Researchers at the University of Alberta have developed a method to 3D print cartilage-like materials consisting of a collagen hydrogel containing human chondrocytes. The printed structures mimic human nasal cartilage in terms of its mechanical, molecular and histological characteristics. The researchers hope the technology could lead to personalized cartilage implants for skin cancer patients who have nasal cartilage defects following surgery to remove their tumors.
The nose is a common site for skin cancer, and in many such patients, removal of the cancerous lesions will result in cartilage defects. At present, surgeons will remove cartilage from a rib and implant it in the nose in an attempt to correct such defects, but this approach has significant drawbacks.
“When the surgeons restructure the nose, it is straight. But when it adapts to its new environment, it goes through a period of remodeling where it warps, almost like the curvature of the rib,” said Adetola Adesida, a researcher involved in the study. “Visually on the face, that’s a problem. The other issue is that you’re opening the rib compartment, which protects the lungs, just to restructure the nose. It’s a very vital anatomical location. The patient could have a collapsed lung and has a much higher risk of dying.”
This new approach avoids these limitations, and involves harvesting a small amount of cartilage from the nose to extract the chondrocytes that reside within. These are then mixed with a collagen hydrogel and 3D printed into a custom shape that is specifically designed to fill the cartilage defects of that patient.
“This is to the benefit of the patient. They can go on the operating table, have a small biopsy taken from their nose in about 30 minutes, and from there we can build different shapes of cartilage specifically for them,” said Adesida. “We can even bank the cells and use them later to build everything needed for the surgery. This is what this technology allows you to do.”
The printed structures are then cultured for a period of four weeks to allow them to mature, before they can be implanted. “It takes a lifetime to make cartilage in an individual, while this method takes about four weeks. So you still expect that there will be some degree of maturity that it has to go through, especially when implanted in the body. But functionally it’s able to do the things that cartilage does,” said Adesida.
The researchers are planning to test the implants in animal models and if this is successful they hope to proceed to a clinical trial. Hopefully a version of this technology can also lead to stronger cartilage-like materials that can be implanted within joints to replace injured or worn-out natural cartilage.