Understanding the Colloidal Behaviour or 45S5 Bioactive Glass Particles to Obtain Bioactive-Glass Based Composite Coatings by EPD

2015 ◽  
Vol 654 ◽  
pp. 15-19
Author(s):  
Sandra Cabanas-Polo ◽  
Aldo R. Boccaccini
Keyword(s):  
Polyvinyl Alcohol ◽  
Bioactive Glass ◽  
Functional Groups ◽  
Polyacrylic Acid ◽  
Glass Phase ◽  
Composite Coatings ◽  
Surface Reactions ◽  
Colloidal Processing ◽  
And Control ◽  
Soft Composite

The interaction between bioactive glass particles and polymers with different functional groups has been established in this work to better understand and control the colloidal processing of the bioactive glass phase. Cationic polyvinylpyrrolidone (PVP), anionic polyacrylic acid (PAA) and neutral polyvinyl alcohol (PVA) were selected and the surface reactions in alcoholic media and between bioactive glass particles and polymers were considered. All three polymers were successfully employed to obtain soft composite coatings incorporating bioactive glass particles.

scholarly journals RHEOLOGY OF WATER-SOLUBLE MONOMERS AND THEIR MIXTURES

2021 ◽  
pp. 113-122
Author(s):  
Межлум Левонович Ерицян ◽  
Армен Мамиконович Арустамян ◽  
Валентина Межлумовна Мависакалян
Keyword(s):  
Acrylic Acid ◽  
Spatial Structure ◽  
Polyvinyl Alcohol ◽  
Aqueous Solutions ◽  
Functional Groups ◽  
Polyacrylic Acid ◽  
Relative Viscosity ◽  
Water Soluble ◽  
Simultaneous Formation

Исследована реология водных растворов полиакриловой кислоты, полиакриламида, поливинилового спирта, сополимера акриловой кислоты с акриламидом, a также смесeй водных растворов этих полимеров. В результате образования ассоциатов между функциональными группами уаказанных полимеров значительно повышается относительная вязкость их водных растворов. Установлено, что при температуре 95C в водных растворах полиакриламида и сополимера акриловой кислоты с акриламидом происходит интенсивное выделение аммиака с одновременным образованием полимера пространственной структуры. The rheology of aqueous solutions of polyacrylic acid, polyacrylamide, polyvinyl alcohol, copolymer of acrylic acid with acrylamide, as well as mixtures of aqueous solutions of these polymers was investigated. As a result of the formation of associates between the functional groups of the polymers indicated, the relative viscosity of their aqueous solutions significantly increases. It was established that at a temperature of 95°C in aqueous solutions of polyacrylamide and a copolymer of acrylic acid and acrylamide, there is an intense release of ammonia with simultaneous formation of a polymer of spatial structure.

scholarly journals Synthesis and Characterization of Silver–Strontium (Ag-Sr)-Doped Mesoporous Bioactive Glass Nanoparticles

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 34
Author(s):  
Shaher Bano ◽  
Memoona Akhtar ◽  
Muhammad Yasir ◽  
Muhammad Salman Maqbool ◽  
Akbar Niaz ◽  
...  
Keyword(s):  
Bioactive Glass ◽  
Composite Coatings ◽  
Antibacterial Properties ◽  
Bone Diseases ◽  
Osteogenic Potential ◽  
Diffusion Method ◽  
Charge Composition ◽  
In Vitro Bioactivity ◽  
Mesoporous Bioactive Glass

Biomedical implants are the need of this era due to the increase in number of accidents and follow-up surgeries. Different types of bone diseases such as osteoarthritis, osteomalacia, bone cancer, etc., are increasing globally. Mesoporous bioactive glass nanoparticles (MBGNs) are used in biomedical devices due to their osteointegration and bioactive properties. In this study, silver (Ag)- and strontium (Sr)-doped mesoporous bioactive glass nanoparticles (Ag-Sr MBGNs) were prepared by a modified Stöber process. In this method, Ag+ and Sr2+ were co-substituted in pure MBGNs to harvest the antibacterial properties of Ag ions, as well as pro-osteogenic potential of Sr2 ions. The effect of the two-ion concentration on morphology, surface charge, composition, antibacterial ability, and in-vitro bioactivity was studied. Scanning electron microscopy (SEM), X-Ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) confirmed the doping of Sr and Ag in MBGNs. SEM and EDX analysis confirmed the spherical morphology and typical composition of MBGNs, respectively. The Ag-Sr MBGNs showed a strong antibacterial effect against Staphylococcus carnosus and Escherichia coli bacteria determined via turbidity and disc diffusion method. Moreover, the synthesized Ag-Sr MBGNs develop apatite-like crystals upon immersion in simulated body fluid (SBF), which suggested that the addition of Sr improved in vitro bioactivity. The Ag-Sr MBGNs synthesized in this study can be used for the preparation of scaffolds or as a filler material in the composite coatings for bone tissue engineering.

