Grafted Polymers and Copolymers of Vinyl Pyrrolidone for Improved Water Dispersible Granules

2009 ◽  
pp. 404-404-9
Author(s):  
E Fu ◽  
RK Chaudhuri ◽  
KS Narayanan
Keyword(s):  
Vinyl Pyrrolidone ◽  
Grafted Polymers ◽  
Water Dispersible

Characterization of N-Vinyl pyrrolidone grafting into silicone rubber

1989 ◽  
Vol 47 ◽  
pp. 882-883
Author(s):  
R. Lee ◽  
R. Greer
Keyword(s):  
Cross Sections ◽  
Silicone Rubber ◽  
Sodium Bicarbonate Solution ◽  
Monomer Concentration ◽  
Surface Preparation ◽  
Vinyl Pyrrolidone ◽  
Grafted Polymers ◽  
Depth Of Penetration ◽  
Structural Reinforcement ◽  
Thickness Measurements

Since 1960, hydrogels have been utilized in a large number of biomedical products. The poor mechanical strength of hydrogels necessitates the use of a stronger support material in order to provide structural reinforcement. Methods of surface preparation include radiation grafting. Parameters of importance for grafting N-vinyl pyrrolidone (NVP) into silicone rubber include the choice of solvent, monomer concentration, radiation dose and use of selective inhibitors. Post irradiation extraction of homopolymer and monomer from the silicone rubber substrate after grafting is an important step. NVP grafted polymers can be stained by many dyes for depth of penetration studies.Fourteen cm sections of non-reinforced Silastic® (silicone rubber, Dow Corning) tubing, 0.078″x0.125″, were boiled for three 1 h periods in aqueous 2.0% sodium bicarbonate solution. Prior to irradiation, monomer solutions used to fill tubes were bubbled with nitrogen for at least 30 min. Several monomer/solvent formulations (100% NVP; 80% NVP/20% methanol; and 60% NVP/40% methanol, and gamma irradiation doses (50, 150, 200 and 250 krad) were used.) After irradiation, samples were flushed with either acetone/methanol (50:50 v/o) or ethanol/water (50:50 v/o) , followed by three 30 min agitated washes in the same type of solution. To test the effect of methanol concentration on rim thickness measurements, 0.5 cm lengths of cleaned Silastic , acetone/methanol extracted Silastic®, and grafted tubing of 100% NVP and 80% NVP/20% methanol formulations were immersed in 0.1% acid fuchsin stains in 10, 50, and 100% methanol for 48 h. After rinsing and drying, cross sections were cut, and the penetration depth of the stain (i.e., graft depth) was measured.

Cellular Uptake and Magneto-Hyperthermia Induced Cytotoxicity using Photoluminescent Fe3O4 Nanoparticle/Si Quantum Dot Hybrids

2020 ◽  
Author(s):  
Morteza Javadi ◽  
Van A. Ortega ◽  
Alyxandra Thiessen ◽  
Maryam Aghajamali ◽  
Muhammad Amirul Islam ◽  
...  
Keyword(s):  
Radio Frequency ◽  
Biomedical Applications ◽  
Short Term ◽  
Water Dispersible ◽  
Optical Responses ◽  
Si Quantum Dot ◽  
Real World Applications ◽  
Potential Benefits ◽  
Low Toxicity ◽  
Si Quantum Dots

<p>The design and fabrication of Si-based multi-functional nanomaterials for biological and biomedical applications is an active area of research. The potential benefits of using Si-based nanomaterials are not only due to their size/surface-dependent optical responses but also the high biocompatibility and low-toxicity of silicon itself. Combining these characteristics with the magnetic properties of Fe<sub>3</sub>O<sub>4</sub> nanoparticles (NPs) multiplies the options available for real-world applications. In the current study, biocompatible magnetofluorescent nano-hybrids have been prepared by covalent linking of Si quantum dots to water-dispersible Fe<sub>3</sub>O<sub>4</sub> NPs <i>via</i> dicyclohexylcarbodiimide (DCC) coupling. We explore some of the properties of these magnetofluorescent nano-hybrids as well as evaluate uptake, the potential for cellular toxicity, and the induction of acute cellular oxidative stress in a mast cells-like cell line (RBL-2H3) by heat induction through short-term radio frequency modulation (10 min @ 156 kHz, 500 A). We found that the NPs were internalized readily by the cells and also penetrated the nuclear membrane. Radio frequency activated nano-hybrids also had significantly increased cell death where > 50% of the RBL-2H3 cells were found to be in an apoptotic or necrotic state, and that this was attributable to increased triggering of oxidative cell stress mechanisms. </p>

scholarly journals Effect of Compatibility on the Foaming Behavior of Injection Molded Polypropylene and Polycarbonate Blend Parts

