Preparation and Pharmaco-Mechanical Characterization of Ketoprofen- Polyvinyl Alcohol Cryogel for Medical Applications

Polyvinyl alcohol is a biocompatible polymer used very commonly both in pharmaceutical and medical fields. Being a water-soluble polymer, it is suitable for the manufacture of hydrogels as well as cryogels used for various medical applications. The present work describes the preparation, structural and physico-mechanical characterization of polyvinyl alcohol cryogels loaded with ketoprofen. By cryogenic technique the polymeric solutions are transformed under certain conditions into porous, elastic and very compressible structures. They are able to absorb a large amount of liquids that they give off by gentle compression. The prepared cryogels were evaluated for different physical, chemical and structural properties, as following: internal morphology, equilibrium swelling ratio and mechanical testing. The cryogel structures show good elasticity and optimal swelling at different temperatures. Due to these properties the studied cryogels are suitable for use in various medical applications involving liquid absorption, mechanical resistance and anti-inflammatory effect.

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Synthesis of Nanostructured Magnetic Mixed-Oxide Ferrite Powders by Using A Novel Chemical Method

MRS Proceedings ◽

10.1557/proc-720-h3.3 ◽

2002 ◽

Vol 720 ◽

Author(s):

N N Ghosh

Keyword(s):

Particle Size ◽

Mixed Oxide ◽

Chemical Method ◽

Average Particle Size ◽

Cost Effective ◽

Water Soluble ◽

Average Particle ◽

Chemical Route ◽

Water Soluble Polymer ◽

Different Temperatures

AbstractIn the present investigation, an attempt has been made to establish a new chemical route for synthesis of the nanostructured mixed oxide ferrite powders. By using this chemical method a variety of ferrite powders having spinel structure and doped with Co, Ni, Mn, Zn etc has been prepared. In this method nitrate salts of the different metals were used as starting materials. The aqueous solutions of the metal nitrates were mixed according to the molar ration of the compositions. Then the mixtures were mixed with an aqueous solution of water soluble polymer (polyvinyl alcohol). This mixture after drying yield fluffy brown powders. These powders were then calcined at different temperatures ranging from 400 °C to 700 °C. Nanostructured powders were obtained from the thermal decomposition of the brown powders. The powders, prepared by calcinations at different temperatures, were characterized by using X-Ray diffraction analysis, IR spectroscopy, TGA/DTA, and TEM. It was observed that the average particle size of the powders are in nanometer scale with a narrow size distribution. The average particle size of the powders was increased with the increase of calcinations temperature.This chemical method has proved to provide a convenient process for the preparation of nanostructured ceramic powders at comparatively low temperatures and offers the potential of being a simple and cost-effective route.

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Rheological properties of pectin, poly(vinyl alcohol) and their blends in aqueous solutions

e-Polymers ◽

10.1515/epoly.2012.12.1.160 ◽

2012 ◽

Vol 12 (1) ◽

Cited By ~ 7

Author(s):

Katarzyna Lewandowska ◽

Aldona Dąbrowska ◽

Halina Kaczmarek

Keyword(s):

Aqueous Solutions ◽

Rheological Properties ◽

Vinyl Alcohol ◽

Water Soluble ◽

Poly Vinyl Alcohol ◽

Concentric Cylinder ◽

Water Soluble Polymer ◽

Flow Measurements ◽

Result Show ◽

Different Temperatures

AbstractThe new blends composed of natural polysaccharide - pectin and synthetic water soluble polymer - poly(vinyl alcohol) (PVA) are attractive materials due to their biocompatibility, non-toxicity and biodegradability. In this work the rheological properties of aqueous solutions of pectin (PEC), poly(vinyl alcohol) and their mixtures at various weight ratios (70/30, 50/50, 30/70) have been investigated. Flow measurements were carried out using a rotary viscometer with concentric cylinder at different temperatures (20-70 ºC) and shear rates (24- 1234 s-1). The flow parameters and energy of activation have been calculated from the flow curves and Arrhenius plots, respectively. It was found that studied polymer solutions exhibited non-Newtonian behavior, moreover, the flow properties were dependent on the blend composition. The result show that practically there was no thixotropy in studied system but some interactions between PVA and pectin in water occurred.

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Preparation, morphological, and mechanical characterization of titanium dioxide (TiO2)/polyvinyl alcohol (PVA) composite for gamma-rays radiation shielding

Journal of Physics Conference Series ◽

10.1088/1742-6596/1279/1/012019 ◽

2019 ◽

Vol 1279 ◽

pp. 012019 ◽

Cited By ~ 1

Author(s):

R. K. Fakher Alfahed ◽

Kareem K. Mohammad ◽

Munaf S. Majeed ◽

Hussain Ali Badran ◽

Kamal M. Ali ◽

...

