Enhanced US/CT/MR imaging of integrin α_vβ₃ for liver fibrosis staging in rat

Liver fibrosis is a global health challenge with high morbidity and mortality rates, and diagnostic sensitivity of liver fibrosis tests can be increased using multimodal molecular agents. We designed cyclic arginine-glycine-aspartic acid (cRGD)-modified nanoparticles (NPs) using ultrasound (US)/computed tomography (CT)/magnetic resonance (MR) triple-modality imaging to evaluate liver fibrosis stages. In vitro and in vivo studies were conducted using primary hepatic stellate cells (HSCs) and a rat model of liver fibrosis induced by carbon tetrachloride (CCl₄). Our results showed cRGD-poly(lactic-co-glycolic acid)-Fe₃O₄-perfluorocarbon bromide (cRGD-PLGA-Fe₃O₄-PFOB) NPs were preferentially internalised by activated HSCs (aHSCs). The main cell types expressing integrin α_vβ₃ during liver fibrogenesis were the aHSCs. The protein levels of α_v and β₃ expressed on aHSCs increased with the progression of liver fibrosis. After intravenous injection of cRGD-PLGA-Fe₃O₄-PFOB NPs, the echo intensity (EI) values, CT values, and T2 values of liver parenchyma correlated well with liver fibrosis severity. cRGD-PLGA-Fe₃O₄-PFOB NPs as multifunction contrast agents showed great potential to reflect the degree of HSC activation and distinguish among different liver fibrotic stages. The ligand-directed and integrin α_vβ₃-mediated accumulation provides active and passive targeting capabilities, permitting the targeted multimodal imaging of cRGD-PLGA-Fe₃O₄-PFOB NPs, which delivers accurate non-invasive diagnosis and real-time monitoring of liver fibrosis development.