In vivo photoacoustic imaging of liver using liver specific targeting conjugates

Abstract

The liver performs important functions in our body such as protein synthesis, and blood cell degradation has been considered a major organ of the human body. Currently, ultrasound imaging and magnetic resonance imaging are frequently used to diagnose liver diseases including cancer and cirrhosis. Ultrasound imaging is commonly used for liver disease because it provides safe, easy-to-use, real-time imaging at low cost. Ultrasound uses anatomical, tissue, and blood flow information to diagnose liver disease. By adding additional information using photoacoustic (PA) imaging, the diagnosis of the liver disease can be further enhanced. In this study, we developed hyaluronate silica nanoparticles (HASi) PA contrast agents that can be targeted to liver specifically. Since the hyaluronic acid receptors such as cluster determinant 44 are overexpressed in the liver, hyaluronic acid is considered a direct marker for fibrogenesis. Therefore, hyaluronic acid conjugates have been researched for liver-specific targeting. To verify liver-specific targeting efficiency and PA contrast agent property, in vivo PA monitoring has been conducted after i.v. injection of HA-Si and silica nanoparticles. ICP-MS analysis of major organs and urine optical absorbance spectra analysis has been performed to investigate biocompatibility of HA-Si. These results demonstrate the possibility of liver-specific drug delivery of the hyaluronic acid complex and the possibility of a PA method for liver lesion monitoring.