Characterization of surface NH+3Cl− groups on poly(styrene-co-Boc-aminostyrene) microspheres obtained by controlled acidic treatment

Covolan, Vera L.; Galembeck, Fernando; Leite, Carlos Alberto de Paula; Ruggeri, Giacomo; Chiellini, Emo

doi:10.1016/j.jcis.2004.01.070

Cited by 5 publications

(3 citation statements)

References 12 publications

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“…In order to expose functional amino groups for the coupling of HER, BOC protective groups were cleaved from the nps surface under acidic conditions in water . Deprotection was performed at pH 1 for 1 h for PCL‐PUR nps and for 30 min for PCL‐PEG‐PUR nps.…”

Section: Methodsmentioning

confidence: 99%

“…In order to expose functional amino groups for the coupling of HER, BOC protective groups were cleaved from the nps surface under acidic conditions in water. 20 Deprotection was performed at pH 1 for 1 h for PCL-PUR nps and for 30 min for PCL-PEG-PUR nps. These conditions had been previously optimized in order to maximize the exposure of surface functional groups without causing polymer degradation, as acidic conditions may cause hydrolysis of ester bonds in polyester urethanes.…”

Section: Preparation Of Immuno-nps -Exposure Of Surface Functional Grmentioning

confidence: 99%

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Surface‐functionalized polyurethane nanoparticles for targeted cancer therapy

Mattu

Silvestri

Wang

et al. 2016

Polymer International

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Polymer nanoparticles (nps) have gained growing interest as carriers for anticancer drugs as they can target tumour tissues by both passive and active pathways. While the passive targeting mechanisms mainly rely on the small size of the carriers, active targeting requires surface modifications of the polymer core in order to introduce specific functionalities to actively recognize cancer cells. The present work proposes an innovative method for the preparation of surface-functionalized nps based on the use of biodegradable polyester-and polyester/ether-urethanes (PURs) embedding amino functionalities. Two polyurethanes were prepared, one based on just poly( -caprolactone) diol (PCL-PUR) and the other based on both PCL diol and poly(ethylene glycol) (PEG) (70/30 ratio, PCL-PEG-PUR). Nanoparticles of small size ranging between 150 and 200 nm and negative potential (ranging from −18 mV to −27 mV) were obtained. Functional groups were exposed post nps preparation as confirmed by X-ray photoelectron spectroscopy, ninhydrin assay and 1 H NMR, which evidenced a 24% tert-butyloxycarbonyl cleavage for PCL-PUR-NH 2 nps and 29% for PCL-PEG-PUR-NH 2 nps. The monoclonal antibody Herceptin (HER), which targets HER-2 receptors, was coupled through ethyl(dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (EDC/NHS) mediated chemistry. The optimal HER:NH 2 ratio was determined to be 1:16 for the PEG-containing PUR and 1:8 for PCL-PUR. HER-nps maintained the intrinsic cytotoxicity of the antibody, as shown by the ca 50% decrease of HER-2-expressing HeLa cell viability. The results indicate that our protocol for surface functionalization of PUR nps, based on surface exposure of previously inserted functional groups followed by covalent coupling of biomolecules, is suitable for the preparation of nps for active recognition of target cells.

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Section: Methodsmentioning

confidence: 99%

Section: Preparation Of Immuno-nps -Exposure Of Surface Functional Grmentioning

confidence: 99%

Surface‐functionalized polyurethane nanoparticles for targeted cancer therapy

Mattu

Silvestri

Wang

et al. 2016

Polymer International

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“…The acceleration is furnished through the enhancement of DNA collision probability by virtue of either the transient interaction of DNA binding-capable reagents with DNA and/or reduction of electrostatic repulsion of negatively charged DNA. Therefore, we have chosen positively charged polystyrene nanospheres (PSNSs) as a demonstrating platform based on the following considerations: (1) Surface-functionalized PSNSs with controllable sizes could be facilely synthesized by emulsion polymerization of styrene in the presence of a minor amount of charge-imparting monomer (e.g., methacrylic acid, , 4-vinylbenzyl amine hydrochloride (4-VBAH), − t -butoxycarbonyl-protected 4-aminostyrene); (2) The amino functional groups on the PSNS surface would be useful for both the covalent conjugation of DNA − and the generation of positively charged environment, thus facilitating electrostatic interaction between aminated PSNS (APSNS) surface and negatively charged DNA and increasing the likelihood of hybridization between complementary DNA strands; (3) The positive surface charge is also expected to reduce the electrostatic repulsion between negatively charged DNA strands and therefore enhance the collision probability of complementary strands.…”

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confidence: 99%

Ultrafast Kinetic DNA Hybridization Assay Based on the Visualization of Threshold Turbidity

Shu

et al. 2012

Anal. Chem.

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We report herein the development of an ultrafast kinetic DNA hybridization assay system based on the visualization of threshold turbidity associated with the assembly of polystyrene nanospheres. Initial testing of our diagnostic protocol on a sequence associated with the anthrax lethal factor indicates that a visually identifiable, turbidity-definitive, and kinetic threshold state could be reached at a time as short as 1 min. The assay scheme allows for both target concentration quantification and differentiation of single base mismatches through registry of the threshold turbidity onset time. The positively charged environment on nanospheres not only contributes to expedited signal generation but also imparts cooperative DNA binding properties. The kinetic visual protocol complements conventionally used thermodynamic strategies and provides an entry point for the circumvention of assay issues associated with ill-defined thermodynamic end points.

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Monodisperse Particles Based on Copolymers of Methyl methacrylate or Styrene with N‐Vinylformamide

Men’shikova

Evseeva

Шевченко

et al. 2009

Macromolecular Symposia

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Sammary: Various techniques of one‐step batch emulsion copolymerization of methyl methacrylate (MMA) or styrene (St) with N‐vinylformamide (NVF) initiated by 2,2′‐azobis(2‐methylpropanamidine) (AIBA) or 2,2′‐azobis[4,5‐dihydroimidazol‐2‐yl] (AIP) dihydrochlorides in the presence of dextran, cetyltrimethylammonium bromide (CTAB) or without any stabilizers were examined to obtain monodisperse submicron and nano‐ particles, having both positive surface charge and hydrophilic surface. After hydrolysis in acidic media, the particle surface contained amino groups originating from NVF units along with carboxylic groups from hydrolyzed initiator residues. The obtained particles were tested as building blocks of hierarchic structures. Owing to their amphiphilic surface, the particles were capable of self‐assembling from their dispersions into three‐dimentional (3D) ordered arrays.

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Characterization of surface NH+3Cl− groups on poly(styrene-co-Boc-aminostyrene) microspheres obtained by controlled acidic treatment

Cited by 5 publications

References 12 publications

Surface‐functionalized polyurethane nanoparticles for targeted cancer therapy

Surface‐functionalized polyurethane nanoparticles for targeted cancer therapy

Ultrafast Kinetic DNA Hybridization Assay Based on the Visualization of Threshold Turbidity

Monodisperse Particles Based on Copolymers of Methyl methacrylate or Styrene with N‐Vinylformamide

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