Relating the dynamics of hydrated poly(vinyl pyrrolidone) to the dynamics of highly asymmetric mixtures and polymer blends

2021 ◽  
pp. 115907
Author(s):  
Kaito Sasaki ◽  
Masanobu Takatsuka ◽  
Naoki Shinyashiki ◽  
Kia L. Ngai
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.


2014 ◽  
Vol 809-810 ◽  
pp. 9-16 ◽  
Author(s):  
Jian Jun Tian

Monodispersed magnetic SmCo nanoparticles have been prepared by polyol synthesis using non-toxic inorganic precursors (nitrates). The effect of the additives of NaOH, HNO3, CH3COOH and poly vinyl pyrrolidone (PVP) on the formation of SmCo nanoparticles is studied in this paper. The results indicate that base solution can boost the reduction of Co while acid solution is helpful for the formation of SmCo due to decreasing the reduction velocity of Co. CH3COOH is appropriate additive for the synthesis of SmCo nanoparticles, but more addition of CH3COOH will result in the emergence of CoC2 phase and decrease the coercivity of the resultants. The additive of PVP not only is a dispersing agent, but can prevent them from oxidating during preparation process. The SmCo nanoparticles with a size of 5-8 nm have the ferromagnetic properties of high coercivity (>1000 Oe).


Sign in / Sign up

Export Citation Format

Share Document