Design and in vivo characterization of kidney-targeting multimodal micelles for renal drug delivery

One in three Americans is at risk for developing chronic kidney disease (CKD) and end-stage renal disease (ESRD), leading to the need for dialysis or a kidney transplant. Small-molecule drugs have been proposed as therapies to manage kidney diseases, but high dosages are often required to achieve therapeutic efficacy, generating off-target side effects, some of which are lethal. To address these limitations, we developed a novel, kidney-targeting multimodal micelle (KM) system for drug delivery applications. Specifically, we incorporated the kidney-targeting peptide (Lysine-Lysine-Glutamic acid-Glutamic acid-Glutamic acid)3-Lysine) ((KKEEE)3K) into micelles. This peptide binds to megalin, a multi-ligand cell surface receptor present on renal tubule cells. When incubated with human kidney proximal tubule cells, KMs were found to be biocompatible in vitro. In vivo, KMs showed higher accumulation in the kidneys as compared to a non-targeted (NT) control upon intravenous injection in wild-type C57BL/6J mice. Histological evaluation showed no signs of tissue damage, while blood urea nitrogen (BUN) and creatinine levels were within normal ranges, validating the preservation of kidney health upon micelle administration. To our knowledge, this is the first utilization of (KKEEE)3K in a nanoparticle formulation, and our study offers strong evidence that this novel nanoparticle platform can be used as a candidate drug delivery carrier to direct therapeutics to diseased tissue in CKD.