Photodynamic therapy with chloroaluminum-sulfonated phthalocyanine. To study the vascular effects of a new photosensitizing agent independent of the influence of tumor growth, a cutaneous wound model was used. Six-week-old Harlan-Sprague-Dawley "Fuzzy" rats were surgically wounded in a standard fashion. The animals were then divided into three groups: the first group received chloroaluminum-sulfonated phthalocyanine only, the second group was treated with light only, and a third group was treated with both chloroaluminum-sulfonated phthalocyanine and light. Photodynamic therapy with chloroaluminum-sulfonated phthalocyanine had a direct effect on the neovasculature of a healing wound. The vasodilatation that was seen in the wound neovasculature that occurred 12 hours after the completion of chloroaluminum-sulfonated phthalocyanine-photodynamic therapy may have indicated a therapeutic "window" at which other therapies can be employed to improve clinical efficacy. 