The use of carefully structured scaffolds to guide tissue regrowth where it would not normally happen shows considerable promise as an approach to regenerative medicine. Here is a recent example of the state of the art for nerve regrowth:
Nerve regeneration is a complex process. Because of this complexity, regrowth of nerves after injury or disease is very rare. In a new study, researchers used a combination of 3D imaging and 3D printing techniques to create a custom silicone guide implanted with biochemical cues to help nerve regeneration. The guide's effectiveness was tested in the lab using rats. To achieve their results, researchers used a 3D scanner to reverse engineer the structure of a rat's sciatic nerve. They then used a specialized, custom-built 3D printer to print a guide for regeneration. Incorporated into the guide were 3D-printed chemical cues to promote both motor and sensory nerve regeneration. The guide was then implanted into the rat by surgically grafting it to the cut ends of the nerve. Within about 10 to 12 weeks, the rat's ability to walk again was improved.
"This represents an important proof of concept of the 3D printing of custom nerve guides for the regeneration of complex nerve injuries. Someday we hope that we could have a 3D scanner and printer right at the hospital to create custom nerve guides right on site to restore nerve function." Scanning and printing takes about an hour, but the body needs several weeks to regrow the nerves. Previous studies have shown regrowth of linear nerves, but this is the first time a study has shown the creation of a custom guide for regrowth of a complex nerve like the Y-shaped sciatic nerve that has both sensory and motor branches. "The exciting next step would be to implant these guides in humans rather than rats."