Membrane-Anchored Polyproline Provides Controlled Microdomain Formation and Permeability in Lipid Vesicles

This study introduces the synthesis of a new class of lipopolymers composed of l-proline monomer units and a phospholipid initiator. By anchoring polyproline chains to the membrane, reversible phase separation was achieved, with clusters forming at high temperature and dispersing upon cooling. Confocal microscopy and FRAP analyses confirmed microdomain formation after heating and restored diffusion properties after cooling, demonstrating dynamic control over local membrane composition. Importantly, the microdomains enhanced membrane permeability, enabling size-controlled release of encapsulated molecules, including synthetic polymers and enzymes. The system showed adaptability across various membrane compositions, suggesting its potential for applications in drug delivery or synthetic biology, especially for mimicking protein-like behavior in lipid vesicles.