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polymer micelle

Gertjan Vancoillie, Richard Hoogenboom
Boronic acid-containing (co)polymers have fascinated researchers for decades, garnering attention for their unique responsiveness toward 1,2- and 1,3-diols, including saccharides and nucleotides. The applications of materials that exert this property are manifold including sensing, but also self-regulated drug delivery systems through responsive membranes or micelles. In this review, some of the main applications of boronic acid containing (co)polymers are discussed focusing on the role of the boronic acid group in the response mechanism...
October 19, 2016: Sensors
Lili Chen, Fangling Ji, Yongming Bao, Jing Xia, Lianying Guo, Jingyun Wang, Yachen Li
The greatest crux in the combination of chemotherapy and gene therapy is the construction of a feasible and biocompatible carrier for loading the therapeutic drug and gene simultaneously. Here, a new amphiphilic bifunctional pullulan derivative (named as PDP) synthesized by grafting lipophilic desoxycholic acid and low-molecular weight (1kDa) branched polyethylenimine onto the backbone of pullulan was evaluated as a nano-carrier for the co-delivery of drug and gene for potential cancer therapy. PDP exhibited good blood compatibility and low cytotoxicity in the hemolysis and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays, respectively...
January 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Amal A Sultan, Sanaa A El-Gizawy, Mohamed A Osman, Gamal M El Maghraby
Mixed micelles provide promising strategy for enhancing dissolution and permeability of drugs. However, their fluid nature limited the stability of the loaded drug and hindered the development of stable oral dosage form. Accordingly, the objective was to develop solid self dispersing mixed micelle forming systems (MMFS) for enhanced dissolution and intestinal permeability of hydrochlorothiazide. Pseudoternary phase diagrams were constructed using sodium cholate, lecithin with either poloxamer 407 or PEG 4000 to determine the composition of MMFS...
October 13, 2016: Colloids and Surfaces. B, Biointerfaces
Takanori Kanazawa, Takahiro Endo, Naoki Arima, Hisako Ibaraki, Yuuki Takashima, Yasuo Seta
This study aimed to build an innovative system to deliver a systemic small interfering RNA (siRNA) treatment for rheumatoid arthritis. We combined arginine-histidine-cysteine based oligopeptide-modified polymer micelles with siRNA targeting the nuclear factor κB subunit, RelA (siRelA). This is a key molecule in the control of inflammation. We tested the cellular uptake of siRNA and its effects on inflammatory cytokine levels in vitro using synoviocytes, and siRNA distribution and therapeutic effects in vivo in mice with collagen-induced arthritis (CIA)...
October 17, 2016: International Journal of Pharmaceutics
G MuŽíková, R Laga
Vaccines have helped considerably in eliminating some life-threatening infectious diseases in past two hundred years. Recently, human medicine has focused on vaccination against some of the world's most common infectious diseases (AIDS, malaria, tuberculosis, etc.), and vaccination is also gaining popularity in the treatment of cancer or autoimmune diseases. The major limitation of current vaccines lies in their poor ability to generate a sufficient level of protective antibodies and T cell responses against diseases such as HIV, malaria, tuberculosis and cancers...
October 20, 2016: Physiological Research
Andrea Träger, Samuel A Pendergraph, Torbjörn Pettersson, Tobias Halthur, Tommy Nylander, Anna Carlmark, Lars Wågberg
In this study the wet adhesion between Layer-by-Layer (LbL) assembled films of triblock copolymer micelles was investigated. Through the LbL assembly of triblock copolymer micelles with hydrophobic, low glass transition temperature (Tg) middle blocks and ionic outer blocks, a network of energy dissipating polymer chains with electrostatic interactions serving as crosslinks can be built. Four triblock copolymers were synthesized through Atom Transfer Radical Polymerisation (ATRP). One pair had a poly(2-ethyl-hexyl methacrylate) middle block with cationic or anionic outer blocks...
October 18, 2016: Nanoscale
Xiao-Juan Wang, Yin-Ping Gao, Nan-Nan Lu, Wei-Shuo Li, Ji-Fang Xu, Xiao-Ying Ying, Gang Wu, Mei-Hua Liao, Chao Tan, Ling-Xiao Shao, Ying-Mei Lu, Chen Zhang, Kohji Fukunaga, Feng Han, Yong-Zhong Du
Clinical treatment for vascular dementia still remains a challenge mainly due to Blood-Brain Barrier (BBB). Here, a micelle based on polysialic acid (PSA) which is a hydrophilic and endogenous carbohydrate polymer, was designed to deliver calmodulin antagonist for therapy of vascular dementia. PSA was firstly chemically conjugated with octadecylamine (ODA), and the obtained PSA-ODA copolymer could self-assemble into micelle in aqueous solution with a 120.0 μg/mL critical micelle concentration. The calmodulin antagonist loaded PSA-ODA micelle, featuring sustained drug release behaviour over a period of 72 h with 3...
