Carbon Nanostructures as Therapeutic Cargoes: Recent Developments and Challenges

Recent developments in nanotechnology and process chemistry have expanded the scope of nanostructures to the biomedical field. The ability of nanostructures to precisely deliver drugs to the target site not only reduces the amount of drug needed but also reduces systemic adverse effects. Carbon nanostructures gained traction in pharmaceutical technology in the last decade due to their high stability, ease of synthesis, tunable surface chemistry, and biocompatibility. Fullerene, nanotubes, nanodiamonds, nanodots, and nanoribbons are among the major carbon nanostructures that have been extensively studied for applications in tissue engineering, biosensing, bioimaging, theranostics, drug delivery, and gene therapy. Due to the fluorescent properties of functionalized nanostructures, they have been extensively studied for use as probes in cellular imaging. Moreover, these nanostructures are promising candidates for delivering drugs to the brain, bones, and deep-seated tumors. Still, research gaps need to be addressed regarding the toxicity of these materials in animals as well as humans. This review highlights the physicochemical properties of carbon nanostructures and their categories, methods of synthesis, various techniques for surface functionalization, major biomedical applications, mechanisms involving the cellular uptake of nanostructures, pharmacokinetic considerations, recent patents involving carbon-based nanostructures in the biomedical field, major challenges, and future perspectives.