graphical abstract

scholarly journals In VitroBioactivity and Antimicrobial Tuning of Bioactive Glass Nanoparticles Added with Neem (Azadirachta indica) Leaf Powder

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
M. Prabhu ◽  
S. Ruby Priscilla ◽  
K. Kavitha ◽  
P. Manivasakan ◽  
V. Rajendran ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Azadirachta Indica ◽  
Sol Gel ◽  
Sem Analysis ◽  
Microbial Infection ◽  
X Ray Diffraction ◽  
Doped Glasses ◽  
Leaf Powder ◽  
Doped Glass

Silica and phosphate based bioactive glass nanoparticles (58SiO2-33CaO-9P2O5) with doping of neem (Azadirachta indica) leaf powder and silver nanoparticles were prepared and characterised. Bioactive glass nanoparticles were produced using sol-gel technique.In vitrobioactivity of the prepared samples was investigated using simulated body fluid. X-ray diffraction (XRD) pattern of prepared glass particles reveals amorphous phase and spherical morphology with a particle size of less than 50 nm. When compared to neem doped glass, better bioactivity was attained in silver doped glass through formation of hydroxyapatite layer on the surface, which was confirmed through XRD, Fourier transform infrared (FTIR), and scanning electron microscopy (SEM) analysis. However, neem leaf powder doped bioactive glass nanoparticles show good antimicrobial activity againstStaphylococcus aureusandEscherichia coliand less bioactivity compared with silver doped glass particles. In addition, the biocompatibility of the prepared nanocomposites reveals better results for neem doped and silver doped glasses at lower concentration. Therefore, neem doped bioactive glass may act as a potent antimicrobial agent for preventing microbial infection in tissue engineering applications.

Preparation of Alginate/Silica Composite Beads with In Vitro Apatite-Forming Ability

2011 ◽  
Vol 236-238 ◽  
pp. 1889-1892 ◽  
Author(s):  
Fan Xiao ◽  
Fei Gao ◽  
Zhi Xian Zhang ◽  
Wei Li
Keyword(s):  
Biomedical Applications ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Phosphate Solution ◽  
X Ray Diffraction ◽  
Silica Composite ◽  
Composite Beads ◽  
Ft Ir ◽  
Diffraction Peaks

Alginate/silica composite beads of mm-size for biomedical applications were prepared from water glass and sodium alginate via a simple sol-gel route. They kept their original shapes when soaked in the phosphate solution of lower pH. In this case, faint calcium phosphate peaks were observed in X-ray diffraction. Peaks corresponding to phosphate group were also found in FT-IR. Apatite was obtained on the surface of beads made with calcium chloride after soaking in phosphate solution while monetite was formed on the surface of beads made with calcium nitrate.

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.

Bioactive Hydroxyapatite Coating on Titanium-Niobium Alloy through a Sol-Gel Process

2009 ◽  
Vol 618-619 ◽  
pp. 325-328 ◽  
Author(s):  
Jian Yu Xiong ◽  
Yun Cang Li ◽  
Peter D. Hodgson ◽  
Cui E Wen
Keyword(s):  
Cell Morphology ◽  
Cell Attachment ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Triethyl Phosphite ◽  
Xrd Analysis ◽  
In Vitro Bioactivity ◽  
Ha Coating ◽  
Sol Gel Process

Hydroxyapatite (HA) was coated on the surface of a titanium-niobium (Ti-Nb) alloy by a sol-gel process. Triethyl phosphite and calcium nitrate were used as the phosphorus (P) and calcium (Ca) precursors respectively to prepare a Ca/P sol solution. The Ti-Nb alloy was dip-coated in the sol and heated at 600°C for 30 minutes. X-ray diffraction (XRD) analysis indicated the major phase constituent of the coating after heat treatment was HA. Scanning electron microscopy (SEM) observation showed that a few cracks were distributed on the HA coating. The in-vitro bioactivity of the HA coated Ti-Nb alloy was assessed using a cell culture of SaOS-2 osteoblast-like cells. The density of cell attachment was determined by MTT assay; the cell morphology was observed by SEM. Results indicated that the density of cell attachment on the surface of the Ti-Nb alloy was significantly increased by HA coating. Cell morphology observation showed that cells attached, spread and grew well on the HA coated surface. It can be concluded that the HA coating improved the in-vitro bioactivity of Ti-Nb alloy effectively.

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.

Synthesis of 60 (wt.)%SiO2-40 (wt.)%CaO Sol-Gel Derived Glass-Ceramic and In Vitro Bioactivity Assessment in SBF Solution

2016 ◽  
Vol 673 ◽  
pp. 161-170 ◽  
Author(s):  
S.A. Syed Nuzul Fadzli ◽  
S. Roslinda ◽  
Firuz Zainuddin
Keyword(s):  
Glass Ceramic ◽  
Sol Gel ◽  
Calcium Nitrate ◽  
Calcium Nitrate Tetrahydrate ◽  
Ceramic Surface ◽  
Ceramic Phase ◽  
Carbonated Apatite ◽  
Heat Treated ◽  
Sbf Solution

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.

scholarly journals Copper-Doped Ordered Mesoporous Bioactive Glass: A Promising Multifunctional Platform for Bone Tissue Engineering

2020 ◽  
Vol 7 (2) ◽  
pp. 45 ◽  
Author(s):  
Francesco Baino
Keyword(s):  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Bone Tissue ◽  
Sol Gel ◽  
Antibacterial Properties ◽  
Textural Properties ◽  
Microbial Infection ◽  
Structure Directing Agent ◽  
Doped Glasses

The design and development of biomaterials with multifunctional properties is highly attractive in the context of bone tissue engineering due to the potential of providing multiple therapies and, thus, better treatment of diseases. In order to tackle this challenge, copper-doped silicate mesoporous bioactive glasses (MBGs) were synthesized via a sol-gel route coupled with an evaporation-induced self-assembly process by using a non-ionic block co-polymer as a structure directing agent. The structure and textural properties of calcined materials were investigated by X-ray powder diffraction, scanning-transmission electron microscopy and nitrogen adsorption-desorption measurements. In vitro bioactivity was assessed by immersion tests in simulated body fluid (SBF). Preliminary antibacterial tests using Staphylococcus aureus were also carried out. Copper-doped glasses revealed an ordered arrangement of mesopores (diameter around 5 nm) and exhibited apatite-forming ability in SBF along with promising antibacterial properties. These results suggest the potential suitability of copper-doped MBG powder for use as a multifunctional biomaterial to promote bone regeneration (bioactivity) and prevent/combat microbial infection at the implantation site, thereby promoting tissue healing.

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