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Showing posts with label Human Cloning. Show all posts
Showing posts with label Human Cloning. Show all posts

Monday, June 14, 2010

'Grow-your-own' organs hope after scientists produce liver in lab from stem cells


By Fiona Macrae

From : http://www.dailymail.co.uk/

Scientists have grown a liver in a laboratory, offering fresh hope to hundreds of thousands of patients with diseased and damaged organs.

It raises the prospect of those in need of transplants one day being offered livers that are ‘made to order’.

The first pieces of lab-grown livers could be used in hospitals within just five years, the researchers said.

Decellularised rat liver

A decellularised rat liver retaining its network of blood vessels, a technique grown by scientists which could be used to grow livers for human transplants

Patches of artificial tissue could be used to repair livers damaged by injury, disease, alcohol abuse and paracetamol overdose.

Other possibilities include sections of artificial livers to keep those needing transplants alive – in much the same way as a dialysis machine is used to treat kidney failure.

HOW TO GROW OWN LIVER

1. Donated but damaged liver bathed in detergent to remove the cells.

2. All that remains is a 'scaffold' made of collagen and blood vessels.

3. Scaffold is seeded with healthy liver cells, made from the stem cells created from the patient's skin.

4. The new liver is used to replace the patient's damaged one. As it is made from their own cells, the body will not reject it.

At least one million of Britons live with liver disease and it claims more than 16,000 lives a year – more than diabetes and traffic accidents combined. Up to 600 transplants are carried out a year.

The latest experiments, which were carried out on animal livers, are still in the early stages but could one day lead to an alternative supply of organs.

The process began with a donor liver being ‘washed’ in detergent, stripping it of its cells, leaving only a collagen and blood vessel ‘scaffold’ in which the new liver cells could grow.

The U.S. scientists then injected it with up to 200 million healthy liver cells, in four shots, each ten minutes apart.

The cells spread across the scaffold, and, provided with an artificial blood supply, the liver survived in a petri dish for up to ten days, the journal Nature Medicine reports.

Tests showed that, just like a real liver, it was capable of breaking up toxins.

The researchers, from Massachusetts General Hospital, Boston, also transplanted the liver into a rat, for several hours.

Lead researcher Dr Korkut Uygun said: ‘As far as we know, a transplantable liver graft has never been constructed in a laboratory setting before.

‘Even though this is very exciting and promising, it is a proof-of-concept study only. Much more work will be required to make long-term functional liver grafts that can actually be transplanted into humans.

‘We haven’t been able to go beyond several hours in rats, but it’s a great start.’

Hurdles to overcome include creating a liver with all the types of cells needed for full function, including specialised cells that destroy bacteria and other invaders.



Wednesday, April 14, 2010

Skin Cell Spraying Bio Printer Can Heal Burn Victims in Three Weeks

skin cells, cell printer, cell sprayer, burn victims, wake forest,  winston salem, medicine, hospital, medical design, 3d printer

Recently we showcased a 3D printer that creates human body parts ready for transplant, and now our frankenstinean fascination with making body parts has unearthed another amazing device. This new bio-printer sprays skin cells on burn victim’s wounds, promoting healthy recovery. The printer is mounted onto a frame that is wheeled over a patient’s hospital bed. A laser reads the depth and shape of the wound, and with the help of a computer the device sprays a precise layer of skin cells that can heal infection-prone wounds in just three weeks.

The skin-spraying project is being developed by scientists and students at Wake Forest University in North Carolina. They are planning to team up with U.S. Armed Forces Institute of Regenerative Medicine to use the device to help wounded soldiers returning from overseas. The process starts as skin cells are separated and purified. They are then placed in a nutritious solution that helps the cells multiply. They are then loaded into the device, sprayed on the skin in layers and voila! Burns are healed. So far they’ve only tested the process on mice, and they were able to successfully heal burns after just three weeks.

Traditionally the only way to fix severe burn wounds is a skin graft. Skin grafts are highly painful and generally leave huge scars. With this new process scientists include some stem cells in the mix which allows hair follicles and sebaceous glands develop in the new layers of skin. It seems that when the cells are sprayed on the wound they know exactly what they are supposed to do, and they develop as naturally as a your own skin would. Eliminating the mass amount of medical rehabilitation involved in getting burn victims back on their feet by spraying on skin cells will eliminate much of the painful process and cut down on the chemical-based medicines used to help them heal.

