Surface functionalities of gold nanoparticles impact embryonic gene expression responses.

Area of Science:

• Nanotechnology
• Toxicology
• Developmental Biology

Background:

• Gold nanoparticles (AuNPs) are increasingly used in consumer products.
• Limited toxicological data exists to assess the safety of AuNPs.
• Understanding AuNP behavior at a molecular level is crucial for risk assessment.

Purpose of the Study:

• To investigate the influence of surface functionalization and charge on molecular responses of gold nanoparticles (AuNPs).
• To assess the toxicological effects of engineered AuNPs in embryonic zebrafish models.
• To determine how different ligands on AuNPs affect biological pathways.

Main Methods:

• Synthesis of precisely engineered 1.5 nm core AuNPs functionalized with specific ligands (MES, TMAT, and an alcohol-based ligand).
• Exposure of embryonic zebrafish to functionalized AuNPs at a consistent concentration.
• Developmental assessments and inductively coupled plasma-mass spectrometry (ICP-MS) to confirm AuNP uptake.
• Analysis of molecular responses, including gene expression pathways related to inflammation, immune response, and transport mechanisms.

Main Results:

• Differential biological responses were observed in zebrafish embryos exposed to functionalized AuNPs.
• AuNP uptake was confirmed in exposed embryos via ICP-MS.
• Exposure to MES- and TMAT-functionalized AuNPs perturbed pathways involved in inflammation and immune response.
• Transport mechanisms were misregulated following exposure to TMAT- and MES-AuNPs.

Conclusions:

• Surface functionalization and charge of AuNPs significantly influence their biological interactions and molecular effects.
• The choice of ligand on AuNPs dictates the specific toxicological pathways affected.
• Embryonic zebrafish are a suitable model for evaluating the safety and molecular impact of nanomaterials like AuNPs.