A stretchy new fabric made by linking together the proteins found in muscle tissue could provide a scaffold for growing new organs. It could also be used as a coating for bandages to help wounds heal quickly and with less scarring. The fabric was made in the laboratory of Kevin Kit Parker, a professor at Harvard’s School of Engineering and Applied Science.
When the body grows new tissue, cells secrete fibronectin–a strong, stretchy type of protein that acts as a supportive scaffold. The shape and structure that fibronectin adopts directs the subsequent growth of new cells, giving the resulting tissue the correct form.
Parker’s team creates the fabric by depositing fibronectin molecules on top of a water-repelling polymer surface. This causes the proteins, which are normally bundled up, to unravel. Next, the protein layer is stamped onto a dissolvable, water-attracting polymer sheet on top of a piece of glass. Adding water and warming the mixture to room temperature makes the proteins link together to form the fabric. It also dissolves the polymer so that the fabric can be peeled away and collected.
The team made swatches of material 10 nanometers thick and about 2.5 centimeters wide. The researchers can control the architecture and mechanical characteristics of the fabric by using different proteins, or changing the way they are aligned.
Different research groups are developing ways to grow replacement tissue in the lab, but a big challenge is providing the right direction for the growth of new cells. Researchers have previously made cellular scaffolds by flushing the living cells from harvested livers and hearts, and by creating cellular skeletons made from polymers.
By building the new scaffold from the protein up, Parker’s team can program direction cues into the architecture of the scaffold, and thus direct the growth of cells in the desired direction. Using natural proteins rather than synthetic polymers or decellularized organs reduces the likelihood that the new tissue will be rejected once it’s implanted.