Via Reuters

Monday, July 20, 2009

How Human Cloning Will Work

Introduction to How Human Cloning Will Work

Cloning Image Gallery

TIME cloning issue
Time & Life Pictures/­Getty Images
Hello, Dolly! After Dolly was cloned in 1997, people worried that humans would be next. See more cloning pictures.

­On July 5, 1997, the most famous sheep in modern history was born. Ian Wilmut and a group of Scottish scientists announced that they had successfully cloned a sheep named Dolly.

If you stood Dolly beside a "naturally" conceived sheep, you wouldn't notice any differences between the two. In fact, to pinpoint the only major distinguishing factor between the two, you'd have to go back to the time of conception because Dolly's embryo developed without the presence of sperm. Instead, Dolly began as a cell from another sheep that was fused via electricity with a donor egg. Just one sheep -- no hanky-panky involved.

While Dolly's birth marked an incredible scientific breakthrough, it also set off questions in the scientific and global community about what -- or who -- might be next to be "duplicated." Cloning sheep and other nonhuman animals seemed more ethically benign to some than potentially cloning people. In response to such concerns in the United States, President Clinton signed a five-year moratorium on federal funding for human cloning the same year of Dolly's arrival [source: Lamb].


­Today, after more than a decade since Dolly, human cloning remains in its infancy. Although cloning technology has improved, the process still has a slim success rate of 1 to 4 percent [source: ­Burton]. That being said, science is headed in that direction -- pending governmental restraints.

Scientists have cloned a variety of animals, including mice, sheep, pigs, cows and dogs. In 2006, scientists cloned the first primate embryos of a rhesus monkey. Then, in early 2­008, the FDA officially deemed milk and meat products from cloned animals and their offspring safe to eat.

But what would human cloning involve, and how could you take sperm out of the reproductive ­equation?

Creating a Human Clone

In January 2001, a small consortium of scientists led by Panayiotis Zavos, a former University of Kentucky professor, and Italian researcher Severino Antinori said that they planned to clone a human in two years [source: Kirby]. At about the same time, news surfaced about an American couple who planned to pay $500,000 to Las Vegas-based company Clonaid for a clone of their deceased infant daughter [source: Clonaid]. Neither venture produced documented success.

cloning
A breakdown of how cloning works.

Then, in 2004, South Korean scientist Hwang Woo-suk announced that he and his research team had cloned 11 human embryos for the purpose of extracting stem cells. However, after reviewing his work, a panel at Seoul National University concluded tha­t his findings were false. There ­hasn't been any confirmed human clone created to date. When discussing cloning in the sense of doing so to make a duplicate of an organism, we refer to it as reproductive cloning

Cloning Corner

­If human reproductive cloning proceeds, the primary method scientists will likely use is somatic ce­ll nuclear transfer (SCNT), which is the same procedure that was used to create Dolly the sheep. Somatic cell nuclear transfer begins when doctors take the egg from a female donor and remove its nucleus, creating an enucleated egg. A cell, which contains DNA, is taken from the person who is being cloned. Then the enucleated egg is fused together with the cloning subject's cell using electricity. This creates an embryo, which is implanted into a surrogate mother through in vitro fertilization.

If the procedure is successful, then the surrogate mother will give birth to a baby that's a clone of the cloning subject at the end of a normal gestation period. As mentioned before, the success rate for this type of procedure is small, working in only one or two out of every 100 embryos. After all, Dolly was the result of 277 previously failed attempts.

­On the surface, human cloning may evoke a similar reaction to the space program's race to the moon -- groundbreaking accomplishment, but what could we actually glean from it? Re-engineering the human reproductive process has made many people nervous that cloning crosses the ethical boundaries of science. But we can't fully evaluate the moral dilemma without first addressing the potential benefits of human cloning.

Cloning Uses

­At the outset of the clone craze, some scientists and companies focused on exploiting the science-fiction aspects of the technology. For instance, Zavos and Antinori, mentioned earlier, aimed to develop cloning to aid infertile couples -- to the tune of approximately $50,000 for the service. The group said that the procedure would involve injecting cells from an infertile male into an egg, which would be inserted into the female's uterus. This child would look the same as his or her father. Then there's the possibility of bringing deceased relatives back to life. A now-defunct company called Genetics Savings & Clone performed this type of cloning for a woman's dead cat, Little Nicky, in 2004.

Cloning on Film

Human reproductive cloning probably won't be a reality any time soon, but you can indulge your curiosity with a few cloning film selections.

