Imagine if conditions that presently cause blindness could be treated by simply by fabricating new tissue, and using it to replace the defective part of the retina. We may not be at that point yet, but we've definitely taken a step closer, thanks to research being conducted at the University of Cambridge. Scientists there have successfully used an inkjet printer to "print" rats' retinal cells onto a substrate, paving the way for the creation of custom-made eye-repair material.

The researchers used ganglion cells and glial cells, from the retinas of adult rats. Retinal ganglion cells relay information from the eye to the brain, while glial cells support and protect neurons.

These cells were suspended in a carrier liquid (in separate batches, not with both types mixed together), then loaded into the reservoir of a MicroFab piezoelectric inkjet printer. From that reservoir, some of the solution was drawn into a glass capillary that narrowed down to a nozzle less than one millimeter wide. Whenever an electrical pulse was applied, cells would be jetted out of that nozzle.

Previous studies had raised concerns over whether the vibrational frequency of piezoelectric print heads could rupture cell membranes. This turned out not to be the case, however, plus the cells appeared to be unaffected by the high shear rates and acceleration they experienced in the jetting process. What's more, the cells continued to exhibit normal growth properties after being printed.

"We plan to extend this study to print other cells of the retina and to investigate if light-sensitive photoreceptors can be successfully printed using inkjet technology," says Prof. Keith Martin, who is co-leading the project with Dr. Barbara Lorber. "In addition, we would like to further develop our printing process to be suitable for commercial, multi-nozzle print heads."

A paper on the research was published yesterday in the journal Biofabrication.