Gold Nanoparticle Adsorption and Uptake are Directed by Particle Capping Agent

Area of Science:

• Biophysics
• Nanotechnology
• Materials Science

Background:

• Nanomaterials offer promising therapeutic applications, but their interactions with biological systems, particularly lipid bilayers, are complex and not fully understood.
• Elucidating these interactions is crucial for designing effective nanomaterial-based drug delivery and diagnostic tools.

Purpose of the Study:

• To investigate the precise mechanisms of interaction between ligand-capped gold nanoparticles (AuNPs) and supported lipid bilayers.
• To determine how variations in the capping agent's size and charge influence AuNP adsorption and lipid bilayer disruption.

Main Methods:

• Utilized a combination of atomic force microscopy (AFM) and molecular dynamics (MD) simulations.
• Studied the interaction of 5 nm gold nanoparticles (AuNPs) with 1,2-di(9Z-octadecenoyl)-sn-glycero-3-phosphocholine (DOPC) lipid bilayers.

Main Results:

• Observed distinct adsorption and bilayer disruption patterns dependent on the capping agent's properties.
• Weakly adsorbed ligands facilitated AuNP insertion into the bilayer's hydrophobic core, while strongly adsorbed ligands inhibited insertion.
• Ligand-dependent headgroup interactions influenced interfacial adhesion or adsorption inhibition.

Conclusions:

• The interaction of gold nanoparticles (AuNPs) with biological membranes is highly dependent on the specific capping agent used.
• Mechanisms of interaction can involve synergistic effects with membrane components, underscoring the need for molecular-level understanding.