Pegylated polymers

Joralemon MJ, McRae S, Emrick T (2010) PEGylated polymers for medicine from conjugation to self-assembled systems. Chem Commun (Camb) 46 1377-1393... 

Solid lipid poly(lactic acid) (PLA), poly(lactide-co-glycotide) (PLGA), poly(e-caprolactone) (PCL), poly(methyl methacrylate), and poly(alkyl cyanoacrylate) derivatives of cyclodextrin and starch some modified polymers (e.g., PEGylated polymers) also used Mainly glycerides and High-pressure... 

PEG as such is not used as an NP. Repeating PEG moieties are usually added to pol5miers to alter electrostatic binding properties and increase hydrophilicity of NPs. The bulky nature of PEGylated polymers can also protect the NPs from degradation by cellular enzymes, increase their stability and prevent aggregation. PEGylation also enhances the transfection efficiency of NPs [74]. 

E. Celasco, I. Valente, D. Marchisio, and A. A. Barresi, Dyncunic hght scattering and X-ray photoelectron spectroscopy characterisation of PEGylated polymer nanocarriers Internal structure and surface properties, Langmuir, 30,8326-8335,2014. [supporting information... 

Enzymatically Synthesized Pegylated Polymers as Nanomicellar Drug Delivery Systems... 

Dai et al. have developed nanosized, reduced 20 nm graphene oxide (nano-rGO) sheets functionalised non-covalently by amphiphilic PEGylated polymer chains (432) with high near-infrared (NIR) light absorbance and biocompatibility for potential photothermal therapy. In the absence of any NIR irradiation, nano-rGO exhibited little toxicity in vitro at concentrations well above the doses needed for photothermal heating. ... 

Polyethylene glycol (PEG) consists of repeating units of ethylene glycol forming linear or branched polymers with different molecular masses. Pegylation is the process by which PEG chains are covalently attached to lEN molecules. Pegylation confers a number of properties on lEN-a molecules, such as sustained blood levels that enhance antiviral effectiveness and reduce adverse reactions, as well as a longer half-life and improved patient compliance (Kozlowski et al. 2001). 

Several of these problems can be solved by polyplex modification with polyethylene glycol (PEG). PEGylation has been broadly explored for surface shielding ( stealthing ) of many liposomal and nanoparticulate carriers. In the case of cationic polymers, Plank et al. [62] demonstrated that complement activation can be reduced when the polymers are PEGylated. Such a modification can be... 

First clinical human gene therapy trials with polyplexes were performed using cancer vaccines based on autologous patient tumor cells. These were modified ex vivo with interleukin-2 pDNA. To obtain high level transfection rates of patient s primary tumor cells, Tf-PLL/pDNA polyplexes linked with inactivated endosomolytic adenovirus particles were applied [221]. Polymer-based in vivo human gene transfer studies were performed with PEGylated PLL polyplexes, delivering CFTR pDNA to the airway epithelium of cystic fibrosis patients [222],... 

PEG is a widely used molecule as a component in pharmaceutical formulations. PEG is particularly useful thanks to its low cost and various simple synthetic methods (26). PEG-lipid has been developed as a means of stabilizing conventional liposomes. A lipid moiety has been linked to the large PEGylated head in order to anchor the molecule to the particles. Instead of shielding a direct layer of polymer PEG around the particle, which would be less stable, the idea is to favor hydrophobic interactions between the PEG-lipid and the particle bilayer lipids. This anchor had led to two conformations of the PEG on the particle surface commonly called mushroom and brush regimes (27), representing a more condensed or extended conformations... 

Spatially confined self-assembly has been further confirmed by localizing ther-molysin on certain areas of a PEGylated surface. Upon immersion of this modified surface into a solution containing self-assembling precursors, nanostructures were formed in the vicinity of the enzyme, as observed through congo-red staining (Fig. 7c) [21]. Thus, enzyme-assisted self-assembly allows for construction of supramolecular polymers with spatiotemporal control, i.e. where and when they are required. 

In addition, the polymer-coated adenovirus particles were able to shield against antibody recognition. In another approach, the PEGylation of the adenovirus capsid protein prolonged transgene expression after systemic delivery of El-deleted adenovirus, and allowed partial readministration with native virus (50). Adenovirus has been explored as vector for the treatment of cystic fibrosis (51), for Duchenne muscular dystrophy (52), to deliver tumor suppressor genes for cancer treatment... 

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