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 study senior investigator and biomedical engineer Paulo Coelho, Dr. Leonard I. Linkow Professor at NYU Dentistry and a professor in the Hansjörg Wyss Department of Plastic Surgery at NYU Langone Health. “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,” adds Coelho.
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. The ceramic implants contain beta tricalcium phosphate, which is similar to components in natural bone, making the implants resorbable over time. They are also coated in dipyridamole, a blood thinning agent that stimulates bone growth and attracts bone stem cells to the implant. “Dipyridamole has proven to be key to the implant’s success,” says study co-investigator Bruce N. Cronstein, the Dr. Paul R. Esserman Professor of Medicine at NYU School of Medicine, who perfected the drug’s use during device testing. Used for more than a half-century to prevent blood clots and treat stroke, dipyridamole has a long-standing safety record, says Cronstein. “And because the implant is gradually resorbed, the drug is released a little at a time and locally into the bone, not into the whole body, thereby minimizing risks of abnormal bone growth, bleeding, or other side effects.”