2017 journal article

A Carbon Nanotube Optical Sensor Reports Nuclear Entry via a Noncanonical Pathway

ACS Nano.

Januka Budhathoki Uprety

author keywords: helical polymer; hyperspectral imaging; cervical cancer; near-infrared sensor; biosensor; polycation; nuclear pore complex
MeSH headings : Active Transport, Cell Nucleus; Cell Nucleus / metabolism; HeLa Cells; Humans; Luminescent Agents / chemistry; Luminescent Agents / metabolism; Microscopy, Fluorescence; Molecular Structure; Nanotubes, Carbon / analysis; Nanotubes, Carbon / chemistry; Optical Imaging; Polymers / chemistry; Tumor Cells, Cultured
TL;DR: A carbon nanotube based hybrid material is developed that elucidate a distinct mechanism of nuclear translocation of a nanomaterial in cultured cells and provides a reporter for the study of nucleus-related pathologies. (via Semantic Scholar)
Source: ORCID
Added: August 27, 2019

Single-walled carbon nanotubes are of interest in biomedicine for imaging and molecular sensing applications and as shuttles for various cargos such as chemotherapeutic drugs, peptides, proteins, and oligonucleotides. Carbon nanotube surface chemistry can be modulated for subcellular targeting while preserving photoluminescence for label-free visualization in complex biological environments, making them attractive materials for such studies. The cell nucleus is a potential target for many pathologies including cancer and infectious diseases. Understanding mechanisms of nanomaterial delivery to the nucleus may facilitate diagnostics, drug development, and gene-editing tools. Currently, there are no systematic studies to understand how these nanomaterials gain access to the nucleus. Herein, we developed a carbon nanotube based hybrid material that elucidate a distinct mechanism of nuclear translocation of a nanomaterial in cultured cells. We developed a nuclear-targeted probe via cloaking photoluminescent single-walled carbon nanotubes in a guanidinium-functionalized helical polycarbodiimide. We found that the nuclear entry of the nanotubes was mediated by the import receptor importin β without the aid of importin α and not by the more common importin α/β pathway. Additionally, the nanotube photoluminescence exhibited distinct red-shifting upon entry to the nucleus, potentially functioning as a reporter of the importin β-mediated nuclear transport process. This work delineates a noncanonical mechanism for nanomaterial delivery to the nucleus and provides a reporter for the study of nucleus-related pathologies.