Improving kidney targeting: The influence of nanoparticle physicochemical properties on kidney interactions

Kidney-targeted nanoparticles have become of recent interest due to their potential to deliver drugs directly to diseased tissue, decrease off-target adverse effects, and increase overall tolerability to patients with chronic kidney disease that require lifelong drug exposure. Given the physicochemical properties of nanoparticles can drastically affect their ability to extravasate past cellular and biological barriers and access the kidneys, we surveyed the literature from the past decade and analyzed how nanoparticle size, charge, shape, and material density affects passage and interaction with the kidneys. Specifically, we found that nanoparticle size impacted the mechanism of nanoparticle entry into the kidneys such as glomerular filtration or tubular secretion. In addition, we found charge, aspect ratio, and material density influences nanoparticle renal retention and provide insights for designing nanoparticles for passive kidney targeting. Finally, we conclude by highlighting active targeting strategies that bolster kidney retention and discuss the clinical status of nanomedicine for kidney diseases.