The technique employs a new dish – crafted from a sugary substance long used in science laboratories – that allows cells to self-assemble naturally and form so-called microtissues.

“It’s a new technology with a lot of promise to improve biomedical research,” said Jeffrey Morgan, a Brown professor of medical science and engineering. He conceived and created the 3-D Petri dish with a team of Brown students.

The clear, rubbery dish is made from a water-based gel made of agarose, a complex carbohydrate long used in molecular biology. This gel is porous, allowing nutrients and waste to circulate, the scientists explain. And, it is non-adhesive, so cells won’t stick to it. At the bottom of the dish sit 820 tiny recesses or wells. When cells are added to the dish – about 1 million at a time – roughly 1,000 sink to the bottom of each well and form a pile. These close quarters allow cells to self-assemble, or form natural cell-to-cell connections, a process not possible in traditional Petri dishes.

The result: microtissues consisting of hundreds of cells, even of different types. The Brown team describes how they combined human fibroblasts, which make connective tissue, and endothelial cells, which line the heart and blood vessels. The cells came together to form spheres and doughnut-shaped clusters. The process was quick – self-assembly took place in less than 24 hours.

Differences in culture techniques matter in biomedicine, according to a growing body of research. Studies show sometimes dramatic differences in the shape, function and growth patterns of cells cultured in 2-D compared with cells cultured in 3-D. For example, nerve cells grown in 3-D environments grew faster, had a more realistic shape and deployed hundreds of different genes compared to cells grown in 2-D environments.; Source: Brown University