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Tunable Gas Bubbles within Gas-Encapsulating Microcapsules (GEMs) for Buoyancy-Driven Purification
Charles K Yeh1, Yijin Huang1, Luuk H Schoenmakers1
1Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States.
ACS Applied Materials & Interfaces
|July 29, 2025
Summary
Scientists created gas bubble-encapsulating microcapsules (GEMs) inspired by aquatic microbes and plants. This novel method uses negative pressure to control bubble size for applications like purification and drug delivery.
Area of Science:
- Biomaterials Science
- Biophysics
- Microfluidics
Background:
- Aquatic microorganisms use intracellular gas vesicles for buoyancy.
- Drought-stressed plants exhibit cavitation, where negative pressure generates gas bubbles.
Purpose of the Study:
- To develop gas bubble-encapsulating microcapsules (GEMs) mimicking natural buoyancy regulation and cavitation.
- To leverage negative pressure for controlled gas bubble nucleation and size regulation in synthetic systems.
Main Methods:
- GEMs fabricated from poly(d,l-lactide-co-glycolide) (PLGA) with aqueous cores and polymeric shells.
- Osmosis-induced cavitation triggered by transferring microcapsules to high osmotic pressure environments.
- Gas bubble nucleation and growth within the microcapsules due to negative internal pressure.
Main Results:
- Precise postfabrication control over gas bubble size by adjusting external salt concentration.
- Demonstrated effective purification of GEMs using buoyancy, removing polymer debris and defective capsules.
- Successful creation of a scalable and controllable method for GEM production.
Conclusions:
- GEMs offer a synthetic analogue to microbial gas vesicle systems.
- Potential applications include purification, ultrasound theranostics, and responsive drug delivery.
- The cavitation-based approach provides a versatile platform for advanced microcapsule technologies.
Keywords:
double emulsionethyl acetategas vesiclesmicroencapsulationmicrofluidicspoly(d,l-lactide-co-glycolide) (PLGA)separationMore Related Videos
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