  • The Island: Set in 2019, wealthy people keep clones of themselves on an island so if they ever get hurt, they can just snag a body part from their clone by murdering him or her.
  • The Boys from Brazil: If you like Gregory Peck, you may want to steer clear to preserve his old-school, dreamboat image. However, if you like movies about neo-Nazi cloning projects, get the popcorn ready!
  • Multiplicity: Doug Kinney has no time for anything, so he clones himself without telling his family -- let the hilarity ensue.

­Therapeutic cloning holds the most promise of valuable medical advancement. Therapeutic cloning is the process by which a person's DNA is used to grow an embryonic clone. However, instead of inserting this embryo into a surrogate mother, its cells are used to grow stem cells. These stem cells could become the basis for customized human repair kits. They can grow replacement organs, such as hearts, livers and skin. They can also be used to grow neurons to cure those who suffer from Alzheimer's, Parkinson's or Rett syndrome. And since the stem cells would come from embryo clones using your own cell's DNA, your body would readily accept them. For more detailed information on stem cells, you can read How Stem Cells Work.

Here's how therapeutic cloning works:

  • DNA is extracted from a sick person.
  • The DNA is then inserted into an enucleated donor egg.
  • The egg then divides like a typical fertilized egg and forms an embryo.
  • Stem cells are removed from the embryo.
  • Any kind of tissue or organ can be grown from these stem cells to treat various ailments and diseases.

To clone human embryos, however, you need eggs. If therapeutic cloning were to begin in earnest, it could increase the demand for such eggs and potentially create additional moral questions regarding the donors [source: Lamb]. Speaking of ethics, there's plenty of related debate to go around when it comes to human cloning.

Human Cloning Ethics

Surveys have shown that few Americans approve of cloning for reproductive purposes, although more are open to therapeutic cloning [source: Burton]. The U.S. government has established strategic roadblocks related to human cloning, although no federal ban exists. First, the government won't fund research focused on human cloning for reproduction. Also, the FDA, which regulates public cloning research, requires anyone in the United States attempting to clone humans to first get its permission. President George W. Bush's appointed Council on Bioethics unanimously opposed cloning for reproductive purposes.

twins at a table
Symphonie/Getty Images
Human reproductive cloning is banned in more than 50 countries.

Certain countries abroad have stricter standards, and more than 50 have legally banned research efforts on reproductive human cloning [source: Medical Devices & Surgical Technology]. In Japan, human cloning is a crime punishable by up to 10 years in prison. England has allowed cloning human embryos for therapeutic use only. Many individual states have also passed laws restricting cloning.

While legal restrictions are one deterrent to pursuing human cloning at this time, some scientists believe today's technology just isn't ready to be tested on humans. Ian Wilmut, one of Dolly's co-creators, has even said that human cloning projects would be irresponsible. Cloning technology is still in its early stages, and nearly 98 percent of cloning efforts end in failure. The embryos are either not suitable for implanting into the uterus, or die some time during gestation or shortly after birth.

Those clones that do survive suffer from genetic abnormalities. Clone cells may age more rapidly, shortening their lifespan, similar to what happened with Dolly. Some clones have been born with defective hearts, lung problems, diabetes, blood vessel complications and malfunctioning immune systems. One of the more famous cases involved a cloned sheep that was born but suffered from chronic hyperventilation caused by malformed arteries leading to the lungs.

­Opponents of cloning point out that while we can euthanize defective clones of other animals, it's morally problematic if this happens during the human cloning process. Advocates of cloning respond that it's now easier to pick out defective embryos before they're implanted into the mother. In 2005, the United Nations attempted to pass a global ban on human cloning, but was unsuccessful due to disagreements over whether therapeutic cloning should be included. For now, human cloning remains in a stalemate from both a scientific and public policy perspective -- the future of human cloning will likely depend on which side gives in first.

Sources

  • Burton, Kelli Whitlock. "Cloning in America." GeneWatch. November/December 2005.
  • Clonaid Web site.
    http://ww­w.clonaid.com/
  • "Cloning Fact Sheet." Human Genome Project Information. Updated July 23, 2008. (Sept. 3, 2008)
    http://www.ornl.gov/sci/techresources/Human_Genome/elsi/cloning.shtml#policy
  • "Human clones: New U.N. analysis lays out world's choices." Medical Devices & Surgical Technology Week. Dec. 2, 2007.
  • Javitt, Gail H.; Suthers, Kristen; and Hudson Kathy. "Cloning: A Policy Analysis." Genetics & Public Policy Center. May 23, 2005. (Sept. 3, 2008)
    http://www.pewtrusts.org/uploadedFiles/wwwpewtrustsorg/Reports/Genetics_and_Public_Policy/GPPC_Cloning_0505.pdf
  • Kirby, Alex. "Cloned human planned 'by 2003.'" BBC News. Jan. 30, 2001.
    http://news.bbc.co.uk/2/hi/science/nature/1144694.stm
  • Lamb, Gregory M. "How Cloning Stacks Up." Christian Science Monitor. July 13, 2006. (Sept. 3, 2008)
    http://www.csmonitor.com/2006/0713/p13s01-stgn.html
  • "Use of Cloning Technology to Clone a Human Being." FDA. Updated Dec. 27, 2002. (Sept. 3, 2008)
    http://www.fda.gov/CBER/genetherapy/clone.htm

