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polymeric nanoparticles

Joachim Laun, Wouter Marchal, Vanessa Trouillet, Alexander Welle, An T Hardy, Marlies K Van Bael, Christopher Barner-Kowollik, Tanja Junkers
Efficient and simple polymer conjugation reactions are critical for introducing functionalities on surfaces. For polymer surface grafting, post polymerization modifications are often required, which can impose a significant synthetic hurdle. Here, we report two strategies that allow for reversible surface engineering via nitrone-mediated radical coupling (NMRC). Macroradicals stemming from activation of polymers generated by copper-mediated radical polymerization are grafted via radical trapping with a surface-immobilized nitrone or a solution-borne nitrone...
February 19, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Dongdong Bi, Lei Zhao, Runqi Yu, Haowen Li, Yifei Guo, Xiangtao Wang, Meihua Han
One major challenge of current surface modification of nanoparticles is the demand for chemical reactive polymeric layers, such modification is always complicated, inefficient, and may lead the polymer lose the ability to encapsulate drug. To overcome this limitation, we adopted a pH-sensitive platform using polydopamine (PDA) as a way of functionalizing nanoparticles (NPs) surfaces. All this method needed to be just a brief incubation in weak alkaline solution of dopamine, which was simple and applicable to a variety of polymer carriers regardless of their chemical reactivity...
November 2018: Drug Delivery
Yiliu Liu, Silvia Pujals, Patrick J M Stals, Thomas Pauloehrl, Stanislav I Presolski, E W Meijer, Lorenzo Albertazzi, Anja R A Palmans
Dynamic single-chain polymeric nanoparticles (SCPNs) are intriguing, bioinspired architectures that result from the collapse or folding of an individual polymer chain into a nanometer-sized particle. Here we present a detailed biophysical study on the behavior of dynamic SCPNs in living cells and an evaluation of their catalytic functionality in such a complex medium. We first developed a number of delivery strategies that allowed the selective localization of SCPNs in different cellular compartments. Live/dead tests showed that the SCPNs were not toxic to cells while spectral imaging revealed that SCPNs provide a structural shielding and reduced the influence from the outer biological media...
February 19, 2018: Journal of the American Chemical Society
Yuyan Jiang, Jingchao Li, Xu Zhen, Chen Xie, Kanyi Pu
Near-infrared (NIR) light is widely used for noninvasive optical diagnosis and phototherapy. However, current research focuses on the first NIR window (NIR-I, 650-950 nm), while the second NIR window (NIR-II, 1000-1700 nm) is far less exploited. The development of the first organic photothermal nanoagent (SPNI-II ) with dual-peak absorption in both NIR windows and its utilization in photothermal therapy (PTT) are reported herein. Such a nanoagent comprises a semiconducting copolymer with two distinct segments that respectively and identically absorb NIR light at 808 and 1064 nm...
February 19, 2018: Advanced Materials
Justin X Zhong, John R Clegg, Eric W Ander, Nicholas A Peppas
Environmentally responsive biomaterials have played key roles in the design of biosensors and drug delivery vehicles. Their physical response to external stimuli, such as temperature or pH, can transduce a signal or trigger the release of a drug. In this work, we designed a robust, highly tunable, pH responsive nanoscale hydrogel system. We present the design and characterization of poly((methacrylic acid) - co - acrylamide) hydrogel nanoparticles, crosslinked with methylenebisacrylamide, through inverse emulsion polymerization...
February 17, 2018: Journal of Biomedical Materials Research. Part A
Yuanyuan Zhang, Dan Yang, Hongzhong Chen, Wei Qi Lim, Fiona Soo Zeng Phua, Guanghui An, Piaoping Yang, Yanli Zhao
In this study, a reduction-sensitive supramolecular polymeric drug delivery system was developed for combinational photothermal-chemotherapy of cancer. The multifunctional system was self-assembled by specific host-guest interactions between hydrophilic β-cyclodextrin functionalized hyaluronic acid and adamantane linked camptothecin/dye conjugate, where a near-infrared (NIR) absorbing dye IR825 was loaded. The hydrophilic hyaluronic acid shell endows the assembly with excellent colloidal stability and biocompatibility...
February 9, 2018: Biomaterials
Jiali Li, Luting Yan
Polydopamine (PDA) film coatings are multifunctional substances because these coatings can adhere to nearly all known solid materials. The self-polymerization of dopamine in aqueous solution was investigated in this study; PDA films are an effective platform for further functionalization similar to the reduction of silver ions into silver nanoparticles (NPs). The films provide a new method to attach metal NPs on substrates. Through this simple method, glucose sensors based on this kind of Ag NPs/ITO exhibited a detection limit of about 10 μM and presented a good sensitivity enough for real use (3-8 mM)...
