Surface Chemistry of Nanodiamond to Control the Interactions with Biological Environments

The application of nanomaterials in the field of biomedicine depends strongly on the interaction of their surface with the surrounding medium, with proteins, saccharides and other components of physiological environments.<br/>Undesired non-specific interactions can prevent the application of otherwise promising nanomaterials, e.g. due to the masking of originally intended functionalities, unwanted agglomeration of nanoparticles or due to issues with biocompatibility.<br/>Here we report on strategies for the functionalization of diamond nanoparticles with different types of organic molecules that effectively suppress the formation of a protein corona originating from unspecific interactions of surface groups with serum proteins. This includes the grafting of zwitterionic moieties onto the nanodiamond particles. Further, using a similar approach, pyrene-based moieties can be established that enable the specific sensing of heavy metals in aqueous environments using functionalized nanodiamond.<br/>Besides, surface modifications with different types of groups such as small peptides, saccharides and polyethers will be presented, that improve the colloidal properties of nanodiamond in physiological media. In vitro experiments with different cell types show the effectiveness of these approaches and allow for future studies of biomedical applications of these materials.