Toru Taharabaru

1 Introduction N-Acetylgalactosamine (GalNAc), which is the ligand for liver asialoglycoprotein receptors (ASGPR), is the most extensively utilized active targeting ligand in contemporary biomedical research [1-3]. Approximately 500 000 copies of ASGPRs express in hepatocytes [4-7], and 5%–10% of them express on the surface of hepatocytes [5, 8]. When ASGPRs interact with their ligands, they get rapidly internalized into the cells and recycled to the cell surface in 5–10 min [9, 10].

Introduction Needle-based injections remain the standard method for administering drugs and are indispensable for delivering different biopharmaceuticals, including insulin, vaccine antigens, and therapeutic antibodies.1,2 However, conventional needle-based injections have several challenges.