Measurement of Tumor Vascular Damage in Mice with 99m Tc‐MIBI Following Photodynamic Therapy

Abstract

The clinical perfusion agent 99mTc-MIBI was used to monitor changes in tumor vascular perfusion (TVP) induced by Photofrin (PII)-mediated photodynamic therapy (PDT). BALB/c mice bearing an EMT-6 tumor on each hind thigh were given an intravenous injection of 1, 2 or 5 mg kg-1 PII. Twenty-four hours later, one tumor was illuminated (600-650 nm, 200 mW cm-2, 400 J cm-2) while the other served as a control. At various time intervals after PDT (0, 2 and 24 h) mice received an intravenous injection of 99mTc-hexakismethoxyisobutylisonitrile (MIBI) (0.18 MBq g-1) and were sacrificed 2 min later. The light-treated and the untreated tumors were then dissected, the radioactivity was counted and the percentage of the injected dose per gram of tumor (%ID g-1) was calculated as a measure of TVP. We observed that TVP is drug dose dependent, develops progressively with time post-PDT and is inversely related to PDT efficacy. Our data show that early tumor retention of 99mTc-MIBI is a simple method to assess TVP and vascular damage induced by PDT.

Synthesis and characterization of novel flavonoid-substituted phthalocyanines using (±)naringenin

“…Additionally, the resonances at 3289 and 1006 cm À1 are assigned to the N-H stretching and bending vibrations for 8. All the IR results of the substituted phthalonitriles and the phthalocyanines are in good agreement with the previous literature [15,16,[20][21][22][23].…”

“…The same effect was observed with the substitutions of the naringenin groups as polyphenolic species, thus the bands appeared at lower wavelengths when they compared with the un-substituted phthalocyanines [16,34,35]. Addition of a second naringenin group to the macroring did not appreciably affect the electronic spectrum.…”

“…Hydroxyphenyl porphyrins have been found to be among the most active compounds in photodynamic therapy studies. Another porphyrinbased substance, Photofrin Ò , a mixture of porphyrin oligomers, is currently in use as an effective treatment against esophageal and endobronchial cancer [16].…”

Syntheses and Photodynamic Activities of Novel Trisulfonated Zinc Phthalocyanine Derivatives

“…Overall, compound 6b appeared the most effective in the series. For comparison, Photofrin, the clinically used photosensitizer, gave a comparable tumor control rate (70%) at 5 mg kg -1 (400 J cm -2 , 24 h pi) . The relative efficiency of the unsymmetrically substituted ZnPc dyes to photoinactivate cells in vitro or to induce tumor regression in mice after PDT follows a similar pattern: 6b ≥ 6a > 6c .…”

“…For comparison, Photofrin, the clinically used photosensitizer, gave a comparable tumor control rate (70%) at 5 mg kg -1 (400 J cm -2 , 24 h pi). 25 The relative efficiency of the unsymmetrically substituted ZnPc dyes to photoinactivate cells in vitro or to induce tumor regression in mice after PDT follows a similar pattern: 6b g 6a > 6c. This was not the case for the ZnPcS 3 and ZnPcS 4 , the former being more photoactive in vitro but less efficient in vivo than the latter.…”