Described are photochemical studies of the nitric oxide precursors,
trans-Cr(L)(ONO)
2+ (L = cyclam = 1,4,8,11-tetraazacyclotetradecane, CrONO, or L = mac = 5,7-dimethyl-6-anthracenylcyclam, mac-CrONO) encapsulated in phosphatidylcholine liposomes. The liposomes pro
vide a means to maintain a localized high concentration of NO releasing complexes and are easily modified for
in vivo targeting through self-assembly. Steady, controlled release of NO is seen after photolysis of the liposome-encapsulated CrONO as compared to the burst of NO release seen by the unencapsulated complex in oxygenated solutions. The quantum yields for photochemical NO release from liposome-encapsulated CrONO and mac-CrONO were determined in both oxygenated and anoxic solutions. The quantum yield for NO release in oxygenated solution for encapsulated CrONO was more than 5 times larger than that of unencapsulated CrONO, thus the net NO released after photolysis in oxygenated solutions is enhanced by encapsulation of CrONO in liposomes. Encapsulated mac-CrONO shows NO release after photolysis with low-intensity blue light. Furthermore, the fluorescence of mac-CrONO can be detected through the liposomes, thus allowing for de
velopment of theranostic NO deli
very
vessels where tracking and imaging can occur simultaneously with therapeutic NO release. This work pro
vides insight into the de
velopment of multifunctional liposome constructs for disease theranostics.
Keywords:
nitric oxide release; theranostic; liposomes; photochemical; very&qsSearchArea=searchText">drug delivery