Wednesday, June 10, 2009

Growing Organs in the Lab

Written on June 8, 2009 – 3:19 pm | by Drew Halley |

Why transplant an organ when you can grow yourself a new one?

lab-grown-bladder-atala

A homegrown bladder (Photo courtesy of BBC)

This research isn’t something that might happen in the distant future. It’s being used today to grow fresh organs, open up new ways to study disease and the immune system, and reduce the need for organ transplants. Organ-farming laboratories are popping up across the planet, and showing impressive results. Here we look at the state of the union of a rapidly advancing field called tissue engineering: what’s been accomplished so far, and what’s right around the corner.

Patients who undergo organ transplants require loads of toxic drugs to suppress their immune systems; otherwise their body might reject the organ. But tissue engineering could make organ transplants a thing of the past. By using a patient’s cells to grow new types of tissue in the lab, researchers are finding new ways to custom-engineer you new body parts by using your own cells.

At the cutting edge of organ engineering is Tengion, a clinical-stage biotech company based outside of Philadelphia. Their most successful research to date led to the creation of the Neo-Bladder. Tengion takes some of your cells and grows them in culture for five to seven weeks around a biodegradable scaffold. When the organ is ready, it can be transplanted without the need to suppress the patient’s immune system (because the organ was grown from the patient’s own cells, it carries no risk of rejection). Once the organ is in, the scaffold degrades and the bladder adapts to its new (old) home.

The Tengion Neo-Bladder is in Phase II testing, meaning that they have already implanted the organ into individuals and studied how the body adapts to it. After 5 years, the company was able to show that the homegrown organs are safe and effective, capable of treating the bladder effects of spina bifida (a neural tube defect that effects bladder function, among other things). After another round of Phase II trials, Tengion will move on to Phase III testing; after that, the Neo-Bladder should be approved and be made commercially available.

atala_organ_growing_regeneration

Atala wants to grow you an organ

Tengion’s Neo-bladder is nearing the completion of its clinical trials, but they weren’t the first to grow one. If anyone on Earth deserves the job title “Organ Farmer,” it’s Dr. Anthony Atala. He and his research team at Wake Forest University Medical Center pioneered the world’s first lab-grown bladder, and they remain at the forefront of the organ-growing field (Atala is also the chairman of Tengion’s scientific advisory board). Wake Forest is the world’s largest regenerative medicine research center, and their current research is growing 22 different types of tissue: heart valves, muscle cells, arteries, and even fingers.

So how many different types of human organs have been grown and transplanted? The lab-grown bladders are among the only transplants of an entire organ, but a wide variety of partial organ transplants have taken place. Skin cells are regularly grown in culture and grafted onto patients’ bodies. A graft was grown from a patient’s trachea cells and transplanted to replace part of her airway that had degraded due to disease. Cartilage has been grown and transplanted into a patient’s knee.

A number of technologies are under development but have yet to be transplanted into human bodies. Recently, Dr. Nicholas Kotov and his lab at the University of Michigan have engineered artificial bone marrow, a task that was previously doomed to failure. Kotov and his colleagues realized that in the body, stem cell differentiation relies on chemical signals in three dimensions (whereas in a petri dish, it takes place in two dimensions). This insight led to a new methodology that more closely replicated the natural environment of stem cell differentiation in bone marrow tissue. The resultant homegrown marrow grew and divided normally, even releasing antibodies in fight off an introduced influenza strain. It can be used to study the role of bone marrow in fighting disease within the body, as well as creating a “bioreactor”: harnessing the artificial marrow within a device to grow cells and tissues.

Tengion is pretty busy these days as well. Their new website lists a variety of new applications on the horizon, including a Neo-Kidney augment, artery replacements (including in the heart), and variations on their bladder technique to replace cancerous organs. Their company pipeline gives a general idea of the relative stages of each project.

