Getting cells to grow in lab dishes and form three-dimensional shapes instead of flat layers has been a major obstacle in efforts to build artificial tissue and organs.
The solution may be a technique called "micromasonry," where living cells are encapsulated in cubes, arranged into three-dimensional structures and held together with a gel-like material, according to a paper published on the web in Advanced Materials.
Developed by researchers at the Harvard-MIT Division of Health Sciences and Technology, the technique involves transforming living cells into tiny blocks dubbed "biological Legos." According to a news release:
Researchers built their "biological Legos" by encapsulating cells within a polymer called polyethylene glycol (PEG), which has many medical uses. Their version of the polymer is a liquid that becomes a gel when illuminated, so when the PEG-coated cells are exposed to light, the polymer hardens and encases the cells in cubes with side lengths ranging from 100 to 500 millionths of a meter.
Once the cells are in cube form, they can be arranged in specific shapes using templates made of PDMS, a silicon-based polymer used in many medical devices. Both template and cell cubes are coated again with the PEG polymer, which acts as a glue that holds the cubes together as they pack themselves tightly onto the scaffold surface.
After the cubes are arranged properly, they are illuminated again, and the liquid holding the cubes together solidifies. When the template is removed, the cubes hold their new structure.
Photo by Javier Gomez Fernandez/MIT