Overview of Carbon Nanotubes for Biomedical Applications

Abstract

The unique combination of mechanical, optical and electrical properties offered by carbon nanotubes has fostered research for their use in many kinds of applications, including the biomedical field. However, due to persisting outstanding questions regarding their potential toxicity when considered as free particles, the research is now focusing on their immobilization on substrates for interface tuning or as biosensors, as load in nanocomposite materials where they improve both mechanical and electrical properties or even for direct use as scaffolds for tissue engineering. After a brief introduction to carbon nanotubes in general and their proposed applications in the biomedical field, this review will focus on nanocomposite materials with hydrogel-based matrices and especially their potential future use for diagnostics, tissue engineering or targeted drug delivery. The toxicity issue will also be briefly described in order to justify the safe(r)-by-design approach offered by carbon nanotubes-based hydrogels.

The Advances in Biomedical Applications of Carbon Nanotubes

“…It must be noted that the different methodologies and approaches for surface functionalization may profoundly affect the biocompatibility, toxicity and physical features of CNTs. In fact, the method of functionalization may directly influence of pharmacokinetics and bio-distribution of CNTs [33]. It was found out that non-covalently functionalized CNTs predominately accumulate in liver and spleen tissues, whilst the covalently functionalized CNTs prone to be excreted through urine [34].…”

The Immobilization of ChEMBL474807 Molecules Using Different Classes of Nanostructures

“…The scope of the functional groups used takes into account aliphatic chains with methoxy, amide, ester, and halogen groups, and aromatic systems that include unsubstituted benzene rings, as well as more complex aromatic systems. The next set of nanosystems worthy of consideration is carbon nanotubes, which have found many applications in the biomedical field e.g., in diagnostics, tissue engineering, or targeted drug delivery [27][28][29]. The characteristic structure of these nanosystems is created by rolling up graphene sheets, and such large surfaces consisting of aromatic systems could exhibit high affinity toward the considered ligand molecule that exhibiting significant activity in stacking interactions.…”

Recent Advances in Carbon Nanotubes for Nervous Tissue Regeneration

“…Academic communities and regulatory agencies have grown in concern about the adverse effects of CNT-based materials and nanomaterials in general. Factors such as particle concentration, exposure route (injection, ingestion, and inhalation [60]), particle size, particle distribution, particle agglomeration, and surface adsorbability and attachment are pivotal to comprehend the huge variability in the nanotoxicity studies of CNTs [61].…”

“…erefore, CNTs show in general good compatibility in vivo with neuronal tissues. e most cautious way to use CNT would be to prevent them from entering the organism freely [60]. Examples like the one discussed in Section 5.4.4 or other CNThydrogel systems [63] comprise the trapping of free CNTs within the hydrogel network, thus limiting standalone CNTs release.…”