Vascularized Organoids Advance Human Tissue Modeling

Recent research has produced organoids—miniature, lab-grown versions of human organs—with integrated blood vessel networks, supporting more complex tissue structures and extended growth in laboratory settings.

Scientists at Stanford University generated heart and liver organoids from human pluripotent stem cells that include vascular systems, which allowed the organoids to reach greater size and persist longer in culture. These models contained a variety of cell types and structures that resemble early-stage human organs.

The heart organoids developed at Stanford contained between 15 and 17 distinct cell types, which researchers stated is similar to the composition of a six-week-old embryonic human heart. The team also introduced a triple-reporter stem cell line that fluoresces in three colors, enabling visualization of the formation of heart and blood vessel cells within the organoids.

Protocols have also been established to create vascularized cerebral organoids by combining brain-specific blood vessel structures with cerebral tissue, resulting in robust vascular networks and the presence of microglia-like cells. In parallel, lung and intestine organoids were produced with organ-specific blood vessels by co-differentiating endoderm and mesoderm from human pluripotent stem cells, which supports disease modeling for conditions such as alveolar capillary dysplasia.

What the numbers show

• Heart organoids included 15–17 different cell types
• Multi-region brain organoids replicated about 80% of developing brain cell types
• Brain organoids reached post-natal maturity after approximately 280 days in culture

Researchers developed brain organoid-on-a-chip devices that use signaling gradients to organize forebrain domains within a single organoid. This approach allows for topographical patterning, which can be used to study brain development in a controlled environment.

A scaffold system inspired by vascular networks, known as VID scaffolds, was created to reduce low-oxygen conditions and promote neural maturation in midbrain organoids. This method supports the development of more mature neural tissues in laboratory-grown models.

Multi-region brain organoids were engineered to combine cerebral, mid/hindbrain, and vascular components. These organoids replicated approximately 80% of the cell types found in the developing human brain and enabled the identification of new signaling pathways between vascular and brain cells.

It was also observed that brain organoids can follow an intrinsic developmental timeline in vitro, reaching a stage comparable to post-natal maturity after about 280 days in culture. This characteristic allows researchers to study human brain development over extended periods using organoid models.

* This article is based on publicly available information at the time of writing.