March 1, 2018: Journal of Nanoscience and Nanotechnology
Jila Talat, Mohammad Sabzi, Behrouz Safibonab, Iraj Hasanzadeh, Ali Arman, Isa Karimzadeh
The aim of this work was to prepare strong and conductive polyurethane acrylate nanocomposites. First, urethane prepolymers with different molecular weights and hydrophilicities were synthetized. Then, their corresponding polyurethane acrylate nanocomposites were prepared by ultrasonically-assisted emulsion polymerization in the presence of various ratios of urethane prepolymers and acrylate monomers. Thermogravimetric analysis (TGA) and tensile results showed that thermal stability and mechanical properties of polyurethane acrylate samples are significantly dependent on the molecular weight and hydrophilicity of the urethane prepolymer as well as the content of acrylate monomers...
February 1, 2018: Journal of Nanoscience and Nanotechnology
Goolia Nikravan, Vahid Haddadi-Asl, Mehdi Salami-Kalajahi
Dual stimuli-responsive yolk-shell nanoparticles with cross-linked poly(acrylic acid) (PAA) pH-responsive core and cross-linked poly(2-hydroxyethyl methacrylate) (PHEMA) temperature-responsive shell were synthesized via two different methods In the first method, silica encapsulated PAA (PAA@SiO 2 ) was used as seed in distillation precipitation polymerization (DPP) of HEMA to yield PAA@SiO 2 @PHEMA from which silica layer was etched by HF solution to produce yolk-shell PAA@air@PHEMA nanoparticles. In the second method, swollen PAA nanoparticles at pH = 10 were used as seeds in emulsion polymerization of HEMA to yield core-shell PAA@PHEMA nanoparticles...
February 9, 2018: Colloids and Surfaces. B, Biointerfaces
Marina González-Burgos, Jose A Pomposo
Ionic liquids (ILs) have shown advantages in organic synthesis and catalysis, energy storage and conversion, as well as a variety of pharmaceutical applications. Understanding the miscibility behavior of IL / monomer, IL / polymer and IL / polymer nanoparticle mixtures is critical for the use of ILs as green solvents in polymerization processes, as well as to rationalize recent observations concerning the superior solubility of some proteins in ILs when compared to standard solvents. In this work, the most relevant results obtained in terms of an extended three-component Flory-Huggins theory concerning the Extra Solvent Power (ESP) of ILs when compared to traditional non-ionic solvents for monomeric solutes (Case I), linear polymers (Case II), dry (i...
February 15, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Gökhan Kocak, Damla Ülker, Cansel Tuncer, Serife Betül Baker, Vural Bütün
A zwitterionic sulfobetaine-based diblock copolymer was successfully synthesized and used in the preparation and stabilization of Ag nanoparticles (AgNPs). For the related block copolymer, a precursor AB type diblock copolymer was synthesized via atom transfer radical polymerization by using a MPEG-based ATRP macroinitiator and 2-(N-dimethylamino)ethyl methacrylate (DMA) comonomer. Tertiary amine residues of PDMA blocks in poly(ethylene glycol) methyl ether-b-poly[2-(N-diethylamino)ethyl methacrylate] (MPEG-b-PDMA) precursor was then converted to polybetaine structures by reacting with 1,3-propanesultone to obtain poly(ethylene glycol) methyl ether-b-poly[3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate] (MPEG-b-PβDMA) derivative...
April 1, 2018: Journal of Nanoscience and Nanotechnology
Zeng-Fang Huang, Xi-Qi Zhang, Xiao-Yong Zhang, Bin Yang, Ke Wang, Shi-Qi Wang, Jin-Ying Yuan, Lei Tao, Yen Wei
Due to the extensive source, good biocompatibility and biodegradability, the starch of carbohydrates has been extensively investigated for application in biological field. Recently, the development of fluorescent organic nanoparticles (FONs) on the basis of aggregation induced emission (AIE) dyes has attracted great research interest. In this article, novel starch-based S-TPEV polymers with AIE property were successfully fabricated by atom transfer radical polymerization (ATRP) of TPEV dye into water-soluble starch for the first time, subsequently, their structure and properties were detailedly investigated by 1H NMR, TEM, UV-vis, FL and FTIR...
April 1, 2018: Journal of Nanoscience and Nanotechnology
Huiping Bai, Caiyun Xiong, Chunqiong Wang, Peng Liu, Su Dong, Qiue Cao
A rhodium (III) ion carbon paste electrode (CPE) based on an ion imprinted polymer (IIP) as a new modifying agent has been prepared and studied. Rh(III) ion imprinted polymer was synthesized by copolymerization of acrylamide-Rh(III) complex and ethylene glycol dimethacrylate according to the precipitation polymerization. Acrylamide acted as both functional monomer and complexing agent to create selective coordination sites in a cross-linked polymer. The ion imprinted carbon paste electrode (IIP-CPE) was prepared by mixing rhodium IIP-nanoparticles and graphite powder in n-eicosane as an adhesive and then embedding them in a Teflon tube...
