scholarly journals Fluorescence Enhancement Effect of TiO2 Nanoparticles and Application for Photodynamic Diagnosis

2019 ◽  
Vol 20 (15) ◽  
pp. 3698 ◽  
Author(s):  
Koki Kanehira ◽  
Yukiko Yano ◽  
Hisashi Hasumi ◽  
Hideo Fukuhara ◽  
Keiji Inoue ◽  
...  
Keyword(s):  
Bladder Cancer ◽  
Titanium Dioxide ◽  
Polyethylene Glycol ◽  
Fluorescence Enhancement ◽  
Aminolevulinic Acid ◽  
Titanium Dioxide Nanoparticles ◽  
Photodynamic Diagnosis ◽  
Enhancement Effect ◽  
Bladder Cancer Cells ◽  
Combined Administration

Photodynamic diagnosis (PDD) can improve diagnostic accuracy by using PDD agents such as 5-aminolevulinic acid (ALA). However, the weakness and photobleaching of fluorescence of PDD agents may lead to insufficient fluorescence visibility for the detection of cancer during resection operations. We focused on the “fluorescence enhancement effect” resulting from the addition of polyethylene glycol-modified titanium dioxide nanoparticles (TiO2-PEG NPs) to address these problems. The results showed that the combined administration of TiO2-PEG NPs and ALA could enhance and prolong fluorescence in bladder cancer cells, similar to in the mixture alone. It was suggested that the fluorescence enhancement was related to the accumulation of TiO2-PEG NPs in cells via endocytosis, causing the light scattering and enhancement of fluorescence. This fluorescence enhancement effect could be applicable for PDD.

In vitro and in vivo effects of HAL on porphyrin production in rat bladder cancer cells (AY27)

2019 ◽  
Vol 23 (07n08) ◽  
pp. 813-820
Author(s):  
Odrun A. Gederaas ◽  
Harald Husebye ◽  
Anders Johnsson ◽  
Susan Callaghan ◽  
Anders Brunsvik
Keyword(s):  
Bladder Cancer ◽  
Cancer Cells ◽  
Aminolevulinic Acid ◽  
Protoporphyrin Ix ◽  
Active Agent ◽  
Laser Scanning Microscopy ◽  
Rat Bladder ◽  
Bladder Cancer Cells

Aminolevulinic acid and hexyl-aminolevulinate serve as biological precursors to produce photosensitive porphyrins in cells via the heme biosynthetic pathway. This pathway is integral to porphyrin-based photodynamic diagnosis and therapy. By adding exogenous hexyl-aminolevulinate to rat bladder cancer cells (AY27, in vitro) and an animal bladder cancer model (in vivo), fluorescent endogenous porphyrin production was stimulated. Lipophilic protoporphyrin IX was identified as the dominant species by reverse high-pressure liquid chromatography. Subcellular porphyrin localization in the AY27 cells was evaluated by confocal laser scanning microscopy and showed almost quantitative bleaching after 20 s. From this study, we ascertained that the protocol described herein is suitable for hexyl-aminolevulinate-mediated photodynamic therapy and diagnosis when protoporphyrin IX is the active agent.

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