Evidence for different mechanisms of EMT-6 tumor necrosis by photodynamic therapy with disulfonated aluminum phthalocyanine or photofrin: tumor cell survival and blood flow.

摘要: A comparison was made of photodynamic therapy (PDT) mediated by two photosensitizers, the disulfonated aluminum phthalocyanine (AlPcS2) and Photofrin* (PII) with regard to their mechanism action on murine tumors. Balb/c mice bearing intradermally growing EMT-6 tumors were injected intravenously either 1 mumol kg-1 body weight AlPcS2 or 5 mg/kg PII 24 h prior red light irradiation from a Xenon lamp (650-700 nm, 200 mW cm-2, for 600-650 400 J cm-2 PII. Tumor cell survival following in vivo PDT determined an vitro clonogenicity assay dissociated Immediately after completion irradiation, reduction approximately 72% number clonogenic cells seen AlPcS2-treated tumor versus 24% that PII-treated tumor. Further loss progressed as function time PDT, considered be consequence indirect action, however, decline viability steeper first 6 PII-PDT than AlPcS2-PDT. capacity both AlPcS2-and treated fell 3% control The effect blood flow measure vascular damage monitored retention 99mTc-MIBI Little AlPcS2-PDT at 0 treatment. Thereafter declined slowly remained 50% level post-PDT. In contrast, provoked 40% immediately photo which then 20% within 2 7% These results indicate involvement direct mechanisms induced necrosis. However, exerted larger phototoxic effect, whereas death greater extent via parallels extensive vasculature.