Functionalized erythrocyte-derived optical nanoparticles to target ephrin-B2 ligands.

Over- or under-expression of erythropoietin-production human hepatocellular receptors (Eph) and their ligands are associated with various diseases. Therefore, these molecular biomarkers can potentially be used as binding targets for the delivery of therapeutic and/or imaging agents to cells characterized by such irregular expressions. We have engineered nanoparticles derived from erythrocytes and doped with the near-infrared (NIR) FDA-approved dye, indocyanine green. We refer to these nanoparticles as NIR erythrocyte-derived transducers (NETs). We functionalized the NETs with the ligand-binding domain of a particular Eph receptor, EphB1, to target the genetically modified human dermal microvascular endothelial cells (hDMVECs) with coexpression of EphB1 receptor and its ligand ephrin-B2. This cell model mimics the pathological phenotypes of lesional endothelial cells (ECs) in port wine stains (PWSs). Our quantitative fluorescence imaging results demonstrate that such functionalized NETs bind to the ephrin-B2 ligands on these hDMVECs in a dose-dependent manner that varies sigmoidally with the number density of the particles. These nanoparticles may potentially serve as agents to target PWS lesional ECs and other diseases characterized with over-expression of Eph receptors or their associated ligands to mediate phototherapy.