PNAS study finds uncharged nanoparticles bind more molecules, whereas charged nanoparticles bind more fat-transporting molecules.
The corona of a nanoparticle – the coating of proteins that bind to the surface when nanoparticles are suspended in blood serum – depends upon both size and surface charge, according to researchers at the Centre for BioNano Interactions at University College, Dublin. This is true even when the nanoparticles are constructed of identical material.
The scientists studied six polystyrene nanoparticles: three surface chemistries (plain PS, carboxyl-modified, and amine-modified) and two sizes of each (50 and 100 nm). They mixed positively charged, negatively charged, and neutral polystyrene nanoparticles with blood plasma and analyzed the proteins that adhered to them.
The research group found that uncharged nanoparticles bound more molecules from the immune system than charged nanoparticles. Charged nanoparticles, however, bound more fat-transporting molecules.
The team proposes that regulatory officials now consider how nanoparticle size and surface properties could affect efficacy and safety in possible drug treatments, rather than simply classifying them according to the material they are made from.
The article appears in the week’s edition of PNAS.