Phospholipid Vesicles as Organized Media in Spectroluminescence Analysis

New insight on the photoreactivity of the phototoxic anti-cancer flutamide: photochemical pathways selectively locked and unlocked by structural changes upon drug compartmentalization in phospholipid bilayer vesicles

“…Vice versa, in the vesicles (Fig. 1), where the relative permittivity is similar to that of isopropyl alcohol 9 and where in principle a blue shift should occur, one observes a marked red shift of this band (about 15 nm), consistent with a larger conjugated system which can only occur through a planarization of the NO 2 group.…”

“…Such organized systems are smectic mesophases of phospholipids with water interspaced among them and characterized by both high aggregation and occupancy number. 8,9 The general observation was that the self-incorporation of FM into the vesicles leads to a highly selective modification of the photochemical outcome. In fact, the chromatographic analysis † performed after 325 nm irradiation revealed the total absence of 1 being consistent with the dramatic inhibition of the nitro-to-nitrite photorearrangement.…”

Direct Spectroscopic Evidence that the Photochemical Outcome of Flutamide in a Protein Environment is Tuned by Modification of the Molecular Geometry: A Comparison with the Photobehavior in Cyclodextrin and Vesicles

“…The lack of photobinding product in the present case accounts for a large predominance of pathway i. This may be attributable to a fast dynamic of the radical species in the BSA environment when compared with the slow motion in phospholipid vesicles [25] [26]. According to this view, a considerable amount of photobinding product was, in fact, noted in this medium [22].…”

Photobinding of Flutamide to Phospholipid Vesicles: Additional Evidence for Photoprocesses Unexpectedly Triggered by Conformational Changes in the Bilayer

“…Such self-assembled structures are smectic mesophases of phospholipids with water interspaced among them, characterized by both high aggregation and high occupancy number. They are commonly accepted to be a suitable functional membrane model [21] [22]. In our brief preliminary communication, we have shown that FM self-incorporates in the phospholipid bilayer, and that such a microenvironment exerts a decisive role in modifying the drug photoreactivity [23].…”