Physically-crosslinked polyvinyl alcohol composite hydrogels containing clays, carbonaceous materials and magnetic nanoparticles as fillers

2020 ◽  
Vol 8 (3) ◽  
pp. 103795 ◽  
Author(s):  
Laura M. Sanchez ◽  
Peter S. Shuttleworth ◽  
Carolina Waiman ◽  
Graciela Zanini ◽  
Vera A. Alvarez ◽  
...  
2021 ◽  
pp. 089270572098557
Author(s):  
M Abu-Abdeen ◽  
O Saber ◽  
E Mousa

A solvent thermal method which depends on a thermal process under critical temperature and pressure was used to prepare cobalt iron oxide magnetic nanoparticles with a molar ratio 2. The prepared particles were in the form of nanoparticles with diameter ranging from 5 to 10 nm and with amorphous structure. Magnetic hysteresis behavior with saturation magnetization 36.31 emu/g and coercivity 4 Oe were observed for the nanoparticles. Polyvinyl alcohol was loaded with different concentrations of cobalt iron oxide nanoparticles using casting technique. Hysteresis loops for the polymer films were observed and both the saturation magnetization and coercivity were increased from 0.36 to 16.03 emu/g and 115 to 293 Oe for samples containing 5 and 20 wt% of nanoparticles, respectively. The elastic modulus of films was increased from 2.7 to 4.9 GPa for unloaded and loaded samples with 20 wt%, respectively. The storage modulus of the polymer films was found to obey the percolation behavior.


2021 ◽  
Author(s):  
Xingyu Chen ◽  
Zuxin Wang ◽  
Shan Gao ◽  
Wanlin Zhang ◽  
Hanwen Gong ◽  
...  

The Tibetan eighteen flavor dangshen pills (TEP) are composed of 18 traditional Tibetan medicines, which are commonly used in the treatment of skin diseases in the Tibetan medicine system. They...


2014 ◽  
Vol 131 (18) ◽  
pp. n/a-n/a ◽  
Author(s):  
Wubin Xiong ◽  
Yueping Guan ◽  
Chen Guo ◽  
Mingzhu Yang ◽  
Tingting Xia ◽  
...  

2021 ◽  
Vol 53 (sup1) ◽  
pp. S25-S26
Author(s):  
S. Schweizer ◽  
I. Monteiro ◽  
A.S Oliveira ◽  
P. Nolasco ◽  
R. Colaço ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3893
Author(s):  
Deevak Ramnandan ◽  
Seipati Mokhosi ◽  
Aliscia Daniels ◽  
Moganavelli Singh

Cancer-based magnetic theranostics has gained significant interest in recent years and can contribute as an influential archetype in the effective treatment of cancer. Owing to their excellent biocompatibility, minute sizes and reactive functional surface groups, magnetic nanoparticles (MNPs) are being explored as potential drug delivery systems. In this study, MgFe2O4 ferrite MNPs were evaluated for their potential to augment the delivery of the anticancer drug doxorubicin (DOX). These MNPs were successfully synthesized by the glycol-thermal method and functionalized with the polymers; chitosan (CHI), polyvinyl alcohol (PVA) and polyethylene glycol (PEG), respectively, as confirmed by Fourier transform infrared (FTIR) spectroscopy. X-ray diffraction (XRD) confirmed the formation of the single-phase cubic spinel structures while vibrating sample magnetometer (VSM) analysis confirmed the superparamagnetic properties of all MNPs. Transmission electron microscopy (TEM) and nanoparticle tracking analysis (NTA) revealed small, compact structures with good colloidal stability. CHI-MNPs had the highest DOX encapsulation (84.28%), with the PVA-MNPs recording the lowest encapsulation efficiency (59.49%). The 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyl tetrazolium bromide (MTT) cytotoxicity assays conducted in the human embryonic kidney (HEK293), colorectal adenocarcinoma (Caco-2), and breast adenocarcinoma (SKBR-3) cell lines showed that all the drug-free polymerized MNPs promoted cell survival, while the DOX loaded MNPs significantly reduced cell viability in a dose-dependent manner. The DOX-CHI-MNPs possessed superior anticancer activity (<40% cell viability), with approximately 85.86% of the drug released after 72 h in a pH-responsive manner. These MNPs have shown good potential in enhancing drug delivery, thus warranting further optimizations and investigations.


2014 ◽  
Vol 1622 ◽  
pp. 37-40
Author(s):  
Tomoyo Sakaguchi ◽  
Suong-Hyu Hyon ◽  
Kazuaki Matsumura

ABSTRACTPhysically crosslinked polyvinyl alcohol (PVA) hydrogels with high mechanical properties can be made by a low temperature crystallization method using a mixed solvent of dimethyl sulfoxide (DMSO) and water. Such hydrogels are studied as the artificial articular cartilage material. But DMSO shows cytotoxycity, and it is also have the effect of accelerating the absorption of harmful substances. Therefore completely elimination must be required for clinical application but the process is difficult.However, PVA hydrogel made by water as a sole solvent by freeze-thawing method became cloudy because of micro-heterogeneous structure, and shows low mechanical properties.Therefore, in this study, we developed the novel hot pressing method for preparing transparent and uniformly cross-linked PVA hydrogels without DMSO from highly concentrated aqueous solution. By this method, PVA hydrogels with high mechanical property and high transparency can be obtained without any harmful organic solvent because of the fast crystallization even at room temperature. The mechanical properties of PVA hydrogels were remarkably depended on their water contents after gelation, regardless of solution concentration.


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