Dynamic Gel Boosts Lab-Grown Organ Reliability

New material helps organoids grow in a more predictable way, enabling 3D printing of stem cells into precise shapes.

Published on Mar. 11, 2026

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Scientists at UC San Francisco have created a new material that helps organoids, miniature organs grown in the lab, develop 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 environment inside the body that tissues normally grow in, enabling 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 tissues.

Why it matters

Organoids have long been seen as a promising approach for studying disease and developing new treatments, but their unpredictable growth patterns have limited their usefulness. This new gel-based material helps organoids develop more consistently, which could unlock their potential for applications like tissue engineering and regenerative medicine.

The details

The key to the new material is its "stress relaxation" properties - it needs to give way at the same pace that tissues are reshaping themselves during development. Mixing alginate microparticles with liquid Matrigel created a wet sand-like material that supported stem cells printed in lines or clumps, giving them 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 team tested the method 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.

  • The research 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

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

University of California, San Francisco (UCSF)

The university where the research was conducted, which is exclusively focused on the health sciences and dedicated to promoting health worldwide.

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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 at UCSF (Nature Materials)

“We're not building tissues like Legos. We place cells where they need to be and let their developmental programs assemble the tissue. The goal is to reach a stage where an organ begins to build itself.”

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

What’s next

The improved growing conditions enabled by the new gel-based material could one day help with the manufacture of replacement tissues for use in regenerative medicine applications.

The takeaway

This research represents an important step forward in the field of organoid development, overcoming a key limitation that has hindered the use of these miniature organs for disease modeling and tissue engineering. The new material's ability to support consistent organoid growth could unlock new possibilities for personalized medicine and regenerative therapies.