Slime molds response to carbon nanotubes exposure: from internalization to behavior

Area of Science:

• Nanotoxicology
• Environmental Science
• Cell Biology

Background:

• Carbon nanotubes (CNTs) have diverse applications but pose environmental risks.
• The ecotoxicity of nanoparticles on simple organisms like slime molds is understudied.
• Physarum polycephalum offers a unique model for nanotoxicology research.

Purpose of the Study:

• To assess the toxicity of double-walled carbon nanotubes (DWCNTs) on the acellular slime mold Physarum polycephalum.
• To investigate DWCNT uptake, bioaccumulation, persistence, and excretion in P. polycephalum.
• To evaluate the impact of DWCNTs on slime mold behavior and physiology.

Main Methods:

• Exposure of P. polycephalum to DWCNTs via topical, food, and environmental routes.
• Monitoring DWCNT internalization, bioaccumulation, and excretion over time.
• Assessing changes in slime mold migration speed, pseudopod formation, and expansion rate.

Main Results:

• DWCNTs were rapidly internalized by P. polycephalum, particularly when ingested or in the environment.
• No significant bioaccumulation or persistence of DWCNTs was observed, with near-complete excretion within 2 days.
• DWCNT exposure significantly altered slime mold migration, pseudopod dynamics, and growth rate.

Conclusions:

• Physarum polycephalum efficiently processes and excretes DWCNTs, showing no long-term accumulation.
• DWCNT exposure demonstrably impacts P. polycephalum's motility and morphology.
• P. polycephalum is validated as a promising and sensitive model organism for nanotoxicological studies.