Photoinduced fluorescence activation and nitric oxide release with biocompatible polymer nanoparticles

A viable strategy to encapsulate a fluorophore/photochrome dyadand a nitric oxide photodonor withinsupramolecular assemblies of a cyclodextrin-based polymer in water was developed.The two photoresponsiveguests do not interact with each otherwithin their supramolecular containerand can be operated in parallel underoptical control. Specifically, the dyadpermits the reversible switching of fluorescenceon a microsecond timescalefor hundreds of cycles, and the photodonorenables the irreversible releaseof nitric oxide. Furthermore, thesesupramolecular assemblies cross themembrane of human melanoma cancercells and transport their cargo in thecytosol. The fluorescence of one componentallows the visualization of thelabeled cells, and its switchable charactercould, in principle, be used to acquiresuper-resolution images, whilethe release of nitric oxide from theother induces significant cell mortality.Thus, our design logic for the constructionof biocompatible nanoparticleswith dual functionality might evolveinto the realization of valuable photoresponsiveprobes for imaging andtherapeutic applications.