Interest in the interactions of nanoparticles with biological cells continues to grow, progressively covering more fields of science such as biomedicine, optoelectronics, ecology, and many others. There are two primary methods that are utilized to combine nanoparticles with biological cells. The first one is delivering nanoparticles inside of cells in order to create new therapeutic agents for targeted drug and gene delivery, efficient systems for high-resolution imaging, or to study intracellular processes.

Another approach is modification of the cell surface with nanomaterials to obtain “hybrid systems” for bioelectronic applications or to provide living cells with a new phenotype depending on the unique physical and chemical properties of the chosen particles. The direct deposition of nanoparticles onto the cells seems to be the simplest route but it has some limitations. These limitations are caused by random endocytosis pathways and direct translocation across the plasma membrane that cells usually use for nonspecific absorption of exogenous molecules or nanoparticles. Therefore, it can be quite challenging to selectively modify only the cell surface and avoid the penetration of nanoparticles inside the cell. In this chapter we will discuss the approaches that are currently used for direct deposition of nanomaterials on the surface of biological cells.