Electroinitiated polymerization of vinyl pyrrolidone

1963 ◽  
Vol 1 (4) ◽  
pp. 181-183 ◽  
Author(s):  
B. Lionel Funt ◽  
Fredrick D. Williams
Author(s):  
Jon Andrade del Olmo ◽  
Leyre Pérez-Álvarez ◽  
Miguel Ángel Pacha-Olivenza ◽  
Leire Ruiz-Rubio ◽  
Oihane Gartziandia ◽  
...  

2021 ◽  
Author(s):  
Martina Rihova ◽  
Oksana Yurkevich ◽  
Martin Motola ◽  
Ludek Hromadko ◽  
Zdeněk Spotz ◽  
...  

This work describes the synthesis of highly photocatalytically active TiO2 tubes (TiTBs) by combining centrifugal spinning and atomic layer deposition (ALD). Poly(vinyl pyrrolidone) (PVP) fibers were first produced by centrifugal...


Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3087
Author(s):  
Rana Smaida ◽  
Luc Pijnenburg ◽  
Silvia Irusta ◽  
Erico Himawan ◽  
Gracia Mendoza ◽  
...  

The treatment of osteochondral defects remains a challenge. Four scaffolds were produced using Food and Drug Administration (FDA)-approved polymers to investigate their therapeutic potential for the regeneration of the osteochondral unit. Polycaprolactone (PCL) and poly(vinyl-pyrrolidone) (PVP) scaffolds were made by electrohydrodynamic techniques. Hydroxyapatite (HAp) and/or sodium hyaluronate (HA) can be then loaded to PCL nanofibers and/or PVP particles. The purpose of adding hydroxyapatite and sodium hyaluronate into PCL/PVP scaffolds is to increase the regenerative ability for subchondral bone and joint cartilage, respectively. Human bone marrow-derived mesenchymal stem cells (hBM-MSCs) were seeded on these biomaterials. The biocompatibility of these biomaterials in vitro and in vivo, as well as their potential to support MSC differentiation under specific chondrogenic or osteogenic conditions, were evaluated. We show here that hBM-MSCs could proliferate and differentiate both in vitro and in vivo on these biomaterials. In addition, the PCL-HAp could effectively increase the mineralization and induce the differentiation of MSCs into osteoblasts in an osteogenic condition. These results indicate that PCL-HAp biomaterials combined with MSCs could be a beneficial candidate for subchondral bone regeneration.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 556
Author(s):  
Luca Éva Uhljar ◽  
Sheng Yuan Kan ◽  
Norbert Radacsi ◽  
Vasileios Koutsos ◽  
Piroska Szabó-Révész ◽  
...  

Nanofibers of the poorly water-soluble antibiotic ciprofloxacin (CIP) were fabricated in the form of an amorphous solid dispersion by using poly(vinyl pyrrolidone) as a polymer matrix, by the low-cost electrospinning method. The solubility of the nanofibers as well as their in vitro diffusion were remarkably higher than those of the CIP powder or the physical mixture of the two components. The fiber size and morphology were optimized, and it was found that the addition of the CIP to the electrospinning solution decreased the nanofiber diameter, leading to an increased specific surface area. Structural characterization confirmed the interactions between the drug and the polymer and the amorphous state of CIP inside the nanofibers. Since the solubility of CIP is pH-dependent, the in vitro solubility and dissolution studies were executed at different pH levels. The nanofiber sample with the finest morphology demonstrated a significant increase in solubility both in water and pH 7.4 buffer. Single medium and two-stage biorelevant dissolution studies were performed, and the release mechanism was described by mathematical models. Besides, in vitro diffusion from pH 6.8 to pH 7.4 notably increased when compared with the pure drug and physical mixture. Ciprofloxacin-loaded poly(vinyl pyrrolidone) (PVP) nanofibers can be considered as fast-dissolving formulations with improved physicochemical properties.


Membranes ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 143
Author(s):  
Lara Grünig ◽  
Ulrich A. Handge ◽  
Joachim Koll ◽  
Oliver Gronwald ◽  
Martin Weber ◽  
...  

In this study, a triblock copolymer was used as additive to fabricate new dual layer hollow fiber membranes with a hydrophilic active inner surface in order to improve their fouling resistance. The polymeric components of the solutions for membrane fabrication were poly(ether sulfone), poly(N-vinyl pyrrolidone), and the triblock copolymer. The additive consists of three blocks: a middle hydrophobic poly(ether sulfone) block and two outer hydrophilic alkyl poly(ethylene glycol) blocks. By varying the additive concentration in the solutions, it was possible to fabricate dual layer hollow fiber membranes that are characterized by a hydrophilic inner layer, a pure water permeance of over 1800 L/(m2 bar h) and a molecular weight cut-off of 100 kDa similar to commercial membranes. Contact angle and composition determination by XPS measurements revealed the hydrophilic character of the membranes, which improved with increasing additive concentration. Rheological, dynamic light scattering, transmission, and cloud point experiments elucidated the molecular interaction, precipitation, and spinning behavior of the solutions. The low-molecular weight additive reduces the solution viscosity and thus the average relaxation time. On the contrary, slow processes appear with increasing additive concentration in the scattering data. Furthermore, phase separation occurred at a lower non-solvent concentration and the precipitation time increased with increasing additive content. These effects revealed a coupling mechanism of the triblock copolymer with poly(N-vinyl pyrrolidone) in solution. The chosen process parameters as well as the additive solutions provide an easy and inexpensive way to create an antifouling protection layer in situ with established recipes of poly(ether sulfone) hollow fiber membranes. Therefore, the membranes are promising candidates for fast integration in the membrane industry.


Biomaterials ◽  
2005 ◽  
Vol 26 (34) ◽  
pp. 7002-7011 ◽  
Author(s):  
Xiaowei Li ◽  
Wenguang Liu ◽  
Guixiang Ye ◽  
Bingqi Zhang ◽  
Dunwan Zhu ◽  
...  

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