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Recent Development of Hemodialysis Membrane Materials
Published in Stephen Gray, Toshinori Tsuru, Yoram Cohen, Woei-Jye Lau, Advanced Materials for Membrane Fabrication and Modification, 2018
Muhammad Irfan, Masooma Irfan, Ani Idris, Ghani ur Rehman
Polyvinylpyrrolidone (PVP) is an amphiphilic, hydrophilic, and inert water-soluble polymer, widely used in dialysis membrane composition. It promotes the macrovoid-free structure in the HFs and enhances the membrane biocompatibility. It is also believed that PVP could form poor miscible blends with hydrophobic polymers due to lack of attractive forces between them. However, as PVP leaching is likely to occur during dialysis, the issue needs to be solved. Researchers prepared binary, ternary, and tetra-blocks or copolymer by composite and covalent methods and blended them with a polymer such as PES (Nissenson and Fine, 2016).
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Published in Mara Cercignani, Nicholas G. Dowell, Paul S. Tofts, Quantitative MRI of the Brain: Principles of Physical Measurement, 2018
PVP (Polyvinylpyrrolidone) is biologically benign (used in postage stamp adhesive and shampoo) and stable. A 25% solution in water at 0oC has T1 = 533 ms, T2 = 519 ms at 1.5T and T1 = 610 ms, T2 = 500 ms at 3T. ADC is 0.49 10−9 m2s−1 (Jerome et al., 2016; Pullens et al., 2017). PVP was first suggested by Pierpaoli et al., in 2009.
Preparation of a carbon-based nanomaterial and its influence on construction engineering
Published in Journal of Experimental Nanoscience, 2023
The dispersant polyvinylpyrrolidone is dissolved in purified water and heated to 60 °C and kept at a constant temperature to completely dissolve. A water-soluble polymer known as polyvinylpyrrolidone (PVP) is generated when N-vinylpyrrolidone is synthesized. PVP is a polymer that helps to encapsulate and deliver both hydrophilic and lipophilic substances. It is non-toxic, inert, temperature-resistant, pH-stable, biocompatible, and biodegradable. High tensile strength, flexibility, and oxygen and aroma barrier properties are all characteristics of poly (vinyl alcohol). It also possesses superior film-forming, emulsifying, and adhesive qualities. The monomer N-vinylpyrrolidone6 is converted into the water-soluble polymer known as poly (vinylpyrrolidone). After that, we add the weighed and functionalized multi-walled carbon nanotubes, and put them in a magnetic stirrer to stir evenly. The mixture was sonicated for 60 min and cooled to room temperature. Then, we add an appropriate amount of defoamer to eliminate surface bubbles, then pour the dispersion into a cement mortar mixer and add a certain proportion of cement. Standard sand, water, and water reducing agent are mixed evenly and put into a standard cement glue triple mold (40 mm × 400mm × 160mm), then smoothed, vibrated, shaped, and covered with a wet cloth. After demolding after 24 h, it is moved to a standard curing box, and the test specimen was obtained after standard curing for 28 days (temperature 20 °C, humidity 95%).
Study and optimization of formulation parameters during freeze–drying cycles of model probiotic: Morphology characterization of lyophilisates by scanning electron microscopy
Published in Drying Technology, 2023
P. Verlhac, S. Vessot, G. Degobert, G. Agusti, C. Cogne, J. Andrieu, L. Beney, P. Gervais, S. Moundanga
For our study, we have selected the strain Lactobacillus casei ATCC 393 as model probiotic bacteria.[5] Simultaneously, the viability of the bacteria in the drying medium was assessed with the addition of two types of cryo-protectants. First, the lactose, a well-known disaccharide used as pharmaceutical excipient as well as an ingredient for dairy or nutrition products for its protective effect.[6] Next, the polyvinylpyrrolidone (PVP), a pharmaceutical grade excipient widely used in different pharmaceutical formulations.[7] The combination of these two protectants offer an interesting perspective for long time conservation, because the PVP is known as a glass forming agent with a high Tg value, and, moreover, it can inhibit the lactose crystallization.[8] The phase diagrams of water mixtures of these three components have been previously deeply investigated in our laboratory by determining the vitreous transition curves of these formulation leading to the Tg values which are known to be key parameters for setting up the optimal sublimation and desorption conditions.[2,9] First, we investigated some freezing protocols (cooling’s rate, nucleation temperature, annealing treatment) leading to the highest survival ratios.[10] Next, with the preselected formulation and the optimal freezing rate we studied the sublimation step by investigating the influence of the sublimation operating parameters, namely the total gas pressure inside the sublimation chamber and the shelf temperature on the bacteria survival ratios and on the sublimation times.
PVP-microneedle array for drug delivery: mechanical insight, biodegradation, and recent advances
Published in Journal of Biomaterials Science, Polymer Edition, 2023
Keisham Nelson Mangang, Pragati Thakran, Jitu Halder, Kuldeep Singh Yadav, Goutam Ghosh, Deepak Pradhan, Goutam Rath, Vineet Kumar Rai
Polyvinylpyrrolidone (PVP) is a synthetic polymer synthesized by polymerizing N-vinylpyrrolidone monomer and Povidone. Being a biocompatible, non-toxic, inert, pH stable, non-ionic, and temperature-resistant polymer with a complex affinity toward water-soluble and water-insoluble drugs [15–17], it has been widely used for preparing MNs for local and systemic uses. It has good solubility in water and organic solvents. It is available in various grades (Table 1) and viscosities [16]. It presents good binding properties and stabilizes suspensions and emulsions [18]. After being introduced as a plasma volume expander in the 1940s [16], it has been widely used in pharmaceuticals [19,20], biomedical [17, 20], cosmetics [21], and food sectors [22]. PVP is used as a binder in many types of tablets [23] and has been recognized for internal use by the Food and Drug Association (FDA) [24]. Its unique features and chemistry facilitate the synthesis of various homopolymers, crosslinked-PVP, and copolymers with different molecular weights (MW) [17]. Despite these properties, little information is available about the mechanical insights and biodegradation potential of PVP alone or in combination.