Nanoparticles polyethylene glycol stabilization

Hou Z, Theyssen N, Brinkmann A et al (2005) Biphasic aerobic oxidation of alcohols catalyzed by polyethylene glycol)-stabilized palladium nanoparticles in supercritical carbon dioxide. Angew Chem Int Ed 44(9) 1346—1349... 

Wang X, Yang H, Feng B et al (2009) Functionalized polyethylene glycol)-stabilized palladium nanoparticles as an efficient catalyst for aerobic oxidation of alcohols in supercritical carbon dioxide/poly(ethylene glycol) biphasic solvent system. Catal Lett 132 34-40... 

Corma et al compared the use of different IL solvents and polyethylene glycol (PEG) using a carbopalladacycle complex as catalyst for Suzuki and Sonogashira reactions. They showed that the dialkyl-substituted imidazolium compounds had poor stability, reactivity and recyclability when compared with trialkyl substituted imidazolium compounds and PEG. They concluded that this result could be attributed to the stabilization of the Pd nanoparticles in the solvent. They showed that PEG was a better solvent since it gave better yields, had good stability, low cost and low toxicity. 

Gold nanoparticles can also be stabilized using polymers that do not have specific functional groups through physisorption. Among the possible stabilizers, the polymers used most often to stabilize Au NPs are the water soluble polymers poly(N-vinylpyrrolidone) (PVP), polyethylene glycol) (PEG), poly(vinyl pyridine), poly(vinyl alcohol) (PVA), poly(vinyl methyl ether) (PVME), and polyelectrolytes such as PAA, chitosan, polyethyleneimine (PEI) or poly(diallyl dimethylammonium) chloride (PDDA) [99]. 

Recent work has been published on the use of SERS reporters for in vivo analysis. In 2008, Shuming Nie published work on the in vivo targeting of tumors in live mice [65]. The SERRS particles consisted of 60 nm gold nanoparticles functionalized with a Raman reporter dye molecule and then stabilized with thiolated polyethylene glycols (PEGs). Targeted SERS nanoparticles were prepared by having a mixed monolayer of thiolated PEG and a heterofunctional thiolated PEG with a carboxylic... 

Coating of silver nanoparticles with polyelectrolytes influences their stability against aggregation. Herein the silver nanoparticles were coated with positive weak poly(allylamine hydrochloride) (PAH, 70kDa or 15kDa) or neutral polyethylene glycol (PEG, 8 kDa) polyelectrolytes. 

To improve the oral bioavailability of calcitonin, Garcia-Fuentes et al. used tripalmitate nanoparticles coated with chi-tosan or polyethylene glycol. The nanoparticles were prepared by a double emulsion solvent evaporation method that was adapted due to its high efficiency for the encapsulation of peptides. The nanoparticles were stabilized with soybean lecithin and the surface coating was done by incubation of the prepared lipid nanoparticles in a chitosan/poloxamer solution or by initial addition of PEG-stearate to the organic phase. Excess stabilizers were removed by centrifugation. Whereas... 

Fig. 3 Multifunctional nanoparticle receptor units recognize the proper target polyethylene glycol (PEG) chains improve the particle stability fluorophores provide a means for detection drug can be hosted inside...

Figure 22.6 shows the tumor growth dynamics in several experimental series using Theraphthal, octasodium salt of zinc octacarboxyphthalocya-nine (ZnPc), and gold nanoparticles stabilized with polyethylene glycol. 

Okitsu et al. [55], carried out the sonochemical synthesis of crystalline nanoparticles of Au, Ag, Pd, and Pt stabilized with polyethylene glycol monostearate (MS-PEG), sodium dodecyl sulfate (SDS, NaCl2H2sS04), and polyvinylpyrrolidone (Okitsu 1996a, b) [233, 234]. The metal particles were produced from 5 run order and are stable for months. 

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