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Polymer Nanoparticles (polymer + nanoparticle)

Distribution by Scientific Domains
Polymers and Materials Science66%

Selected Abstracts

Multifunctioning pH-responsive nanoparticles from hierarchical self-assembly of polymer brush for cancer drug delivery

AICHE JOURNAL, Issue 11 2008
Youqing Shen
Abstract Polymer nanoparticles are extensively explored as drug carriers but they generally have issues of premature burst drug release, slow cellular uptake, and retention in acidic intracellular compartments. Herein, we report multifunctioning three-layered nanoparticles (3LNPs) that can overcome these problems. The 3LNPs have a poly(,-caprolactone) (PCL) core, a pH-responsive poly[2-(N,N-diethylamino)ethyl methacrylate](PDEA) middle layer and a polyethylene glycol (PEG) outer layer. The pH-responsive PDEA layer is insoluble at pH above 7 but becomes positively charged and soluble via protonation at pH lower than 6.5. Thus, this layer has three functions: it covers on the PCL core inhibiting the premature burst drug release at the physiological pH, becomes positively charged and thus promotes endocytosis for fast cellular internalization in the acidic interstitium of solid tumors, and is highly positively charged in lysosomes to disrupt the lysosomal membrane and release the nanoparticle into the cytosol. The multifunctioning nanoparticles are an efficient carrier for cancer cytosolic drug delivery. © 2008 American Institute of Chemical Engineers AIChE J, 2008 [source]

Recent progress in the use of soluble ionic polymers as pseudostationary phases for electrokinetic chromatography

ELECTROPHORESIS, Issue 23-24 2004
Christopher P. Palmer
Abstract This review concerns the development, characterization, and application of soluble ionic polymeric materials as pseudostationary phases for electrokinetic chromatography since 2002. Cationic polymers, anionic siloxanes, polymerized surfactants (micelle polymers), and chiral polymers are considered. The use of stable suspensions of polymer nanoparticles in electrokinetic chromatography is also reviewed. [source]

Conjugated Polymer Nanoparticles for Two-Photon Imaging of Endothelial Cells in a Tissue Model

ADVANCED MATERIALS, Issue 34 2009
Nur Aida Abdul Rahim
Fabrication and characterization of 8-nm-sized conjugated polymer nanoparticles (CPNs) and two-photon (2P) imaging of CPN labeled endothelial cells in a collagen-gel-based microfluidic device is described. CPNs exhibit super brightness and photostability comparable to quantum dots. The hydrophilicity and non-toxicity of CPNs enable long-term monitoring of cells in a tissue model, supporting CPNs' potential in biological and biomedical applications. [source]

Unique Phase-Separation Structures of Block-Copolymer Nanoparticles,

ADVANCED MATERIALS, Issue 17 2005
H. Yabu
Block-copolymer nanoparticles with lamellar phase-separation structures (see Figure) have been prepared by a slow-precipitation process. Regular-sized polymer nanoparticles are formed after evaporation of a good solvent from a polymer solution containing a non-volatile poor solvent and a volatile good solvent. [source]

Using anionic polymerizable surfactants in ultrasonically irradiated emulsion polymerization to prepare polymer nanoparticles

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2008
Yuhui He
Abstract An ionic polymerizable surfactant, sodium sulfopropyl-laurylmaleate (M12), was synthesized and used as an emulsifier, an initiator, and a comonomer in ultrasonically irradiated emulsion polymerization. FTIR spectra and gravimetric method results indicated that copolymers P(Styrene-M12) and P(Butylacrlate-M12) were prepared successfully by ultrasonically irradiated emulsion polymerization and the composition of M12 elevated with the increasing concentration of M12 added. TEM photographs of P(St-M12) showed that the nanoparticles with small diameters (20,45 nm) were prepared. With the increase of M12 concentration, the particle size became smaller and the size distribution became wider. The P(BA-M12) particles size was also small (<100 nm) but the size distribution was wide due to the high reactivity of BA. Because surfmer M12 was chemically bonded with the latex particles, the stability of the copolymer latex prepared by ultrasonically irradiated emulsion polymerization was much better than that of the homopolymer latex (PSt or PBA) prepared by the same way. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

Eudragit RL100 nanoparticle system for the ophthalmic delivery of cloricromene

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 7 2004
Claudio Bucolo
A Eudragit RL100 polymer nanoparticle system loaded with cloricromene was prepared and characterized on the basis of physicochemical properties, stability and drug release features. To investigate the ocular bioavailability of cloricromene after inclusion in the polymer matrix, the new nanoparticle system was topically administered in the rabbit eye and compared with an aqueous solution of the same drug. The nanoparticle system showed interesting size distribution and surface charge values, suitable for ophthalmic application. The results indicated that the dispersion of cloricromene within Eudragit RL100 polymer nanoparticles increased its ocular bioavailability and enhanced the biopharmaceutical profile. The new cloricromene-loaded nanoparticle system described here may be useful in clinical practice. [source]

A versatile preparation of azobenzene-dye functionalized colored polymer nanoparticles by surface modification

