Toxicity and Gene Expression Profiling of Copper- and Titanium-Based Nanoparticles Using Air-Liquid Interface...

Area of Science:

• Nanotoxicology
• In vitro toxicology
• Air-liquid interface (ALI) exposure systems

Background:

• Traditional in vitro toxicity studies use submerged conditions, not reflecting inhalation exposure.
• Air-liquid interface (ALI) exposure offers more physiologically relevant conditions for nanoparticle assessment.
• Understanding nanoparticle toxicity is crucial for risk assessment and occupational safety.

Purpose of the Study:

• To evaluate the toxicological potential of copper oxide (CuO) and titanium dioxide (TiO2) nanoparticles (NP) using an ALI exposure system.
• To assess NP impact on genomic stability and cellular responses in A549 lung cells.
• To combine ALI exposure with high-throughput RT-qPCR for comprehensive toxicological profiling.

Main Methods:

• Exposure of A549 cells to CuO and TiO2 nanoparticles at an air-liquid interface (ALI).
• High-throughput RT-qPCR to analyze gene expression related to metal homeostasis, stress, and DNA damage.
• Measurement of intracellular copper concentration, reactive oxygen species (ROS) levels, DNA strand breaks, and apoptosis/necrosis via flow cytometry.

Main Results:

• TiO2 NP showed no cytotoxicity or genotoxicity up to 25.8 μg/cm².
• CuO NP induced dose-dependent cytotoxicity starting at 4.9 μg/cm².
• CuO NP triggered altered gene expression (metal homeostasis, stress, DNA damage), increased ROS, DNA strand breaks, and apoptosis/necrosis.

Conclusions:

• The ALI exposure system combined with RT-qPCR effectively quantifies NP deposition and genomic impact.
• CuO NP exhibit significant toxicity, including cytotoxicity, genotoxicity, and induction of stress responses, consistent with intracellular copper ion release.
• ALI exposure provides reliable dose-response data for comparing the relative toxic potencies of different nanoparticles.