Chinese scientists have successfully grown humanized kidneys inside pig embryos, marking a significant milestone for organ transplantation.
Breakthrough in xenotransplantation: Detailed in a study published in journal Cell Stem Cell on Sept. 7, the remarkable achievement represents the first time a solid humanized organ has been cultivated within another species, offering a potential solution to the critical shortage of donor organs for transplantation.
The researchers, led by Liangxue Lai from the Guangzhou Institutes of Biomedicine and Health in China, reportedly took five years to overcome the challenges of interspecies organ generation.
Why it’s important: The breakthrough represents a beacon of hope for over a quarter of the global kidney patients who have no access to healthy organs for transplantation. In the U.S. alone, over 88,000 people are currently in dire need of kidneys.
Creating human-pig chimeric embryos: The scientists utilized CRISPR gene editing to deactivate two genes crucial for kidney development in pig embryos, effectively establishing a specialized “niche.” They then introduced human pluripotent stem cells into this niche, nurturing their growth in a controlled environment.
Of the 1,820 embryos transferred into 13 surrogate sows, five were analyzed after 25 to 28 days. These embryos exhibited functionally normal kidneys, with human cells constituting an impressive 50-60% of the organ’s composition. The high percentage of human cells within the pig’s kidneys sets a remarkable precedent, potentially paving the way for further refinement of the technique.
Ethical challenges: While experts have acknowledged that the breakthrough is undeniably promising, they also point out the ethical and biological hurdles that lie ahead. To address concerns about the presence of human cells in the pig embryos’ brains, the research team said it plans to remove genes responsible for human cell differentiation into neurons and reproductive cells, mitigating the risk of uncontrolled human-pig hybridization.
Biological challenges: It is worth noting that the composition of these organs still contains pig-derived vascular cells, which could lead to rejection if transplanted into humans. The researchers acknowledged that to achieve fully functional human organs in pigs, they must continue to refine their methods.