Liver cell specific targeting by the preS1 domain of hepatitis B virus surface antigen displayed on protein nanocages

Masaharu Murata,^1,2 Sayoko Narahara,^1,2 Kaori Umezaki,¹ Riki Toita,^1,2 Shigekazu Tabata,¹ Jing Shu Piao,¹ Kana Abe,¹ Jeong-Hun Kang,³ Kenoki Ohuchida,^1,4 Lin Cui,⁴ Makoto Hashizume<sup>1,2

1</sup>Department of Advanced Medical Initiatives, Faculty of Medical Science, Kyushu University, Fukuoka, Japan; ²Innovation Center for Medical Redox Navigation, Kyushu University, Fukuoka, Japan; ³Department of Biomedical Engineering, National Cerebral and Cardiovascular Center Research Institute, Osaka, Japan; ⁴Department of Surgery and Oncology, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan

Abstract: Protein nanocages are self-organized complexes of oligomers whose three-dimensional architecture can been determined in detail. These structures possess nanoscale inner cavities into which a variety of molecules, including therapeutic or diagnostic agents, can be encapsulated. These properties yield these particles suitable for a new class of drug delivery carrier, or as a bioimaging reagent that might respond to biochemical signals in many different cellular processes. We report here the design, synthesis, and biological characterization of a hepatocyte-specific nanocage carrying small heat-shock protein. These nanoscale protein cages, with a targeting peptide composed of a preS1 derivative from the hepatitis B virus on their surfaces, were prepared by genetic engineering techniques. PreS1-carrying nanocages showed lower cytotoxicity and significantly higher specificity for human hepatocyte cell lines than other cell lines in vitro. These results suggested that small heat-shock protein-based nanocages present great potential for the development of effective targeted delivery of various agents to specific cells.

Keywords: protein nanocages, drug delivery system, hepatocyte cell lines specific, hepatitis B virus