Toxicity of nanoparticles embedded in paints compared with pristine nanoparticles in mice

Area of Science:

• Environmental Science
• Toxicology
• Materials Science

Background:

• Engineered nanoparticles (ENPs) like titanium dioxide (TiO2), silver (Ag), and silicon dioxide (SiO2) are increasingly used in industrial applications, including paints, due to their unique properties.
• These ENPs offer benefits such as UV protection, self-cleaning, air purification, antimicrobial activity, and enhanced durability.

Purpose of the Study:

• To compare the toxic effects and biodistribution of pristine ENPs versus ENPs embedded in aged paint formulations.
• To evaluate the safety of TiO2, Ag, and SiO2 ENPs when used as paint additives in a mouse model.

Main Methods:

• BALB/c mice were oropharyngeally aspirated weekly for 5 weeks with pristine ENPs or paint particles (TiO2, Ag, SiO2) or control paints.
• Bronchoalveolar lavage, systemic blood toxicity analysis (cell counts, cytokines, blood parameters), and tissue biodistribution (lung, liver, kidney, spleen, heart) were performed.

Main Results:

• Pristine ENPs induced subtle lung effects and negligible blood alterations, with silver ENPs causing the most pronounced toxicity (increased neutrophils, pro-inflammatory cytokines KC and IL-1ß).
• Paints containing TiO2 ENPs mildly induced inflammatory cytokines, while paints with Ag or SiO2 ENPs showed no significant toxicity.
• Biodistribution revealed Ag and Si outside the lung after exposure to pristine Ag or SiO2 ENPs, respectively.

Conclusions:

• Direct exposure to pristine ENPs can induce toxicological effects.
• When embedded within a complex paint matrix, ENPs demonstrated significantly reduced or negligible adverse toxicological effects, suggesting a safer profile in this application.