title: Construction of anti-EGFR immunoliposomes via folate-folate binding protein affinity.
abstract: A novel method for synthesis of anti-EGFR immunoliposomes using folate-folate binding protein (FBP) affinity is described. An anti-EGFR antibody (cetuximab or C225) was covalently linked to FBP via a thioether bond. Liposomes incorporating a lipophilic folate derivative (folate-PEG-cholesterol) were prepared by polycarbonate membrane extrusion. Anti-EGFR immunoliposomes were then obtained by combining FBP-C225 and folate-liposomes and evaluated for uptake and cytotoxicity in EGFR-overexpressing U87 human glioblastoma cells. Anti-EGFR immunoliposomes constructed via folate-FBP affinity exhibited excellent stability under physiological pH, and quickly released the bound FBP-C225 upon low pH (pH 3.5) treatment. Flow cytometry and fluorescence microscopy showed similar receptor-specific binding and internalization for both folate-FBP affinity-coupled and covalently coupled C225-immunoliposomes, but not for the non-targeted IgG-immunoliposomes. C225-immunoliposomes loaded with anticancer drug doxorubicin were more cytotoxic than non-targeted immunoliposomes in EGFR-overexpressing U87 glioma cells. Folate-FBP affinity is a potential method for construction of immunoliposomes and may have applications in synthesis of targeted drug carriers in general.
authors.affiliation: Division of Pharmaceutics, College of Pharmacy; The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Xiaogang
authors.initials: X
authors.lastname: Pan
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Lee
mesh_terms: D000911:Antibodies, Monoclonal / Q000008:administration & dosage / Q000494:pharmacology*; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D001692:Biological Transport; D002352:Carrier Proteins / Q000008:administration & dosage / Q000494:pharmacology; D045744:Cell Line, Tumor; D000068818:Cetuximab; D004317:Doxorubicin / Q000008:administration & dosage / Q000494:pharmacology; D016503:Drug Delivery Systems; D004355:Drug Stability; D066246:ErbB Receptors / Q000187:drug effects* / Q000276:immunology / Q000378:metabolism; D005434:Flow Cytometry; D058973:Folate Receptors, GPI-Anchored; D005492:Folic Acid; D005909:Glioblastoma; D006801:Humans; D006863:Hydrogen-Ion Concentration; D018796:Immunoconjugates / Q000008:administration & dosage / Q000494:pharmacology*; D008081:Liposomes; D008856:Microscopy, Fluorescence; D011076:Polycarboxylate Cement; D011956:Receptors, Cell Surface / Q000008:administration & dosage
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000970:Antineoplastic Agents; D002352:Carrier Proteins; D058973:Folate Receptors, GPI-Anchored; D018796:Immunoconjugates; D008081:Liposomes; D011076:Polycarboxylate Cement; D011956:Receptors, Cell Surface; C005506:polycarbonate; D004317:Doxorubicin; D005492:Folic Acid; D066246:ErbB Receptors; D000068818:Cetuximab