Dye-sensitized photoinactivation of tumor cells in vitro.

The in vitro photodynamic inactivation of a wide variety of tumor cells was studied with various dyes used as sensitizcrs. The capacity of dyes to act as photosensitizers in this system parallels their capacity to sensitize the photoinactivation of many other substrates and correlates with their capacity to undergo photoreduction. Some dyes are able to inactivate tumor cells in the abscnce of light. :Photodynamic inactivation of the tumor cells dcstroys their tumor-producing capacity but docs not change their dycbinding capacity.