Quantification of C₆₀-induced membrane disruption using a quartz crystal microbalance

Area of Science:

• Nanotechnology and Materials Science
• Biophysics and Cell Biology
• Environmental Toxicology

Background:

• Direct contact between fullerene C60 nanoparticles (NPs) and cell membranes is a key mechanism of their cytotoxicity.
• Understanding NP-cell membrane interactions is crucial for predicting environmental hazards and biological impacts.

Purpose of the Study:

• To investigate the influence of fullerene C60 NPs on lipid membranes.
• To develop and validate a new method for quantifying NP-induced membrane disruption.

Main Methods:

• Utilized giant unilamellar vesicles (GUVs) to observe membrane disruption.
• Employed a supported lipid bilayer (SLB) and small unilamellar vesicles (SUVs) on a quartz crystal microbalance (QCM) sensor to quantify NP adhesion and membrane disruption.
• Analyzed mass changes (Δm) and surface area ratios (A) to determine the degree of disruption.

Main Results:

• Fullerene C60 NPs disrupted positively charged GUVs but not negatively charged ones, confirming the role of electrostatic forces.
• The QCM method demonstrated significant membrane disruption by C60 NPs, with Δm_SLB > Δm_SUV despite A_SLB < A_SUV.
• C60 NPs caused negligible changes in membrane phase, indicating membrane gelation is not a primary cytotoxicity mechanism.

Conclusions:

• A novel QCM-based method was established to quantify NP-induced membrane disruption using Δm_SUV/Δm_SLB and A_SUV/A_SLB ratios.
• This method allows for comparative analysis of membrane damage caused by different types of NPs.
• The findings provide critical data for predicting environmental risks and evaluating the membrane toxicity of fullerene NPs.