3D-Printed Implants Shown to Help Grow 'Real Bone'

Researchers have reported that chemically coated ceramic implants successfully guided the regrowth of missing bone in lab animals while steadily dissolving. Surgeons and scientists at NYU School of Medicine and NYU College of Dentistry say their implanted scaffolds were naturally absorbed by the test animals' bodies as new bone gradually replaced the devices.

Modeled after the bone pieces they are meant to help replace, the implants were assembled onsite using 3D robotic printing, a technology that uses a fine-point print head to push out a gel-like ink material. The material is printed onto a platform, and the printer repeats the process until 2D layers stack up into a 3D object, which is then superheated into its final ceramic form. Available for more than a decade, the technology has only of late been applied in medicine to print out replacement ears, skin, and heart valves.

"Our 3D scaffold represents the best implant in development because of its ability to regenerate real bone," says Paulo Coelho, DDS, Ph.D., the study’s senior investigator and a biomedical engineer. "Our latest study results move us closer to clinical trials and potential bone implants for children living with skull deformations since birth, as well as for veterans seeking to repair damaged limbs." Coelho is the Dr. Leonard I. Linkow Professor at NYU Dentistry and a professor in the Hansjörg Wyss Department of Plastic Surgery at NYU Langone Health.

The scientists say their novel ceramics more closely resemble real bone shape and composition than other experimental bone implants in which plastic elasticizers are added to make the implant flex. Although the ability to flex offers some advantages, the plastic does not have the same healing ability as NYU's scaffold.

An important feature of the ceramic devices is that they are made of beta tricalcium phosphate, a compound of the same chemicals found in natural bone that makes the implants resorbable.

One of the secrets to the rapid growth of native bone with the NYU devices is a coating of dipyridamole, a blood thinner shown in other experiments to speed up bone formation by more than 50 percent. The chemical also attracts bone stem cells, which spur the formation of nourishing blood vessels and bone marrow within the newly grown bone. These soft tissues, researchers say, lend to their scaffold-grown bone the same flexibility as natural bone.

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