A number of initiatives are under way to create an artificial pancreas, which would revolutionize the way we treat diabetes. By providing diabetics with a healthy pancreas, doctors could restore their natural control of blood glucose by giving them an endogenous source of insulin. Anyone with experience of diabetes knows the difficulty of manually monitoring and controlling your sugar levels, not to mention regularly injecting insulin. A lab-grown pancreas replacement would be an incredible benefit to the 23.6 million individuals in America alone who suffer from diabetes.

ratheart

The Minnesota rat heart

As we previously reported, researchers at the University of Minnesota grew an entire rat heart in a laboratory last year. Their next goal is to grow a pig heart, a significant milestone towards growing a human heart due to their similar structure. Researchers hope to combine the scaffold of a pig heart with human cardiac tissue to grow a hybrid heart suitable for transplant.

Another exciting frontier is the field of printable tissue and organs, which is just what it sounds like. Inkjet cartidges are cleaned out and loaded with a mixture of live human cells and “smart gel.” Then, layer by layer, the cells are printed atop one another until a 3D organ is constructed. Just as a normal printer can deposit different colored ink, organ printing allows scientists to specify where to place different cell types. Organ printing has already created beating cardiac cells, and could soon produce organs that are viable for transplant. But unlike other 3D printers, I wouldn’t want this one in my living room.

The hottest areas in tissue growth are the types hardest to make: nerve, liver, kidney, heart and pancreas cells. But these are precisely where Alata and Tengion are heading, pushing the industry into fresh territory. Coupled with new regenerative treatments like Cook biotech’s foams and stem-cell organ patching, tissue engineering will be keeping our organs young and healthy in the years to come.

Merely a decade ago, tissue engineering was still a new field that struggled to find funding and support. Today, thousands of scientists worldwide are coordinating efforts to reach new breakthroughs, and the demonstrated potential of these methods has helped bring in investors. That should keep the organ growing field moving forward in the future months and years, and we’ll be covering new advances as they emerge.

Check out this Wired Science video that tours around Atala’s lab:

Tuesday, June 9, 2009

Hybrid hearts could solve transplant shortage

A "decellularised" pig's heart


Video: Hybrid heart

"IT'S amazing, absolutely beautiful," says Doris Taylor, describing the latest addition to an array of tiny thumping hearts that sit in her lab, hooked up to an artificial blood supply.

The rat hearts beat just as if there were inside a live animal, but even more remarkable is how each one has been made: by coating the stripped-down "scaffolding" of one rat's heart with tissue grown from another rat's stem cells.

Taylor, a stem cell scientist at the University of Minnesota in Minneapolis, now wants to repeat the achievement on a much larger scale, by "decellularising" hearts, livers and other organs taken either from human cadavers or from larger animals such as pigs, and coating them in stem cells harvested from people.

This could lead to a virtually limitless supply of organs for transplantation that are every bit as intricate as those that grow naturally, except that they don't provoke the catastrophic immune response that obstructs the use of traditional "xenotransplants".

The organs don't provoke the immune response that prevents traditional xenotransplants

"We're already working with heart, kidney, liver, lung, pancreas, gallbladder and muscle," Taylor says. Rival groups are using similar procedures to create new livers and muscle too.

Human organs for transplant are scarce. One option is to engineer organs from scratch in the lab, using artificial scaffolds. While bladders and skin can be grown in the lab, growing more complex organs and their intricate blood-vessel networks, has proved tricky.

Xenotransplants from pigs are another possibility, though fraught with problems. You have to prevent the recipient's immune system from destroying the organ, and also ensure the transplant is free of pig viruses that could be passed on.

Taylor's organs avoid these problems. For starters, building an intricate scaffold from scratch is unnecessary. "It's letting nature do most of the work," she says. What's more, because the stem cells that "clothe" the naked scaffold are taken from the patient, the organ stands a higher chance of being accepted by their immune system.

The idea is fairly simple: take an organ from a human donor or animal (see image), and use a mild detergent to strip away flesh, cells and DNA (see image) so that all is left is the inner "scaffold" of collagen, an "immunologically inert" protein (see image). Add stem cells from the relevant patient to this naked shell of an organ and they will differentiate into all the cells the organ needs to function without inducing an immune response after transplant, or any new infections.

The idea has already worked with simple organs. Last year Claudia Castillo received a transplant made a stripped-down windpipe from a dead human donor. Researchers cut it to size and seeded the scaffold with her stem cells, which grew into the right tissues and gave her a new windpipe. Anthony Hollander of the University of Bristol, UK, a member of the team, says Castillo no longer needs to take drugs and is back at her job.

