Tens of thousands of women have mastectomies to treat breast cancer each year and a new study lends hope to the idea that reconstructive surgery could make breastfeeding possible afterward.
In experiments, researchers induced breast cells to self-assemble into aligned, ductal shapes, overcoming the "subtrate stiffness" problem in cell alignment; the stiffness of the tissue scaffold to which cells bind. They built 3-D scaffolds out of protein gel by placing the gel over silicone molds. Depending on each mold’s shape, the gel solidified into different shapes with various levels of stiffness throughout. Then, breast cells were placed on top of the gel and the researchers recorded time-lapse microscopic video of the cells’ response to the scaffold environment.
The stiffness gradient—how stiffness changed throughout the tissue scaffold—was the key driver in how cells aligned themselves, rather than stiffness itself. So they were able to organize breast cells into various structures, including continuous, long tubular shapes similar to those in breast tissues, with control of tube spacing.
“In mammalian bodies, breast cells align to form hollow tubes, where milk is transported,” says Jimmy Hsia, a professor in the departments of biomedical engineering and mechanical engineering at Carnegie Mellon University, said in a statement. “To date, no one has been able to generate breast tissue with these hollow tubes. Our study is the first step toward realizing such functionalities in reconstructed breast tissues.”