Polyprolinated Liposomes: Toward Thermoresponsive Shielding and Controlled Release

The development of stimuli-responsive liposomes paves the way for targeted and controlled drug delivery. This includes thermoresponsive liposomes, in which increased temperature can promote bilayer destabilization. This thermoresponsiveness can be achieved by incorporating lipids with defined melting transitions or LCST-type polymers that are anchored to the membrane. In this study, we developed nanometric liposomes decorated with lipopolyproline, an LCST-type polymer anchored to the membrane. These systems, termed polyprolinated liposomes, were characterized by cryoSEM, cryoTEM, DLS, and 2 H and 31 P solid-state NMR to highlight the temperature-dependent changes in surface properties and morphology. Quantitative measurement of sulforhodamine B release demonstrated increased membrane permeability with temperature changes, highlighting the potential of polyprolinated liposomes as thermoresponsive drug delivery systems or drug reservoirs in multicompartmental systems.