Millions of people suffer from knee cartilage problems, either from arthritis or an injury. Thanks to WFIRM (Wake Forest Institute for Regenerative Medicine), scientists developed a method to bioprint a type of cartilage that could eventually restore knee functions damaged by injury or arthritis.
The cartilage known as fibrocartilage helps tendons, bones, and ligaments primarily found in the knee’s meniscus, which is the tough, rubbery cartilage that forms a C-shape cushion that acts as a shock absorber. It prevents the bones of your lower and upper legs from rubbing against each other.
Over time old injuries and normal wear and tear erode the cartilage. It results in painful bone-on-bone friction, which may feel like a clicking, grinding, or grating sensation, as well as stiffness in your joints. Ultimately simple movements could be painful.
Arthroscopic or keyhole surgery is one of the most common orthopedic operations currently performed. There is a shortage of available therapies besides surgery.
This surgery is a minimally invasive surgical procedure performed using an arthroscope, an endoscope inserted into the joint through a small incision. However, it is still considered a major surgical procedure, which involves risks, and requires appropriate postoperative rehabilitation. The recovery period is probably about six weeks.
The scientists have now been able to develop a new method for 3D bioprinting, which creates both the supporting structures and the cartilage.
The team used the (ITOPS) Integrated Tissue and Organ Printing System used previous studies to print complex tissues, such as muscles, bones, and ears.
The method deposits biodegradable and plastic-like materials to form the tissue “shape” and bioinks that comprise the cells to produce new tissues and organs.
An associate professor at WFIRM and author of the paper recently published by Chemistry of Materials journal Sang Jin Lee, Ph.D., said the results demonstrate that this bioprinted construct allows a versatile and encouraging alternative production of this type of tissue.
In this study, Lee and the WFIRM team tested various formulas and measured responses applied to forces, stresses, and the swelling ratio of the material flexibility and strength. One presented the proper cellular microenvironment to maintain the cells and help them to grow, while the other bioink offered excellent biomechanical performance and structural integrity.
The concluding formula of the two bioinks used was co-printed layer by layer to create a mesh-like pattern. The constructs were embedded into a small animal model for observation for ten weeks and assessed at intermittent periods, showing proper function.
James Yoo, MD, Ph.D., also a professor at WFIRM, said a more extensive preclinical study is needed to further examine the body’s functions and responses to the joint’s recovery using this regenerative medicine treatment.
Anthony Atala, MD, director of WFIRM, said there is a great need for effective treatments and therapies to help people deal with degenerative joint problems, especially the knee.
This proof-of-concept study helps point their work in the right direction, and someday, they will be able to engineer this critical tissue that is so valuable.
Journal Reference: Chemistry of Materials.