- Scientists have discovered a new method to create cartilage using stem cells.
- The technique could potentially lead to the development of new therapeutics for patients with cartilage damage.
- A scaffold-free method to cartilage tissue generation using embryonic stem cells.
Cartilage cells play an essential role as cushions in joints in the human body. Healthy cartilage tissue keeps joints smooth, flexible, and pain-free. If cartilage tissue is damaged, it is likely to be irreparable. Joints can become difficult to move, and they lose their flexibility. Cartilage cannot regenerate itself naturally within the body.
After a certain period, the bones begin to rub against each other. The joints start to become stiff and inflamed unless an artificial joint is placed. The painful process signifies the inevitable development of osteoarthritis.
Cartilage injuries are common incidents; millions of patients visit hospitals across the U.S. each year for various wrist, knee, and ankle problems. The wear and tear of the articular cartilage can result in the loss of cartilage tissue and expose the bony edges, which leaves them exposed and without protection. This finally deteriorates into the most common arthritis–osteoarthritis (or degenerative joint disease). It is reported that osteoarthritis is a problem for 33.6 percent (12.4 million) of people aged 65 or older within the U.S. Given the rising number of people, particularly the elderly, who have longer lifespans, the frequency of osteoarthritis and injuries will surely increase, not just across the U.S. but worldwide.
As with other tissues that repair themselves, cartilage is not able to regenerate itself. In the event of injury, cartilage can be more difficult to repair.
Traditional Surgical Technique for Replacing Damaged Cartilage
Cartilage can be treated surgically to encourage healing and stimulate new cartilage growth. The techniques used to treat cartilage articular like microfracture, subchondral bone drill debridement, lavage, perichondral and periosteal surgery, autologous bone grafting, or autologous chondrocyte implant (ACI), and autogenetic cancellous bone-grafts have all been tried to create an entirely new chondral surface. But, these procedures are restricted to a tiny fracture or a medium-sized one and cannot regenerate genuine cartilage hyaline. However, ACI has produced positive results; however, because of the insufficient supply of chondrocytes and their tendency to differentiate into fibroblasts and degenerate in damaged cartilage and tendons, it has limited their effectiveness.
Regenerating Cartilage Tissues Using Embryonic Stem Cells
Cartilage connects the tissues found in the body with a variety of functions which include cushioning joints. When cartilage is damaged because of age and injury, it could lead to chronic illnesses like arthritis. There is no medication available to restore cartilage when it has been damaged or degraded, and surgeries on the joint are typically needed to prevent the possibility of disability. Although surgical methods are used to repair damaged cartilage injury using cartilage cells that have been cultivated from patients in the laboratory, the removal of these cells to perform the procedure could also result in further injury to the joint in question. In the future, growing cartilage created from the embryonic stem cells of humans may avoid this issue.
Stem cells have been known for quite some time to have the ability to transform into chondrocytes capable of making cartilage, so the quest was how can we harness this potential and use it to regenerate cartilage for the treatment of osteoarthritis. An international team of researchers from Stanford University School of Medicine in Stanford, California, has developed a method to do just that, using embryonic stem cells.
Chondrocytes are the sole type of cell that can be found in cartilage. They produce collagens as well as other components that form the extracellular matrix that is found in cartilage. In a procedure published by the Journal Scientific Reports, researchers differentiated human embryonic stem cells into chondrocytes and then examined how they developed in different conditions and media. The researchers then measured the growth of cartilage and the expression of genes involved in the formation of collagen.
They observed that in the ideal conditions described, they could create three-dimensional cartilage pieces that measured up to 6mm in size without the need for any scaffolding; which is a major improvement over previous efforts that were only able to grow 1mm. The cartilage was awash in chondrocytes and type II collagen, which was found throughout the extracellular matrix. This showed the cartilage had the same mechanical and structural characteristics as human cartilage.
This implies that it can be used in surgical procedures to repair cartilage damaged by injury and help restore mobility and ease the pain for patients. It is believed that it can be more effective as compared to current methods.
The study also shows that stem cells derived from fat that has been liposuctioned – could be converted into chondrocytes that make cartilage, offering a low-cost and plentiful source for stem cell treatments. The research has been published in Cell.
Adult Stem Cells
Most stem cells used in the research-based treatment of cartilage damage can be classified as adult mesenchymal stem cells (MSCs). Researchers can easily extract these stem cells from bone marrow, the bloodstream or fat tissue. MSCs can turn into cartilage, bone tendon, muscle, ligaments, or fats -in fact, just about any type of cells- depending on the kind of tissue surrounding them. This is why researchers are investigating MSCs as a part of stem cell therapies for cartilage damage.
Studies have shown that MSCs release anti-inflammatory elements that aid in healing and reducing discomfort. In injections into joints, some research suggests they can help ease swelling, pain, and loss of motion.
Stem cells are also employed to construct artificial tissue in the lab through a process known as tissue engineering. The lab-created tissue can be placed in a joint to aid in rebuilding (repairing) injured ligaments, bone, and cartilage.
Studies to date have shown that stem cell treatments utilizing the patient’s cells are likely to provide a safe treatment for cartilage damage. Most injection-based therapies use patients’ own MSCs (called autologous MSCs) obtained from bone marrow or fat. The simple release of one’s own stem cells using stem cell mobilizers, also known as plant-based stem cell enhancers; has been documented to alleviate cases of arthritis.
Certain stem cell therapies use stem cells that come from the tissues of other people (called MSCs that are allogeneic). There could be a risk when donor stem cells are utilized.