Silver nano-particles can rein in replication of hepatitis B virus

    HONG KONG, April 28 (Xinhua) -- Silver nano-particles with an average diameter of 5 to 50 nanometers can rein in the in vitro replication of hepatitis B viruses (HBV) through direct interaction with its DNA and viral particles, researchers said Monday.

    Lei Lu, a Ph.D. candidate at the Hong Kong University, said his team found that the ultra-tiny silver particles could reduce the extra cellular DNA formation of HBVs by over 50 percent, and could check their intracellular RNA formation, too.

    "Silver nano-particles have special properties such as larger active surface and porosity so that they can easily bind with small molecules," Lu said, referring to a hypothetical explanation they had put forward on the new antiviral mechanism.

    "The finding provides a new direction for developing new anti- HBV drugs, with nano-particles used as drug carrier to enhance the antiviral efficacy while minimizing the undesirable side effects," Lu told a press conference Monday.

    The young researcher said there are currently only two kinds of drugs approved for treating chronic HBV infection, namely immunomodulators and nucleoside analogues. But their uses are affected by side effects and drug-resistant mutations.

    Hepatitis B is one of the worst killers as it chronically infects over 400 million people worldwide, with certain developing countries and regions hit hardest.

    Lu said silver nano-particles have an additional distinct advantage. It is unlikely that HBV can become resistant to silver nano-particles because the interaction is determined by the physiochemical properties of the tiny particles.

    The study on silver nano-particles is still in the laboratory stage and any drugs it may lead to are still 3 to 5 years away from clinic use, Lu said.

    The study, conducted jointly by researchers at the Department of Medicine and the Department of Chemistry of the Hong Kong University, has been published in the March issue of Antiviral Therapy, the world's leading antiviral research journal.

http://news.xinhuanet.com/english/2008-04/28/content_8068288.htm

HK researchers prove silver nano-particles can battle hepatitis B virus

Hong Kong University researchers said Monday they believe that silver may hold a solution to one of China¡¯s worst health concerns, the spread of hepatitis B, which can cause liver cancer and liver failure.

Author: Dorothy Kosich
Posted:  Tuesday , 29 Apr 2008

RENO, NV - 

Researchers at Hong Kong University Monday told the Chinese news media that silver nano-particles have been proven to rein in the growth of the hepatitis B virus (HBV) considered one of the worst killers, hitting Asian and Pacific Islander nations, the hardest.

It is estimated that 130 million people in China are HBV carriers, or almost one-third of the infected population globally, believed to be at 350 million to 400 million. In many rural areas, doctors have reused syringes and unknowingly spread the disease, particularly among children.

In 2002, 250,000 Chinese were believed to have died from Hepatitis B, which damages the liver and can cause liver cancer and liver failure. Since that time China has immunized 11.1 million children in the country's poorest and most remote western and central provinces against hepatitis B.

Many chronic hepatitis B carriers have no symptoms and feel perfectly healthy. Most Asian and Pacific Islanders carrying the disease are infected at birth by their mothers. Others may get the disease through unprotected sex with carriers. Men who have sex with men are also susceptible to the disease, according to the U.S. Center for Disease Control.

Lei Lu, a doctoral candidate at Hong Long University, said his team found that silver nano-particles could reduce the extra cellular DNA formation of HBVs by more than half, and could check their intracellular RNA formation as well.

During a press conference Monday, Lu said, "Silver nano-particles have special properties such as larger active surface and porosity so they can easily bind with small molecules. ...The finding provides a new direction for developing new anti-HBV drugs, with nano-particles used as a drug carrier to enhance the antiviral efficacy while minimizing the undesirable side effects."

Lu also noted that silver nano-particles have another advantage since it is unlikely that HBV can become resistant to silver nano-particles because the interaction is determined by the physiochemical properties of the tiny particles. The study is still in the laboratory stage and any findings it may generate are still three to five years away from clinic use, according to Lu.

The study was conducted jointly by researchers at the Departments of Medicine and Chemistry at Hong Kong University and has been published in the March issue of the Antiviral Therapy research journal.

Meanwhile, in an unrelated development, Mississauga, Ontario-based Covalon Technologies announced Monday that its antimicrobial silver coating on Foley catheters has eliminated the incidence of nosocomial catheter-associated urinary tract infections during a six month study at the St. Vincent Rehabilitation Hospital in Sherwood Arkansas.

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