Cargo Release from Polymeric Vesicles under Shear

Area of Science:

• Polymer Science
• Materials Science
• Computational Chemistry

Background:

• Polymeric nano-carriers, such as polymersomes, are promising for targeted cargo delivery.
• Understanding cargo release mechanisms under external stimuli like shear is crucial for their application.

Purpose of the Study:

• To investigate cargo release from different polymersomes (ABC, ABA, AB) under shear flow.
• To determine the influence of polymer architecture and confinement on release kinetics.
• To identify conditions for controlled cargo release for engineering applications.

Main Methods:

• Dissipative particle dynamics (DPD) simulations were employed.
• Vesicles formed from star block copolymers (ABC, ABA) and linear block copolymers (AB) were studied.
• Simulations involved applying shear in bulk and between solvophobic walls.

Main Results:

• In bulk shear, cargo release was similar across vesicle types, with no preferred location.
• High cargo release rates between walls were observed specifically for the ABC vesicle upon wall contact.
• For ABC vesicles, interface formation with walls was critical for release, overriding shear rate effects.
• A solvophilic pathway facilitated cargo transport from the vesicle interior to the exterior.

Conclusions:

• Polymersome design significantly impacts cargo release under shear.
• Controlled cargo release can be achieved by engineering polymersomes and their environment, such as creating interfaces.
• These findings support the use of polymersomes for targeted delivery in applications like friction modification.