Good News guys.
but it might cost more than 10,000 colones
American Urological Association
Wake Forest Institute for Regenerative Medicine
In a “landmark development†researchers have created an “artificial penis†that has allowed rabbits with damaged penises to successfully mate. The urologists say that the procedure might one day help treat men with severe erectile dysfunction.
The technique involves a new method of tissue-engineering which enabled the team to use the animals' own cells to build the spongy tissue structure that makes up the bulk of the penis.
The functioning penises were the latest achievement of Anthony Atala and colleagues at the Wake Forest Institute for Regenerative Medicine in Winston-Salem, North Carolina, US. This is the same team that hit the headlines in April with the first bio-engineered human bladders which were successfully implanted into patients.
In the recent experiment, smooth muscle and blood vessel cells were taken from rabbits’ penises and seeded onto a collagen matrix – a scaffold-like structure upon which the tissue regenerates. This approach was pioneered by Atala and was the one used previously to grow the artificial bladders.
Mating resumed
The rabbit cells seeded on the matrix were designed to develop into the “corpora†structures – on either side of the urethra – that make up a substantial amount of the penis. The penis contains two of these sponge-like structures, which fill with blood during erection. They have a tube-like shape which can extend 20 centimetres in humans – roughly one-third of which extends inside the body.
The urologists implanted the newly engineered corpora tissue into the rabbits with penises that had had all of this tissue previously removed, and within a month the animals had resumed their mating.
The regenerated tissue also showed the same blood pressure during an erection as in normal rabbits. Moreover, the rabbits with the corpora implants could still ejaculate sperm into their mates and impregnate them. All the females delivered healthy pups from these encounters, the researchers say.
Silicone implants
Each animal received corpora tissue grown from its own cells, Atala stresses. The idea behind this is that the engineered tissue – whether in rabbits or in humans – is a perfect match and so it is not rejected by the body's immune system.
The research could lead to better treatments for erectile dysfunction in humans, he hopes, by replacing problematic tissue.
There are many popular drugs on the market for this condition, which strikes more than half of men between the ages of 40 and 70. But in more severe cases, doctors implant silicone into the penises of their patients. This however, fails to fully restore the patients’ capacity for natural erection.
Proper integration
In severe erectile dysfunction, known as corporal fibrosis, the spongy corpora tissue does not get enough oxygen and begins to get replaced by scar tissue. Growing new spongy corpora tissue for implantation could help these patients, the researchers say.
Experts caution, however, that researchers would have to establish that the engineered corporal chambers were properly integrated with the rest of the organ – this includes making sure that all the blood vessels are connected so that the new tissue functions and does not turn into scar tissue like the original tissue.
“This obviously looks promising,†comments Allen Seftel of the University Hospitals of Cleveland, Ohio, US. But he also cautions that “this is very, very preliminaryâ€.
"Landmark development"
The technique may also help people with congenital penile abnormalities or those who have lost part of the organ to cancer. To do this, however, the researchers would have to combine several bio-engineered tissues together.
“We already know how to engineer the urethra,†Atala says, which functions to pass urine and semen out of the body and is contained in the third tube-like structure in the penis, the corpus spongiosum. He said the corpora tissue was tougher to regenerate in the lab because it is not a hollow structure like the urethra.
“I think this [tissue-engineering method] is a landmark development in surgery in general,†comments Ira Sharlip, a clinical professor of urology at the University of California, San Francisco, US, who was not involved in the study.
Atala presented the new findings earlier this week at the annual meeting of the American Urological Association in Atlanta, Georgia, US.
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