Scientists Successfully Regenerate Functional Lymph Nodes in Mice

World-First Medical Breakthrough

A team of researchers from Tokyo University of Science has achieved what they describe as the world's first successful regeneration of fully functional lymph nodes through cell transplantation, potentially offering a transformative treatment pathway for the millions of cancer survivors who develop secondary lymphedema after tumour removal surgeries.

The study, published in Nature Communications in November twenty twenty-five, details a novel technique for creating bioengineered lymphatic tissue that can restore lymphatic flow after lymph node removal. The research, led by Associate Professor Kosuke Kusamori, demonstrated that transplanting the engineered tissue into mice with surgically removed lymph nodes restored normal limb function within weeks.

How the Technology Works

The method relies on what the researchers call a centrifugal cell stacking technique. Mesenchymal stem cells, known for supporting tissue regeneration, are placed in culture plates and centrifuged to form a uniform bottom layer. Lymphatic endothelial cells are then added and centrifuged to create a second layer, followed by another layer of stem cells. The result is a three-layered structure the team calls centrifuge-based bioengineered lymphatic tissue, or CeLyT.

When transplanted into mice whose lymph nodes had been removed, the bioengineered tissue integrated with the host's cells within days. The mice showed restored lymphatic flow, normalised limb thickness, recovery of immune cell populations including T cells and macrophages, and reduced fat accumulation in affected areas. Therapeutic effects persisted for at least one hundred days after transplantation.

Addressing a Growing Medical Need

Secondary lymphedema affects a substantial portion of cancer patients who undergo lymph node removal during treatment. Research indicates lymphedema incidence ranges from six to twenty-nine percent after sentinel lymph node biopsy to twenty-two to twenty-nine percent following axillary lymph node dissection. Up to forty percent of patients may develop the condition after lymph node removal, which manifests as chronic swelling, discomfort, and reduced mobility.

Current treatment options remain limited. Complete decongestive therapy, involving compression bandaging, manual lymphatic drainage, and exercise, is considered the gold standard but requires lifelong management and does not address the underlying cause. Surgical options such as lymph node transplantation exist but do not cure the condition.

Superior to Existing Treatments

The researchers found CeLyTs outperformed existing approaches. "Although compression therapy represents the gold standard for the treatment of lymphedema in clinical practice, it usually delays the swelling," Kusamori noted. "By contrast, CeLyTs were more effective at suppressing lymphedema, also exhibiting strong therapeutic effects even in a more severe chronic lymphedema model."

The tissue was also prepared using human cells, suggesting potential for clinical translation. While the research remains in animal models, it represents a potential shift from symptom management to actual functional restoration of the lymphatic system, a goal that has long eluded regenerative medicine.