Renal-targeting peptide-microRNA nanocomplex for near IR imaging and therapy of renal ischemia/reperfusion injury

Renal ischemia-reperfusion injury (RI/R) is one of the main causes of acute renal injury and a common clinical disease with high morbidity and mortality. It is of great significance to deliver microRNAs (miRNAs) to cells and in vivo to realize gene regulation and treatment of related diseases. In this study, we reported that the nanocomplex FMN-17 could realize both therapeutic and functional monitoring simultaneously in vivo and in vitro. The nanocomplex comprised a cationic cell-penetrating peptide nona-arginine, a targeting ligand folic acid, a caspase-3 responsive moiety, and a Cy imaging moiety. The nanocomplex FMN-17 has been shown to deliver miR-17-5p efficiently and selectively into HK-2 cells and tissues. Treatment of HK-2 cells with the nanocomplex significantly increased the miR-17-5p level and inhibited apoptosis, as evident by reducing the expression of active caspase-3 and reactive oxygen species. Uptake of FMN-17 in vivo alleviated renal tissue injury by histological assessment. In summary, we designed and synthesized a new miRNA delivery system with high transfection efficiency, good therapeutic effect, and near-infrared imaging in renal ischemia/reperfusion injury.