Basic study on therapeutic effect distribution formation along depth using high-intensity pulsed photodynamic therapy

Sayaka Ohmori; Kensuke Masuda; Tsunenori Arai

doi:10.1117/12.592890

8 April 2005 Basic study on therapeutic effect distribution formation along depth using high-intensity pulsed photodynamic therapy

Sayaka Ohmori, Kensuke Masuda, Tsunenori Arai

Author Affiliations +

Proceedings Volume 5689, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XIV; (2005) https://doi.org/10.1117/12.592890
Event: SPIE BiOS, 2005, San Jose, CA, United States

Abstract

Photodynamic therapy against murine macrophage like cells with the second-generation hydrophilic photosensitizer ME2906 (mono-L-aspartyl chlorin e₆:NPe6) was performed in vitro to study therapeutic effect distribution formation along depth with high-intensity pulsed irradiation. The photocytotoxicity of macrophage like cell with ME2906 under various fluence rates was measured. We found photocytotoxicity suppression from 64% to 16% in the cell lethality ranging the fluence rate of a pulsed laser from 20 to 400mW/cm² (corresponding pulse peak power: from 0.07 to 1.4 MW/cm²). The cell lethality of about 80 % was obtained with continues wave laser irradiation under the fluence of 10 J/cm². Photobleaching and oxygen consumption of the photosensitizer solution, were measured to know photoreaction of the photosensitizer solution under the high fluence rate pulsed irradiation. Type-II photochemical reaction suppression was indicated with the high fluence rate pulsed irradiation. The transient absorption of the photosensitizer solution during pulse irradiation was measured by the pump-and-probe technique with pulse peak power density up to 1.2 MW/cm² to investigate absorption saturation. In the case of the pump beam peak power of 1.2MW/cm², the transmittance of the probe beam increased approximately 7% from that of without the pump beam, so that huge absorption saturation did not occur in this case. We think the main cause of the photocytotoxicity suppression in this study may not to be attributed to the absorption saturation. This photocytotoxicity suppression induced by the high-intensity irradiation may be available to control treatment depth of PDT to preserve healthy internal wall of a hollow organ.

Citation Download Citation

Sayaka Ohmori, Kensuke Masuda, and Tsunenori Arai "Basic study on therapeutic effect distribution formation along depth using high-intensity pulsed photodynamic therapy", Proc. SPIE 5689, Optical Methods for Tumor Treatment and Detection: Mechanisms and Techniques in Photodynamic Therapy XIV, (8 April 2005); https://doi.org/10.1117/12.592890

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available