Keyword(s):

Titanium Dioxide ◽

Polyvinyl Alcohol ◽

Gamma Rays ◽

Mechanical Characterization ◽

Radiation Shielding

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Mechanical Characterization of Woven Composites at Different Temperatures.

10.2172/1463795 ◽

2018 ◽

Author(s):

Huiqing Jin ◽

Timothy Briggs ◽

April Nissen ◽

Kevin Nelson

Keyword(s):

Mechanical Characterization ◽

Woven Composites ◽

Different Temperatures

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Epipyrone A, a Broad-Spectrum Antifungal Compound Produced by Epicoccum nigrum ICMP 19927

Molecules ◽

10.3390/molecules25245997 ◽

2020 ◽

Vol 25 (24) ◽

pp. 5997

Author(s):

Alex J. Lee ◽

Melissa M. Cadelis ◽

Sang H. Kim ◽

Simon Swift ◽

Brent R. Copp ◽

...

Keyword(s):

Antifungal Activity ◽

Fungal Spores ◽

Chemical Characterization ◽

Water Soluble ◽

Antifungal Compound ◽

Alkaline Ph ◽

Epicoccum Nigrum ◽

Different Temperatures ◽

Excellent Stability

We have isolated a filamentous fungus that actively secretes a pigmented exudate when growing on agar plates. The fungus was identified as being a strain of Epicoccum nigrum. The fungal exudate presented strong antifungal activity against both yeasts and filamentous fungi, and inhibited the germination of fungal spores. The chemical characterization of the exudate showed that the pigmented molecule presenting antifungal activity is the disalt of epipyrone A—a water-soluble polyene metabolite with a molecular mass of 612.29 and maximal UV–Vis absorbance at 428 nm. This antifungal compound showed excellent stability to different temperatures and neutral to alkaline pH.

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Production and Characterization of Hydroxyapatite-Zirconia Composites

High Temperature Materials and Processes ◽

10.1515/htmp-2012-0006 ◽

2012 ◽

Vol 31 (6) ◽

pp. 749-753 ◽

Cited By ~ 1

Author(s):

Melis Ozmen ◽

Ipek Akin ◽

Muzeyyen Marsoglu

Keyword(s):

Mechanical Properties ◽

Fracture Toughness ◽

Sintering Temperature ◽

Medical Applications ◽

Mineral Component ◽

Human Teeth ◽

Zirconia Composites ◽

Different Temperatures

AbstractHydroxyapatite (HA) ceramics are used extensively in different medical applications, such as biomaterial for repair or replacement of bone tissues since it resembles mineral component of bone and teeth. However, HA exhibits low fracture toughness due to its lack of strength and brittleness, thereby providing an obstacle to its application in implants that must withstand to high loads. In this study, HA was synthesized from human teeth by using a single calcinations method. Hydroxyapatite powders were mixed with different amounts of zirconia. The composites were sintered at different temperatures and characterized in terms of mechanical properties and the optimum sintering temperature was determined for good mechanical properties.

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Tantalum(V) peroxido complexes as phosphatase inhibitors: a comparative study vis-a-vis peroxidovanadates

New Journal of Chemistry ◽

10.1039/d1nj01005k ◽

2021 ◽

Author(s):

Gangutri Saikia ◽

Hiya Talukdar ◽

Kabirun Ahmed ◽

Nand Kishor Gour ◽

Nashreen S Islam

Keyword(s):

Comparative Study ◽

Water Soluble ◽

Sodium Acrylate ◽

Soluble Polymer ◽

Water Soluble Polymer ◽

Phosphatase Inhibitors ◽

Comprehensive Characterization

The present work illustrates the synthesis and comprehensive characterization of novel peroxidotantalum(V) complexes anchored to water soluble polymer (WSP) matrices viz., [Ta2(O2)6(carboxylate)2]-PA, [PA= poly(sodium acrylate)] (PATa) and [Ta(O2)3(sulfonate)2]-PSS, PSS= poly(sodium...

