Photodynamic effects of Zinc(II) phthalocyanine-loaded polymeric micelles in human nasopharynx KB carcinoma cells

GARCIA VIOR M.C.; MARINO V.J.; ROGUIN, L. P; SOSNIK A ; AWRUCH J

PHOTOCHEMISTRY AND PHOTOBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2013 vol. 89 p. 492 - 500

0031-8655

A major difficulty in photodynamic therapy is the poor solubility of the photosensitizer (PS) under physiological conditions which correlates with low bioavailability. PS aggregation leads to a decrease in the photodynamic efficiency and a more limited activity in vitro and in vivo. To improve the aqueous solubility and prevent the aggregation of tetrakis-[(2-dimethylamino)ethylsulfanyl]phthalocyaninatozinc(II) (ZnPc), the encapsulation into four poloxamine polymeric micelles (T304, T904, T1107, T1307) displaying a broad spectrum of molecular weight and hydrophilic-lipophilic balance was investigated. The aqueous solubility of ZnPc was increased up to thirty times. Morphological evaluation showed the formation of ZnPc-loaded spherical micelles in the nanosize range. UV/Vis and fluorescence studies indicated that ZnPc is less aggregated upon encapsulation in comparison with ZnPc in water-DMSO 2%, and remained photo-stable for 1 h. ZnPc-loaded micelles generated singlet molecular oxygen in high yields. Photocytotoxicity assays using human nasopharynx KB carcinoma cells confirmed that the encapsulation of ZnPc in T1107 and T1307 increases its photocytotoxicity by ten times in comparison with the free form in water-DMSO. In addition, ZnPc incorporated into cells was mainly localized in lysosmes.