Pictured is a 3D-printed scaffold created to help heal osteochondral injuries, held up to the camera by Rice University graduate student Sean Bittner. The initial study is a proof-of-concept to see if printed structures can mimic the gradual transition from smooth, compressible cartilage to hard bone at the end of long bones. (Photo courtesy of Jeff Fitlow/Rice University)
The possibility of 3D-printed artificial tissues to help heal bone and cartilage typically damaged in sports-related injuries to knees, ankles and elbows may be moving closer to reality, scientists suggest.
Rice University and University of Maryland researchers report their first success at engineering scaffolds that replicate the physical characteristics of osteochondral tissue — basically, hard bone beneath a compressible layer of cartilage that appears as the smooth surface on the ends of long bones.
Injuries to these bones, from small cracks to pieces that break off, can be painful and often stop athletes’ careers in their tracks. Osteochondral injuries can also lead to disabling arthritis.
The gradient nature of cartilage-into-bone and its porosity have made it difficult to reproduce in the lab, but Rice scientists led by bioengineer Antonios Mikos and graduate student Sean Bittner have used 3D printing to fabricate what they believe will eventually be a suitable material for implantation.
Their results are reported in Acta Biomaterialia, a media release from Rice University explains.
“Athletes are disproportionately affected by these injuries, but they can affect everybody,” says Bittner, a third-year bioengineering graduate student at Rice, a National Science Foundation fellow, and lead author of the paper.
“I think this will be a powerful tool to help people with common sports injuries.”
The key is mimicking tissue that turns gradually from cartilage (chondral tissue) at the surface to bone (osteo) underneath. The Biomaterials Lab at Rice printed a scaffold with custom mixtures of a polymer for the former and a ceramic for the latter with imbedded pores that would allow the patient’s own cells and blood vessels to infiltrate the implant, eventually allowing it to become part of the natural bone and cartilage.
“For the most part, the composition will be the same from patient to patient,” Bittner adds. “There’s porosity included so vasculature can grow in from the native bone. We don’t have to fabricate the blood vessels ourselves.”
The future of the project will involve figuring out how to print an osteochondral implant that perfectly fits the patient and allows the porous implant to grow into and knit with the bone and cartilage, the release continues.
“What we’ve done here is impactful and may lead to new regenerative medicine solutions,” Mikos comments.
