Cross-linked magnetic nanoparticles from poly(ethylene glycol) and dodecyl grafted poly(succinimide) as magnetic resonance probes

2011 ◽  
Vol 47 (46) ◽  
pp. 12518 ◽  
Author(s):  
Hee-Man Yang ◽  
Chan Woo Park ◽  
Sujin Lim ◽  
Sung-Il Park ◽  
Bong Hyun Chung ◽  
...  
2020 ◽  
Vol 44 (4) ◽  
pp. 1313-1319
Author(s):  
Xu Yang ◽  
Kunhao Yang ◽  
Li Wu ◽  
Jingkui Yang ◽  
Yujian He

Mechanism of Fe3O4@CPTES@PEG magnetic nanoparticles for selectively adsorbing Au(iii) from aqueous solution at pH = 1.0.


2012 ◽  
Vol 1416 ◽  
Author(s):  
Christopher S. Brazel ◽  
James B. Bennett ◽  
Amanda L. Glover ◽  
Jacqueline A. Nikles ◽  
Maaike Everts ◽  
...  

ABSTRACTA thermally-activated micelle consisting of a crystallizable poly(caprolactone), PCL, core and a poly(ethylene glycol), PEG, corona was developed to contain magnetic nanoparticles and anti-cancer agent doxorubicin as well as display a targeting RGD peptide. This system has the potential to target cancer cells, deliver combination hyperthermia and chemotherapy, and offer magnetic resonance imaging contrast. The micelles self-assemble in aqueous solutions and form a crystalline core with a melting transition ranging from 40 to 50 °C, depending on the length of the PCL blocks, with dynamic light scattering showing micelle sizes typically ranging from 20 to 100 nm, depending on block lengths and added drug or nanoparticles. The micelles become unstable as they are heated above their melting point, creating a thermally-activated drug release mechanism. By adding magnetite (Fe3O4) nanoparticles into the PCL core, the micelles can be heated using an externally applied AC magnetic field to induce hyperthermia in combination with the thermally-activated drug release. The polymers and magnetic nanoparticles (MNPs) were synthesized and characterized in our laboratories. The melting transitions of the PCL micelle cores were investigated using microcalorimetry. The heating of nanoparticles and magnetomicelles was conducted using a custom-built hyperthermia coil capable of generating fields of several hundred Oersteds at frequencies ranging from 50 to 450 kHz. Heating of MNPs was maximized at high field intensities. RGD peptides were attached to the PEG corona using maleimide chemistry, and the ability of the RGD-derivatized micelles to target integrin-expressing cells was investigated using fluorescent dye PKH26 to identify the localization of micelles in cultured human kidney (293) cells in vitro. The crystallizable (and meltable) cores in these micelles were designed to overcome drug leakage common in liposome systems and release the drug on demand after a period of time for localization to integrin receptors.


2007 ◽  
Vol 56 (4) ◽  
pp. 506-511 ◽  
Author(s):  
Alberto Prior-Cabanillas ◽  
José M Barrales-Rienda ◽  
Gloria Frutos ◽  
Isabel Quijada-Garrido

2020 ◽  
Vol 982 ◽  
pp. 26-33
Author(s):  
Ling Wei ◽  
Da Wei Li

Solid-state high-resolution 13C/7Li nuclear magnetic resonance (NMR) study was performed on the phase structure and chain dynamics of PEG-PPG-PEGn/LiCF3SO3 (n=3, 6, 12) copolymer electrolytes. PEG repeating units and Li+ form PEG3:LiCF3SO3 crystalline complex and PE3/Li+ amorphous complex in all the samples. PPG repeating units and Li+ form different complexes with respect to O:Li+ feed ratio (denoted as PP/Li+-3/6/12). The 13C chemical shifts and half widths of the signals from PP/Li+-3/6/12 remain unchanged, which implies the structures of PP/Li+-3/6/12 are similar at least in a very short range. The half width of the 7Li signals from PP/Li+-3/6/12 becomes narrower and narrower as the Li+ concentration decreases. This indicates the chain mobility of the amorphous phase increases with the decrease of ionic concentration. Moreover, neat crystalline PEG, neat amorphous PEG and neat amorphous PPG start to appear when O:Li+ is greater than 3:1 and their contents increase with the increase of O:Li+. Overall, solid-state high-resolution NMR is a powerful and unique method for understanding the phase structure and chain dynamics of solid polymer electrolytes (SPEs), more applications of this technique to studies on SPEs is expecting.


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