Melanin-like nanoparticles alleviate ischemia-reperfusion injury in the kidney by scavenging reactive oxygen species and inhibiting ferroptosis.

Kidney transplantation is essential for patients with end-stage renal disease; however, ischemia-reperfusion injury (IRI) during transplantation can lead to acute kidney damage and compromise survival. Recent studies have reported that antiferroptotic agents may be a potential therapeutic strategy, by reducing production of reactive oxygen species (ROS). Therefore, we constructed rutin-loaded polydopamine nanoparticles (PEG-PDA@rutin NPs, referred to as PPR NPs) to eliminate ROS resulting from IRI. Physicochemical characterization showed that the PPR NPs were ∼100 nm spherical particles with good ROS scavenging ability. Notably, PPR NPs could effectively enter lipopolysaccharide (LPS)-treated renal tubular cells, then polydopamine (PDA) released rutin to eliminate ROS, repair mitochondria, and suppress ferroptosis. Furthermore, in vivo imaging revealed that PPR NPs efficiently accumulated in the kidneys after IRI and effectively protected against IRI damage. In conclusion, PPR NPs demonstrated an excellent ability to eliminate ROS, suppress ferroptosis, and protect kidneys from IRI.