A functionally amenable copolymer of polyethylene glycol (PEG) and allyl glycidyl ether (AGE) that improves the specificity and targeting of nanoparticles compared to PEG coating.
- Amphiphilic properties significantly reduce non-specific adsorbtion of proteins compared to PEG.
- Improves targeting and cell-specific uptake of nanoparticles.
- Minimizes nanoparticle toxicity.
A major challenge to the use of nanoparticles in the clinic is non-specific interactions between nanoparticles and the the body’s natural biomolecules. This process, called biofouling, can reduce the efficiency of the nanoparticle in several applications. For drug delivery, biofouling reduces targeting efficiency, causing toxicity in normal tissues. For imaging, it increases background signal, decreasing the contrast of the image. Although the most commonly used nanoparticle coating is PEG, this polymer facilitates the formation of a water-based film around the particle, interefering with protein interactions and cellular uptake. Further, the method by which functional targeting moieties are added to PEG promotes an ionic charge that can promote phagocytosis by macrophages. With these limitations, an improved nanoparticle coating polymer is crucial for advances in clinical nanoparticle use.
Emory inventors created a PEG-based coating material that exhibits anti-biofouling properties and maintains properties for functional targeting. The new material incorporates aminated hydrophilic PEG chains with hydrophobic allyl glycidyl ether (AGE) moieties into a diblock PEG-b-AGE polymer. Notably, the AGE moieties provide control of the functional ligand density during polymerization and can be utilized for the attachment of a variety of other functional groups. As a result, the PEG-b-AGE reduces non-specific protein adsorption onto the nanoparticle surface,Â improves targeting efficiency, and improves image contrast. Due to the “stealth” nature of this polymer, other potential applications include the coating of medical and biological devices.
The PEG-b-AGE polymer has been tested for biofouling properties in vitro and in vivo.
Publication: Li, Y. et al. (2015). Journal of Materials Chemistry B. 3(17):3591-3603.