Scientists grow synthetic kidneys inside mice– cosmosmagazine.com

While stem cell-derived kidney organoids promise to provide patient-specific models for disease research, and may even one day produce functional tissue for regenerative medicine, researchers have not yet been able to recreate the immense complexity of the organ’s patterning and functions.

Models tend to focus on either the kidney’s nephrons – functional units which filter blood and produce urine – or its collecting ducts, which concentrate urine and transport it to the bladder.

Now, researchers have brought these together in ‘assembloids’ which are the most mature and complex kidney structures grown in the lab to date.

“This is a revolutionary tool for creating more accurate models for studying kidney disease, which affects one in 7 adults,” says corresponding author Zhongwei Li, associate professor of medicine, and stem cell biology and regenerative medicine at the University of Southern California, US.

“It’s also a milestone towards our long-term goal of building a functional synthetic kidney for the more than 100,000 patients in the US awaiting transplant – the only cure for end-stage kidney disease.”

Li and collaborators grew mouse and human assembloids from kidney progenitor cells in the lab and then transplanted them into the abdomens of living mice. There, the assembloids matured further – growing larger and developing connective tissue and blood vessels.