Simultaneous two-photon excitation of photodynamic therapy agents

Eric A. Wachter; W. P. Partridge Jr.; Walter G. Fisher; Craig Dees; Mark G. Petersen

doi:10.1117/12.312332

8 July 1998 Simultaneous two-photon excitation of photodynamic therapy agents

Eric A. Wachter, W. P. Partridge Jr., Walter G. Fisher, Craig Dees, Mark G. Petersen

Proceedings Volume 3269, Commercial Applications of Ultrafast Lasers; (1998) https://doi.org/10.1117/12.312332
Event: Optoelectronics and High-Power Lasers and Applications, 1998, San Jose, CA, United States

Abstract

The spectroscopic and photochemical properties of several photosensitive compounds are compared using conventional single-photon excitation (SPE) and simultaneous two-photon excitation (TPE). TPE is achieved using a mode-locked titanium:sapphire laser, the near infrared output of which allows direct promotion of non-resonant TPE. Excitation spectra and excited state properties of both type I and type II photodynamic therapy (PDT) agents are examined. In general, while SPE and TPE selection rules may be somewhat different, the excited state photochemical properties are equivalent for both modes of excitation. In vitro promotion of a two-photon photodynamic effect is demonstrated using bacterial and human breast cancer models. These results suggest that use of TPE may be beneficial for PDT, since the technique allows replacement of visible or ultraviolet excitation with non- damaging near infrared light. Further, a comparison of possible excitation sources for TPE indicates that the titanium:sapphire laser is exceptionally well suited for non- linear excitation of PDT agents in biological systems due to its extremely short pulse width and high repetition rate; these features combine to effect efficient PDT activation with minimal potential for non-specific biological damage.

Citation Download Citation

Eric A. Wachter, W. P. Partridge Jr., Walter G. Fisher, Craig Dees, and Mark G. Petersen "Simultaneous two-photon excitation of photodynamic therapy agents", Proc. SPIE 3269, Commercial Applications of Ultrafast Lasers, (8 July 1998); https://doi.org/10.1117/12.312332

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