October 17, 2016: ACS Applied Materials & Interfaces
Peng Wei Zhu, Luguang Chen
A persistence length is a key parameter for the quantitative interpretation of the flexibility of polymers. We have studied the complexes composed of spherical poly(N-isopropylacrylamide) (PNIPAM) brush and sodium dodecyl sulfate (SDS) micelle in efforts to characterize the flexibility of tethered PNIPAM below the lower critical solution temperature TLCST. An analytical mean-field model is utilized to describe the persistence length Lp in a broad range of ψ, the number of bound micelles per chain. The persistence length of the micelle-constrained PNIPAM is quantitatively correlated with the thermal energy kBT, electrostatic repulsion fC, and effective excluded volume parameter νeff...
October 17, 2016: Journal of Physical Chemistry. B
Kyaw Hpone Myint, Jonathan R Brown, Anne R Shim, Barbara E Wyslouzil, Lisa Michelle Hall
The formation of block copolymer micelles with and without hydrophobic nanoparticles is simulated using dissipative particle dynamics. We use the model developed by Spaeth et al. [J. Chem. Phys. 134, 164902 (2011)], and drive micelle formation by adjusting the interaction parameters linearly over time to represent a rapid change from organic solvent to water. For different concentrations of added nanoparticles, we determine characteristic times for micelle formation and coagulation, and characterize micelles with respect to size, polydispersity, and nanoparticle loading...
October 17, 2016: Journal of Physical Chemistry. B
Kyoung-Ran Kim, Hyo Young Kim, Yong-Deok Lee, Jong Seong Ha, Ji Hee Kang, Hansaem Jeong, Duhee Bang, Young Tag Ko, Sehoon Kim, Hyukjin Lee, Dae-Ro Ahn
Nanoparticle delivery systems have been extensively investigated for targeted delivery of anticancer drugs over the past decades. However, it is still a great challenge to overcome the drawbacks of conventional nanoparticle systems such as liposomes and micelles. Various novel nanomaterials consist of natural polymers are proposed to enhance the therapeutic efficacy of anticancer drugs. Among them, deoxyribonucleic acid (DNA) has received much attention as an emerging material for preparation of self-assembled nanostructures with precise control of size and shape for tailored uses...
October 14, 2016: Journal of Controlled Release: Official Journal of the Controlled Release Society
M Bohdan, J Sprakel, J van der Gucht
The dynamics and mechanics of networks depend sensitively on their spatial connectivity. To explore the effect of connectivity on local network dynamics, we prepare transient polymer networks in which we systematically cut connecting bonds. We do this by creating networks formed from hydrophobically modified difunctionalized polyethylene glycol chains. These form physical gels, consisting of flowerlike micelles that are transiently cross-linked by connecting bridges. By introducing monofunctionalized chains, we can systematically reduce the number of bonds between micelles and thus lower the network connectivity, which strongly reduces the network elasticity and relaxation time...
September 2016: Physical Review. E
Neda Khameh Khorshid, Kaizheng Zhu, Kenneth D Knudsen, Sara Bekhradnia, Sverre Arne Sande, Bo Nyström
The thermoresponsive amphiphilic block copolymer poly(d,l-lactic acid-co-glycolic acid)-block-poly(ethylene glycol)-block-poly(d,l-lactic acid-co-glycolic acid) (PLGA-PEGn -PLGA), which exhibits a reversible temperature-induced sol-gel transition at higher polymer concentrations in aqueous solution has attached a great deal of interest because of its potential in biomedical applications. In the present work, the length of the hydrophobic PLGA blocks is kept constant, whereas the length of the hydrophilic PEG block is altered and this variation has a pronounced impact on the phase behavior of the aqueous samples and the structure of the polymer...
October 14, 2016: Macromolecular Bioscience
Aristeidis Papagiannopoulos, Anastasia Meristoudi, Stergios Pispas, Aurel Radulescu
We investigate the potential of self-assembled nanostructures of the PnBA-b-PAA amphiphilic diblock polyelectrolyte as candidates for protein nanocarriers. Three PnBA-b-PAA copolymers with different molecular weights and PnBA/PAA weight ratios are tested. The system with the most well-defined core-shell micellar structure is chosen for complexation with lysozyme. Its solutions are found to contain well-defined core-shell micelles that are stable upon increase of solution salt content to physiological levels...
October 12, 2016: Biomacromolecules
Yuhao Wang, Svetlana A Sukhishvili
We investigate the phase behavior, morphology, and temperature response of hydrogen-bonded assemblies formed by a triblock copolymer Pluronic® F127 (F127) and polycarboxylic acids of varied hydrophobicity and chain lengths. As confirmed by FTIR, the complexes of poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA) with F127 at acidic pH were stabilized by multiple hydrogen bonding between carboxylic acid groups of polyacids and ether groups of F127. The colloidal stability of the polyacid/F127 complexes (their occurrence as stable dispersions, slowly coagulating dispersions or precipitates) was dependent on the composition of complexes, polyacid molecular weight and hydrophobicity, as well as temperature...
