scholarly journals A thermodynamic discourse on the dissolution behavior of bioactive glasses

2016 ◽  
Vol 2 (1) ◽  
Author(s):  
Barbara Pföss ◽  
Reinhard Conradt
Keyword(s):  
Bioactive Glass ◽  
Body Fluid ◽  
Solid Material ◽  
Aqueous System ◽  
Dissolution Behavior ◽  
Glassy Material ◽  
Bioactive Glasses ◽  
Gibbs Energies ◽  
The Impact ◽  
Glass Compositions

AbstractThe interaction between bioactive glass and body fluid is crucial for the special properties of this material, therefore a large number of experimental data is available in literature. However, a frame for systematic interpretation of these results in terms of understanding the mechanisms at the interface between glass and body medium and the relation between glass composition and dissolution behavior is still missing. For two multicomponent bioactive glasses, 45S5 and 13-93, the Gibbs energies of the glassy material on one side and their aqueous system on the other side were calculated individually. The difference between solid material and aqueous system further constitutes the pH dependent Gibbs energy of hydration, ∆Ghydr. The impact of glass compositions and glassy or crystalline state on ∆Ghydr is demonstrated referring to chemical durability. Along considerations regarding the aqueous system, the thermodynamic calculations proof the precipitation of hydroxyapatite inwater and simulated body fluid for a systemcontaining P2O5 and Ca2+. In the course of deriving the Gibbs energies for bioactive glass compositions via constitutional compounds, bioactive behavior is discussed from the point of coexisting equilibrium phases in the system of Na2O-CaO-SiO2.

scholarly journals Hierarchical Structures and Shaped Particles of Bioactive Glass and ItsIn VitroBioactivity

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
U. Boonyang ◽  
F. Li ◽  
A. Stein
Keyword(s):  
Body Temperature ◽  
Simulated Body Fluid ◽  
Bioactive Glass ◽  
Body Fluid ◽  
Colloidal Crystals ◽  
Hierarchical Structures ◽  
The Other ◽  
Bioactive Glasses ◽  
Ordered Macroporous

In this study, bioactive glass particles with controllable structure and porosity were prepared using dual-templating methods. Block copolymers used as one template component produced mesopores in the calcined samples. Polymer colloidal crystals as the other template component yielded either three-dimensionally ordered macroporous (3DOM) products or shaped bioactive glass nanoparticles. Thein vitrobioactivity of these bioactive glasses was studied by soaking the samples in simulated body fluid (SBF) at body temperature (37°C) for varying lengths of time and monitoring the formation of bone-like apatite on the surface of the bioactive glass. A considerable bioactivity was found that all of bioactive glass samples have the ability to induce the formation of an apatite layer on its surface when in contact with SBF. The development of bone-like apatite is faster for 3DOM bioactive glasses than for nanoparticles.

Hydroxyapatite Formation on Cellular Alumina Coated with Bioactive Glasses

2006 ◽  
Vol 309-311 ◽  
pp. 1027-1030
Author(s):  
Cheol Y. Kim ◽  
Dong Hyun Kim
Keyword(s):  
Compressive Strength ◽  
Bioactive Glass ◽  
Body Fluid ◽  
Bioactive Glasses ◽  
Simulate Body Fluid ◽  
Bioactive Ceramics ◽  
Hydroxyapatite Formation

Various works have been done to produce a cellular form of bioactive ceramics for a scaffold. However, the most of these cellular implants have low compressive strength. In this study, therefore, glass-infiltrated cellular alumina with compressive strength of 7.3MPa was first prepared. Bioactive glass was then coated on the cellular alumina. When the specimen was reacted in simulate body fluid, hydroxyapatite developed on the bioactive glass coat in 18 hours.

