Binding and Internalization of Iron Oxide Nanoparticles Targeted To Nuclear Oncoprotein
- *Corresponding Author:
- Linda C. Knight, PhD
Temple University Pharmacy Bldg, Room B-49
3307 N. Broad Street, Philadelphia, PA 19140
Tel: (215) 707-4940
Fax: (215) 707-8110
E-mail: [email protected]
Received Date: September 29, 2010; Accepted Date: October 30, 2010; Published Date: November 01, 2010
Citation: Knight LC, Romano JE, Krynska B, Faro S, Mohamed FB, et al. (2010) Binding and Internalization of Iron Oxide Nanoparticles Targeted To Nuclear Oncoprotein. J Mol Biomark Diagn 1:102.doi:10.4172/2155-9929.1000102
Copyright: © 2010 Knight LC, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
A targeted nanoconjugate is being developed for non-invasive detection of gene expression in cells expressing the JC virus oncoprotein, T-antigen, which has been associated with medulloblastoma and other cancers. JC virus T-antigen localizes predominantly to the nucleus via a classical monopartite nuclear localization signal (NLS). An antibody fragment which recognizes JC virus T-antigen was attached to cross-linked dextran coated iron oxide nanoparticles. Radiolabeled conjugates were added to mouse medulloblastoma cells expressing the target T-antigen to test their ability to bind to tumor cells and be internalized by the cells. All conjugates containing targeting antibody bound to cells and were internalized, with increasing levels over time. There was no difference in cell binding or internalization among conjugates containing 2, 4, 6 or 8 antibody fragments per nanoparticle. Conjugates with only nonspecific antibody on nanoparticles, or unconjugated nonspecific antibody, had significantly lower total binding and internalization than conjugates with targeting antibody. Unconjugated targeting antibody had equivalent or lower cell uptake compared with targeted nanoparticle conjugates. Specificity of uptake was demonstrated by >80% reduction of nanoconjugate uptake in the presence of 100 fold excess of unconjugated antibody. The presence of a membrane translocation peptide (Tat) on the nanoparticles in addition to targeting antibody did not improve nanoconjugate internalization over the internalization caused by the antibody alone. This antibody nanoconjugate demonstrates feasibility of targeting a nuclear protein and suggests that a minimum number of antibody fragments per nanoparticle are sufficient for achieving binding specificity and efficient uptake into living cells.