Nano-Bio Interfaces in Colloids and Nanoparticles

Nanomaterials have been used in many biomedical applications, resulting in their incorporation into biological systems. The biotic-abiotic interface between nanomaterials and biological molecules, known as the nano-bio interface, is the interface between a nanoparticle (NP) and a biomolecule tethered to its surface, or the interface between the NP and its biological environment. While originally it was not accounted for, the nano-bio interface has been determined to play a critical role in the biological and medical applications of nanomaterials. It has been challenging to understand its fundamental properties as it is difficult to experimentally probe, control, and predict. However, key advancements in its characterization have given rise to an understanding of its properties. Here we discuss the fundamentals of the surface energies and forces at the nano-bio interface. Because characterizing the nano-bio interface requires novel approaches, we describe some of the techniques that have been used to gain information about the interface. Finally, we describe ways in which the nano-bio interface has been explicitly designed for and leveraged for its unique properties. These promising efforts in engineering the interface to impart a desired biological identity of NPs have the potential to lead to novel uses of nanomaterials in nanomedicine.