Growth of Hydroxyapatite on Strontium Oxide Modified Bioactive Glass

2015 ◽  
Vol 1107 ◽  
pp. 397-402
Author(s):  
H.J.M. Ridzwan ◽  
N.H. Jamil ◽  
S.A. Syamsyir ◽  
W.A.W. Razali
Keyword(s):  
Simulated Body Fluid ◽  
Bioactive Glass ◽  
Body Fluid ◽  
Sol Gel ◽  
Amorphous State ◽  
Strontium Oxide ◽  
Bioactive Glasses ◽  
Xrd Pattern ◽  
Gel Method ◽  
Sol Gel Method

The bioactive glasses of SiO2-CaO-P2O5-SrO system have been prepared by a quick alkali mediated sol-gel method. The prepared bioactive glass of 1, 3, 5 wt% of SrO (coded: SR1, SR3, SR5, respectively) were characterized by SEM, XRD and FTIR. XRD pattern of all glasses calcined at 700°C in air confirmed that the calcined bioactive glass generally existed in amorphous state. The samples were immersed in simulated body fluid (SBF) to investigate the presence of hydroxyapatite (HA). All bioactive glass samples can induce the formation of hydroxyapatite (HA) as verified by SEM and XRD.

scholarly journals Bioactivity and dissolution behavior of boron-containing bioactive glasses under static and dynamic conditions in different media

2019 ◽  
Vol 5 (1) ◽  
pp. 124-139 ◽  
Author(s):  
Marcela Arango-Ospina ◽  
Leena Hupa ◽  
Aldo R. Boccaccini
Keyword(s):  
Body Fluid ◽  
Boron Content ◽  
Dissolution Behavior ◽  
Bioactive Glasses ◽  
Dynamic Conditions ◽  
Glass Dissolution ◽  
Dissolution Studies ◽  
Boron Doped ◽  
Acidic Conditions ◽  
Static Conditions

Abstract The present study reports the dissolution studies of a family of boron-doped bioactive glasses based on the composition ICIE16. Simulated body fluid (SBF), Tris-buffered solution and lactic acid were used as dissolution media for studies under static and dynamic conditions. The leaching of ions from the glasses under the evaluated conditions and media was compared and the bioactive behaviour of the glasses was evaluated. Influence of the incorporation of boron in the thermal properties of the glass was also analysed. Glasses exhibited faster bioactivity under dynamic dissolution configuration compared to static conditions. Moreover, the glass dissolution rate was faster in acidic conditions than in SBF or Tris solutions. It was found that at increasing boron content the dissolution of the glass is faster.

scholarly journals Bioactive Glass—An Extensive Study of the Preparation and Coating Methods

Coatings ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1386
Author(s):  
Maxim Maximov ◽  
Oana-Cristina Maximov ◽  
Luminita Craciun ◽  
Denisa Ficai ◽  
Anton Ficai ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Medical Devices ◽  
Mechanical Stability ◽  
Treatment Options ◽  
Extensive Study ◽  
Glassy Material ◽  
Bioactive Glasses ◽  
Preparation Methods ◽  
Mechanical Hardness ◽  
Coating Methods

Diseases or complications that are caused by bone tissue damage affect millions of patients every year. Orthopedic and dental implants have become important treatment options for replacing and repairing missing or damaged parts of bones and teeth. In order to use a material in the manufacture of implants, the material must meet several requirements, such as mechanical stability, elasticity, biocompatibility, hydrophilicity, corrosion resistance, and non-toxicity. In the 1970s, a biocompatible glassy material called bioactive glass was discovered. At a later time, several glass materials with similar properties were developed. This material has a big potential to be used in formulating medical devices, but its fragility is an important disadvantage. The use of bioactive glasses in the form of coatings on metal substrates allows the combination of the mechanical hardness of the metal and the biocompatibility of the bioactive glass. In this review, an extensive study of the literature was conducted regarding the preparation methods of bioactive glass and the different techniques of coating on various substrates, such as stainless steel, titanium, and their alloys. Furthermore, the main doping agents that can be used to impart special properties to the bioactive glass coatings are described.

