What are tendons? What is the function of tendons?
Tendons are connective tissues which are rich in extracellular matrix fibers. The main function of tendons is to transfer mechanical forces from muscle to bone, which enables movement. These tissues are essential for locomotion and often transmit large physical forces between muscle and bone, which makes tendons particularly vulnerable to injury [1, 2].
Tendon injuries may occur in any part of the body that contains tendons, with the most commonly affected joints being the shoulders, elbows, ankles, knees, and fingers. Unfortunately, tendon injuries are quite common, accounting for up to 50% of musculoskeletal injuries in the United States [3].
Tendon Injury
Tendon damage can occur due to a variety of reasons. Acute tendon injuries may result from lacerations that cut through the tendon, or from injuries sustained playing contact sports such as football, wrestling, and rugby. Chronic injuries, on the other hand, often occur due to overuse and age-related tendon degeneration, which triggers inflammation, further weakening, and potential rupture [2, 3].
In response to injury, mammalian tendons often heal slowly and imperfectly due to their poor vascularization and cellular composition. The repair process often results in disorganized fibrotic scar tissue with reduced biomechanical function compared to the healthy tendon, which can leave patients with a weaker tendon that is more likely to re-rupture and may increase the chances of developing degenerative tissue conditions [1].
Treatments for Tendon Injury
Tendon repair surgery is often performed to treat torn or severely damaged tendons. The primary goal of surgery is to repair tendon structure and restore functionality [4, 5]. However, such repair is often imperfect and many patients fail to regain full tendon function. Moreover, re-rupture of the tendon often occurs following surgery [5]. As such, many researchers have sought novel treatment methods to repair damaged tendons [6].
Recent therapeutic advances include treatments such as gene therapy, stem cell therapy, platelet-rich plasma (PRP) therapy, growth factor therapy, and tissue engineering. These therapies aim to enhance tendon repair by applying stem cells, growth factors, natural and/or artificial biomaterials to promote tissue regeneration and functional restoration [6].
Despite such advances, managing tendon injuries remains a clinical challenge. As such, many current research efforts are geared towards developing novel therapeutic approaches to improve treatment outcomes [6].
Peptides: Properties, Physiological Functions, and Potential Applications
What are peptides?
Peptides are short chains of amino acids, whose length can range from 2-50 amino acids [7]. Peptides are smaller than proteins, but nonetheless play crucial roles in various biological processes. Peptides can act as hormones, neurotransmitters, and/or growth factors, which allows them to regulate a diverse range of physiological functions [7]. By binding to cognate cell surface receptors or intracellular molecules, peptides can trigger various intracellular pathways, making them an integral part of many biological mechanisms and healing processes.
Peptides for Tendon Repair
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