Human knees are notoriously vulnerable to injury or wearing out with age, often culminating in the need for surgery. Now researchers have created new hybrid bioinks that can be used to 3D print structures to replace damaged cartilage in the knee.
The meniscus is the rubbery cartilage that forms a C-shaped cushion in your knee, preventing the bones of your upper and lower leg from rubbing against each other. This stuff is susceptible to damage from sports injuries, but can also wear out with age – and if it gets particularly bad, sometimes the only thing left to do is surgically remove some of the damaged meniscus.
For the new proof-of-concept study, researchers at the Wake Forest Institute for Regenerative Medicine (WFIRM) demonstrated a new method for 3D bioprinting that creates both the cartilage and the supporting structures. The team used the Integrated Tissue and Organ Printing System (ITOPS), which has been used in past studies to print complex tissues such as bones, muscles and even ears.
This time, the researchers used several bioinks together to print the entire fibrocartilage tissue layer by layer, in an interleaved crosshatch pattern. The first was a composite gellan gum and fibrinogen ink, which encourages the body’s own cells to repopulate. The second bioink is a silk fibroin methacrylate, which helps keep the structure strong and flexible.
In lab tests using pig cells, the team found that the cells were able to proliferate and remain viable, while the structure itself stayed biomechanically sound. Follow up experiments involved implanting the printed structures into mice, and observations during the 10 weeks after surgery showed that the mice began to regenerate their own fibrocartilage as hoped.
The team says that more studies will need to be conducted to investigate what kinds of responses the body might have to the implant, whether it restores function to the joint, and of course whether the results translate to humans.
The research was published in the journal Chemistry of Materials.
Source: WFIRM
But this looks less invasive and back what you doing in no time.
My implants are titanium, and were done by a proven and highly respected surgeon and the outcome is successful despite the long recovery period. It was six months before I could function normally, despite ongoing pain, stiffness. The worry is rejection of the foreign bodies in the knee, and clotting which causes DVT. They had me up and walking so as to stimulate blood circulation in the leg. I had heard about walking the next day, suggesting that the procedure is a cakewalk, but I learned that the effort is supreme, the pain huge, and the intent is to get blood flowing again.
Having experienced this, I wouldn't want an experimental procedure when the degree of intrusion seems similar and where a revision would be required if it didn't work.
The concept of having meniscus regrow is exciting and promising, but I've been told by two surgeons that this just doesn't happen. Considering knee movement and imposed body weight, how could meniscus reform?