Evaluation of a Ruthenium coordination complex as photosensitizer for PDT of bladder cancer: Cellular response, tissue selectivity and in vivo response

Abstract

Abstract TLD1433, a Ru(II) polypyridyl complex, was recently introduced. It can be activated in the 520 to 540 nm range. Here we report on the use of TLD1433 for the treatment of bladder carcinomas in vitro and in an in vivo orthotopic model. The electrostatic properties of the normal urothelium vs a tumor compromised urothelium provide for a high selective uptake ratio. In vitro, a 1000 difference in the LD 50 between dark and 22.5 J cm −2 irradiation at 530 nm was achieved for two bladder cell lines (T24 and AY‐27). In dogs and rats the plasma concentration for TLD1433 was below 100 ng kg −1 at 72 hours following intravenous injection at a dose of up to 3.5 mg kg −1 and below 10 ng kg −1 following intrabladder instillation for 1 hour at a concentration of 6 mg mL −1 . Successful tumor necrosis close to 1.5 mm in depth was achieved.