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2008
Caroline Cannizzo
Abstract A series of stable and translucent colored nanolatex, that is, colloidal aqueous suspensions of dye-tagged polymer nanoparticles (NPs) in the 15- to 20-nm diameter range, have been prepared by covalent attachment of azobenzene chromophores to the surface of reactive NPs. Primary crosslinked NPs bearing chlorobenzyl groups were produced by microemulsion copolymerization of styrene and vinylbenzylchloride. Amine-functionalized NPs were obtained after a second functionalization step with polyamines (cyclam and polypropyleneimine dendrimers of first and third generations). Dye-doped particles were obtained by reacting pyridylazo-dimethylaminobenzene (PADA) with chlorobenzyl-NPs and by reacting amine-reactive dimethylaminoazobenzene dyes (DABsyl, DAB-ITC) as well as Disperse Red 1 acrylate with polyamine-coated NPs. Regardless the dye solubility, the grafting readily proceeded in aqueous suspensions at room temperature in the presence of a cationic surfactant without added solvent. Purple, red, and orange suspensions (maximum absorption around 550, 500, 430 nm), with dye loads ranging from 0.3 to 1.2 mmol/g, corresponding to 400,1800 azobenzene residues per NP, are obtained. The reported results indicate that functional polymer NPs, with remarkably accessible multiple anchoring sites, are useful building blocks. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3375,3386, 2008 [source]

Synthesis and Evaluation of Water-Soluble Fluorinated Dendritic Block-Copolymer Nanoparticles as a 19F-MRI Contrast Agent

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 14 2010
Michihiro Ogawa
Abstract Well-defined water-soluble fluorinated polymer nanoparticles (PNPs) with a high fluorine content and biocompatibility were successfully prepared by living radical polymerization (LRP) of 2,2,3,3-tetrafluoropropyl methacrylate (TFPMA) from the polyamidoamine dendrimer macroinitiator (PAMAM-Br), and successive block polymerization of carboxybetaine monomer (CMB). The obtained core,shell type PNPs (PAMAM- g -PTFPMA- b -PCMB) showed high solubility in water and a sphere-like structure with a diameter in the range of 15,80,nm in water. The short 19F-NMR spin,lattice relaxation time (T1) (<250,ms) of PAMAM- g -PTFPMA- b -PCMB allowed the use of fast repetition time. The spin,spin relaxation time (T2) was evaluated to be as low as 10 ms. 19F-MRI in vitro signals can be detectable even at concentrations lower than 1 µM (particle concentration). These results demonstrate that a new type of 19F-MRI contrast agent can be developed by the molecular design using the dendrimer-initiated LRP method. [source]

Fluorinated Polymer Nanoparticles as a Novel 19F MRI Contrast Agent Prepared by Dendrimer-Initiated Living Radical Polymerization

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 12 2010
Michihiro Ogawa
Abstract Novel fluorinated polymer nanoparticles (PNPs) for 19F MRI were prepared by living radical polymerization initiated by a dendrimer. The dendritic macroinitiator with Br substituents was synthesized from hydroxy-group-terminated G2 polyamidoamine dendrimers. The arborescent fluorinated polymers of 2,2,3,3-tetrafluoropropyl methacrylate and 2,2,2-trifluoroethyl methacrylate were characterized in molecular weight, the number of arms, the degree of polymerization per arm, and the diameter as a whole. The PNP diameter was precisely controlled by the molecular weight in the range of 3,25,nm. In addition, the fluorinated PNP gave a narrow resonance by 19F NMR spectroscopy. These results indicate that the fluorinated PNP can be used as a new type of 19F MRI agent. [source]

Mass transport studies of different additives in polyamide and exfoliated nanocomposite polyamide films for food industry

PACKAGING TECHNOLOGY AND SCIENCE, Issue 2 2010
David Antonio Pereira de Abreu
Abstract The development of new food packaging films through the incorporation of nanoparticles, and the effect of the nanoparticles on the process of migration of the substances used in manufacturing the new films is expected to lead to an improvement in the shelf life of food and thus, consumer safety and health. In recent years, attention has focused on nanocomposites because these compounds often exhibit unexpected hybrid properties derived from synergistic reactions between nanoparticles and the polymeric matrix. The exfoliation of nanoclays in polyamide film provides a film with better barrier properties than that obtained through the intercalation of nanoclays. Migration of chemicals from food packaging into food may produce potential adverse health effects because of exposure to toxic compounds. The present study addressed the migration of caprolactam, 5-Chloro-2-(2,4-dichlorophenoxy)phenol (triclosan) and trans,trans-1,4-diphenyl-1,3-butadiene (DPBD) from polyamide and polyamide-nanoclays to different types of food simulants. The values for limit of detection (LOD) obtained for caprolactam, triclosan and DPBD was 0.5,mg/L, 0.02,mg/L and 0.01,mg/L, respectively. Furthermore, instrumental precision was evaluated through repeatability injections, resulting in relative standard deviations lower than 3.08%. Diffusion coefficients were calculated according to a mathematical model based on Fick's Second Law, and the results were discussed in terms of the parameters that may have the greatest effect on migration. The presence of polymer nanoparticles was found to slow down the rate of migration of substances from the matrix polymer into the food up to six times. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Synthesis of oligocaprolactone vinyl ether macromonomers and their use for indomethacin encapsulation in polymer nanoparticles based on polycaprolactone macromonomer,maleic anhydride,N -vinyl pyrrolidone terpolymers

POLYMER INTERNATIONAL, Issue 2 2006
Cristina Iojoiu
Abstract Oligocaprolactone macromonomers functionalized with vinyl ether have been synthesized by polymerization of ,-caprolactone in the presence of hydroxy ethyl or butyl vinyl ether and characterised by NMR and Maldi time-of-flight mass spectroscopy. These macromonomers have been copolymerized with maleic anhydride and N -vinyl pyrrolidone to give terpolymers, which have been used to obtain nanoparticles by the phase-separation-dialysis method. Previously dissolving indomethacin in the terpolymer solution allows one to encapsulate the drug inside the nanoparticles. Copyright © 2005 Society of Chemical Industry [source]