Preparation of liposomes containing small gold nanoparticles using electrostatic interactions

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Engineering

Background:

• Liposome-nanoparticle systems offer versatile platforms for drug delivery.
• Encapsulating nanoparticles within liposomes requires controlled synthesis methods.
• Metallic nanoparticles show promise for various therapeutic applications.

Purpose of the Study:

• To investigate a strategy for encapsulating small metallic nanoparticles (<4nm) within multilamellar vesicles.
• To develop liposome-gold nanoparticle (lipo-GNP) systems using electrostatic interactions.
• To evaluate the nanoparticle encapsulation efficacy and control over loading content.

Main Methods:

• Utilized the reverse-phase evaporation method to prepare lipo-GNP systems.
• Employed cationic or anionic surface-functionalized gold nanoparticles with oppositely charged lipids.
• Performed post-formulation PEGylation and characterized structures using electron microscopy and elemental analysis.
• Quantified encapsulation efficacy by comparing lipid to gold concentration ratios via colorimetric assay and atomic emission spectroscopy.

Main Results:

• Demonstrated a regular distribution of gold nanoparticles between lipid bilayers in intact liposomes.
• Observed a significant difference in nanoparticle encapsulation efficacy between the two lipo-GNP systems (p=0.03).
• Confirmed the effectiveness of electrostatic interactions in controlling nanoparticle loading content.

Conclusions:

• The developed synthetic strategy is effective for preparing liposome-nanoparticle colloids.
• This approach allows for control over the relative concentration of encapsulated particles to lipids.
• The lipo-GNP systems show potential for multifunctional therapeutic platforms.