In a new study, researchers have successfully used live-cell, genetically engineered pig skin (xenograft) for the temporary closure of a burn wound.
Through an FDA-cleared phase one clinical trial led by, this procedure marks the first-time pig tissue derived from an animal with gene edits has been transplanted directly onto a human wound.
The research was done by burn specialists at Massachusetts General Hospital (MGH)
Human cadaveric skin—or allografts—obtained from national skin banks is a standard of care for a deep second and third-degree burns to temporarily close massive burn wounds.
Cadaveric skin, as with other organs, is often subject to national shortages, expensive and requires strictly regulated tissue banks for processing.
The cadaveric skin allows time for the patient to stabilize and it protects the underlying wound while the patient awaits permanent closure with their own skin.
To address these issues, the team designed and implemented the safety protocols for the special live pig tissue graft, known as xenoskin.
The genetic modifications of these particular swine remove a gene-specific to pigs and not present in humans, allowing the pig skin to appear less foreign to the human immune system.
During the procedure, a 5-by-5-centimeter piece of genetically engineered pig skin was placed on the recipient’s burn wound after it had been cleared of necrotic tissue.
The pig skin graft was placed next to a much larger piece of cadaveric skin and both were secured with surgical staples and gauze bandages.
Five days later, surgeons removed the temporary cadaveric skin and xenograft. Both skin grafts were adherent to the underlying wound bed and appeared indistinguishable from each other.
No adverse events were further observed or reported and the wound was then treated further with a skin graft harvested from the patient’s own thigh. Healing has progressed as anticipated and the patient will soon return to work.
Analyses show no transmission of porcine endogenous retroviruses, or PERVs, which have always posed a theoretical roadblock for the transplantation of pig tissues or organs transplanted into human recipients.
The team says this small step represents a massive number of hours spanning decades of research in a multitude of fields including transplantation biology, immunology and genetic engineering.
Additionally, rapid advancements in gene-editing technology open a vast new avenue for genetically modifying pig skin that isn’t rejected, representing the next chapter in standards of care for burn and transplant patients alike.
The leader of the study is surgeon Jeremy Goverman, MD, of the MGH Sumner Redstone Burn Service.
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