Microbubbles decorated with dendronized magnetic nanoparticles for biomedical imaging: effective stabilization via...

Area of Science:

• Nanotechnology
• Materials Science
• Biomedical Engineering

Background:

• Iron oxide nanoparticles (IONPs) are utilized for imaging and therapeutic applications.
• Dendrons with oligo(ethylene glycol) (OEG) chains can modify nanoparticle properties.
• Surface functionalization is crucial for controlling nanoparticle behavior in biological systems.

Purpose of the Study:

• To synthesize and characterize dendronized IONPs with fluorinated or hydrogenated end groups.
• To investigate the effect of these dendronized IONPs on microbubble (MB) formation and stability.
• To explore the role of fluorous interactions in the adsorption of dendronized IONPs.

Main Methods:

• Synthesis of dendrons with OEG chains, fluorinated/hydrogenated end groups, and bisphosphonate heads.
• Grafting of dendrons onto IONPs, followed by characterization using dynamic light scattering.
• Interfacial tension measurements and adsorption studies at gas/water interfaces.
• Preparation and characterization of perfluorohexane-stabilized microbubbles using optical microscopy and acoustics.
• Atomic force microscopy of mixed phospholipid films.

Main Results:

• Dendronized IONPs showed increased adsorption to gas/water interfaces in the presence of fluorocarbon gas, indicating fluorous interactions.
• Microbubbles incorporating fluorinated dendronized IONPs were smaller and more stable than those with hydrogenated dendrons.
• Microbubbles with C2F5-terminated dendrons (radius ~1.0 μm) achieved a half-life of ~6.0 hours.
• Atomic force microscopy revealed fluorinated dendronized IONPs embedded within phospholipid films, while hydrogenated ones remained at the surface.

Conclusions:

• Fluorinated end groups on dendrons enhance the stability and performance of IONP-loaded microbubbles.
• Fluorous interactions play a significant role in the interfacial behavior of these dendronized nanoparticles.
• The developed dendronized IONPs are promising for microbubble-mediated imaging and therapeutic applications.