Targeting of epidermal growth factor receptor (EGFR)-expressing tumor cells with sterically stabilized affibody liposomes (SAL).

Abstract

Affibody molecules are small and stable antigen-binding molecules derived from the B domain of protein A. We applied a bivalent, high-affinity epidermal growth factor receptor (EGFR)-specific affibody molecule for the generation of targeted PEGylated liposomes. These sterically stabilized affibody liposomes (SAL) were produced by chemical coupling of the cysteine-modified affibody molecule to maleimide-PEG(2000)-DSPE and subsequent insertion into PEGylated liposomes. These SAL showed strong and selective binding to EGFR-expressing tumor cell lines. Binding was dependent on the amount of inserted affibody molecule-lipid conjugates and could be blocked by soluble EGF. Approximately 30% of binding activity was still retained after 6 days of incubation in human plasma at 37 degrees C. Binding of SAL to cells led to efficient internalization of the liposomes. Using mitoxantrone-loaded liposomes, we observed for SAL, compared to untargeted liposomes, an enhanced cytotoxicity toward EGFR-expressing cells. In summary, we show that SAL can be easily prepared from affibody molecules and thus may be suitable for the development of carrier systems for targeted delivery of drugs.

• Authors: Julia Beuttler, Miriam Rothdiener, Dafne Müller, Fredrik Y Frejd, Roland E Kontermann
• Journal: Bioconjugate chemistry (Bioconjug Chem) Vol. 20 Issue 6 Pg. 1201-8 (Jun 2009) ISSN: 1520-4812 [Electronic] United States
• PMID: 19435362 (Publication Type: Journal Article)

Chemical References

• Antibodies
• Liposomes
• Maleimides
• Phosphatidylethanolamines
• Recombinant Fusion Proteins
• 1,2-distearoylphosphatidylethanolamine
• maleimide
• Polyethylene Glycols
• Mitoxantrone
• ErbB Receptors
• Cysteine

Topics

• Antibodies (chemistry, immunology, metabolism)
• Biological Transport
• Cell Line, Tumor
• Cysteine (chemistry)
• ErbB Receptors (immunology, metabolism)
• Gene Expression Regulation, Neoplastic
• Humans
• Inhibitory Concentration 50
• Liposomes (chemistry, metabolism)
• Maleimides (chemistry)
• Mitoxantrone (chemistry, pharmacology)
• Nanostructures (chemistry)
• Neoplasms (pathology)
• Phosphatidylethanolamines (chemistry)
• Polyethylene Glycols (chemistry)
• Recombinant Fusion Proteins (chemistry, immunology, metabolism)
• Substrate Specificity