Objective To evaluate the ultrasonic molecular imaging ability of CNA35 targeted perfluoropentane nanoparticles (PFP-NPs) for renal fibrosis in diabetic nephropathy. Methods Preparation of non-targeted fluorescent labeled (non-targeted) PFP-NPs and CNA35 collagen-targeted fluorescent labeled (targeted) PFP-NPs. TGF-β induced interstitial transformation of human renal tubular epithelial cells HK-2. The cells were co-incubated with non-targeted PFP-NPs and targeted PFP-NPs

and the fluorescence signal of the cells was observed under a fluorescence microscope. The DN rat model was established

and the model rats were given intravenous injection of non-targeted PFP-NPs and targeted PFP-NPs

respectively. The kidney tissue was taken to detect the fluorescence signals of PFP-NPs and type I collagen in the kidney tissue. Ultrasound molecular imaging was used to detect renal fibrosis imaging. The expression level of type I collagen in renal tissue was analyzed by immunohistochemistry

and the correlation between the signal intensity of renal ultrasound molecular imaging and the level of type I collagen was analyzed. Results The fluorescence signal of HK-2 incubated with targeted PFP-NPs was significantly stronger than that of cells incubated with non-targeted PFP-NPs (P < 0.05). The fluorescence signal of PFP-NPs in the kidney tissue of DN rats in the targeted group was significantly stronger than that in the non-targeted group (P < 0.05)

and the fluorescence signal of PFP-NPs coincided with the fluorescence signal area of type I collagen. Ultrasound molecular imaging showed that the renal signal intensity of rats injected with targeted PFP-NPs was significantly higher than that of rats injected with non-targeted PFP-NPs (P < 0.05). Pearson correlation analysis showed that the percentage of type I collagen distribution area in rat kidney was positively correlated with the signal intensity of renal ultrasound molecular imaging. Conclusion CNA35 targeted PFP-NPs can target the high expression of collagen in the kidney

and achieve targeted ultrasound molecular imaging of diabetic nephropathy.