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Study on the Preparation and Lipophilic Properties of Polyvinyl Alcohol (PVA) Nanofiber Membranes via Green Electrospinning

Nanomaterials ◽

10.3390/nano11102514 ◽

2021 ◽

Vol 11 (10) ◽

pp. 2514

Author(s):

Jun Cong Ge ◽

Guirong Wu ◽

Sam Ki Yoon ◽

Min Soo Kim ◽

Nag Jung Choi

Keyword(s):

Polyvinyl Alcohol ◽

Adsorption Capacity ◽

Surface Area ◽

Environmentally Friendly ◽

Contact Angles ◽

Water Soluble ◽

Engine Oil ◽

Bet Surface Area ◽

Water Soluble Polymer ◽

Nanofiber Membranes

As an environmentally friendly water-soluble polymer, polyvinyl alcohol (PVA) has attracted extensive attention because of its non-toxic, degradable, low cost, and good biocompatibility. Electrospinning is a kind of nanotechnology, and the nanofiber membrane prepared by it has the advantages of large surface area-to-volume ratios, nano- to micron-sized fibers, etc. Herein, a simple and facile one-step green electrospinning method was developed to fabricate various environmentally friendly PVA nanofiber membranes. The lipophilic properties of PVA membranes were investigated and optimized according different PVA concentrations. The PVA electrospun fiber prepared from the solution at a concentration of 10 wt% had the highest adsorption capacity for the adsorption of new and waste engine oils, and the waste engine oil adsorption capacity (12.70 g/g) was higher than that of new engine oil (11.67 g/g). It also has a relatively large BET surface area (12.05 m2/g), a pore volume (0.04 cm3/g), and an appropriate pore diameter (13.69 nm) and fiber diameter (174.21 nm). All electrospun PVA membranes showed excellent lipophilic properties due to their oil contact angles of much less than 30°. Therefore, PVA electrospun fibrous membranes have great application potential in the field of purifying engine oil due to the excellent lipophilic properties and oil absorption capacity.

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A novel esterase DacApva from Comamonas sp. strain NyZ500 with deacetylation activity for acetylated polymer polyvinyl alcohol

Applied and Environmental Microbiology ◽

10.1128/aem.03016-20 ◽

2021 ◽

Author(s):

Chao-Fan Yin ◽

Ying Xu ◽

Shi-Kai Deng ◽

Wen-Long Yue ◽

Ning-Yi Zhou

Keyword(s):

Polyvinyl Alcohol ◽

High Energy ◽

Water Soluble ◽

Backbone Cleavage ◽

Water Soluble Polymer ◽

Prevotella Ruminicola ◽

Rich Media ◽

Acetyl Group ◽

High Pollution ◽

Novel Esterase

As a water-soluble polymer, the widely used polyvinyl alcohol (PVA) is produced from hydrolysis of polyvinyl acetate. Microbial PVA carbon backbone cleavage via a two-step reaction of dehydrogenation and hydrolysis has been well studied. Content of acetyl group is a pivotal factor affecting performance of PVA derivatives in industrial application, and deacetylation is a non-negligible part in PVA degradation. However, the genetic and biochemical studies of its deacetylation remain largely elusive. Here, Comamonas sp. strain NyZ500 was isolated for its capability of growing on acetylated PVA from activated sludge. A spontaneous PVA-utilization deficient mutant strain NyZ501 was obtained when strain NyZ500 was cultured in rich media. Comparative analysis between the genomes of these two strains revealed a fragment (containing a putative hydrolase gene dacApva) deletion in NyZ501 and dacApva-complemented strain NyZ501 restored the ability to grow on PVA. DacApva, which shares 21% identity with xylan esterase AxeA1 from Prevotella ruminicola 23, is a unique deacetylase catalyzing the conversion of acetylated PVA and its derivatives to deacetylated counterparts. This indicates that strain NyZ500 utilizes acetylated PVA via acetate as a carbon source to grow. DacApva also possessed the deacetylation ability for acetylated xylan and the antibiotic intermediate 7-aminocephalosporanic acid (7ACA) but the enzymes for the above two compounds had no activities against PVA derivatives. This study enhanced our understanding of the diversity of microbial degradation of PVA and DacApva characterized here is also a potential biocatalyst for the eco-friendly biotransformation of PVA derivatives and other acetylated compounds. IMPORTANCE: Water-soluble PVA, which possesses a very robust ability to accumulate in the environment, has a very grave environmental impact due to its widespread use in industrial and household applications. On the other hand, chemical transformation of PVA derivatives is currently being carried out at high energy consumption and high pollution conditions using hazardous chemicals (such as NaOH, methanol) under high temperatures. The DacApva reported here performs PVA deacetylation under mild conditions, then it has a great potential to be developed into an eco-friendly biocatalyst for biotransformation of PVA derivatives. DacApva also has deacetylation activity for compounds other than PVA derivatives, which facilitates its development into a broad-spectrum deacetylation biocatalyst for production of certain desired compounds.

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