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.

scholarly journals Bioactive glasses and electrospun composites that release cobalt to stimulate the HIF pathway for wound healing applications

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Anu K. Solanki ◽  
Ferdinand V. Lali ◽  
Hélène Autefage ◽  
Shweta Agarwal ◽  
Amy Nommeots-Nomm ◽  
...  
Keyword(s):  
Wound Healing ◽  
Bioactive Glass ◽  
Hypoxia Inducible Factor ◽  
Magnesium Content ◽  
Ion Release ◽  
Bioactive Glasses ◽  
Covalent Bonds ◽  
Cobalt Ions ◽  
Hif Pathway ◽  
Glass Compositions

Abstract Background Bioactive glasses are traditionally associated with bonding to bone through a hydroxycarbonate apatite (HCA) surface layer but the release of active ions is more important for bone regeneration. They are now being used to deliver ions for soft tissue applications, particularly wound healing. Cobalt is known to simulate hypoxia and provoke angiogenesis. The aim here was to develop new bioactive glass compositions designed to be scaffold materials to locally deliver pro-angiogenic cobalt ions, at a controlled rate, without forming an HCA layer, for wound healing applications. Methods New melt-derived bioactive glass compositions were designed that had the same network connectivity (mean number of bridging covalent bonds between silica tetrahedra), and therefore similar biodegradation rate, as the original 45S5 Bioglass. The amount of magnesium and cobalt in the glass was varied, with the aim of reducing or removing calcium and phosphate from the compositions. Electrospun poly(ε-caprolactone)/bioactive glass composites were also produced. Glasses were tested for ion release in dissolution studies and their influence on Hypoxia-Inducible Factor 1-alpha (HIF-1α) and expression of Vascular Endothelial Growth Factor (VEGF) from fibroblast cells was investigated. Results Dissolution tests showed the silica rich layer differed depending on the amount of MgO in the glass, which influenced the delivery of cobalt. The electrospun composites delivered a more sustained ion release relative to glass particles alone. Exposing fibroblasts to conditioned media from these composites did not cause a detrimental effect on metabolic activity but glasses containing cobalt did stabilise HIF-1α and provoked a significantly higher expression of VEGF (not seen in Co-free controls). Conclusions The composite fibres containing new bioactive glass compositions delivered cobalt ions at a sustained rate, which could be mediated by the magnesium content of the glass. The dissolution products stabilised HIF-1α and provoked a significantly higher expression of VEGF, suggesting the composites activated the HIF pathway to stimulate angiogenesis.

scholarly journals Incorporation of Novel Elements in Bioactive Glass Compositions to Enhance Implant Performance

2021 ◽  
Author(s):  
Joy-anne N. Oliver ◽  
Olanrewaju Akande ◽  
Melanie Ecker
Keyword(s):  
Cell Proliferation ◽  
Bioactive Glass ◽  
Bacterial Infections ◽  
Glass Composition ◽  
Medical Applications ◽  
The Novel ◽  
Bioactive Glasses ◽  
Overall Performance ◽  
A Site ◽  
Glass Compositions

Increasing popularities of bioactive-glasses and their potential medical applications have led to countless studies into improving their material characteristics and overall performance. Some scientists hope to create new bioactive-glass compositions, while others seek to merely modify existing ones such as the novel 45S5 bioactive-glass composition; created by Dr. Larry Hench. These modifications aim to address potential complications that may arise at a site following implantation such as bacterial infections. In other cases, the incorporation of a selected element or compound may aim to improve the implant functioning by increasing cell proliferation. Although possibilities are plentiful, researchers avoid compromising the typical bioactive glass characteristics when doping with elements such as silver, or gold to achieve additional properties. This chapter elaborates on the incorporation of popular elements by doping bioactive-glass compositions to introduce desired properties based on the implant application.

