Carbon nanotubes as multifunctional biological transporters and near-infrared agents for selective cancer cell destruction

TLDR

Biological systems are highly transparent to 700–1,100‑nm near‑infrared light. The study demonstrates that single‑walled carbon nanotubes’ strong NIR absorbance can be harnessed for optical stimulation inside living cells, enabling multifunctional nanotube transporters. The authors employ NIR laser pulses to trigger endosomal rupture, allowing oligonucleotides carried by SWNTs to enter the nucleus, and functionalize SWNTs with folate to selectively internalize them into folate‑receptor‑positive tumor cells for NIR‑induced cell death. In vitro, continuous NIR exposure induces cell death via local heating of SWNTs, and the study shows that functionalized SWNTs can serve as novel nanomaterials for targeted drug delivery and cancer therapy.

Abstract

Biological systems are known to be highly transparent to 700- to 1,100-nm near-infrared (NIR) light. It is shown here that the strong optical absorbance of single-walled carbon nanotubes (SWNTs) in this special spectral window, an intrinsic property of SWNTs, can be used for optical stimulation of nanotubes inside living cells to afford multifunctional nanotube biological transporters. For oligonucleotides transported inside living cells by nanotubes, the oligos can translocate into cell nucleus upon endosomal rupture triggered by NIR laser pulses. Continuous NIR radiation can cause cell death because of excessive local heating of SWNT in vitro . Selective cancer cell destruction can be achieved by functionalization of SWNT with a folate moiety, selective internalization of SWNTs inside cells labeled with folate receptor tumor markers, and NIR-triggered cell death, without harming receptor-free normal cells. Thus, the transporting capabilities of carbon nanotubes combined with suitable functionalization chemistry and their intrinsic optical properties can lead to new classes of novel nanomaterials for drug delivery and cancer therapy.