The connection of active ingredients to the particle surface or their storage in pores or cavities in the particle core enables the safe transport of a large number of molecules in the human body. The particle surface can also be used for the attachment of cell-specific ligands to achieve enrichment of the active substances in the desired cells. In addition to mesoporous particles made of silicon dioxide, which can also be in the form of a hollow structure, we also use core-shell structures with iron oxides or gold to enable tracking in the cells. Applications include cancer as well as antibacterial infections.