Localized functionalization of individual colloidal carriers for cell targeting and imaging

Fabricating drug particles for therapeutic delivery and imaging presents important challenges in the design of the particle surfaces. Drug nanoparticle surfaces are currently functionalized with site-specific targeting ligands, biocompatible polymers, or fluorophore-polymer conjugates for specific imaging. However, if these functionalizations were to be synthesized on the drug carrier in localized, nanoscale regions on the particle surface, new schemes of drug delivery could be realized. Here we describe the use of our particle lithography technique that enables the synthesis of individual colloidal carrier assemblies that can be imaged and targeted to integrin-expressing cells. We show localized adhesion specificity for cells expressing the target integrin followed by receptor-mediated endocytosis. With the addition of localized delivery by adding drug nanoparticles to a specific region on the particle surface, our colloidal carrier assemblies have the potential to target, deliver therapeutic agents to, sense, and image diseased endothelium.