Attachment of antibody to biotinylated red blood cells: immuno-red blood cells display high affinity to immobilized antigen and normal biodistribution in rats.
Streptavidin-mediated attachment of biotinylated antibodies (b-Ab) to biotinylated red blood cells (b-RBC) is useful for preparation of immuno-red blood cells, a prospective vehicle for drug targeting. However, streptavidin (SA) induces lysis of extensively biotinylated RBC by complement due to cross-linking and inactivation of RBC complement regulators. To reduce cross-linking of RBC membrane proteins, we utilized mild biotinylation of RBC with 20 microM biotin ester (b20-RBC). SA effectively binds to rat b20-RBC (10(5) SA molecules/cell) and provides for following attachment of 5 x 10(4) molecules of b-IgG/SA per b20-RBC. By in vitro assay, b-Ab/SA/b20-RBC were stable in fresh rat serum. Serum-stable immuno-red blood cells (b-Ab/SA/b20-RBC) specifically bound to antigen-coated surfaces, but not to BSA-coated surfaces. Biodistribution of 51Cr-labelled b-Ab/SA/b20-RBC in rats was similar to that of control RBC, with no indication of lysis in vivo. These results suggest b-Ab/SA/b20-RBC may be explored as a vehicle for drug targeting.
Muzykantov
V R
VR
Institute for Environmental Medicine, University of Pennsylvania, Philadelphia, USA.
Murciano
J C
JC
D000818:Animals; D000906:Antibodies / Q000008:administration & dosage* / Q000378:metabolism; D000915:Antibody Affinity; D000941:Antigens; D001709:Biotechnology; D001710:Biotin; D004337:Drug Carriers; D016503:Drug Delivery Systems; D004355:Drug Stability; D004912:Erythrocytes / Q000276:immunology*; D066298:In Vitro Techniques; D051381:Rats; D014018:Tissue Distribution
D000906:Antibodies; D000941:Antigens; D004337:Drug Carriers; D001710:Biotin