Metal Contamination of Stream Waters under the Impact of Tanneries

2006 ◽  
Vol 33 (2) ◽  
pp. 55 ◽  
Author(s):  
MARIA LUCIA KOLOWSKI RODRIGUES ◽  
MILTON LUIZ LAQUINTINIE FORMOSO
Keyword(s):  
Water Quality ◽  
Water Discharge ◽  
Solid Material ◽  
Total Variance ◽  
Oxygen Conductivity ◽  
Contamination Degree ◽  
Iron Aluminum ◽  
Relevant Variables ◽  
Stream Waters ◽  
The Impact

This study evaluated the contamination of water samples from Cadeia and Feitoria rivers (Rio Grande do Sul State, Brazil), affected by tannery activities. From July 1999 to April 2000, four sampling campaigns were performed at ten sites in order to evaluate selected metals and ancillary physicochemical variables. Sample preservation and analyses followed recommendations of the Standard Methods. Factor analysis was used to obtain statistical indexes representing the contamination degree of waters evaluated. The information was summarized in two principal components. The first, which accounted for 50% of the total variance, was associated to a tannery contribution and generated a contamination index. Total, Suspended and Dissolved Solids, Dissolved Oxygen, Conductivity, Chromium, Manganese, Copper, Nickel, Sodium, Calcium, Potassium, and Magnesium were the well-correlated variables with this first component. The water quality decreased from headwaters up to mouth along both streams, but the most contaminated sites were located at the lower reach of Feitoria river (Ivoti and Lindolfo Collor cities), where tanneries are concentrated. After the entrainment of Feitoria waters (São Sebastião do Caí municipality), Cadeia river also presented an increased contamination degree. The application of statistical randomization tests highlighted these same sites as significantly distinct from the others. Water contamination also showed association to flow variations, and a poorer water quality was observed during the dry period (January). The second component, in which Iron, Aluminum, and Suspended Solids were the relevant variables, was loaded with 15% of the total variance. It was linked to natural events, since higher factor scores in this component were obtained during a period of increased water discharge (October), which caused resuspension and entrainment of solid material to the rivers bed. As a final result of the study, sampling stations were classified according to the contamination degree, and graphically represented on a basin map, which synthesized the environmental diagnosis.

scholarly journals The Correlation between Physical Crosslinking and Water-Soluble Drug Release from Chitosan-Based Microparticles

Pharmaceutics ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 455
Author(s):  
Emilia Szymańska ◽  
Katarzyna Woś-Latosi ◽  
Julia Jacyna ◽  
Magdalena Dąbrowska ◽  
Joanna Potaś ◽  
...  
Keyword(s):  
Drug Release ◽  
Polymer Matrix ◽  
Drug Loading ◽  
Water Soluble ◽  
Dissolution Behavior ◽  
Complex Nature ◽  
Prolonged Release ◽  
Scanning Calorimetry ◽  
Burst Effect ◽  
The Impact

Microparticles containing water-soluble zidovudine were prepared by spray-drying using chitosan glutamate and beta-glycerophosphate as an ion crosslinker (CF). The Box–Behnken design was applied to optimize the microparticles in terms of their drug loading and release behavior. Physicochemical studies were undertaken to support the results from dissolution tests and to evaluate the impact of the crosslinking ratio on the microparticles’ characteristics. The zidovudine dissolution behavior had a complex nature which comprised two phases: an initial burst effect followed with a prolonged release stage. The initial drug release, which can be modulated by the crosslinking degree, was primarily governed by the dissolution of the drug crystals located on the microparticles’ surfaces. In turn, the further dissolution stage was related to the drug diffusion from the swollen polymer matrix and was found to correlate with the drug loading. Differential Scanning Calorimetry (DSC) studies revealed the partial incorporation of a non-crystallized drug within the polymer matrix, which correlated with the amount of CF. Although CF influenced the swelling capacity of chitosan glutamate microparticles, surprisingly a higher amount of CF did not impact the time required for 80% of the drug to be released markedly. The formulation with the lowest polymer:CF ratio, 3:1, was selected as optimal, providing satisfactory drug loading and displaying a moderate burst effect within the first 30 min of the study, followed with a prolonged drug release of up to 210 min.

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