This review presents key peptide and antibody based kidney-targeting ligands, with a focus on use in nanoparticle systems.

As atherosclerosis remains the leading cause of death, there is an urgent need to develop better tools for treatment of the disease. The ability to improve current treatments relies on enhancing the accuracy of in vitro and in vivo atherosclerotic models. While in vivo models provide all the relevant testing parameters, variability between animals and among models used is a barrier to reproducible results and comparability of NP efficacy. In vitro cultures isolate cells into microenvironments that fail to take into account flow separation and shear stress, which are characteristics of atherosclerotic lesions. Flow-based in vitro models provide more physiologically relevant platforms, bridging the gap between in vivo and 2D in vitro models. This is the first review that presents recent advances regarding endothelial cell-targeting using adhesion molecules in light of in vivo and flow-based in vitro models, providing insights for future development of optimal strategies against atherosclerosis.

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. Open image in new window