Light‐Activated Release of Nitric Oxide with Fluorescence Reporting in Living Cells

A multifunctional β-cyclodextrin-conjugate photodelivering nitric oxide with fluorescence reporting

“…According to what already demonstrated in our previous studies (Vittorino et al, 2011;Kirejev et al, 2014), this drastic fluorescence quenching can be explained on the basis of a photoinduced energy transfer between the anthracene fluorophore and the nitroaniline components in the conjugate, which is encouraged by the close proximity of the donor and acceptor, both linked at the same rim. Note that, the suppression of the quenching of the excited state of anthracene after NO release reflects also in the capability of this component to photosensitize the formation of singlet oxygen ( 1 O 2 ), the key species in photodynamic therapy of cancer and bacterial diseases (Hasan et al, 2000).…”

“…In this compound, the typical emission of the anthracene fluorophore is completely suppressed by a photoinduced energy transfer to the nitroaniline moiety. We demonstrated that the photorelease of NO leads to the revival of the fluorescence of anthracene fluorophore which acts as a fluorescent reporter for the NO delivery in living cells (Vittorino et al, 2011;Kirejev et al, 2014).…”

“…Recently, we have reported interesting properties of an ad-hoc designed molecular conjugate integrating two chromogenic centers within the same covalent skeleton (Vittorino et al, 2011;Kirejev et al, 2014), an anthracene moiety and a nitroaniline derivative, this latter as a suitable NOPD (28). In this compound, the typical emission of the anthracene fluorophore is completely suppressed by a photoinduced energy transfer to the nitroaniline moiety.…”

Photoactivable Platforms for Nitric Oxide Delivery with Fluorescence Imaging

“…[16] Compounds 19, 20,a nd 21 ( Figure 5) have fluorescein, oligo-phenylene vinylene, and anthracene fragments, respectively,i ncorporated as latent fluorophores in the molecular structure of the NO photocages and represent prototypes in which NO photorelease is accompanied by simultaneousO FF-ON fluorescences ignals. [48][49][50] In all cases, the emission of the fluorogenic components is effectively quenched due to thermodynamically feasible photoinduced energy-transfer processes from the excited latent fluorophores to the NO photocages. Photodissociation of NO is accompanied by the concomitant formation of co-products, where the energy-transfer mechanism is not feasible, leading to ar emarkable restoration of the typical fluorescenceo ft he fluorogenic components in the green and blue region.…”

“…The molecular hybrid 21 permeates cellular membranes without the need of delivery vehicles,a nd these features allow the monitoring of NO photorelease with fluorescent reporting directly in living cancer cells. [50] The possibility to activate both the release andr eport events by the more biocompatible NIR light through TPE represents as ignificant step forward towards practical applications of photoactivated therapies. The well-known TPE properties of oligo-phenylene vinylenes [51] and functionalized anthracenes [52] allow to photoactivate 20 and 21 by TPE with NIR Scheme2.The release and report working principle:excitationofthe photocage liberatesNOa nd concomitantly af luorescent co-product, which acts as an optical counter for the amount of NO released.…”