Posts Tagged ‘wake forest institute of regenerative medicine’
World’s First Tissue-Engineered Urethras Deemed a Success
The organs were grown from the patients' own cells
The success of the transplants is a victory for the field of tissue engineering and regenerative medicine on the whole. For Professor Anthony Atala and his team at Wake Forest, it’s another feather in a crowded cap. Just last week at TED Atala printed out a biocompatible model of a human kidney on stage using a an desktop printer analog loaded with cells rather than ink. In other words, he’s kind of a regenerative medicine badass.
The recipients of the new urethras--the living tissue tubes that convey urine from the bladder--were all aged 10 to 14 at the time of the transplants and had all suffered injuries due to accident or illness. To create replacement tissues from the boys’ own cells, researchers took small samples from the boys bladders. From these samples they isolated the individual cell types they would need to regrow the urethra, then placed them on biological scaffolds custom built in the shapes needed to fit each patient.
Left to incubate for a week, the cells grew into the shape of the mesh scaffolds. They were then surgically transplanted back into the patients in place of their damaged tissues. Six years later, independent medical evaluators say the boys are all healthy teens with normally functioning urethras. In fact, within just three months of implant the new urethras began taking on a natural architecture within the boys' bodies.
That’s no small feat; not only did the transplants take hold and mesh with the body’s biology (keep in mind the organs were built from the boys’ own cells, so the body recognizes them as native organs), but they actually functioned like the original urethra, growing normally along with the teens’ own bodies. If the holy grail of regenerative medicine is the ability to custom build vital organs like kidneys, livers, or hearts, these fully-functioning lab-grown urethras bode well.
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Researchers Grow Miniature, Working Human Livers in the Lab
To create the mini livers, the team took animal livers and washed out the animal cells with a mild detergent, a method known as that leaves behind only the cellular scaffold that gives the organ its structure. They then piped human cells into place via the natural vessel network that remains in the liver after the decellularization process. Connected to a bioreactor – a machine that mimics the conditions inside a living body by feeding nutrients and oxygen to the organ – the human cells began to form human liver tissue, albeit in miniature stature.
The final goal of this research, of course, is to find a means to engineer donor livers in the lab to close the supply-demand gap between those who need livers for transplant and the shortage of donor organs on hand. But engineered livers could also be used to test drugs for safety and efficacy in the lab.
Animal livers have been created in the lab using this process before, but it was never clear if researchers could do the same with human cells. Now that they’ve demonstrated the ability, the next step will be to get one into a living animal and see how it functions. Then, ostensibly, they’ll try to grow larger, more complex organs equivalent to full-grown human organs. As such, the era of made-to-order livers is still a ways off. But this important step forward for bio-engineering could contribute not only to lab-grown livers, but also to other engineered tissues that are in short supply, like kidneys or pancreases.
Inkjet Cell Fabricator Prints Healing Flesh Directly Onto Wounds
The device itself consists of a tank holding a mixture of harvested skin cells, stem cells, and nutrients, and a computer-controlled nozzle that places the cells exactly where they need to go. The spray works similar to a color printer, first spraying down a layer of fibroblast skin cells as a substrate, and then blasting on a layer of protective keratinocyte cells. Both sprays also contain a slurry of some undeveloped skin cells.
In initial tests on wounded lab mice, burns treated with the cell printer healed in two weeks, compared with the usual five weeks skin grafts take to heal. Additionally, the mice with the printed-on skin showed less scarring and more hair regeneration, as the sprayed-on stem cells better incorporated themselves into all the various cell types of the burned flesh.
Successful mouse tests have driven the Wake Forest scientists onward to tests with pigs, whose skin more closely resembles that of humans. After the tests with pigs conclude, the doctors can finally move on to human trials, and eventual FDA approval. Additionally, the Wake Forest team is working with the U.S. Armed Forces Institute of Regenerative Medicine to utilize this technology on the battlefield, to print shut bullet wounds and blast damage.
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