Preparation, Phototoxicity and Biodistribution Studies of Anti‐Carcinoembryonic Antigen Monoclonal Antibody‐Phthalocyanine Conjugates

摘要: Immunophototherapy of cancer combines the specificity a monoclonal antibody (MAb) to an overexpressed tumor marker with phototoxic properties conjugated dye. Aluminum tetrasulfophthalocyanine (AlPcS4) was covalently coupled 35A7 MAb directed against carcinoembryonic antigen (CEA) via five-carbon spacer chain (A1) yield conjugates molar ratio ranging from 5 16 mol AlPcS4 per MAb. Conjugates were labeled radioiodine for characterization. The immunoreactivity conjugates, determined in direct binding assay on CEA sepharose, not modified by AlPcS4A1 molecules. In vivo, these evaluated nude mice bearing human colon carcinoma xenografts (T380). MAb-(AlPcS4A1)5, MAb-(AlPcS4A1)12 and MAb-(AlPcS4A1)16 displayed uptake 35 +/- 5.0%, 40 5.7% 32 3.3% injected dose gram tissue, respectively, corresponding 97%, 104% 91% as compared that unconjugated each experimental group, tumor-to-normal tissue ratios obtained almost identical those Average values 1.8, 7 about 30 blood, liver muscle, respectively. Phototoxic efficacy conjugate demonstrated vitro LoVo cell line giving growth inhibition 2.50 micrograms/mL concentration. We conclude demonstrate clear vivo tumor-seeking capacity photocytotoxic properties. Such could thus be promising candidate drugs clinical photodynamic therapy cancers expressing CEA.