Thermal and Acoustic Stabilization Of Volatile Phase-Change Contrast Agents Via Layer-By-Layer Assembly.

Area of Science:

• Biomedical Engineering
• Nanotechnology
• Acoustic Imaging

Background:

• Phase-change contrast agents (PCCAs) are perfluorocarbon nanodroplets (NDs) used in ultrasound imaging.
• PCCAs show promise for drug delivery and treating cancerous/inflammatory diseases.
• Improving thermal and acoustic stability of PCCAs is crucial for clinical applications.

Purpose of the Study:

• To investigate the stabilizing effects of layer-by-layer (LBL) assemblies on PCCAs.
• To determine the impact of LBL coatings on the thermal and acoustic stability of PCCAs.

Main Methods:

• Layer-by-layer (LBL) assemblies were used to coat decafluorobutane gas-condensed nanodroplets (DFB-NDs).
• Coated nanodroplets (LBL6NDs and LBL10NDs) were characterized for zeta potential and particle size.
• Thermal stability was assessed by incubation at 37°C and 45°C, followed by acoustic droplet vaporization (ADV) measurements.

Main Results:

• Successful application of up to 10 layers of biopolymers onto DFB-NDs was achieved.
• Layered PCCAs exhibited significantly increased half-lives at 37°C and 45°C, indicating enhanced thermal stability.
• No statistically significant difference was found in the acoustic vaporization energy required for layered and non-layered DFB-NDs.

Conclusions:

• Biopolymeric layering enhances the thermal stability of PCCAs.
• LBL coating does not alter the acoustic vaporization thresholds of PCCAs.
• Enhanced thermal stability of PCCAs is achievable without compromising acoustic properties for imaging.