Physicochemical Properties Affecting Cellular Uptake of Carbon Nanotubes

Abstract

Carbon nanotubes (CNTs) are widely used for biomedical applications as intracellular transporters of biomolecules owing to their ability to cross cell membranes. In this article, we survey the reported literature and results of our published work in an attempt to provide a rational view of the various CNT internalization mechanisms. Essentially three uptake mechanisms (phagocytosis, diffusion and endocytosis) have been reported in the literature. In addressing the subject of cellular internalization of CNTs, the unique physicochemical characteristics of CNTs that influence and drive the cell uptake pathway are considered. According to available evidence, the degree of dispersion, the formation of supramolecular complexes and the nanotube length are crucial factors in determining the exact mechanism of cellular uptake. In conclusion, phagocytosis appears to be the internalization pathway for CNT aggregates, bundles, cluster or single dispersed nanotubes 1 µm or more in length; endocytosis is the internalization mechanism for nanotubes forming supramolecular structures; and diffusion is the internalization mechanism for submicron CNTs that do not form supramolecular complexes. This information may be relevant to the rational design of CNT-based carriers for cell therapy.

Keywords::

• carbon nanotubes
• internalization mechanisms
• physical and chemical properties

Financial & competing interests disclosure

This work has been performed in the framework of the Non Invasive Nanotransducer for In vivo Gene Therapy (NINIVE) project funded by the European Commission (Contract No. 033378). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Additional information

Funding

This work has been performed in the framework of the Non Invasive Nanotransducer for In vivo Gene Therapy (NINIVE) project funded by the European Commission (Contract No. 033378). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.