Science has recently taken a giant leap forward in trying to solve one of the biggest headaches in healthcare today: the lack of donors. A team of researchers has achieved the birth of the first cloned pig with genetic modifications specific to ensure that their organs are compatible with humans, marking a turning point in biomedical research outside the usual major powers.
In this process, three genes that usually cause the human body to immediately reject any foreign tissue have been deactivated, an advance that places this development in the select club already comprised of United States and ChinaAlthough the news originated in Argentina, the impact is global, since the technique used opens the door for research centers in Europe and Spain to replicate similar models to reduce the endless waiting lists.
Why pigs to save human lives?
The technique known as xenotransplantationHuman transplantation, which involves the transplantation of cells, tissues, or organs from an animal species into a human, has found the ideal candidate in pigs. This is not by chance, but because these animals exhibit a striking anatomical and physiological similarity to us, in addition to having a very rapid reproductive cycle that facilitates large-scale research.
The major obstacle has always been that our immune system identifies the pig organ as a complete invader and destroys it in a matter of minutes. To avoid this, scientists from the University of Buenos Aires and the University of San MartÃn have worked hand in hand with the startup CrofaBiotech, using the CRISPR-Cas9 technology to edit the DNA of piglets and make them "invisible" to our defenses.
The engineering of the Triple Knockout
What makes this specimen special is that its DNA has been designed under the concept of triple knockoutIn scientific jargon, this means that three specific genes responsible for triggering that aggressive immune response that usually ruins transplants between different species have been "switched off".
The project's success lies not only in the breeding process, but also in the fact that the animal was born and raised healthy under strict veterinary supervision. According to experts involved, such as Adrián Mutto, this milestone allows us to dream of a future where we are not exclusively dependent on the generosity of human donors, whose availability rate barely covers the ten percent of the demand worldwide according to the WHO.
A high-precision surgical procedure
The journey from the laboratory to the pigpen has been a true feat of surgical engineering. Unlike conventional insemination, in this case a minimally invasive laparotomy to implant the edited and fertilized embryos directly into the natural duct that connects the ovary to the uterus of the recipient sow.
This method allowed up to 120 edited embryos in a single procedure, ensuring a much higher success rate than traditional techniques. Marcelo Acerbo, a specialist in swine reproduction, pointed out that they are responsible for overseeing gestation and farrowing, ensuring that piglets are born in optimal conditions for their subsequent rearing in environments of maximum biosecurity.
Organs on demand and the road ahead
The next step in this ambitious project is to add even more genetic modifications, reaching a total of ten or twelve changes. This would include blocking the growth hormonesThis is essential to prevent a pig's heart or liver from growing too large inside a human body, since an adult animal can easily exceed 200 kilos in weight.
They are even working with smaller breeds, known as mini-pigs, whose organs would be perfect for pediatric patients. The ultimate goal is to establish a biosecure organ breeding facility where animals crossbreed naturally and pass these genetic edits on to their offspring, eliminating the need for individual cloning for each patient.
This research marks the beginning of a validation phase that will last several years and require extensive preclinical studies before we see the first porcine organ functioning in a human on a large scale. Current data are very promising, as preliminary tests indicate that the human immune system does not recognize the organ as foreign among the... seventy and eighty percent of the modified cells, which represents a real hope for the thousands of people who await a transplant each year.