While it is widely recognized that charge plays an important role in controlling the interaction of nanoparticle with cell membranes and the resulting biological impact, much less is known about how the precise ligand strucutre and associated spatial distribution of charge influences there interactions. To address this queston, we used a model suite of ligands varying in length and structure, including linear ligands and polymer wraps, all containing primary or quaternary amino groups. Our results show that while all these nanoparticles have large positive zeta potentials, they differ markedly in their ability to damage baterial cell membranes. Complementary studies using vesicles show a similarly strong effect. NMR studies of the ligands and of the phosphate groups within vesicles show that membrane damage is greatest when nanoparticles are functionalized with polymer chains that extend into solution, forming isolated, freely tumbling groups. In contract, linear ligands, even with high density of amino groups and very large positive zeta potential, have much less effect. Our data and molecular dynamics simulations all indicate that the ability of positively charged nanoparticles to induce strong biological response is controlled by higly mobile segments that are able to extend into solution and intercalate into membranes.

Influence of nanodiamond surface ligand structure on interaction with model membranes and bacterial membranes

ACS Spring Meeting 2021

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