Taylor's team is using the same technique to create much more complex organs such as hearts, and extending it to using animal, as well as human, scaffolds.

A big challenge with complex organs is ensuring that all their cells are infused with blood. Without blood, cells in the centre of the organ would be starved of oxygen and die after transplantation. Taylor says her method overcomes this problem.

A big breakthrough came in January 2008, when her team produced a beating heart by filling a rat heart scaffold with heart cells from newborn rats (Nature Medicine, vol 14, p 213). These hearts kept their 3D shape, including spaces for all the blood vessels. When they were seeded with new cells (see image), some grew into blood vessel lining (see image).

Since then, Taylor says they have managed to "pretty much repopulate the whole vascular tree" with cells, which includes veins, arteries and capillaries. "Because we've retained the blood vessels, we can take the plumbing and hook it up to the recipient's natural blood supply," says Taylor. "That's the beauty of this."

Although Taylor only added stem cells to the hearts, these cells differentiated into many different cells, in all the correct places, which is the best part of using decellularised scaffolds. The stem cells transformed into endothelial cells in the ventricles and atria, for example, and into vascular and smooth-muscle cells in the spaces for blood vessels, just as in a natural heart. Taylor thinks this happened because she pumped blood and nutrients through the organ, producing pressure in each zone which helps to determine how cells differentiate there.

But chemical, as well as mechanical, cues seem to have guided differentiation. Taylor has evidence that growth factors and peptides remained anchored to the scaffold even after the flesh was washed off. These chemicals likely signalled to the stem cells, indicating how many should migrate to which areas and what to change into in each zone. "Our mantra is to give nature the tools and get out of the way," she says.

Her team has implanted the reclothed hearts into the abdomens of rats, where they survived temporarily and were not rejected. The next step is to see if the transplants can replace an existing heart and keep the animal alive and healthy. To do this, Taylor says they will need to come up with ways to grow more muscle tissue on the hearts. "We've built the vasculature but we don't think we've built enough muscle to keep animals alive."

The next step is to see if the transplants can replace an existing heart and keep the rat alive and healthy

She is also gearing up to repeat the rat experiments with pig hearts and livers. This could be easier because pig organs are larger and easier to handle than tiny rat hearts. Decellularised livers could also appear in humans before hearts because it may not be necessary to recreate entire livers for them to be useful.

Others are also working on livers. Steven Badylak says he has unpublished "proof of concept" that liver recellularisation works in rats and mice. A team lead by Martin Yarmush at Massachusetts General Hospital in Boston has manufactured recellularised rat grafts that provide liver function "in the lab and when transplanted", according to team member Korkut Uygun. But he stresses that the team's ultimate goal is to decellularise human, not animal, organs for transplantation.

Not everyone believes that turning decellularised tissue into a complex, functional organ is as simple as it sounds. "We're a long way from being able to make functional tissues and organs," says Alan Colman of the Singapore Stem Cell Consortium. "We'll be able to make structures that look like the organ, but with almost none of the correct functionality."

David Cooper of the University of Pittsburgh School of Medicine in Pennsylvania, a leading developer of xenotransplants, says that "naked" pig hearts would still carry traces of alpha-Gal, which the human immune system recognises and will attack.

But Chris Mason, professor of regenerative medicine at University College London points out that many decellularised pig components have been used in people without the need for immunosuppressive drugs (see "Pig parts"). He says sufficiently rigorous sterilisation destroys these residues. Otherwise, says Mason, millions of people would already have had adverse reactions to the pig heart valves and tissues they've received.

Taylor says people who find the idea of pig parts unacceptable should consider their current uses in humans. "We're not ready for prime time yet, but we're moving in the right direction," she says.

Pig parts already commonplace

IMPLANTING organs made from the scaffold of a pig organ may sound off-putting and even dangerous, but millions of patients have already been treated with decellularised pig parts without being infected by stowaway pig viruses or suffering disastrous immunological reactions.

Pig heart valves are often used to replace faulty ones in people. In the past, patients who got such valves had to take immunosuppressive drugs. But this isn't necessary with newer pig valves, made by the company AutoTissue in Berlin, which have been thoroughly decellularised.

For years, companies have also been selling decellularised pig gut to produce patches that help the healing of diabetic ulcers, hernias and strained ligaments. Cook Biotech of West Lafayette, Indianapolis, sells patches made from pig sub-mucosal collagen membrane, which provides mechanical strength to the small intestine. "Since 1998, we've treated more than a million patients," says the company's Michael Hiles. Meanwhile, Tissue Regenix of Leeds, UK, is about to start testing tissue from pig heart membranes for patching up holes in arteries.

