Multimodal and Noninvasive Diagnosis of MNP-PEG-Gd Nanoprobe for Hepatic Fibrosis Based on Magnetic Resonance and Photoacoustic and Photoacoutic Microscopy Imaging.

Hepatic fibrosis is a pivotal transitional phase in the progression of various chronic hepatic diseases toward cirrhosis and hepatocellular carcinoma. Timely detection and precise staging of hepatic fibrosis are crucial for reversing the disease trajectory. A single imaging modality often fails to dehepatically provide the comprehensive diagnostic information necessary for accurate disease assessment. Multimodal imaging, which integrates various imaging techniques, has the potential to enhance diagnostic accuracy through complementary benefits. In this study, we utilized endogenous natural melanin as a nanocarrier to develop the multimodal nanoprobe MNP-PEG-Gd. This probe facilitates the complementary integration of Magnetic Resonance Imaging (MRI), which provides excellent anatomical resolution with highly sensitive Photoacoustic Imaging (PAI) and high-spatial-resolution Photoacoustic Microscopy (PAM). The MNP-PEG-Gd nanoprobe passively targets and accumulates in thehepatic region, and in vivo results indicate that MRI/PAI/PAM diagnoses align closely with biopsy findings. Moreover, our MNP-PEG-Gd nanoprobe demonstrates excellent biosafety in both in vitro and in vivo settings. This work suggests that MNP-PEG-Gd is a promising candidate for use as a contrast agent in diagnosing stages of hepatic fibrosis through multimodal imaging.