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 300 ◽  
Author(s):  
Bei Su ◽  
Ying-Guo Zhou ◽  
Bin-Bin Dong ◽  
Cao Yan
Keyword(s):  
Morphological Structure ◽  
Potential Method ◽  
Grafted Polymers ◽  
Dynamic Mechanical Analyzer ◽  
Blowing Agent ◽  
Cell Nucleation ◽  
Foaming Behavior ◽  
Thermal Features ◽  
Injection Molded ◽  
Scanning Electron

To improve the foaming behavior of a common linear polypropylene (PP) resin, polycarbonate (PC) was blended with PP, and three different grafted polymers were used as the compatibilizers. The solid and foamed samples of the PP/PC 3:1 blend with different compatibilizers were first fabricated by melt extrusion followed by injection molding (IM) with and without a blowing agent. The mechanical properties, thermal features, morphological structure, and relative rheological characterizations of these samples were studied using a tensile test, dynamic mechanical analyzer (DMA), scanning electron microscope (SEM), and torque rheometer. It can be found from the experimental results that the influence of the compatibility between the PP and PC phases on the foaming behavior of PP/PC blends is substantial. The results suggest that PC coupling with an appropriate compatibilizer is a potential method to improve the foamability of PP resin. The comprehensive effect of PC and a suitable compatibilizer on the foamability of PP can be attributed to two possible mechanisms, i.e., the partial compatibility between phases that facilitates cell nucleation and the improved gas-melt viscosity that helps to form a fine foaming structure.

Antibacterial catechol-based hyaluronic acid, chitosan and poly (N-vinyl pyrrolidone) coatings onto Ti6Al4V surfaces for application as biomedical implant

2021 ◽  
Author(s):  
Jon Andrade del Olmo ◽  
Leyre Pérez-Álvarez ◽  
Miguel Ángel Pacha-Olivenza ◽  
Leire Ruiz-Rubio ◽  
Oihane Gartziandia ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Vinyl Pyrrolidone ◽  
Biomedical Implant

scholarly journals ALD coating of centrifugally spun polymeric fibers and postannealing: case study for nanotubular TiO2 photocatalyst

2021 ◽  
Author(s):  
Martina Rihova ◽  
Oksana Yurkevich ◽  
Martin Motola ◽  
Ludek Hromadko ◽  
Zdeněk Spotz ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Vinyl Pyrrolidone ◽  
Tio2 Photocatalyst ◽  
Polymeric Fibers ◽  
Layer Deposition ◽  
Centrifugal Spinning ◽  
Poly Vinyl Pyrrolidone

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...

scholarly journals Potential Implantable Nanofibrous Biomaterials Combined with Stem Cells for Subchondral Bone Regeneration

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3087
Author(s):  
Rana Smaida ◽  
Luc Pijnenburg ◽  
Silvia Irusta ◽  
Erico Himawan ◽  
Gracia Mendoza ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Regeneration ◽  
Subchondral Bone ◽  
Therapeutic Potential ◽  
Sodium Hyaluronate ◽  
Vinyl Pyrrolidone ◽  
Regenerative Ability ◽  
Poly Vinyl Pyrrolidone

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.

scholarly journals In Vitro Drug Release, Permeability, and Structural Test of Ciprofloxacin-Loaded Nanofibers

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 556
Author(s):  
Luca Éva Uhljar ◽  
Sheng Yuan Kan ◽  
Norbert Radacsi ◽  
Vasileios Koutsos ◽  
Piroska Szabó-Révész ◽  
...  
Keyword(s):  
Amorphous State ◽  
Physical Mixture ◽  
Water Soluble ◽  
Vinyl Pyrrolidone ◽  
Amorphous Solid Dispersion ◽  
Release Mechanism ◽  
Dissolution Studies ◽  
In Vitro Diffusion ◽  
Poly Vinyl Pyrrolidone

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.

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