Mesoscale size-promoted targeted therapy for acute kidney injury through combined RONS scavenging and inflammation alleviation strategy.

Acute kidney injury (AKI) is a heterogeneous, high-mortality clinical syndrome with diverse pathogenesis and prognosis, but it lacks the effective therapy clinically. Its pathogenesis is associated with production of reactive oxygen/nitrogen species and infiltration of inflammatory cells. To overcome these pathogenic factors and improve the therapeutic efficiency, we synthesized triptolide-loaded mesoscale polydopamine melanin-mimetic nanoparticles (MeNP) as the antioxidant plus anti-inflammatory therapeutic platform to synergistically scavenge reactive oxygen/nitrogen species (RONS), inhibit the activity of macrophages and dendritic cells, and generate Treg cells for AKI therapy. It was demonstrated that mesoscale size was beneficial for MeNP to specifically accumulate at renal tubule cells, and MeNP could significantly attenuate oxidative stress, reduce proinflammatory immune cells in renal, and repair renal function in cisplatin-induced AKI mouse model. MeNP might be a potential candidate to inhibit oxidative damages and inflammatory events in AKI.