Researchers from New York University have developed implanted, chemically coated scaffolds that successfully led to bone regrowth in lab animals.
To make the scaffolds, the researchers 3D printed the material onto a platform with the printer repeating the process until 2D layers stack up into a 3D object that is then superheated into its final ceramic form.
“Our 3D scaffold represents the best implant in development because of its ability to regenerate real bone,” study senior investigator and biomedical engineer Paulo Coelho, DDS, PhD, said in a statement. “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.”
The ceramic implants closely resemble real bone in both shape and composition, surpassing other experimental bone implants where plastic elasticizes are added to make the implant flex. While it is beneficial to make the implants flex, the plastic used does not have the same healing properties as the newly developed scaffold.
The new ceramic devices are made of beta tricalcium phosphate—a compound comprised of the same chemicals found in natural bone. The devices are also coated with dipyridamole—a blood thinner that has been proven to speed up bone formation by more than 50 percent and attract bone stem cells that spur the formation of nourishing blood vessels and bone marrow within the newly grown bone.
These soft tissues lend to their scaffold-grown bone the same flexibility as natural bone.
“Dipyridamole has proven to be key to the implant’s success,” study co-investigator Bruce Cronstein, MD, the Dr. Paul R. Esserman Professor of Medicine at NYU School of Medicine, who perfected the drug’s use during device testing, said in a statement. “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.”
The researchers tested the scaffolds on small holes surgically made in the skulls of mice and missing bone pieces as long as 1.2 centimeters in rabbit limbs and jaws.
The team found that the mammal’s body resorbed 77 percent of each scaffold six months after implantation. They also observed that new bone grew into the lattice-like structural supports of the scaffold, which then dissolves. In addition, some CT scans showed almost no trace of the beta tricalcium phosphate.
Weight-bearing tests also showed that the new bone was of equivalent strength as original, undamaged bone.
Next, the team plans to test the scaffolds in larger animals and eventually conduct clinical trials, although that may not be for several years.
The study was published in the Journal of Tissue Engineering and Regenerative Medicine.