title: Development of technology for linking photosensitizers to a model monoclonal antibody.
abstract: A procedure is described whereby the photosensitizer, benzoporphyrin derivative monoacid ring A (BPD-MA) was covalently linked to a model monoclonal antibody in a manner which is reproducible, quantifiable, and retains both the biological activity of the antibody and the cytotoxicity of the photosensitizer. Preliminary steps involved the linkage of BPD-MA to a modified polyvinyl alcohol (PVA) backbone, followed by conjugation to the antibody using heterobifunctional linking technology. Briefly, polyvinyl alcohol (MW ca. 10,000) was modified with 2-fluoro-1-methyl pyridinium toluene-4-sulfonate and 1,6-hexanediamine to produce side chains containing free amino groups. The free carboxyl group of BPD-MA was utilized to conjugate photosensitizer molecules to modified PVA using a standard carbodiimide reaction. Final linkage of the PVA-BPD to a model monoclonal antibody involved further substitution of the carrier with 3-mercaptopropionic acid and carbodiimide to introduce 3-4 sulfhydryl residues per carrier molecule, and introduction of sulfo-m-maleimidobenzoyl-N-hydroxysulfosuccinimide ester residues to the monoclonal (3-4 residues/molecule). Conjugation was effected by reaction of the two species at pH 5.5 for 18 h. Detailed methodology and tests for efficacy of the procedure are provided.
authors.affiliation: Department of Microbiology, University of British Columbia, Vancouver, Canada.
authors.forename: F N
authors.initials: FN
authors.lastname: Jiang
authors.forename: S
authors.initials: S
authors.lastname: Jiang
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.forename: A
authors.initials: A
authors.lastname: Richter
authors.forename: J G
authors.initials: JG
authors.lastname: Levy
mesh_terms: D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000494:pharmacology; D000918:Antibody Specificity; D006063:Chorionic Gonadotropin / Q000276:immunology; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D011142:Polyvinyl Alcohol / Q000737:chemistry; D011838:Radiation-Sensitizing Agents / Q000737:chemistry*; D014407:Tumor Cells, Cultured / Q000187:drug effects
chemical_list: D000911:Antibodies, Monoclonal; D006063:Chorionic Gonadotropin; D003432:Cross-Linking Reagents; D004337:Drug Carriers; D011838:Radiation-Sensitizing Agents; D011142:Polyvinyl Alcohol