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

Abstract

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 carbon nanotube-based hybrid material which elucidated a distinct mechanism of nuclear translocation of a nanomaterial in cultured cells. We developed a nuclear-targeted nanotube 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 non-canonical mechanism for nanomaterial delivery to the nucleus and provides a reporter for the study of nucleus-related pathologies.

Molecular Imaging with 68Ga Radio-Nanomaterials: Shedding Light on Nanoparticles

“…Examples of these include Au nanoparticles [149,150], dendrimers [151,152], carbon nanotubes [153,154], or silica nanoparticles [155,156].…”

Near‐Infrared Light Activated Thermosensitive Ion Channel to Remotely Control Transgene System for Thrombolysis Therapy

“…[30] With the development of nanomaterials, different types of NIR light absorbing nanomaterials were reported and exhibited high photothermal energy conversion efficiencies. [31][32][33][34][35][36][37] Although diverse NIR photo thermal responsive nanomaterials have performed as promising photothermal nanotransducers in biological studies and biomedical applications, their applications in the remote and precise control of transgene expression of therapeutic agents in vivo remain to be explored. [38][39][40][41][42][43][44][45][46] Herein, we developed a bioengineered cell system with an artificial signaling circuit to remotely and precisely control the production of uPA for antithrombotic therapy in response to NIR light-caused photothermal effects with the help of nanotransducers (Scheme 1).…”

Fluorescent Polymer—Single‐Walled Carbon Nanotube Complexes with Charged and Noncharged Dendronized Perylene Bisimides for Bioimaging Studies

“…Polymers are attractive dispersing agents for SWNTs because they can wrap around the SWNT backbones attaching different functional moieties onto their sidewalls . The well‐established polymer wrapping method benefits from the tight and uniform enclosure of the SWNTs by the polymer, which endures filtration processes, modification of pH, and other environmental changes .…”