May 1, 2018: Journal of Nanoscience and Nanotechnology
P Paulraj, A Manikandan, E Manikandan, K Pandian, M K Moodley, K Roro, K Murugan
In the present work, Poly(o-phenylenediamine) (POPD) stabilized silver nanoparticles (POPD@AgNPs) nanocomposites was synthesized by solid state oxidative polymerization method using o-phenylenediamine dihydrochloride (oPD-HCl) as monomer and silver nitrate (AgNO3) used as metal precursor as well as oxidizing agent no other external oxidizing agent was used. POPD@AgNPs nanocomposites were characterized by various instrumental techniques to confirm their size, shape and its composition. The electrocatalytic activity of POPD and POPD@AgNPs modified electrode was investigated over the oxidation of hydrazine (N2H4) and reduction of hydrogen peroxide (H2O2) using Cyclic Voltammetry (CV), Differential Pulse Voltammetry (DPV) and Chronoamperometry techniques...
June 1, 2018: Journal of Nanoscience and Nanotechnology
Maria de Fatima V Marques, Renato J B Oliveira, Rafael S Araujo
Polypropylene nanocomposites with expanded graphite nanosheets (xGN) were synthesized by In Situ polymerization employing a Ziegler-Natta catalyst supported on particles of MgCl2 containing xGN (mass ratio 1:1) and internal electron donor to control isotacticity, and their properties were compared with those of neat polypropylene obtained using a prepared standard Ziegler-Natta catalyst. SEM micrographs showed an alteration in the morphology of the catalyst with nanoparticles when compared with the standard one...
July 1, 2018: Journal of Nanoscience and Nanotechnology
Yongtao Tan, Ying Liu, Zhenghua Tang, Zhe Wang, Lingbin Kong, Long Kang, Zhen Liu, Fen Ran
N-doped carbon nanosheets/vanadium nitride nanoparticles (N-CNS/VNNPs) are synthesized via a novel method combining surface-initiated in-situ intercalative polymerization and thermal-treatment process in NH3/N2atmosphere. The pH value of the synthesis system plays a critical role in constructing the structure and enhancing electrochemical performance for N-CNS/VNNPs, which are characterized by SEM, TEM, XRD, and XPS, and measured by electrochemical station, respectively. The results show that N-CNS/VNNPs materials consist of 2D N-doped carbon nanosheets and 0D VN nanoparticles...
February 13, 2018: Scientific Reports
Rebecca Momper, Julian Steinbrecher, Matthias Dorn, Irina Rörich, Simon Bretschneider, Manuel Tonigold, Charusheela Ramanan, Sandra Ritz, Volker Mailänder, Katharina Landfester, Markus B Bannwarth
HYPOTHESIS: Carbon dot systems are highly surface sensitive fluorescent nanomaterials. In the presence of specific molecules or ions, the fluorescence properties can be strongly influenced. Often their fluorescent properties are activated or strongly enhanced through passivation agents such as polymer coatings. While several passivating polymers have been directly attached to the carbon dot systems, the interaction of carbon dot systems with the polymer surface of colloids has not been investigated as a way to activate or enhance the photoluminescent properties...
January 31, 2018: Journal of Colloid and Interface Science
L Coelho, I F Almeida, J M Sousa Lobo, J P Sousa E Silva
PURPOSE: Several active compounds are sensitive to light, especially to the ultraviolet radiation (UV-R) leading to their degradation or modification, with lost or decrease of their biological activity. The aim of this study was to perform a systematic review regarding photostabilization strategies used on health products and perform a critical appraisal of their effectiveness. RESULTS: The bibliographic search identified 2261 results and merely 40 studies met the selection criteria...
February 10, 2018: International Journal of Pharmaceutics
Djordje Medarević, Jelena Djuriš, Svetlana Ibrić, Miodrag Mitrić, Kyriakos Kachrimanis
The aim of this study is to develop nanosuspension of carvedilol (CRV) by wet media milling. Concentration of polymeric stabilizer (hydroxypropyl cellulose-HPC-SL), milling speed and size of milling beads were identified as critical formulation and process parameters and their effect on CRV particle size after 60 min of milling was assessed using a Box-Behnken experimental design. Optimized nanosuspension was solidified using spray drying and freeze drying and subjected to solid state characterization. Low stabilizer concentration (10%), low milling speed (300 rpm) with small milling beads (0...
February 10, 2018: International Journal of Pharmaceutics
Yijie Chen, Mengchun Chen, Yue Zhang, Joo Hee Lee, Tamara Escajadillo, Hua Gong, Ronnie H Fang, Weiwei Gao, Victor Nizet, Liangfang Zhang
Neutralization of bacterial toxins has become a compelling approach to treating bacterial infections as it may pose less selective pressure for the development of bacterial resistance. Currently, the majority of toxin neutralization platforms act by targeting the molecular structure of the toxin, which requires toxin identification and customized design for different diseases. Therefore, their development has been challenged by the enormous number and complexity of bacterial toxins. Herein, biomimetic toxin nanosponges are formulated by coating membranes of human red blood cells (hRBCs) onto polymeric nanoparticles, which act as a toxin decoy to absorb and neutralize a broad-spectrum of hemolytic toxins regardless of their molecular structure...
February 13, 2018: Advanced Healthcare Materials
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