Synthetic protein targeting by the intrinsic biorecognition functionality of poly(ethylene glycol) using PEG...

Biointerfaces capable of biological recognition and specificity are sought after for conferring bioinspired functionality onto synthetic biomaterials systems. This is important for biosensing, bioseparations, and biomedical materials. Here, we demonstrate how intrinsic polymer-protein interactions between highly localized polyethylene glycol (PEG) brushes and PEG-binding antibodies can be used for sorting specific biomolecules from complex bulk biological fluids to synthetic nanoscale targets. A principal feature lies with the antifouling property of PEG that prevents unspecific binding. Exclusive access is provided by anti-PEG, which acts as a biohybrid molecular adaptor that sifts out and targets specific IgG "cargo" from solution to the PEG. The PEG can be reversibly washed and targeted in blood serum, which suggests potential benefits in technological applications. Moreover, anti-PEG binding triggers a stimuli-responsive conformational collapse in the PEG brush, thereby imparting an intrinsic "smart" biorecognition functionality to the PEG that can considerably impact its use as an antifouling biomaterial.