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.
Gomez Fernandez and Khademhosseini used this method to build tubes that could function as capillaries, potentially helping to overcome one of the most persistent problems with engineered organs lack of an immediate blood supply. "If you build an organ, but you can't provide nutrients, it is going to die," says Gomez Fernandez, now a postdoctoral fellow at Harvard. They hope their work could also lead to a new way to make artificial liver or cardiac tissue.
Other researchers have developed a technique called organ printing to create complex 3-D tissues, but that process requires a robotic machine that is not in widespread use. The new technique does not require any special equipment. "You can reproduce this in any lab," says Gomez Fernandez. "It's very simple."
To get to the point where these engineered tissues could become clinically useful, "the short-term next step is really looking at different cell types and the viability of tissue growth," says Elisseeff. The researchers are now doing that, and they are also exploring the use of different polymers that could replace PEG and offer m
|Contact: Jennifer Hirsch|
Massachusetts Institute of Technology