Kidney Podocytes as Specific Targets for cyclo(RGDfC)-Modified Nanoparticles

Renal nanoparticle passage opens the door for targeting new cells like podocytes, which constitute the exterior part of the renal filter. When cyclo(RGDfC)-modified Qdots are tested on isolated primary podocytes for selective binding to the alpha v beta 3 integrin receptor a highly cell- and receptor-specific binding can be observed. In displacement experiments with free cyclo(RGDfC) IC50 values of 150 nM for alpha v beta 3 integrin over-expressing U87-MG cells and 60 nM for podocytes are measured. Confocal microscopy shows a cellular Qdot uptake into vesicle-like structures. Our ex vivo study gives clear evidence that, after renal filtration, nanoparticles can be targeted to podocyte integrin receptors in the future. This could be a highly promising approach for future therapy and diagnostics of podocyte-associated diseases.