Knocking Out Hepatitis C

March 7, 2014

By Medical Discovery News

Hepatitis C

Good news awaits Hepatitis C patients. In the next few years, new drugs that specifically target the Hepatitis C virus, curing a person more quickly without the severe side effects, will become available. Some physicians and patients are even opting to wait for these new drugs rather than endure the current therapy.

Today, this viral infection is most often acquired by drug users sharing needles. The Hepatitis C virus can cause a mild illness lasting a few weeks but in some people it can cause a serious lifelong illness. One major problem is that many people are unaware that they are infected until they have symptoms of liver damage. It is the leading cause of cirrhosis and liver cancer and the most common reason for liver transplantation in the United States.

An estimated three to four million Americans are infected, and deaths from Hepatitis C are expected to rise in the future as those unaware of their infections begin to have symptoms. There is no vaccine and the current drug regimens can cure about 70 percent of infected people but the serious side effects include anemia, insomnia, depression, fever, and severe rashes.

Hepatitis C is most commonly treated with a combination of interferon and ribavirin for 24 to 48 weeks. However, because of their side effects and the fact that the drugs do not work for everyone, drug companies have been working hard to develop new treatments.

These new drugs are predicted to wipe out Hepatitis C infections with one pill per day for as little as eight weeks, without severe side effects. The only downside is their predicted costs range from $60,000 to more than $100,000 for a course of treatment. The new drugs, much like those that are used to treat HIV infection, target enzymes the Hepatitis C virus requires to reproduce.  However, the Hepatitis C virus does not make its genetic information a permanent part of a cell’s genome like HIV does, so it can be eliminated, therefore curing the person. If the virus is eliminated the liver can heal itself to some extent, but people cured of Hepatitis C may still be at higher risk for liver cancer.

One of these new drugs, called sofosbuvir by Gilead Sciences, inhibits the enzyme that copies the virus’s genetic information, therefore blocking virus reproduction. The effectiveness of the drug depends on the type of Hepatitis virus. The majority of Hepatitis C patients in the U.S. would require the addition of interferon for 12 weeks. Gilead has a second drug nearly ready called ledipasvir, which in combination with ribavirin could eliminate the need for interferon, the source of the worst of the side effects of current treatments.

Several other companies are racing to introduce additional medications to treat Hepatitis C. Having tolerable therapies available will encourage people to get tested and treated earlier for Hepatitis C, before liver damage begins. This is a huge benefit to public health that will substantially reduce the need for liver transplants and the number of deaths from liver failure and liver cancer.

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Life-Saving Printers

Sept. 27, 2013

By Medical Discovery News

3-D printers have proven capable of creating guns that actually fire bullets, pizza (although there’s no assurance of its taste), and now, livers. 3-D printing technology or stereolithography  has been used to create miniature human livers, the first step toward producing livers and eliminating the long wait for a liver transplant.

3-D printing originated with the invention of the ink jet printer in 1976, which was then adapted to print with materials other than inks in 1984. The first machine to print in 3-D was created in 1992 to make objects by applying layer after layer of material governed by computer. By 2002, engineers and scientists developed methods to print biomaterials and make functional miniature kidneys. Since then, 3-D printers have been used to make cars, robotic aircrafts, blood vessels, jewelry, and even prosthetics.

The miniature livers produced thus far are only one-half of a millimeter thick and four millimeters long. To create them the printer lays down about 20 layers of liver cells called hepatocytes and stellate cells. Hepatocytes are the most prevalent type of cell in the liver and stellate cells are vital in liver regeneration and other functions. The printing also includes cells that line blood vessels in order to create a meshwork of small channels to provide oxygen and nutrients, thereby extending the life of these printed livers. The printer used by Organovo was able to place the cells in precise spatial patterns that resemble the natural liver.

These printed livers function like healthy, natural livers. They produced albumin, which is a protein that helps move many small molecules through the blood, including bilirubin, calcium, progesterone, and medications. It also plays an important role in keeping the fluid in the blood from leaking out into the tissues. They also synthesized cholesterol and detoxified key enzymes called cytochrome P450s that metabolize drugs and toxins to protect the body.

The goal of this research is to eventually print full-sized livers that could be transplanted into those who need them. Currently, over 15,000 people are waiting for a liver, and last year, 1,550 died while waiting for a liver transplant. Liver transplants can be the only option for people whose livers are damaged by alcoholism, infections like hepatitis, clots that block blood flow, autoimmune liver diseases, cancer, birth defects, and genetic disorders. Liver failure causes many health problems including malnutrition, blood clotting, bleeding from the gastrointestinal tract, and jaundice. Because the human body needs a functioning liver, a person experiencing liver failure will die without a transplant.

One of the major challenges to printing full-sized human livers is developing a way to print larger branched networks of blood vessels, as these are absolutely essential to the survival of the printed organ. But medical uses for 3-D printing, such as using it to model facsimiles of patients’ organs in preparation for surgeries, show that this technology has the potential to save lives.  

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