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Versatile Nature of Poly(Vinylpyrrolidone) in Clinical Medicine
Published in P. Mereena Luke, K. R. Dhanya, Didier Rouxel, Nandakumar Kalarikkal, Sabu Thomas, Advanced Studies in Experimental and Clinical Medicine, 2021
K. R. Dhanya, P. Mereena Luke, Sabu Thomas, Didier Rouxel, Nandakumar Kalarikkal
It is synthesized by free radical polymerization reaction using free radical initiator azobisisobutyronitrile. PVP is prepared from N-vinylpyrrolidone (NVP) and radical polymerization of NVP in bulk, solution, or in suspension, yields poly(vinylpyrrolidone) (Figure 4.2).
Elements of Polymer Science
Published in E. Desmond Goddard, James V. Gruber, Principles of Polymer Science and Technology in Cosmetics and Personal Care, 1999
E. Desmond Goddard, James V. Gruber
where M represents the monomer molecule and R*a free radical produced in the initial step. Commonly used initiators are peroxides, such as potassium persulfate (soluble in water) or benzoyl peroxide (soluble in organic solvents), and aliphatic azo compounds, such as azobisisobutyronitrile (AIBN).
Design of Bioresponsive Polymers
Published in Deepa H. Patel, Bioresponsive Polymers, 2020
Anita Patel, Jayvadan K. Patel, Deepa H. Patel
Stable free radicals, like nitroxides, are used as reversible terminating agents in the NMRP method, to manage the polymerization process [31, 32]. These radicals have a structure analogous to that of nitrogen monoxide. Through reversible deactivation of the growing chains, during covalent bond formation, dormant chains are produced. The single unpaired electron is delocalized over the nitrogen-oxygen bond, and this delocalization and the captodative structure of the radical ads to its permanence. The deactivation happens via the recombination of the radical chain ending by such stable nitroxide. The created C–O–N bond is thermolabile; moreover, the bond goes through a homolytic cleavage to make the active growing chain along with the nitroxide radical at high temperatures (90–130°C). The reaction temperature controls the equilibrium between active and dormant species. Activation is succeeded by a fast deactivation, where a handful of monomer units are integrated into the propagating chain. The development of a hydrido nitroxide is the latest foremost progress in nitroxide-mediated polymerization, wherein the existence of a hydrogen atom on the α-carbon results in a considerable rise in the range of vinyl monomers that go through controlled polymerization [33]. The beginning of the reaction can be attained via common initiators, for example, azobisisobutyronitrile or benzoyl peroxide. Iniferter is another approach in which the initiating as well as terminating moiety united in one molecule. By means of multifunctional iniferters, distinctive polymer structures such as block, star, or graft copolymers can be created [34, 35]. For instance, telechelic PNIPAAms could be produced through nitroxide-mediated controlled polymerization by introducing distinct end-group moieties. Through a triazole moiety different functional groups, connected to the central nitroxide-initiator arising from the so-called azide/alkyne-”click” reactions, were explored with isopropylacrylamides and butyl acrylate as monomers with regard to competence and livingness [36].
Glutathione conjugation and protein modification resulting from metabolic activation of venlafaxine in vitro and in vivo
Published in Xenobiotica, 2021
Yilin Li, Yang Wang, Na Zhang, Shenzhi Zhou, Ying Peng, Jiang Zheng
VLF was supplied by Meryer Chemical Technology Co., Ltd. (Shanghai, China). ODV was obtained from Shanghai Jizhi Biochemical Technology Co., Ltd. (Shanghai, China). The purity of VLF and ODV were both >98%. Glutathione (GSH), cysteine, DL-dithiothreitol (DTT), S-hexylglutathione and reduced nicotinamide adenine dinucleotide phosphate (NADPH) were purchased from Sigma-Aldrich (St. Louis, MO). N-Bromosuccinimide (NBS) and azobisisobutyronitrile (AIBN) were obtained from Shanghai Aladdin Biochemical Technology Co., Ltd. (Shanghai, China). Manganese dioxide was purchased from Tianjin Damao Chemical Reagent Co., Ltd. (Tianjin, China). Mouse (Kunming, male) liver microsomes were prepared in our laboratory (Lin et al. 2014). Recombinant human P450 enzymes were obtained from BD Gentest (Corning, MA). Pronase E and chymotrypsin were acquired from Solarbio (Beijing, China). Distilled water was provided from Wahaha Co., Ltd. (Hangzhou, China). All organic solvents were from Fisher Scientific (Springfield, NJ). All reagents and solvents were of either analytical or HPLC grade.
