Organ Repair, Not Replacement

Fully implantable 3-D printed organs may be a long way off but researchers are already taking steps in that direction. But before patients start getting their artificial organs out of a printer they'll have a chance to let 3-D printing fix the organs they already have.

Thanks to researchers at Harvard Medical School's Wyss Institute major heart attack sufferers may have a viable alternative to a full-on heart transplant. The researchers have used 3-D printing to create artificial cardiac tissue that could someday be implanted in patients. These “MeTro” hydrogels incorporate a protein called tropoelastin, which is found in all elastic human tissues and can be fabricated in about a minute. Using the gels, researchers were able to grow working heart cells that can function when printed in both 2-D and 3-D structures. The team's next step is to see if the MeTro gels will effectively regenerate heart tissue in the artery of a sheep. The hope is that MeTro gels could be used to engineer new heart valves or to model cardiac diseases. 

Cochlear implants restore hearing by placing an electrode and microphone directly into the inner ear. However, placing the implant is a very delicate operation that can result in further damage if done incorrectly. German company Laser Zentrum Hannover e.V. (LZH) is building a better cochlear implant using laser-additive manufacturing. 3-D printing lets the company produce tiny cochlear implant electrodes made of nickel-titanium shape memory alloys, (NiTi-SMA). Using NiTi-SMA allows for creating customized implants that can change shape when heated to make insertion easier and deeper for further improving patient hearing.

Blindness often results from a loss of cells in the retina. Replacing these cells could hold the key to slowing the onset of blindness or halting it altogether. Researchers at the University of Cambridge are using piezoelectric inkjet printers to created cell-based structures derived from a rat's retinal ganglion cells (RGC) and glia. Testing showed the cells were healthy and also retained their ability to grow in a culture. With more research this technology could be used for retinal repair and for cell grafts for other nervous system cells as well.