Megalin-targeted acetylcysteine polymeric prodrug ameliorates ischemia-reperfusion-induced acute kidney injury.

Acute kidney injury (AKI), a condition associated with reactive oxygen species (ROS), causes high mortality in clinics annually. Active targeted antioxidative therapy is emerging as a novel strategy for AKI treatment. In this study, we developed a polymeric prodrug that targets the highly expressed Megalin receptor on proximal tubule cells, enabling direct delivery of N-Acetylcysteine (NAC) for the treatment of ischemia reperfusion injury (IRI)-induced AKI. We conjugated NAC with low molecular weight chitosan (LMWC), a biocompatible and biodegradable polymer consisting of glucosamine and N-acetylglucosamine, to enhance its internalization by tubular epithelial cells. Moreover, we further conjugated triphenylphosphonium (TPP), a lipophilic cation with a delocalized positive charge, to low molecular weight chitosan-NAC in order to enhance the distribution of NAC in mitochondria. Our study confirmed that triphenylphosphonium-low molecular weight chitosan-NAC (TLN) exhibits remarkable therapeutic effects on IRI-AKI mice. This was evidenced by improvements in renal function, reduction in oxidative stress, mitigation of pathological progress, and decreased levels of kidney injury molecule-1. These findings suggested that the polymeric prodrug TLN holds promising potential for IRI-AKI treatment.