When derivatized with zwitterions, planar and (nano)particulate surfaces can show exceptional resistance to the adsorption of proteins and cells. In a recent head-to-head comparison of PEG oligomers and short-chain zwitterions, both were found to be roughly equivalent in preventing adsorption and stabilizing colloids (Langmuir, 27 , 6794-6800 (2011)). Zwitterion passivation is achieved with only a minimal thickness (< 1 nm) at the surface, which can be critical for nanoparticles' in vivo transport and selective excretion. In this presentation we will compare the effectiveness of polymeric and monomeric zwitterions in guiding the selective adsorption of cells on surfaces and in stabilizing suspensions of nanoparticles. A simple mechanism by which both zwitterions and PEG prevent adsorption will be presented. The mechanism is based on removing entropic driving forces caused by the loss of counterions and water molecules at the surface.

Nonadsorbing properties of the zwitterion surface

243rd National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.