The Lancet simultaneously publishes the results of two pioneering projects in reconstructive surgery. Using similar techniques, scientists in Switzerland have engineered human cartilage, while teams in the US and Mexico have grown artificial vaginas.
The area of the body most affected by skin cancer is the nose, due to its cumulative exposure to sunlight. When removing skin cancers, surgeons also have to cut away cartilage from the patient's nasal septum, ear or rib to use as grafts for reconstructing the area where the tumor was. But this is a painful procedure involving major surgery, which also comes with attached complications.
At the University of Basel in Switzerland, a team of scientists led by Prof. Ivan Martin has broken new ground in perfecting an alternative approach.
The team extracted cartilage cells (called "chondrocytes") from the patients' septum. Then, by exposing the cells to growth factors, they were able to multiply them. The multiplied cells were then seeded onto collagen membranes and cultured for an additional 2 weeks.
This process generated 40 times as much cartilage as had been originally harvested from the patient. The engineered cartilage was then shaped according to the defect and implanted.
One year later, the five patients who received this procedure all report that they are happy with the appearance of their nose, that they are able to breathe normally and have not encountered any subsequent side effects.
Routine adoption of these procedures 'is still rather distant'
However, Prof. Martin admits "the use of these procedures in the routine clinical practice is still rather distant," as rigorous testing in patients is required, as well as the development of business models to guarantee cost-effectiveness.
"There are difficult challenges to address to translate the above protocols in a clinical trial," Prof. Martin told Medical News Today. "Currently, only a few reference teams have access to certified production facilities and associated personnel for the generation of cell-based transplant products."
Despite this, a parallel clinical study is currently underway at Basel, repairing cartilage in the knee. "Eight patients have been treated so far," Prof. Martin informed us, "with very promising results."He also thinks the technique has other applications, including joint lesions that affect cartilage surface and the underlying bone.
"Tissue-engineered cartilage grafts could be used for reconstructive purposes not only on the nose, but also for other facial reconstructions such as ear or eyelid," he added.
Fully functional vaginas, lab-grown in 4-6 weeks
The scientists from these studies have "addressed some of the most important questions facing translation of tissue engineering technologies."
On the other side of the globe, Prof. Anthony Atala, from Wake Forest School of Medicine in Winston-Salem, NC, has been leading a team pursuing similar techniques to craft artificial vaginas.
The recipients of the team's treatment are four females aged between 13 and 18, who have a condition called Mayer-Rokitansky-Küster-Hauser syndrome. Women with this condition have underdeveloped or absent vaginas.
A vulvar tissue biopsy was obtained from each patient. Similar to the nasal reconstruction, Prof. Atala's team used the biopsied tissue to grow smooth muscle cells and vaginal epithelial cells in their lab. The cells were placed onto vagina-shaped biodegradable scaffolds and left to grow.
"It took a total of 4 to 6 weeks from the time of the biopsy until the time the engineered organ was implanted," Prof. Atala told Medical News Today. "The cells were in culture for 3 to 5 weeks. After the vagina-shaped scaffold was coated with cells, it was incubated for 7 days before implantation."
Now, 8 years after implantation, all of the recipients - who are sexually active - report that they feel no pain or encounter any sexual dysfunction.
Prof. Atala believes this technique has many advantages over other options for vaginal reconstruction. Other reconstructive methods involve using non-vaginal tissue - such as segments of large intestine or skin - as grafts, which can lead to complications including infection and graft shrinkage.
"The same strategies we used for the vaginal organ have previously been used for the bladder and for urine tubes," he told us. "Theoretically, this strategy could be applied to almost any area of the body, though complex organs such as the liver and kidney will definitely be more challenging than tubular or hollow structures."
In a linked comment, Prof. Martin Birchall, of University College London Ear Institute, London, UK, writes:
"These authors have not only successfully treated several patients with a difficult clinical problem, but addressed some of the most important questions facing translation of tissue engineering technologies."
Written by David McNamee