Dissipative Particle Dynamics Models of Encapsulated Microbubbles and Nanoscale Gas Vesicles for Biomedical...

Area of Science:

• Biophysics
• Nanotechnology
• Biomedical Engineering

Background:

• Ultrasound-guided drug and gene delivery (USDG) utilizes microbubbles (EMBs) and gas vesicles (GVs) for precise, noninvasive therapeutic delivery.
• Accurate modeling of EMBs and GVs is essential for optimizing USDG efficacy, but current continuum models have limitations.
• Limitations include inability to capture shell thickness variations, constituent interactions, and surface functionalizations.

Purpose of the Study:

• To develop a general particle-based modeling framework for encapsulated bodies like EMBs and GVs.
• To accurately capture the elastic and rheological properties of these nanostructures at mesoscopic and nanoscale levels.
• To enable detailed modeling of surface functionalizations and their impact on biological interactions.

Main Methods:

• Utilized dissipative particle dynamics (DPD) to model the solvent, gaseous core, and triangulated surfaces of encapsulated bodies.
• Performed stretching, buckling, and shear flow simulations to analyze elastic and rheological behaviors.
• Validated the model by comparing predicted GV buckling pressure with existing experimental data.

Main Results:

• Developed a robust particle-based framework capable of simulating nanoscale and microscale encapsulated bodies.
• Accurately captured the elastic properties, including buckling behavior, of GVs and EMBs.
• Demonstrated the model's ability to handle complex geometries and local anisotropy.

Conclusions:

• The particle-based modeling approach provides a powerful tool for understanding the physical properties of EMBs and GVs.
• This framework facilitates large-scale simulations of encapsulated body dynamics, interactions, and collective behavior.
• Enables advancements in the design and application of ultrasound-mediated therapeutic delivery systems.