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One-Step Generation of Cell-Encapsulating Compartments via Polyelectrolyte Complexation in an Aqueous Two Phase
Sarah D Hann1, Tagbo H R Niepa1, Kathleen J Stebe1
1Department of Chemical and Biomolecular Engineering, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States.
ACS Applied Materials & Interfaces
|September 1, 2016
Summary
Researchers developed a novel aqueous two-phase system for creating biocompatible microcapsules without oil. This method precisely controls polyelectrolyte interactions at interfaces for functional cell encapsulation and triggered release.
Area of Science:
- Biomaterials science
- Chemical engineering
- Cell biology
Background:
- Biologically compatible encapsulation is crucial for drug delivery and cell studies.
- Traditional methods often use oil phases, which can be detrimental.
- Aqueous two-phase systems offer a promising oil-free alternative.
Purpose of the Study:
- To develop an oil-free method for creating functional microcapsules using aqueous two-phase systems.
- To investigate the role of polyelectrolyte complexation at interfaces for membrane formation.
- To demonstrate the utility of these microcapsules for live cell encapsulation and triggered release.
Main Methods:
- Utilized an aqueous two-phase system of poly(ethylene glycol) (PEG) and dextran.
- Formed microcapsules by controlling the interfacial complexation of polyelectrolytes between PEG-rich and dextran-rich phases.
- Tuned relative polyelectrolyte fluxes to direct complexation to the interface for stable membrane formation.
- Demonstrated live cell encapsulation (Pseudomonas aeruginosa PAO1) and assessed viability using a Live/Dead assay.
Main Results:
- Successfully formed microcapsules using PEG-dextran aqueous two-phase systems, eliminating the need for an oil phase.
- Identified conditions for interfacial polyelectrolyte complexation leading to stable microcapsule membranes.
- Demonstrated that microcapsules respond to stimuli like salt concentration and osmotic pressure for controlled release.
- Confirmed successful encapsulation and viability assessment of live bacterial cells within the microcapsules.
Conclusions:
- This novel aqueous encapsulation method provides a biocompatible and oil-free platform for creating functional microcapsules.
- Precise control over interfacial complexation enables the formation of versatile functional membranes.
- The system is suitable for encapsulating living cells and facilitating triggered release applications.
