Mussel-inspired adhesive prevents organ rejection

A new technology has been developed to suppress immune rejection, the biggest challenge in organ transplantation, without causing systemic side effects. A research team from Pohang University of Science and Technology (POSTECH) and Ewha Womans University has developed the "Immune-Shield" technology, which directly sprays immunosuppressants onto the surface of organs using mussel-derived adhesive protein.

These findings were recently published in the Journal of Controlled Release, an international academic journal in the fields of pharmacology and drug delivery.

Organ transplantation is the most effective treatment for restoring organs damaged by accidents or diseases. However, there is a critical global shortage of transplantable organs. While xenotransplantation-the transplantation of animal organs into humans-has gained attention as an alternative, immune rejection remains a major challenge, as the human immune system recognizes transplanted organs as foreign invader.

To prevent this, patients must continuously take immunosuppressants. However, oral or injection-based administration distributes the drugs throughout the body, which can lead to serious side effects such as kidney toxicity and increased risk of infection. This paradoxical situation repeats itself: drugs intended to preserve organs actually weaken the patient's immune system.

The research team, led by Professor Hyung Joon Cha (Department of Chemical Engineering and School of Convergence Science and Technology) at POSTECH, along with Ph.D. candidates Sangmin Lee and Hyun Tack Woo, Dr. Geunho Choi, and Professor Kye Il Joo of the Department of Chemical Engineering and Materials Science at Ewha Womans University, focused on delivering drugs directly to transplanted organs rather than systemically throughout whole body.

The research team developed a technique that leverages the principle of mussels' strong adhesiveness even underwater to directly attach microscopic gel particles containing immunosuppressants to the surface of organs. This method involves coating the surface of biological tissues using adhesive microgels, which the team named "Immune-Shield."

The "Immune-Shield" is applied via a spray method. This system stably coats even wet organ surfaces, and the microgels remain on the surface to slowly release the immunosuppressant. By forming an invisible protective layer on the organ, the system ensures the drug is delivered specifically to the transplant site instead of spreading through the bloodstream to the rest of the body.

In xenotransplantation experiments, the application of the "Immune-Shield" significantly reduced immune cell infiltration and inflammatory responses, significantly extending the survival of transplanted tissues. This finding is significant in that it demonstrated that an immunosuppressive effect was more than twofold higher than that of conventional drug delivery methods.

We propose a strategy to solve the long-standing challenge of immunosuppressants by using mussel adhesive protein, an original biomaterial developed in Korea. Since the spray method allows for easy application to complex organ surfaces, it is expected to serve as a key technology to increase the success rate in the field of xenograft transplantation in the future."

Hyung Joon Cha, Study Lead and Professor, Pohang University of Science & Technology