Targeting activity is one of the goals for diagnostic and therapeutic personalized medicine. Antibodies are the natural macromolecules for such an activity, and nanomedicine takes advantage of their activity, when nanoparticles, which are useful for theranostic, are functionalized with these molecules and become more effective. However, antibodies could induce an adverse immune response and usually their cost is very high.
The alternative is using small targeting molecules like peptides, which are not, usually, immunogenic and cost much less. The activity of such small molecules, however, is not usually equivalent to that of antibodies.
We report the results of a study of a small peptide organized on the surface of gold nanoparticles, which shows very interesting targeting activity against EGFR. It will be shown that their organization, using an engineered linking, makes possible to outperform the targeting activity of a specific antibody, like cetuximab, organized on the same nanoparticles.
The nanoparticles are also functionalized with a small molecule, which shows strongly enhanced SERS signals, namely vibrational resonances which rival fluorescence for imaging, but makes possible an easy multiplexing analysis.
Sensitivity and specificity of about 90% are obtained with the synthesized nanostructures.