Carbon nanohybrids as electro-responsive drug delivery systems

Electro-responsive nanomaterials are usually made with polyelectrolytes able to undergo shrinkage or swelling by tuning on electrical fields. Nevertheless, the electrical conductivity of many polymeric materials used for the fabrication of release devices is not high enough to achieve an effective modulation of the drug release. The incorporation of conducting materials (e.g. carbon nanostructures) in polymeric networks has been proposed as a valuable strategy to overcome this limitation. In this regard, carbon nanotubes and graphene, by virtue of their unique chemical structures and attractive physiochemical properties, have been receiving exciting attention primarily in biology and medicine. By their incorporation into composite hydrogels, the biocompatibility and biodegradability of polymers can be merged with the favorable properties of carbon nanostructures, such as enhanced cellular uptake, electromagnetic, and magnetic behavior. The applicability of carbon hybrid materials to modulate release of therapeutics in response to an external current voltage, is being extensively investigated in the present review.