The human knee is very sensitive to trauma and aging, which often necessitates surgical intervention. Researchers have created a new, hybrid bionic that makes it possible to 3D print and replace damaged knee cartilage.

The meniscus is a rubber cartilage that forms a kind of C-shaped “cushion” in the knee, thereby cushioning the leg bones above and below it. This area can be damaged during a sports injury, but it is also affected by aging. The condition sometimes takes on such a complex form that the only solution is surgical removal of the damaged part of the meniscus.

Researchers at the Wake Forest Institute for Regenerative Medicine (WFIRM) conducted the innovative concept study. They outlined a new method of 3D printing that makes it possible to make both meniscus cartilage and its supporting structures. The research team used the Organ and Integrated Tissue Printing System (ITOPS). The latter was used in previous studies to print such complex tissues as bones, muscles and even ears.

This time, the researchers used several bionics at once to print the complete fiber-cartilage apparatus in layers. The first layer was composed of composite gel geranium and fibrinogen ink, which pushes the body to proliferate its own cells. The second bionic was silk fiber methacrylate, which gives the whole structure strength and flexibility.

In a laboratory test, the researchers used pig cells, at which point they found that the latter could reproduce and maintain viability, while the whole structure was biomechanically stable. A further experiment was already on surgical transplantation, for which the researchers used laboratory mice. They observed the non-operative rodents for a further 10 weeks, and as it turned out, their bodies began to rebuild their fiber-cartilage apparatus, as scientists had suggested.

The group of study authors notes that the body’s response to implants and the conversion of data obtained in humans into further studies are needed.