Surface Modification of Nanodiamond for Tailored Interaction in Biological Media

The surface of nanoparticles plays a major role in their interaction with biological systems and media. Especially undesired nonspecific adsorption e.g. of proteins as well as unwanted agglomeration in physiological fluids hamper the application of nanoparticles in biomedicine and related fields. This holds true for nanodiamonds, too.<br/>Here, we present several strategies involving covalent surface functionalization of nanodiamond with peptides, hydophilic/lipophilic hybrid systems, zwitterions and oligoethers which enable the formation of stable colloidal solutions of nanodiamond even at high ionic concentrations and prevent the formation of a protein corona when such nanodiamonds are exposed to serum proteins.[1]<br/>Complex architectures combining different of these elements have been investigated for their effect on the dispersibility, colloidal stability and inhibition of protein adsorption.<br/>First in vitro experiments confirm the low toxicity and high biocompatibility of these functionalized nanodiamonds.<br/>Such functionalized nanodiamonds can now be used to introduce specific functional moieties, which can then selectively interact with their environment, a prerequisite for sensing, imaging and drug delivery.<br/>[1] Viktor Merz, Julian Lenhart, Yvonne Vonhausen, Maria E. Ortiz Soto, Juergen Seibel, Anke Krueger, <i>Small</i> <b>2019</b>, 1901551, DOI: 10.1002/smll.201901551<br/><br/>This research has received funding by the Volkswagen foundation under grant agreement number 88 393.