Effects of leukocyte‑ and platelet‑rich plasma on tendon disorders based on in vitro and in vivo studies (Review)

Abstract

Tendon-related disorders are common musculoskeletal system disorders in clinical practice, accounting for 30-50% of all sports-related injuries, and they are difficult to treat due to the hypovascular structure of the tendons. Platelet-rich plasma (PRP), including pure PRP and leukocyte-and platelet-rich plasma (L-PRP), has been attracting increasing attention, as it may stimulate tissue regeneration through the release of growth factors and cytokines. The aim of the present review was to provide a summary of the effects of L-PRP on tendon disorders and the underlying mechanisms through a comprehensive examination of the published literature, including in vitro, animal and clinical studies. It has been demonstrated that L-PRP results in comparatively greater pain relief and improved function in patients suffering from tendon disorders. Furthermore, L-PRP may exert its effects through a diverse range of mechanisms, such as neovascularization, cell proliferation and differentiation of tendon/progenitor stem cells into tenocytes, as well as extracellular matrix reorganization by transforming type III to type I collagen fibers. It has also been indicated that the effects of leukocytes in L-PRP depend on the biological state of the injured tissue and its surrounding microenvironment. L-PRP is beneficial and promotes tendon healing at the early stage, whereas it is likely detrimental to the repair of tendon at a later stage because of the risk of excessive catabolic and inflammatory responses. Overall, the application of L-PRP in tendon disorders appears to be a promising field that is worthy of further research. Contents 1. Introduction 2. Effects of L-PRP on tendon healing based on basic studies 3. Effects of L-PRP on tendon healing based on clinical studies 4. Conclusion and perspectives

The Role of Vascular Endothelial Growth Factor in Tendon Healing

“…VEGF can promote angiogenesis in vivo , promoting vascular wall permeability and the growth and proliferation of vascular endothelial cells and perivascular cells, the latter of which are self-renewing and regenerative ( Molloy et al, 2003 ; Parsons-Wingerter et al, 2006 ; Wu et al, 2017 ; Peach et al, 2018 ). In addition, VEGF could also promote fibroblast proliferation, chemotactic for macrophages and granulocytes and initiate the production of other growth factors ( Zhang et al, 2003 ; Liu et al, 2021 ).…”

Biological and Mechanical Factors and Epigenetic Regulation Involved in Tendon Healing

“…The proliferation of vascular endothelial cells and perivascular cells is conducive to neovascularization, and VEGF has also been shown to stimulate the self-renewal ability of these cells, assist in angiogenesis, and improve the permeability of the neovascularization wall [56][57][58][59]. Additionally, VEGF can stimulate fibroblast multiplication and promote leukocyte chemotaxis [60,61].…”

Exokine and the Youth-Boosting Treatment Based on One's Own Serum: Wheat and Chaff

“…15 What we would like to assess is that the use of PRP is an example of "autologous orthobiologics," a biological way used in medicine and surgery to renew and recover damaged or functionally impaired tissues accounting on the regenerative potential of autologous tissue transfer, such as haemoderivatives. 32 Hemoderivatives, for example, PRP, are functionally promising agents also in musculoskeletal disorders such as tenditopathies, 33,34 involving an anatomical district where is particularly effective also ACS.…”