Читать книгу The SAGE Encyclopedia of Stem Cell Research - Группа авторов - Страница 309

Ligaments are soft yet mechanical tissues that are capable of load bearing. They are of enormous mechanical strength, yet the regeneration process is not robust because of the decreased requirement of nutrients and oxygen for the ligament tissue. This results in the formation of weak tissue and so the regeneration of ligament has been gaining a fair amount of attention. One of the first therapy options for the purposes of regeneration is to apply biomolecules at the site of the wound. These biomolecules, such as TGF-beta and PDGF, promote the formation of ligament—inside the body. This process uses the human body as a bioreactor to generate the ligament. Some of the other options are very similar to those of cartilages and ligaments wherein stem cells are isolated from the body, differentiated in vitro, and then later applied to the site of the wound. Biomaterials and biomimetics are said to generate structure to generate the inserts of desirable shape.

Another important consideration in choosing scaffolding material in the case of ligaments is that, considering the function of ligaments, they need to be durable and strong. The load-bearing capacity of the scaffolding tissue is tested in vitro before it can be applied to the bone. Since ligaments are mostly tissue that are attached to bone and facilitate the easy movement of the joint, the shape and pliability of the scaffold are also very important. Natural and synthetic polymers can be used as scaffolds. The advantage of a natural polymer over synthetic polymer is that it offers a surface that is adherent for the cells. Natural polymers also do not release acidic chemicals on hydrolysis, but one of the significant disadvantages is that they are degradable, and once inside the body system, the degradation curve cannot be controlled as yet.

The regeneration of bone commonly involves the regeneration of soft tissues as well, because the bones and joints are held together with the help of cartilage, tendons, and ligaments. All the processes in concert with one another are required for efficient regeneration of the structural system. When a bone regenerates, the tendons and cartilage also need to regenerate to hold the structure in place. Combinations of scaffolds and different biomaterials for bone, cartilage, tendons, and ligaments are being theorized to facilitate a complete healing of the skeletal subunit.