Kidney disease management and treatment are currently causing a substantial global burden. The kidneys are the most important organs in the human urinary system, selectively filtering blood and metabolic waste into urine via the renal glomerulus. Based on charge and/or molecule size, the glomerular filtration apparatus acts as a barrier to therapeutic substances. Therefore, drug distribution to the kidneys is challenging, resulting in therapy failure in a variety of renal illnesses. Hence, different approaches to improve drug delivery across the glomerulus filtration barrier are being investigated. Nanotechnology in medicine has the potential to have a significant impact on human health, from illness prevention to diagnosis and treatment. Nanomaterials with various physicochemical properties, including size, charge, surface and shape, with unique biological attributes, such as low cytotoxicity, high cellular internalization and controllable biodistribution and pharmacokinetics, have demonstrated promising potential in renal therapy. Different types of nanosystems have been employed to deliver drugs to the kidneys. This review highlights the features of the nanomaterials, including the nanoparticles and corresponding hydrogels, in overcoming various barriers of drug delivery to the kidneys. The most common delivery sites and strategies of kidney-targeted drug delivery systems are also discussed.
Keywords: drug release; glomeruli; hydrogel; kidney disorders; nanoparticles; renal delivery; targeted delivery.