Patent ID: 8207212

Claim:
A method for protecting epithelial tissue during photodynamic therapy using a pre-photosensitizing agent, the method comprising the steps of: administering a pre-photosensitizing agent to epithelial tissue and a targeted treatment site underlying the epithelial tissue; performing at least one of the following steps: applying a chemical inhibitor to the epithelial tissue such that the chemical inhibitor is concentrated primarily in the epithelial tissue, wherein the chemical inhibitor comprises at least one of 4,6-dioxoheptanoic acid, succinyl acetone, pridoxal-5-phosphate, zinc ions, ferrous ions, lead ions, and combinations and derivatives thereof; or creating a temperature gradient between the epithelial tissue and tissue at the targeted treatment site; and irradiating the targeted treatment site to activate the photosensitizing agent at the targeted treatment site, wherein the epithelial tissue is substantially unaffected.