Poly(ethylene glycol) (PEG) helps nanomaterials evade the immune system by modifying the composition of proteins that are adsorbed on the surface of the materials

Writing in Nature Nanotechnology (online: 2/15/2016, read the full text publication: http://www.nature.com/nnano/journal/vaop/ncurrent/full/nnano.2015.330.html), Frederik Wurm and colleagues now challenge our understanding of how neutral hydrophilic polymers alter the biological fate of nanoparticles. A polystyrene nanocarriers that have been modified with PEG have been exposed to plasma proteins exhibit a low cellular uptake, which show that in addition to reducing protein adsorption, PEG can affect the composition of the protein corona that forms around nanocarriers, and the presence of distinct proteins is necessary to prevent non-specific cellular uptake.