Korean scientists propose novel way to treat damaged cartilage.

Researchers have invented a magnetic microbot that delivers stem cells to damaged cartilage in the knee, a discovery that could lead to treatments that prevent debilitating osteoarthritis.

The device was tested in animals, but the authors, led by Eunpyo Choi at the Korea Institute of Medical Microrobotics in Gwangju, Korea, are aiming to get approval for clinical trials in humans.

The knee is lined with a glossy coat of hyaline cartilage that smooths and lubricates the hinge joint. But the cartilage is easily damaged in sporting injuries and through general wear and tear.

The result can be bone scraping on bone and painful osteoarthritis, eventually leading to a joint replacement – the incidence of knee cartilage damage nearly tripled between 1996 and 2011, with the number of knee replacements projected to grow 85% by 2030.

There are treatments that try to repair the defect and slow the progression to arthritis, although none comes up to snuff.

One involves drilling into the bone to stimulate the bone marrow to make more cartilage. But it produces an inferior grade called fibrocartilage that doesn’t stand up to the mechanical stresses.

Scientists are also experimenting with mesenchymal stem cells, sourced from the person’s fat or bone marrow and put into the cartilage defect. The problem is when you inject the cells into the knee, they mostly float away in the fluid that fills the joint during surgery.

The current research, published in Science Robotics, offers an ingenious way of targeting the stem cells at the injured bit of cartilage and keeping them there.

Read the full story in Cosmos magazine here