Synthesis and biological evaluation of 99mTc-DMP-NGA as a novel hepatic asialoglycoprotein receptor imaging agent

A novel bifunctional coupling agents-biomolecular compound DMP-NGA was prepared by coupling the SATP with galactosyl-neoglycoalbumin (NGA). The DMP-NGA was labeled with technetium-99 m, and the radiochemical purity in excess of 98% after purified with HPLC. In vivo biodistribution showed that 99mTc-DMP-NGA had very high initial liver uptake with good retention. The liver accumulated 99.35±9.77%, 74.25±3.03%, 52.47±7.58% of the injected dose per gram at 5, 30 and 120 min after injection, respectively. It had relative higher initial liver uptake and much lower blood uptake than that of 99mTc-GSA. The liver/blood ratio reached 83.4 at 30 min post-injection, while the ratio of liver/kidney was 14.4. The uptakes in other organs in the abdomen were also slightly low. In addition, the hepatic uptake of 99mTc-DMP-NGA was blocked by preinjecting free GSA as blocking agent. The result indicates that 99mTc-DMP-NGA has specific binding to ASGP receptor. Images acquired with Kodak In-Vivo Imaging System FX Pro showed significant difference before and after inhibition. The promising biological properties of 99mTc-DMP-NGA afford potential applications in liver receptor imaging for assessment of hepatocyte function.