scholarly journals Direct access to spirocycles by Pd/WingPhos-catalyzed enantioselective cycloaddition of 1,3-enynes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Long Li ◽  
Shan Wang ◽  
Pengfei Luo ◽  
Ran Wang ◽  
Zheng Wang ◽  
...  
Keyword(s):  
Drug Discovery ◽  
Functional Groups ◽  
Organic Synthesis ◽  
Enantioselective Synthesis ◽  
Direct Access ◽  
Cycloaddition Reactions ◽  
Drug Discovery And Development ◽  
Spirocyclic Compounds ◽  
And Control ◽  
By Products

AbstractSpirocycles play an important role in drug discovery and development. The direct, catalytic, and enantioselective synthesis of spirocycles from readily available starting materials and in an atom economic manner remains a highly sought-after task in organic synthesis. Herein, an enantioselective Pd-hydride-catalyzed cycloaddition method for the synthesis of spirocyclic compounds directly from two classes of commonly available starting materials, 1,3-enynes and cyclic carbon−hydrogen (C−H) bonds, is reported. The reactions employ a chiral Pd/WingPhos catalyst to both suppress the formation of bis-allenyl by-products and control the stereoselectivity. 1,3-Enynes are used as dielectrophilic four-carbon units in the cycloaddition reactions, which also enables an enyne substrate-directed enantioselectivity switch with good levels of stereocontrol. The present spirocycle synthesis tolerates a broad range of functional groups of 1,3-enyne substrates, including alcohols, esters, nitriles, halides, and olefins. A variety of diverse cyclic nucleophiles, including pharmaceutically important heterocycles and carbocycles, can be flexibly incorporated with spiro scaffolds.

Electrophoretic deposition of carbon nanotubes and bioactive glass particles for bioactive composite coatings

2010 ◽  
Vol 36 (1) ◽  
pp. 307-312 ◽  
Author(s):  
M. Charlotte Schausten ◽  
Decheng Meng ◽  
Rainer Telle ◽  
Aldo R. Boccaccini
Keyword(s):  
Carbon Nanotubes ◽  
Bioactive Glass ◽  
Electrophoretic Deposition ◽  
Composite Coatings

Hybrid Bioactive Glass-Polyvinyl Alcohol Prepared by Sol-Gel

2008 ◽  
Vol 587-588 ◽  
pp. 62-66 ◽  
Author(s):  
Hermes S. Costa ◽  
Alexandra A.P. Mansur ◽  
Edel Figueiredo Barbosa-Stancioli ◽  
Marivalda Pereira ◽  
Herman S. Mansur
Keyword(s):  
Mechanical Properties ◽  
Polyvinyl Alcohol ◽  
Bioactive Glass ◽  
Sol Gel ◽  
Degree Of Hydrolysis ◽  
Bioactive Glasses ◽  
Composite Foams ◽  
Composition Ratios ◽  
Hybrid Scaffolds ◽  
Hydrolysis Of

Bioactive glasses are materials that have been used for the repair and reconstruction of diseased bone tissues, as they exhibit direct bonding with human bone tissues. However, bioactive glasses have low mechanical properties compared to cortical and cancellous bone. On the other hand, composite materials of biodegradable polymers with inorganic bioactive glasses are of particular interest to engineered scaffolds because they often show an excellent balance between strength and toughness and usually improved characteristics compared to their individual components. Composite bioactive glass-polyvinyl alcohol foams for use as scaffolds in tissue engineering were previously developed using the sol-gel route. The goal of this work was the synthesis of composite foams modified with higher amounts of PVA. Samples were characterized by morphological and chemical analysis. The mechanical behavior of the obtained materials was also investigated. The degree of hydrolysis of PVA, concentration of PVA solution and different PVA-bioactive glass composition ratios affect the synthesis procedure. Foams with up to 80 wt% polymer content were obtained. The hybrid scaffolds obtained exhibited macroporous structure with pore size varying from 50 to 600 µm and improved mechanical properties.

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