---
title: "UCSF researchers develop composite to standardize organoid development"
url: https://www.voxelmatters.com/ucsf-researchers-develop-composite-to-standardize-organoid-development/
date: 2026-03-16
modified: 2026-03-15
lang: en
author: "Joseph Caron-Dawe"
description: "Scientists at the University of California, San Francisco have developed a new biomaterial that enables 3D printing of stem cells into precise configurations within petri dishes. The development addresses a..."
categories:
  - "Bioprinting"
  - "Medical Research"
tags:
  - "future"
image: https://www.voxelmatters.com/wp-content/uploads/2026/03/UCSF-cells_01-e1773618396369-640x401.jpg
word_count: 384
---

# UCSF researchers develop composite to standardize organoid development

Scientists at the University of California, San Francisco have developed a new [biomaterial](https://www.voxelmatters.com/wearable-biomaterial-inks-developed-by-researchers/) that enables [3D printing of stem cells](https://www.voxelmatters.com/cellink-3d-printed-stem-cells-space/) into precise configurations within petri dishes. The development addresses a longstanding reproducibility problem in [lab-grown organ research](https://www.voxelmatters.com/3d-biolabs-demonstrates-new-approach-for-producing-organs/).

Organoids, which are miniature lab-grown organs capable of self-organizing into complex structures, are valuable tools for studying disease. Their unpredictable development, however, has made experimental reproducibility difficult.

The UCSF team wanted to address this by mixing microparticles of alginate, a complex carbohydrate derived from algae, into Matrigel, the standard gel medium used to culture organoids. The resulting composite behaved more like the soft, supportive environment in which tissues develop naturally, and allowed stem cells to be printed into defined shapes before maturation began.

The key property of the new material was its stress relaxation profile — its ability to gradually yield as developing tissue exerts force on its surroundings.

[![UCSF researchers develop composite to standardize organoid development](https://www.voxelmatters.com/wp-content/uploads/2026/03/UCSF-cells_03-640x640.jpg)](https://www.voxelmatters.com/wp-content/uploads/2026/03/UCSF-cells_03.jpg)

[![UCSF researchers develop composite to standardize organoid development](https://www.voxelmatters.com/wp-content/uploads/2026/03/UCSF-cells_02-640x640.jpg)](https://www.voxelmatters.com/wp-content/uploads/2026/03/UCSF-cells_02.jpg)

“What turned out to matter most was how the material relaxes over time — something we call stress relaxation,” stated Zev Gartner, PhD, Professor of Pharmaceutical Chemistry at UCSF and senior author of the research paper. “It needs to give way at the same pace that tissues are reshaping themselves.”

Standard Matrigel alone proved unsuitable for bioprinting. “Liquid Matrigel is too runny to print into, and once it solidifies, it pushes back too much,” said Austin Graham, PhD, a postdoctoral fellow in Gartner's lab and first author of the paper. “We wanted a material that lets us place cells exactly where we want them but still allows them to grow and organize themselves.”

The alginate-Matrigel mixture produced a wet sand-like consistency that held printed cell clusters in position while loosening as growth progressed. The team validated the method across multiple tissue types, including mouse intestinal and salivary gland cells, human vascular cells, and human stem-cell-derived brain cells. 

Intestinal cells printed in linear configurations formed fluid-carrying tubes resembling the structure of the human intestine.

“We're not building tissues like Legos,” Gartner said. “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.”

The researchers said the approach could eventually support the manufacture of replacement human tissues, including for cardiac repair following a heart attack.