24493-59-2Relevant articles and documents
Unique associative properties of copolymers of sodium acrylate and oligo(ethylene oxide) alkyl ether methacrylates in water
Tomatsu, Itsuro,Hashidzume, Akihito,Yusa, Shin-Ichi,Morishima, Yotaro
, p. 7837 - 7844 (2005)
A series of random copolymers of sodium acrylate and oligo(ethylene oxide) alkyl ether methacrylates (CnEmMA) with different lengths of ethylene oxide (EO) and alkyl groups were prepared by free-radical copolymerization at varying copolymer compositions. The lengths of the EO units (the number of EO units) (m) and the numbers of carbon atoms in the alkyl groups (n) ranged fro'm 0 to 8.7 and 1 to 6, respectively. The copolymers with n = 1 and m = 1-8.7 exhibited a marked increase in solution viscosity at polymer concentrations (Cp) higher than their overlap concentrations (C*) when the CnEmMA contents (x) in the copolymers were in a certain limited range. Namely, there was an optimum x value that yielded the highest viscosity as a consequence of the competition between inter- and intrapolymer associations; the maximum viscosities occurred around x ≈ 25, 15, 10, 7, and 3 mol % for m = 1, 2, 3, 4.2, and 8.7, respectively. The maximum viscosity decreased significantly as n was increased on going from 1 to 6, and for the copolymers with n = 6, no increase in the viscosity occurred, a trend opposite to what is expected to interpolymer hydrophobic associations. When Cp > C*, steady-shear viscosity depended on the nature of countercations; the viscosities were found to be higher in the order Li + > Na+ ? NH4+, whereas reduced viscosity in dilute regime (Cp C*) was independent of the species of the cations. Rheological properties were found to be typical of transient networks formed through very weak interpolymer associations. Thus, the large increase in solution viscosity was explained by simultaneous interactions of countercations with EO units via coordination and with the polyanion via counterion condensation.
Shape-shifting micro- and nanopatterns controlled by temperature
Kolodziej, Christopher M.,Maynard, Heather D.
, p. 12386 - 12389 (2012)
Herein, features that alter their shape to form a different pattern upon an external trigger are described. Electron-beam lithography was used to fabricate micrometer- and nanometer-sized surface immobilized poly(triethylene glycol methacrylate) (pTEGMA) that exhibits significant thermal responsivity; the resulting hydrogels collapsed by up to 95% of their height upon addition of heat. Multicomponent features composed of both the thermoresponsive polymer and nonresponsive poly(ethylene glycol) (PEG) were then prepared. Upon increase in temperature, only the thermally responsive component of the pattern collapsed, causing a significant and predictable alteration in the overall pattern. Reversible micrometer- and nanometer-sized square-to-triangles, squares-to-checkerboards, smiles-to-neutral face, and zeros-to-ones shapes were shown.
Composite electrolytes comprised of poly(ethylene oxide) and silica nanoparticles with grafted poly(ethylene oxide)-containing polymers
Jia, Zhe,Yuan, Wen,Zhao, Hui,Hu, Heyi,Baker, Gregory L.
, p. 41087 - 41098 (2014)
We designed, synthesized and characterized several novel hybrid inorganic/organic nanocomposite electrolytes that consist of poly(ethylene oxide) (PEO) based polymer grafted from silica nanoparticles. Poly(ethylene glycol)methyl ether methacrylate (PEGMA) was tailored on the silica surface through atom transfer radical polymerization (ATRP). A series of silica-polymers were synthesized with different lengths of PEO side chains. Electrolytes were prepared from the functionalized particles and low-molecular weight polyethylene glycol dimethyl ether (PEGDME) with the addition of LiI. Upon the introduction of particles, electrolytes became viscous and gel-like. With the increase of PEO side chains, the viscosity of the electrolytes increased dramatically, among which, silica-poly(PEGMA-1100) became solid-state. The room temperature conductivities of the hybrid silica-polymer electrolytes are in the range of 6 × 10-5to 1.2 × 10-4S cm-1. Silica-poly(PEGMA-475) and silica-poly(PEGMA-1100), with higher viscosity, exhibited better ionic conductivity. Surface-initiated copolymerization was also conducted to optimize the electrochemical performance of polymer coated silica nanoparticles. This journal is
Enzyme and thermal dual responsive amphiphilic polymer core-shell nanoparticle for doxorubicin delivery to cancer cells
Kashyap, Smita,Singh, Nitesh,Surnar, Bapurao,Jayakannan, Manickam
, p. 384 - 398 (2016/01/20)
Dual responsive polymer nanoscaffolds for administering anticancer drugs both at the tumor site and intracellular compartments are made for improving treatment in cancers. The present work reports the design and development of new thermo- and enzyme-responsive amphiphilic copolymer core-shell nanoparticles for doxorubicin delivery at extracellular and intracellular compartments, respectively. A hydrophobic acrylate monomer was tailor-made from 3-pentadecylphenol (PDP, a natural resource) and copolymerized with oligoethylene glycol acrylate (as a hydrophilic monomer) to make new classes of thermo and enzyme dual responsive polymeric amphiphiles. Both radical and reversible addition-fragmentation chain transfer (RAFT) methodologies were adapted for making the amphiphilic copolymers. These amphiphilic copolymers were self-assembled to produce spherical core-shell nanoparticles in water. Upon heating, the core-shell nanoparticles underwent segregation to produce larger sized aggregates above the lower critical solution temperature (LCST). The dual responsive polymer scaffold was found to be capable of loading water insoluble drug, such as doxorubicin (DOX), and fluorescent probe-like Nile Red. The drug release kinetics revealed that DOX was preserved in the core-shell assemblies at normal body temperature (below LCST, ≥ 37 °C). At closer to cancer tissue temperature (above LCST, ～43 °C), the polymeric scaffold underwent burst release to deliver 90% of loaded drugs within 2 h. At the intracellular environment (pH 7.4, 37 °C) in the presence of esterase enzyme, the amphiphilic copolymer ruptured in a slow and controlled manner to release >95% of the drugs in 12 h. Thus, both burst release of cargo at the tumor microenvironment and control delivery at intracellular compartments were accomplished in a single polymer scaffold. Cytotoxicity assays of the nascent and DOX-loaded polymer were carried out in breast cancer (MCF-7) and cervical cancer (HeLa) cells. Among the two cell lines, the DOX-loaded polymers showed enhanced killing in breast cancer cells. Furthermore, the cellular uptake of the DOX was studied by confocal and fluorescence microscopes. The present investigation opens a new enzyme and thermal-responsive polymer scaffold approach for DOX delivery in cancer cells.
