UCSF Scientists Develop Algae-Infused Dynamic Gel to Enable Reliable 3D Bioprinting of Complex Human Organoids

UCSF researchers invent a new "womb-like" material that enables consistent 3D bioprinting of lab-grown organs by mimicking body tissue flexibility.

By: AXL Media

Published: Mar 12, 2026, 11:28 AM EDT

Source: Information for this report was sourced from University of California - San Francisco

Standardizing the Development of Lab-Grown Organoids

Miniature organs grown in laboratory settings, known as organoids, have long been hindered by their tendency to organize into unpredictable shapes, making them difficult to use as consistent models for studying disease. Historically, these biological structures rarely developed the same way twice, creating a significant hurdle for clinical research. However, a team at UC San Francisco has introduced a new material that provides the necessary guidance for more predictable cellular growth. By balancing support with flexibility, the researchers have discovered a method to ensure that stem cells develop with a level of structural accuracy and repeatability that was previously unattainable.

Engineering a Womb-Like Growth Environment

The technological breakthrough involves mixing microparticles of alginate—a complex carbohydrate derived from algae—into Matrigel, the industry-standard gel used for culturing cells. This mixture creates a unique "wet sand" consistency that effectively supports stem cells printed into specific shapes while they mature. Dr. Zev Gartner, a professor of Pharmaceutical Chemistry at UCSF, noted that the material's success depends on "stress relaxation," which allows the gel to loosen its grip at the same pace that the growing tissues reshape themselves. This dynamic environment mirrors the soft but supportive internal conditions of the human body, facilitating more natural development.

Overcoming the Limitations of 3D Bioprinting

While 3D printing has been used for flat biological structures like skin, it has traditionally failed to produce complex three-dimensional organoids in standard gels. Liquid Matrigel is typically too fluid to maintain printed shapes, while its solidified form pushes back too hard against expanding cells, stalling their development. Postdoctoral fellow Austin Graham explained that the team required a material that could hold cells in exact positions while still allowing them to grow and organize autonomously. The new algae-infused gel provides this critical balance, acting as a temporary scaffold that gradually gives way as the biological structure takes hold.