Design of light-responsive amphiphilic self-assemblies: A novel application of the photosensitive diazirine moiety

Diazirine is one of the smallest photo-sensitive moieties discovered to date. When incorporated in the structure of phospholipids, its minimal size has a low impact on the morphology of the resultant liposomes. A DMPC-diazirine analogue was designed and subsequently used to generate liposomes with a lower permeability and a lower phase-transition temperature compared to control DMPC liposomes. Contrary to control liposomes, in the absence of light, the photosensitive nanoparticles retained the cargo (calcein) for at least 10 days. However, upon irradiation, diazirine’s conversion triggered the fluorophore release within minutes. The kinetics of the release could be tuned by the power and duration of the irradiation process. The same approach can be used on other nanomaterials, with the final goal of discovering a release profile appropriate not only for therapeutic applications, but also for agrochemicals delivery or cosmoceutics.