Dynamic characteristics of silver nanoparticles in physiological fluids: toxicological implications

Area of Science:

• Nanotoxicology
• Environmental Health
• Materials Science

Background:

• Nanomaterial (NM) exposure poses risks, but how physiological conditions modify NM properties is underexplored.
• Understanding these modifications is crucial for accurate risk assessment of inhaled NMs.

Purpose of the Study:

• To investigate environmental-specific modulations of silver NMs (Ag-HC and Ag-PS) in artificial physiological fluids.
• To assess the impact of these modulations on NM behavior and biological effects in an alveolar macrophage model.

Main Methods:

• Silver NMs with hydrocarbon (Ag-HC) and polysaccharide (Ag-PS) coatings were dispersed in artificial alveolar, lysosomal, and interstitial fluids.
• Alveolar macrophage cells were exposed to NMs at dosages simulating occupational exposure (0.5 and 25 ng/mL).
• Changes in NM morphology, aggregation, reactivity, and cellular responses (cytotoxicity, phagocytosis, inflammation) were analyzed.

Main Results:

• Both Ag-HC and Ag-PS NMs showed significant alterations in morphology, aggregation, and reactivity after dispersion in artificial fluids.
• Ag-PS NMs experienced coating loss, leading to increased cytotoxicity, phagocytosis, and inflammation.
• NM behavior and toxicity were significantly modulated by the physiological environment.

Conclusions:

• Physiological environments dynamically alter NM properties, potentially increasing their toxicity over time.
• The dynamic and insoluble nature of NMs critically influences their bioeffects.
• Characterizing NM behavior in physiological systems is essential for understanding nanotoxicology and risk assessment.