Nanoparticle wrapping at small non-spherical vesicles: curvatures at play

Area of Science:

• Biophysics
• Cell Biology
• Nanotechnology

Background:

• Nanoparticles interact with various biological membranes, including intracellular and extracellular vesicles.
• Extracellular vesicles, like exosomes, are crucial for cell signaling and have roles in diseases such as tumor metastasis.
• Vesicles also show potential as targeted drug delivery systems.

Purpose of the Study:

• To systematically characterize the wrapping of spherical nanoparticles entering and exiting vesicles.
• To investigate the influence of particle size, vesicle size, reduced volume, and membrane spontaneous curvature on nanoparticle-vesicle interactions.
• To predict complex wrapping behaviors, especially at large particle-to-vesicle size ratios.

Main Methods:

• Computational modeling to simulate nanoparticle-vesicle interactions.
• Analysis of membrane deformation energy and shape transitions.
• Prediction of boundary conditions imposed by partially wrapped nanoparticles.

Main Results:

• Complex wrapping behaviors were predicted, particularly for large particle-to-vesicle size ratios.
• Coupled transitions between nanoparticle wrapping and vesicle shape were observed.
• Partial wrapping imposed boundary conditions that stabilized specific vesicle shapes during entry and exit.

Conclusions:

• Nanoparticle entry and exit dynamics are governed by size, membrane properties, and vesicle shape.
• Nanoparticles may induce autophagocytic engulfment, facilitating lysosomal transport and degradation.
• This has implications for understanding nanoparticle fate in biological systems and for designing drug delivery systems.