Aggregation Reduces Subcellular Localization and Cytotoxicity of Single-Walled Carbon Nanotubes

Area of Science:

• Nanotechnology
• Biomedical Engineering
• Materials Science

Background:

• Fluorescent single-walled carbon nanotubes (SWCNTs) are widely used in biomedical applications.
• It is often assumed SWCNTs interact with cells in a pristine, dispersed state.
• However, nanomaterials tend to aggregate in biological environments before cellular interaction.

Purpose of the Study:

• To investigate the impact of SWCNT aggregation state on cellular internalization, intracellular processing, and toxicity.
• To compare the behavior of initially aggregated vs. less aggregated SWCNTs within live cells.

Main Methods:

• Utilized DNA-functionalized SWCNTs with controlled aggregation.
• Employed near-infrared hyperspectral microscopy for cellular imaging.
• Conducted long-term cytotoxicity and real-time proliferation assays.

Main Results:

• Despite equal internalization rates, initially aggregated SWCNTs did not accumulate further within subcellular locations.
• SWCNTs with low initial aggregation induced significant deleterious effects in cytotoxicity and proliferation assays.
• Markedly different toxicological responses were observed based on initial aggregation state.

Conclusions:

• The aggregation state of SWCNTs is a critical factor influencing their intracellular fate.
• Aggregation state significantly affects the toxicological response of engineered nanomaterials.
• Findings highlight the need to consider nanomaterial aggregation in biomedical applications and safety assessments.