Created by team that implanted lab-grown vaginas into women this year

Engineered penises now being tested for 'safety, function and durability'

, or those who have undergone radical surgery for cancer or suffered trauma to the area

Organs would be given to men with

Scientists have successfully grown penises in a laboratory and say they could be tested on humans within five years.

The organs would be used to help men who have suffered a serious injury to the region, had surgery for cancer or are suffering from a congenital abnormality.

The work is being carried out the Wake Forest Institute for Regenerative Medicine, North Carolina.

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The laboratory grown penises could help men who have suffered a serious injury to the region, had radical surgery for cancer or who have a congenital abnormality

Scientists there are now assessing engineered penises for safety, function and durability, The Guardian reports.

It is hoped the US Food and Drug Administration will give the green light for testing on humans within five years.

Earlier this year, the same team of researchers declared they had successfully grown vaginas in a laboratory and implanted them into four teenage patients.

The new organs were given to women born with MRKH - Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome, a rare genetic condition in which the vagina and uterus are underdeveloped or absent.

The treatment could also potentially be applied to patients with vaginal cancer or injuries.

it is being funded by the US Armed Forces Institute of Regenerative Medicine, in the hope soldiers with battlefield injuries can be helped.

Professor Anthony Atala, director of the institute, oversaw the team's successful engineering of penises for rabbits in 2008.

He told The Guardian the results of the rabbit studies were 'very encouraging' - but several safety hurdles had to be overcome to satisfy medical regulators.

Professor Atala said: 'Our target is to get the organs into patients with injuries or congenital abnormalities.'

To avoid the body rejecting the lab-grown organ, the penises would be made using cells from each individual patient's body.

This would be done by taking cells from what remains of the man's penis and growing these in culture for up to six weeks.

HOW THE ORGANS ARE MADE To avoid the body rejecting the lab-grown organ, the penises would be made using cells from each individual patient's body. This would be done by taking cells from what remains of the man's penis and growing these in culture for up to six weeks. To make the structure of the penis, a donor penis is washed with detergent to remove the donor's cells. A fortnight later, all that is left is just a collagen scaffold of the penis, which the cultured cells from the patient are added to. Advertisement

To make the structure of the penis, a donor penis is washed with detergent to remove the donor's cells.

A fortnight later, all that is left is just a collagen scaffold of the penis, which the cultured cells from the patient are added to.

Commenting on the breakthrough, Asif Muneer, a consultant urological surgeon at University College hospital, London, said if the engineered penises proved to be successful, they would be a huge leap forward in the sophistication of treatments offered to men who have suffered injury or suffered a disease such as penile cancer.

The current option involves reconstructing the penis using skin from the arm or the thigh - with a pump to help a man obtain an erection.

Mr Munner said: 'My concern is that they might struggle to recreate a natural erection.

'Erectile function is a coordinated neurophysiological process starting in the brain, so I wonder if they can reproduce that function or whether this is just an aesthetic improvement.'

Professor Atal's colleagues are working on a related project - treating erectile dysfunction by replacing part of the penis.

Impotence occurs when the tissue that fills will blood to help a man get an erection becomes damaged, meaning the penis cannot fill properly with blood.

An erection is caused by blood flowing into special chambers along the length of the penis.

U.S. scientists are now assessing the engineered penises for safety, function and durability

These chambers are supplied by a network of delicate blood vessels - and so anything that damages these vessels will disrupt blood supply and could lead to impotence.

It is for this reason that men with high blood pressure, cholesterol and diabetes are at increased risk of erectile dysfunction. Some estimates suggest that 50 to 75 per cent of diabetic men are affected.

The lab-grown vaginas described earlier in the year were re engineered using muscle and epithelial cells (the cells that line the body's cavities) from a small biopsy of each patient's external genitals.

The cells were then extracted from the tissues, expanded and then placed on a biodegradable material that was hand-sewn into a vagina-like shape.

These scaffolds were tailor-made to fit each patient.

About five to six weeks after the biopsy, surgeons created a canal in the patient's pelvis and sutured the scaffold to reproductive structures.

Previous research in Dr Atala's lab has shown that once cell-seeded scaffolds are implanted in the body, nerves and blood vessels form and the cells expand and form tissue.

At the same time the scaffolding material is being absorbed by the body, the cells lay down materials to form a permanent support structure – gradually replacing the engineered scaffold with a new organ.

Follow-up testing on the lab-engineered vaginas showed the margin between native tissue and the engineered segments was indistinguishable.