Interface interaction between high-siliceous/calcareous mineral granules and model cell membranes dominated by...

Area of Science:

• Biophysics
• Materials Science
• Toxicology

Background:

• High-siliceous and calcareous mineral granules can cause cytotoxicity through interactions with cell membranes.
• Understanding these interactions is crucial for assessing the health risks associated with inhalable mineral particles.

Purpose of the Study:

• To investigate the interaction mechanisms between various mineral granules (micro calcite, micro quartz, nano calcium carbonate, nano silica) and artificial cell membranes (GUVs and SUVs).
• To elucidate the role of electrostatic forces and granule size in membrane disruption.
• To identify specific molecular interactions between mineral granules and phospholipid components.

Main Methods:

• Utilized giant unilamellar vesicles (GUVs) and small unilamellar vesicles (SUVs) as model cell membranes.
• Employed confocal laser scanning microscopy (CLSM) and fluorescence labeling to observe interactions.
• Conducted Fourier-transform infrared spectroscopy (FTIR) and molecular dynamics simulations to analyze molecular interactions.

Main Results:

• Nano calcium carbonate (nano CaCO₃) and nano silica (nano SiO₂) induced membrane gelation by disrupting oppositely charged membranes, highlighting the significance of electrostatic forces.
• Mineral granule size influenced electrostatic interactions and subsequent membrane damage.
• FTIR and molecular dynamics revealed interactions primarily with -PO₂^-, -OH, and -C-N(CH₃)₃⁺ groups in phospholipids.
• Nano SiO₂ exhibited stronger electrostatic forces and hydrogen bonding with the -PO₂^- group compared to nano CaCO₃, resulting in more significant membrane damage.

Conclusions:

• Electrostatic forces play a critical role in the interaction between mineral nanoparticles and cell membranes.
• Nano silica demonstrates a greater capacity to damage artificial membranes compared to nano calcium carbonate due to stronger electrostatic and hydrogen bonding interactions.
• This study provides fundamental insights into the mechanisms by which inhalable mineral granules interact with and potentially damage cell membranes.