title: Conjugation of an anti-B-cell lymphoma monoclonal antibody, LL2, to long-circulating drug-carrier lipid emulsions.
abstract: Long-circulating submicron lipid emulsions, stabilized with poly(ethylene glycol)-modified phosphatidylethanolamine (PEG-PE), are promising drug carriers with substantial capacity for solubilization of lipophilic anticancer agents. This study describes the conjugation of the anti-B-cell lymphoma monoclonal antibody LL2 to the surface of lipid-emulsion globules by use of a novel poly(ethylene glycol)-based heterobifunctional coupling agent. The efficiency of coupling of LL2 to the lipid emulsion was 85% (approx.) and essentially independent of the LL2/emulsion particle ratio and amount of surface-bound PEG-PE. Results from sucrose-gradient centrifugation and Sepharose CL-4B gel filtration indicated stable binding of the antibody to the emulsion. The immunoreactivity of the emulsion-LL2 conjugates was tested with alkaline phosphatase-conjugated LL2 against a monoclonal anti-idiotype antibody, WN. The binding of the conjugates to WN increased with increasing surface density of LL2 up to 40 monoclonal antibodies/emulsion particle, and exceeded that for the free monoclonal antibody (approx. 20 molecules/particle). Results from competitive-binding ELISA were indicative of similar displacement curves for free LL2 and emulsion-LL2 conjugates. Direct cellular ELISA revealed similar binding of emulsion-LL2 complexes to three types of Burkitt's lymphoma cell lines, Raji, Ramos and Daudi. The results from this study indicate that emulsion-LL2 complexes might be a useful drug-carrier system for more specific delivery of anticancer drugs to B-cell malignancy.
authors.affiliation: Department of Biochemistry and Pharmacy, Abo Akademi University, BioCity, Finland.
authors.forename: B B
authors.initials: BB
authors.lastname: Lundberg
authors.forename: G
authors.initials: G
authors.lastname: Griffiths
authors.forename: H J
authors.initials: HJ
authors.lastname: Hansen
mesh_terms: D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000737:chemistry / Q000276:immunology / Q000627:therapeutic use; D000915:Antibody Affinity; D004337:Drug Carriers; D004655:Emulsions; D006801:Humans; D008024:Ligands; D008055:Lipids / Q000737:chemistry; D016393:Lymphoma, B-Cell / Q000188:drug therapy / Q000276:immunology*; D010714:Phosphatidylethanolamines / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011956:Receptors, Cell Surface / Q000378:metabolism; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D004337:Drug Carriers; D004655:Emulsions; D008024:Ligands; D008055:Lipids; D010714:Phosphatidylethanolamines; D011956:Receptors, Cell Surface; C095913:bectumomab; C067972:dioleoyl-N-(monomethoxypolyethylene glycol succinyl)phosphatidylethanolamine; D011092:Polyethylene Glycols