October 10, 2016: Soft Matter
Sheetal Parida, Chiranjit Maiti, Y Rajesh, Kaushik K Dey, Ipsita Pal, Aditya Parekh, Rusha Patra, Dibakar Dhara, Pranab Kumar Dutta, Mahitosh Mandal
BACKGROUND: Gold nanorods, by virtue of surface plasmon resonance, convert incident light energy (NIR) into heat energy which induces hyperthermia. We designed unique, multifunctional, gold nanorod embedded block copolymer micelle loaded with GW627368X for targeted drug delivery and photothermal therapy. METHODS: Glutathione responsive diblock co-polymer was synthesized by RAFT process forming self-assembled micelle on gold nanorods prepared by seed mediated method and GW627368X was loaded on to the reduction responsive gold nanorod embedded micelle...
October 6, 2016: Biochimica et Biophysica Acta
Jye Yng Teo, Willy Chin, Xiyu Ke, Shujun Gao, Shaoqiong Liu, Wei Cheng, James L Hedrick, Yin Yan Yang
Diblock copolymers of poly(ethylene glycol) (PEG) and biodegradable polycarbonate functionalized with GSH-sensitive disulfide bonds and pH-responsive carboxylic acid groups were synthesized using PEG having different molecular weights as macroinitiators through organocatalytic ring-opening polymerization of functional cyclic carbonates. These narrowly-dispersed polymers had predictable molecular weights, which were used to load doxorubicin (DOX) into micelles primarily through ionic interactions. The DOX-loaded micelles exhibited the requisite small particle size (< 100 nm), narrow size distribution and high drug loading capacity...
October 6, 2016: Nanomedicine: Nanotechnology, Biology, and Medicine
Yan Wang, Ling Zhou, Meng Xiao, Zhong-Liang Sun, Chang-Yuan Zhang
In the present study, we have synthesized an amphiphilic pH-sensitive structure of poly(ethylene glycol) methyl ether-b-(poly lactic acid-co-poly(b-amino esters)) (MPEG-b-(PLA-co-PAE)) to load paclitaxel to increase the therapeutic efficacy in leukemia. The micelles exhibit excellent drug-loading capacities for paclitaxel (PTX) and exhibited a typical pH-responsive drug release pattern. The release of PTX from the micelles was significantly accelerated by decreasing pH from 7.4 to 5.0 which just fitted the pathological process...
September 13, 2016: Colloids and Surfaces. B, Biointerfaces
Xiaofang Zhang, Wenjing Lin, Liyang Wen, Na Yao, Shuyu Nie, Lijuan Zhang
Unimolecular polymeric micelles have several features, such as thermodynamic stability, small particle size, biocompatibility, and the ability to internalize hydrophobic molecules. These micelles have recently attracted significant attention in various applications, such as nano-reactors, catalysis, and drug delivery. However, few attempts have explored the formation mechanisms and conditions of unimolecular micelles due to limited experimental techniques. In this study, a unimolecular micelle system formed from β-cyclodextrin-graft-{poly(lactide)-block-poly(2-(dimethylamino) ethyl multimethacrylate)-block-poly[oligo (2-ethyl-2-oxazoline) methacrylate]} β-CD-g-(PLA-b-PDMAEMA-b-PEtOxMA) star-like block copolymers in aqueous media was investigated by dissipative particle dynamics (DPD) to explore the formation process of unimolecular micelles...
September 29, 2016: Physical Chemistry Chemical Physics: PCCP
Ye Zhu, Chenglin Yi, Qiong Hu, Wei Wei, Xiaoya Liu
In this study, a series of random copolymer poly(acrylic acid-co-styrene) (P(AA-co-St)) and block copolymer poly(acrylic acid)-b-polystyrene (PAA-b-PSt) with similar chemical composition but different chain microstructure were synthesized. The self-assembly behavior of random and block copolymers in selective solvent was investigated, and the structural evaluation of random and block copolymers micelles was carried out by transmission electron microscopy (TEM), dynamic light scattering (DLS) measurement, and X-ray photoelectron spectroscopy (XPS)...
September 21, 2016: Physical Chemistry Chemical Physics: PCCP
Ying Ji, Shuo Shan, Mingyu He, Chih-Chang Chu
Amino acid-based poly(ester amide)s are a new family of biodegradable polymers that exhibit "pseudo-protein" characteristics and the structural varieties of poly(ester amide)s make them hold great potential in multiple biomedical applications. In this study, a lysine-phenylalanine-based pseudo-protein is developed as the self-assembled nanomicellar carrier for efficient delivery of doxorubicin. The lysine moieties from the pseudo-protein provide available sites for further functionalization, and methylcoumarin is introduced for easy and photocontrollable crosslinking, to effectively improve the micellar stability in serum containing environment and against dilution...
October 6, 2016: Small
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