Engineered Relaxin as theranostic nanomedicine to diagnose and ameliorate liver cirrhosis

Hepatic cirrhosis is a growing health problem with increasing mortality worldwide. So far, there is a lack of early diagnosis and no clinical therapy is approved for the treatment. In this study, we developed a novel theranostic nanomedicine by targeting relaxin (RLX) that is known to possess potent anti-fibrotic properties but simultaneously has poor pharmacokinetics and detrimental off-target effects. We conjugated RLX to PEGylated superparamagnetic iron-oxide nanoparticles (RLX-SPIONs) and examined hepatic stellate cells (HSCs) specific binding/uptake. Thereafter, we assessed the therapeutic efficacy of RLX-SPIONs on human HSCs in vitro and in vivo in CCl4-induced liver cirrhosis mouse model. RLX-SPIONs showed specific binding and uptake in TGFβ-activated HSCs, and inhibited TGFβ-induced HSCs differentiation, migration and contraction. In vivo, RLX-SPIONs strongly attenuated cirrhosis and showed enhanced contrast in MR imaging. Altogether, this study presents RLX-SPIONs as a novel theranostic nanomedicine that provides new opportunities for the diagnosis and treatment of liver cirrhosis.