Histological Responses of Cutaneous Vascular Lesions Following Photodynamic Therapy with Talaporfin Sodium: A Chicken Comb Model

Abstract

Background: Mono-L-aspartyl chlorin e6 (Talaporfin sodium) is a novel photosensitizer, and is currently being used in photodynamic therapy for various malignant tumors in combination with irradiation with a 664 nm laser. An interesting characteristic of Talaporfin sodium is that the skin photosensitivity after injection of this agent disappears faster than any other existing photosensitizers. This study examined the vascular events that occurred postirradiation in the chicken comb as a capillary malformation model after photosensitization with Talaporfin sodium. Materials and Methods: A single intravenous bolus injections of Talaporfin sodium was administered to the chickens, and a 1 cm diameter area of the comb of each animal was irradiated with a 664 nm visible red laser. The gross changes in the chicken combs were recorded for 7-14 days after photodynamic therapy. For the histological examination, HE, PTAH and Azan stained sections were analyzed. Results: All treated chicken combs had blanched after photodynamic therapy. Microscopy demonstrated an absence of erythrocytes and the vessel lumina were obliterated, leaving the normal overlying epidermis completely intact. Concomitantly with selective destruction of the capillaries in the target area, moderate invasion of inflammatory cells and a slight increase in the stroma were observed. Conclusions: In the chicken comb model, photodynamic therapy with Talaporfin sodium effectively achieved selective destruction of the microvasculature while leaving the epidermis intact. Our results strongly suggest that photodynamic therapy with Talaporfin sodium could be a feasible method to treat dermal hypervascular lesions. (Keio J Med 58 (3) : 176 -184, September 2009)

Synergic effect of photodynamic therapy using talaporfin sodium with conventional anticancer chemotherapy for the treatment of bile duct carcinoma

“…Based on this preliminary study, the photosensitizer dose and light dose were already determined, which was applied in the present study. Talaporfin sodium (TPS)-PDT has been used for lung cancer treatment, 12 and the strong cytotoxicity in cancer cells was experimentally evaluated, 38,39 which is the most adequate for the PDT treatment of bile duct carcinoma at this stage. Using the current laser apparatus, the necrotic tumor area, percent of apoptotic positivity, proliferative activity and VEGF expression were similar to that of the previous apparatus (data not shown).…”

Hypericin Damages the Ectatic Capillaries in a Roman Cockscomb Model and Inhibits the Growth of Human Endothelial Cells More Potently Than Hematoporphyrin Does through Induction of Apoptosis

“…Port‐wine stains are characterized by congenital abnormal superficial capillary proliferation and deformity. The cockscomb and Leghorn cock wattle tissue structures are similar to the capillary hemangiomas found in human skin and mucous membranes . In this study, we used HUVECs and Roman chicken cockscombs as models of human PWSs.…”

Zinc Coproporphyrin I Derived from Meconium Has an Antitumor Effect Associated with Singlet Oxygen Generation

“…It is commercially available from Light Sciences Oncology Inc. (Bellevue, Wash., USA). It accumulates well in tumor cells and has a T1/2β of 134 h, which is shorter than that of Photofrin® [23]. PDT can be performed 4-6 h after intravenous administration of Laserphyrin®.…”