Chris Mason, professor of regenerative medicine at University College London, says the work of these companies bodes well for the idea of one day implanting much more complicated decellularised pig organs into people.

Available thumbnails

A "decellularised" pig's heart A pig's heart before the process of decellularisation (Image: courtesy of the University of Minnesota) A pig's heart undergoing decellularisation in the lab (Image: courtesy of the University of Minnesota) A re-celled rat's heart (Image: courtesy of the University of Minnesota) A rat heart undergoing decellularisation (top three images), and during recellularisation (bottom) (Image: courtesy of the University of Minnesota)

Monday, June 8, 2009

The First GM Human Embryo Could Dramatically Alter the Future

Human_embryo “The advance of genetic engineering makes it quite conceivable that we will begin to design our own evolutionary progress.”

~Isaac Asimov, famous thinker and sci-fi writer

Cornell University researchers in New York revealed that they had produced what is believed to be the world’s first genetically altered human embryo—an ironic twist considering all the criticism the US has heaped on South Korea over the past several years for going “too far” with its genetic research programs. The Cornell team, led by Nikica Zaninovic, used a virus to add a green fluorescent protein gene, to a human embryo left over from an in vitro fertilization procedure. The research was presented at a meeting of the American Society of Reproductive Medicine last year, but details have emerged only after new controversy has emerged over the ethics and science of genetically modifying humans.

Zaninovic has pointed out that in order to be sure that the new gene had been inserted and the embryo had been genetically modified, scientists would ideally want to keep growing the embryo and carry out further tests. However, the Cornell team did not get permission to keep the embryo alive. The GM embryos created could theoretically have become the world’s first genetically altered man or woman, but it was destroyed after five days.

British regulators form the Human Fertilization and Embryology Authority (HFEA), have warned that such controversial experiments cause “large ethical and public interest issues”.

Much of the debate stems from the fact that the effects of genetically altering an embryo would be generational and permanent. In other words, if we create a mutant baby and it grows up to have children of it’s own—they’ll all be mutant gene carriers too. Genes injected into embryos and reproductive cells, such as sperm, affect every cells in the body and would be passed on to future generations. Critics say current humans don’t have the right to tamper with the gene pool of future generations.

On the other hand, proponents of such technology say that this science could potentially erase diseases such as cystic fibrosis, hemophilia and even cancer. In theory, any “good” gene could be added to embryos to offset any “bad” genes they are currently carrying. That could potentially mean the difference between life and death for many children.

John Harris, the Sir David Alliance Professor of Bioethics at Manchester University, takes it a step further. He believes that as parents, citizens, and scientists, we are morally obliged to do whatever we can genetically to make life better and longer for our children and ourselves. Society currently devotes so much energy and resources towards saving lives, which, in reality, is simply postponing death, he notes. If it is right to save life, Harris reasons, then it should also be right to postpone death by stemming the flow of diseases that carry us to the grave.

For Harris, having the ability to improve our species lot in life but refusing to do so, makes little sense. He has a difficult time understanding why some people are so insistent that we shouldn’t try to improve upon human evolution.

“Can you imagine our ape ancestors getting together and saying, ‘this is pretty good, guys. Let’s stop it right here!’. That’s the equivalent of what people say today.”

Ethicists, however, warn that genetically modifying embryos will lead to designer babies preloaded with socially desirable traits involving height, intelligence and coloring.

Dr David King, director of Human Genetics Alert, warns, “This is the first step on the road that will lead to the nightmare of designer babies and a new eugenics.”

Harris, however, doesn’t support that argument. He says it’s not about “beauty” it’s about health, and what parent wouldn’t want a healthy child, he asks.

“Certainly, sometimes we want competitive advantage [for our children], but for the enhancements I talk about, the competitive advantage is not the prime motive. I didn’t give my son a good diet in the hope that others eat a bad diet and die prematurely. I’m happy if everyone has a good diet. The moral imperative should be that enhancements are generally available because they are good for everyone.”

The only other route to equality, he says, is to level down so that everyone is as uneducated, unhealthy and unenhanced as the lowest in society – which would be much more unethical in his opinion. Even though we can’t offer a liver transplant to all who need them, he says, we still carry them out for the lucky few. “Much better to try to raise the baseline, even if some are left behind.”

