Using an inkjet printer, researchers have succeeded in printing adult eye cells for the first time. The demonstration is a step toward producing tissue implants that could cure some types of blindness.
Scientists have previously printed embryonic stem cells and other immature cells. But scientists had thought adult cells might be too fragile to print. Now, researchers have printed cells from the optic nerves of rats, finding the cells not only survived, but also retained the ability to grow and develop.
Martin and his colleagues separated retinal ganglion cells (which transmit signals from the eye to the brain) and glial cells (which provide support and protection for neurons) from the retinal tissue of adult rats. They used a piezoelectric inkjet printer to print both types of cells into a vial at a rate of about 30 mph, or about 100 cells per second, recording the process with high-speed video. Then they performed tests to see how well the printed cells survived and grew.
Despite the shearing forces the cells experienced during printing, the printed retinal ganglion cells (also called optic nerve cells) and the glial cells appeared to survive as well as nonprinted cells. In addition, the optic nerve cells retained the ability to sprout neurites, the fingerlike filaments that form connections with other nerve cells.