Carbon Nanotubes Used as Nanocarriers in Drug and Biomolecule Delivery

Abstract

Carbon nanotubes (CNTs), an artificial allotrope of carbon recently discovered in 1991, are made of graphite and constructed in cylindrical tubes having nanometer in diameter and several millimeters in length. The structures of CNTs are classified in two types: single-walled carbon nanotubes (SWCNTs) and multiwalled carbon nanotubes (MWCNTs). Due to their small size and mass, strong mechanical potency, and high electrical and thermal conductivity, CNTs have been successfully applied in different areas of pharmacy and medicine for drug preparation and therapy. They have been first proven to be an excellent nano-vehicle for the delivery of different therapeutic agents (drugs, biomolecules, etc.) directly into cells without metabolism by the body. Thanks to their tiny structure, CNTs can effectively cross the cell membrane and directly deliver the transported drug into the cell. CNTs are able to maintain the drug intact during this transport and protect the drug against the metabolism by the body. The important characteristics of this nanotechnology in pharmaceutics are to revolutionize the methods of drug delivery since traditional drug administration cannot resolve the problems of toxicity and/or bioavailability of numerous effective drugs, thereby limiting their use in therapeutics. As CNTs are not water soluble, surface functionalization is required before their linkage with drugs or biomolecules. CNTs have also been proposed in biomolecule delivery such as DNA, proteins, antibodies, etc., for gene therapy, tissue regeneration, artificial implants and diagnosis of human diseases. This review focuses the applications of CNTs used as nanocarriers in drug and biomolecule delivery for chemotherapeutic use and also studies 165the pharmacokinetics, metabolism and toxicity of different forms of CNTs. Finally, it discusses the prospect of this promising bio-nanotechnology in the future clinical exploitation.