Effect of liposomal confinement on photochemical properties of photosensitizers with varying hydrophilicity.
Preferential tumor localization and the aggregation state of photosensitizers (PSs) can depend on the hydrophilic/hydrophobic nature of the molecule and affect their phototoxicity. In this study, three PSs of different hydrophilicity are introduced in liposomes to understand the structure-photochemistry relationship of PSs in this cellular model system. Absorbance and fluorescence spectra of amphiphilic aluminum (III) phthalocyanine disulfonate chloride adjacent isomer (Al-2), hydrophilic aluminum (III) phthalocyanine chloride tetrasulfonic acid (Al-4), and lipophilic 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide (HPPH) are compared in a liposomal confined state with free PS in bulk solution. For fluorescence measurements, a broad range of concentrations of both bulk and liposomal confined PSs are examined to track the transition from monomers to dimers or higher order aggregates. Epifluorescence microscopy, absorbance, and fluorescence measurements all confirm different localization of the PSs in liposomes, depending on their hydrophilicity. In turn, the localization affects the aggregation of molecules inside the liposome cell model. Data obtained with such cellular models could be useful in optimizing the photochemical properties of photosensitizing drugs based on their structure-dependent interactions with cellular media and subcellular organelles.
Noiseux
Isabelle
I
INO (National Optics Institute), Department of Biophotonics, 2740 Einstein Street, Quebec G1P 4S4, Canada.
Mermut
Ozzy
O
Bouchard
Jean-Pierre
JP
Cormier
Jean-François
JF
Desroches
Patrice
P
Fortin
Michel
M
Gallant
Pascal
P
Leclair
Sébastien
S
Vernon
Marcia L
ML
Diamond
Kevin R
KR
Patterson
Michael S
MS
D004337:Drug Carriers / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D008027:Light; D008081:Liposomes / Q000737:chemistry*; D008422:Materials Testing; D010777:Photochemistry / Q000379:methods; D017319:Photosensitizing Agents / Q000737:chemistry*; D012542:Scattering, Radiation
D004337:Drug Carriers; D008081:Liposomes; D017319:Photosensitizing Agents