Filling carbon nanotubes for nanobiotechnological applications

With the great development in new filling methodologies for preparing endohedral carbon nanotubes, encapsulation strategies employing biomedically relevant molecular guests have emerged rapidly in recent years. All of these hybrid nanomaterials feature distinct properties and potential applications depending on both the chemical nature and spatial arrangement of the encapsulated molecular guests. In this focus article, we discuss the most significant examples in which carbon nanotube (CNTs) hybrids, filled with suitable molecular species, are used for biomedical applications. CNTs containing strongly emitting molecules hold great promises for diagnostic devices, whereas those filled with radioactive species and magnetically-active nanoparticles are attracting considerable attention for theranostic applications. Examples describing the use of the CNTs' tubular cavity as an active reservoir for the controlled release of drugs are also discussed. Carbon nanotubes can host biomedically-relevant moieties inside their hollow cavities, thus offering new opportunities in imaging and other therapeutic applications. The most recent literature reports in these directions are discussed.