Leaky by Design: Unlocking Polymersome Permeability Using Moderately Hydrophobic Polymer Blocks

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomimetic Systems

Background:

• Polymersome nanoreactors are key for compartmentalized catalysis and biomimetic systems.
• Achieving intrinsic membrane permeability in polymersomes typically requires artificial components like channel proteins.
• Previous research focused on enzyme encapsulation, with limited success in creating inherently permeable vesicles.

Purpose of the Study:

• To develop polymersome nanoreactors with inherent membrane permeability.
• To demonstrate the utility of poly(butylene oxide) in creating permeable polymer vesicles.
• To showcase the application of these permeable vesicles in enzyme-mediated catalysis.

Main Methods:

• Synthesis and characterization of diblock and triblock copolymers with poly(butylene oxide) and poly(glycidol).
• Self-assembly of copolymers into polymer vesicles.
• Demonstration of inherent small molecule permeability using various assays.
• Encapsulation of a model enzyme (horseradish peroxidase) and assessment of substrate/product transport.

Main Results:

• Polymer vesicles composed of poly(butylene oxide) exhibit inherent permeability to small molecules.
• This permeability is attributed to the moderate hydrophobicity and membrane hydration of poly(butylene oxide).
• Enzyme-loaded vesicles successfully facilitated enzyme-mediated catalysis due to permeable substrates and products.

Conclusions:

• Polymer vesicles with poly(butylene oxide) offer a novel platform for inherently permeable nanoreactors.
• This strategy simplifies the design of nanoreactors, eliminating the need for artificial porogenic components.
• The developed permeable polymersomes are applicable to a broad range of enzymes and proteins for catalysis.