The Human Fertilization and Embryology Bill in currently under consideration in Britain will likely make it legal to create GM embryos in that country, but only for research—implantation in the womb will still be banned—at least for now. However, ethicists believe that the legislation could easily be relaxed even further in the future.

People who believe that genetically modified humans is something way into the future might want to consider that many experts are worried that some forms of it are already happening in the sports world.

Faster, bigger, better, stronger—in theory, the single most effective way to radically alter your physical capacities is to manipulate your genes. Athletes are beginning to take notice. Now that we’ve mapped out the human genome and identified exactly which genes make you buff, tough and rough—experts are concerned about the future of genetic doping.

Gene doping could spawn athletes capable of out-running, out-jumping and out-cycling even the world’s greatest champions. However, researchers at the University of Florida are attempting to prevent that from happening by detecting the first cases of gene doping in professional athletes before the practice becomes mainstream.

Montreal-based World Anti-Doping Agency (WADA), responsible for monitoring the conduct of athletes, is working with investigators around the globe to develop testing to identify competitors who have injected themselves with genetic material that is capable of enhancing muscle mass or heightening endurance.

“If an athlete injects himself in the muscle with DNA, would we be able to detect that?” asked one of France’s leading gene therapy researchers, Philippe Moullier, M.D., Ph.D., director of the Gene Therapy Laboratory at the Universite de Nantes in France.

Right now, he says the answer is clearly “no”. But that may soon change. The UF scientists are among several groups collaborating with national and global anti-doping organizations to develop a test that can detect evidence of “doped” DNA.

“WADA has had a research program in place for some years now, to try to develop tests for gene-based doping,” said Theodore Friedmann, M.D., head of the agency’s panel on genetic doping and director of the gene therapy program at the University of California, San Diego.

Nearly every day now we are inundated with new genetic discoveries. Scientists can now pinpoint many specific genes including being lean, living a long life, improved self-healing, thrill seeking behavior, and having an improved memory among many other incredible traits. Many believe that these genes can be manipulated in ordinary humans, in effect creating Super-Mutants.

Theoretically, options are nearly limitless. Even a gene that exists in another species could be brought over to a human cell. Imagine some of the incredible traits of the animal kingdom that some humans don’t possess such as night vision, amazing agility, or the ability to breath underwater. The precedence for these types of radical changes is already in place. Experimental mice, for example, were successfully given the human ability to see in color. If animals can be engineered to have human traits, then humans can certainly be mutated to have desirable animal traits.

It is even thought possible to so drastically alter human genomes that a type of superhuman species could emerge. The fear with germline engineering is that since it is inheritable, offspring and all succeeding generations would carry the modified traits. This is one reason why this type of engineering is currently banned- it could lead to irreversible alteration of the entire human species.

Ethics, not scientific limitations, is the real brick wall. Most scientists believe manipulating genes in order to make an individual healthy is a noble and worthwhile pursuit. Some are against even that notion, arguing that historically amazing individuals have sometimes been plagued by genetic mental and physical disorders, which inadvertently shaped the greatness of their lives. Should we rob the human race of character shaping frailty? Very few scientists would dare to publicly endorse the idea of using genetic engineering to make a normal, healthy individuals somehow superior to the rest of the human race.

“The push to redesign human beings, animals and plants to meet the commercial goals of a limited number of individuals is fundamentally at odds with the principle of respect for nature,”
said Brent Blackwelder, President of Friends of the Earth in his testimony before the Senate Appropriations Committee.

However, would it be so bad if the human race were slightly improved? What if a relatively simple procedure could make an individual and his or her offspring resistant to cancer? After all, Nature isn’t always right. Nature has naturally selected many people to carry the burden of uncomfortable and often lethal genetic disorders. If nature knows best, then shouldn’t we quit trying to “improve” upon nature by “curing” people of genetic conditions we consider inferior? Many say we shouldn’t change human genetics, UNLESS it’s the RIGHT thing to do. Who gets to decide where the line is between righteous endeavor and the corruption of nature? These are the questions facing our generation.

Posted by Rebecca Sato

Thursday, April 23, 2009

Fertility expert: 'I can clone a human being'

Controversial doctor filmed creating embryos before injecting them into wombs of women wanting cloned babies

By Steve Connor, Science Editor


Cady, died aged 10 in a car crash in the US. Her blood cells were frozen and sent to Dr Zavos, who fused them with cow eggs to create cloned human animal hybrid embryos

Cady, died aged 10 in a car crash in the US. Her blood cells were frozen and sent to Dr Zavos, who fused them with cow eggs to create cloned human animal hybrid embryos