Anti-tumor effects of liposome-encapsulated titanium dioxide in nude mice.
Anatase particles of titanium dioxide (TiO2) absorb ultraviolet (UV) light which is shorter than 415 nm. Photoexcited TiO2, a strong oxidizer, is expected to inhibit malignant cell growth. Liposomes accelerate endophagocytosis to the cytoplasm of encapsulated materials. In this study, we examined anti-tumor effects of TiO2 and liposome-encapsulated TiO2 (LT) with UVA irradiation by an air pouch cancer model using NBT-II bladder cancer cells, which simulates bladder cancer. Injection of TiO2 or LT into the air pouch was followed by UVA irradiation via the opened pouch. Tumors of TiO2 + UVA and LT + UVA groups showed more pronounced necrotic areas, apoptotic indices, nitrotyrosine formation, tumor growth inhibition and increased survival compared with control groups. Especially the LT + UVA group showed more remarkable anti-tumoral effects than the TiO2 + UVA group, which was associated with higher TiO2 incorporation. These findings suggest that LT might be more effective than noncoated TiO2 in the treatment of bladder cancer.
Chihara
Yoshitomo
Y
Department of Urology, Nara Medical University School of Medicine, Kashihara, Japan.
Fujimoto
Kiyohide
K
Kondo
Hideaki
H
Moriwaka
Yukiko
Y
Sasahira
Tomonori
T
Hirao
Yoshihiko
Y
Kuniyasu
Hiroki
H
D000818:Animals; D045744:Cell Line, Tumor; D004195:Disease Models, Animal; D004797:Enzyme-Linked Immunosorbent Assay; D008081:Liposomes; D008297:Male; D051379:Mice; D008819:Mice, Nude; D018384:Oxidative Stress; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage*; D014025:Titanium / Q000008:administration & dosage*; D014443:Tyrosine / Q000031:analogs & derivatives / Q000096:biosynthesis / Q000187:drug effects; D001749:Urinary Bladder Neoplasms / Q000188:drug therapy* / Q000473:pathology
D008081:Liposomes; D017319:Photosensitizing Agents; C009495:titanium dioxide; C002744:3-nitrotyrosine; D014443:Tyrosine; D014025:Titanium