Development and characterization dual responsive magnetic nanocomposites for targeted drug delivery systems
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Lida Ahmadkhani, Abolfazl Akbarzadeh, Mojtaba Abbasian
PEG, biological grade, with a molecular weight (MW) of 4000 was supplied by the Sigma-Aldrich (St. Louis, MO). N-Isopropyl-acrylamide (Sigma-Aldrich, St. Louis, MO, >99%, NIPAM) was recrystallized from n-hexane. Methacrylic acid (Merck, Kenilworth, NJ, >99%, methacrylic acid (MA)) was distilled under vacuum before use. Azobisisobutyronitrile (AIBN, Merck, Kenilworth, NJ) is a free radical initiator, which, was recrystallized from methanol former to use. Tetrahydrofuran (Scharlau, Hamburg, Germany, >99%, THF), n-hexane (Merck, Kenilworth, NJ, >99%), dimethyl formamide (Sigma-Aldrich, St. Louis, MO, 99%, DMF), dichloromethane (Chem-Lab, Fishers, IN, >99.8%, DCM), chloroform (Mojallali, Tehran, Iran, >99%), ethanol (Merck, Kenilworth, NJ, 99.9%), methanol (Merck, Kenilworth, NJ, 99.9%) were used as purchased without further purification and used as received. 4-Cyano-4-((thiobenzoyl)sulfanyl)pentanoic acid as an RAFT agent was supplied by the Sigma-Aldrich (St. Louis, MO). Foetal bovine serum (FBS) (Gibco, Invitrogen, Paisley, UK), RPMI 1640, TRIzol reagent, Trypsin-EDTA and antibiotics were purchased from Invitrogen (Paisley, UK). (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (Sigma-Aldrich, St. Louis, MO, MTT) were purchased and used without purification. Lung cancer cell was prepared from Pasteur Institute Cell Bank of Iran. Doxorubicin hydrochloride (Sigma-Aldrich, St. Louis, MO, DOX) were used without purification.
Development of poly(hydroxyethyl methacrylate) nanogel for effective oral insulin delivery
Published in Pharmaceutical Development and Technology, 2018
Xiaomei Wang, Dan Cheng, Linglin Liu, Xuejun Li
The insulin-loaded nanogel was synthesized via microemulsion polymerization. Briefly, 0.3 g Span 80, 0.35 g Tween-80 and 5 mg azobisisobutyronitrile (AIBN) initiator were dissolved in 10 ml hexane and kept in an ice bath. Five milligram human-recombined insulin or 5 mg FITC-dextran (for nanoparticle tracking study), 100 mg HEMA monomer and 2 mg N,N′-methylenebisacrylamide (MBAA) (for the soft nanogel) or 20 mg MBAA (for the stiff nanogel) were dissolved in 0.5 ml Tris–HCl buffer that controlled pH = 4. Under vigorous stirring, the two solutions were mixed in a flask followed by strong sonication to form a microemulsion. The flask was sealed and purged nitrogen at 4 °C for 1 h to remove dissolved oxygen completely. The reaction was carried out in 50 °C bath under nitrogen protection with overnight polymerization. The product was washed for three times with hexane to remove the surfactants, and Ultra centrifugal filter with the cutoff weight of 100 kD (Amicon, Ultracel-100 K; Millipore, Temecula, CA) was applied three times using deionized water as mobile phase to purify the nanogel from unreacted small molecule and residue organic solvent. The insulin or FITC-dextran loaded nanogel was finally freeze-dried and stored in vacuum before use.