Polymersomes, synthetic vesicles formed from diblock copolymers, are promising candidates for delivery applications due to their tunability and robust nature. Compared to liposomes, their bilayer membranes are typically thicker, enabling encapsulation of hydrophilic cargo within the aqueous lumen as well as incorporation of hydrophobic constituents into the membrane itself. In this work, we investigate the incorporation of plasmonic gold nanoparticles (AuNPs) into the hydrophobic region of polymersome membranes. Small dodecanethiol-functionalized AuNPs can partition into the bilayer during the self-assembly of both micron- and nano-scale polymersomes. Due to their localized surface plasmon resonance (LSPR), AuNPs strongly absorb light in the visible to near-infrared region. Under pulsed irradiation resonant with the LSPR, photothermal and photomechanical effects can destabilize the membrane, leading to outcomes ranging from transient poration to complete rupture. Beyond light responsiveness, AuNP incorporation also alters other vesicle properties, including susceptibility to common surfactants such as Triton X-100, Polysorbate-20, and sodium dodecyl sulfate. This combined study of micron- and nano-scale polymersomes leverages multiple characterization techniques to probe plasmonically induced membrane disruption and the governing factors, including laser parameters and nanoparticle loading. Collectively, these findings provide insight into how nanoparticle organization within the membrane contributes to vesicle stability, advancing the development of a tunable, stimuli-responsive delivery platform.
Salzer et al. (Sun,) studied this question.