Novel pH-sensitive multifunctional envelope-type nanodevice for siRNA-based treatments for chronic HBV infection.
OBJECTIVE
Antiviral agents including entecavir (ETV) suppress the replication of the hepatitis B virus (HBV) genome in human hepatocytes, but they do not reduce the abundance of viral proteins. The present study focused on effectively reducing viral protein levels.


METHODS
We designed siRNAs (HBV-siRNA) that target consensus sequences in HBV genomes. To prevent the emergence of escaped mutant virus, we mixed three HBV-siRNAs (HBV-siRNAmix); the mixture was encapsulated in a novel pH-sensitive multifunctional envelope-type nanodevice (MEND), a hepatocyte-specific drug delivery system. Coagulation factor 7 siRNA was used to assess delivery and knockdown efficiencies of MEND/siRNA treatments in mice. The potency of MEND/HBV-siRNAmix was evaluated in primary human hepatocytes and in chimeric mice with humanized liver persistently infected with HBV.


RESULTS
Effective knockdown of targets, efficient delivery of siRNA, and liver-specific delivery were each observed with MEND. MEND/HBV-siRNA caused efficient reduction of HBsAg and HBeAg in vitro and in vivo. However, ETV treatment did not efficiently reduce HBsAg or HBeAg when compared with a single MEND/HBV-siRNAmix treatment. Furthermore, the suppressive effects of a single dose of MEND/HBV-siRNAmix persisted for 14days in vitro and in vivo.


CONCLUSIONS
We demonstrated that MEND/HBV-siRNA controlled HBV more efficiently than did ETV. Furthermore, the effect of a single dose of MEND/HBV-siRNA persisted for a long time. These results indicated that MEND/HBV-siRNA may be a promising novel HBV treatment that is more effective than reverse transcriptase inhibitors.
Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan.
Naoki
N
Yamamoto
Laboratory of Innovative Nanomedicine, Faculty of Pharmaceutical Sciences, Hokkaido University, Hokkaido 060-0812, Japan.
Yusuke
Y
Sato
Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan.
Tsubasa
T
Munakata
PhoenixBio Co., Ltd., 3-4-1, Kagamiyama, Hiroshima 739-0046, Japan.
Masakazu
M
Kakuni
PhoenixBio Co., Ltd., 3-4-1, Kagamiyama, Hiroshima 739-0046, Japan.
Chise
C
Tateno
Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan.
Takahiro
T
Sanada
Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan.
Yuichi
Y
Hirata
Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, Japan.
Shuko
S
Murakami
Department of Virology and Liver Unit, Nagoya City University Graduate School of Medical Sciences, Nagoya 467-8601, Japan.
Yasuhito
Y
Tanaka
Department of Medicine and Molecular Science, Division of Frontier Medical Science, Programs for Biomedical Research, Graduate School of Biomedical Sciences, Hiroshima University, Minami-ku, Hiroshima 734-8551, Japan.
Kazuaki
K
Chayama
Laboratory of Innovative Nanomedicine, Faculty of Pharmaceutical Sciences, Hokkaido University, Hokkaido 060-0812, Japan.
Hiroto
H
Hatakeyama
Laboratory of Innovative Nanomedicine, Faculty of Pharmaceutical Sciences, Hokkaido University, Hokkaido 060-0812, Japan.
Mamoru
M
Hyodo
Laboratory of Innovative Nanomedicine, Faculty of Pharmaceutical Sciences, Hokkaido University, Hokkaido 060-0812, Japan.
Hideyoshi
H
Harashima
Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan. Electronic address: kohara-mc@igakuken.or.jp.
Michinori
M
Kohara
D000818:Animals; D004279:DNA, Viral / Q000032:analysis; D018014:Gene Transfer Techniques; D006514:Hepatitis B Surface Antigens / Q000032:analysis; D006513:Hepatitis B e Antigens / Q000032:analysis; D006515:Hepatitis B virus / Q000235:genetics; D019694:Hepatitis B, Chronic / Q000628:therapy*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008081:Liposomes; D051379:Mice; D034741:RNA, Small Interfering / Q000008:administration & dosage*
D004279:DNA, Viral; D006514:Hepatitis B Surface Antigens; D006513:Hepatitis B e Antigens; D008081:Liposomes; D034741:RNA, Small Interfering
Chronic HBV infection; RNAi therapy; pH-sensitive multifunctional envelope-type nanodevice