Multifunctional carbon-based nanostructures (CBNs) for advanced biomedical applications – a perspective and review

Abstract

Carbon-based nanostructures (CBNs) have attracted immense attention from biomedical researchers due to their unique combination of extraordinary mechanical, thermal, electrical, and optical properties. They can be easily conjugated with several organic and inorganic molecules, enhancing their potential to perform advanced therapeutic actions, which are not possible with existing materials and techniques. As such, the current advances in some of the diagnostic and therapeutic applications of CBNs are discussed in this review. In particular, the applications of carbon nanotubes (CNTs), graphene, and its oxides, as well as diamond-like carbon in tissue engineering, drug delivery, antimicrobial coatings, and medical diagnostics are critically reviewed. Among the several types of CBNs currently in use, it is shown that nanocomposites of functionalized graphene oxide outweigh the mechanical strength of other biomaterials by 110% without compromise to their biocompatibility. Similarly, due to the unique combination of the surface properties of CNTs, such as charge, polarity, and chemistry, these materials are useful for detecting protein molecules at concentrations as low as 5 ng mL⁻¹. Due to its ease of production, robust mechanical strength, and biocompatibility, DLC is effective as an antimicrobial coating for biomedical implants and devices. Further, we provide insight into the biotoxicity and limitations of current CBNs and highlight the need for a novel biomaterial that can outperform the materials that are currently in use. Finally, the future perspective of carbon-based nanostructures in biomedical applications is discussed by introducing Q-carbon, a newly discovered ferromagnetic phase of carbon with interesting structural and functional properties. We describe the structure and multifunctional capabilities of Q-carbon. We envision Q-carbon as an alternative to CBNs for therapeutic applications, diagnostic applications, and as a protective coating for medical devices.