Shape-Shifting Gel Aids 3D-Printed Organ Growth

New material helps miniature lab-grown organs develop in a more predictable way, enabling better study of disease.

Mar. 14, 2026 at 11:10am by Ben Kaplan

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Scientists at UC San Francisco have created a new material that helps miniature lab-grown organs, called organoids, grow in a more predictable way. They mixed microparticles of alginate, a complex carbohydrate derived from algae, into Matrigel, the standard gel used to grow organoids. This made the gel more akin to the soft but supportive womb-like environment that tissues normally grow in and enabled the team to 3D print stem cells into precise shapes in petri dishes before they began to mature. The improved growing conditions could one day help with the manufacture of replacement human tissues.

Why it matters

Miniature organs grown in the lab can organize themselves into complex shapes, which enables scientists to use them to study disease. However, the organoids never develop the same way twice, making it difficult for researchers to repeat their experiments. The new material developed at UCSF helps organoids grow more consistently, which could lead to breakthroughs in tissue engineering and regenerative medicine.

The details

The team mixed alginate microparticles with liquid Matrigel to create a wet sand-like material that supported stem cells printed in lines or clumps. This gave the cells a consistent shape and size to build on. As the cells grew, the material loosened its grip, allowing the organoids to expand and fold into more natural forms. The method was tested with several organoid-forming tissues, including mouse intestinal and salivary gland cells, human vascular cells, and human stem-cell-derived brain cells. Printed clusters grew into healthy organoids and often matured by sprouting developmental buds. Intestinal cells printed in long lines formed tubes that could carry fluid, much like the human intestine.

  • The study was published in Nature Materials on March 10, 2026.

The players

Zev Gartner

Professor of Pharmaceutical Chemistry at UCSF and senior author of the paper.

Austin Graham

Postdoctoral fellow in Gartner's lab and first author of the paper.

UC San Francisco

The university where the research was conducted.

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What they’re saying

“What turned out to matter most was how the material relaxes over time - something we call stress relaxation. It needs to give way at the same pace that tissues are reshaping themselves.”

— Zev Gartner, Professor of Pharmaceutical Chemistry (Nature Materials)

“Liquid Matrigel is too runny to print into, and once it solidifies, it pushes back too much. We wanted a material that lets us place cells exactly where we want them but still allows them to grow and organize themselves.”

— Austin Graham, Postdoctoral fellow (Nature Materials)

What’s next

The improved growing conditions could one day help with the manufacture of replacement human tissues, for example replacing damaged tissue following a heart attack.

The takeaway

This new material developed at UCSF represents a significant advancement in the field of tissue engineering and regenerative medicine, as it enables researchers to grow miniature organs in a more predictable and consistent way, which is crucial for studying disease and developing new treatments.