Stem Cells and Platelet-Rich Plasma Enhance the Healing Process of Tendinitis in Mice

Abstract

Objective Achilles tendon pathologies occur frequently and have a significant socioeconomic impact. Currently, there is no evidence on the best treatment for these pathologies. Cell therapy has been studied in several animal models, and encouraging results have been observed with respect to tissue regeneration. This study is aimed at evaluating the functional and histological effects of bone marrow stem cell or platelet-rich plasma implantation compared to eccentric training in the treatment of Achilles tendinopathy in rats. Methods Fourty-one male Wistar rats received collagenase injections into their bilateral Achilles tendons (collagenase-induced tendinopathy model). The rats were randomly divided into four groups: stem cells (SC), platelet-rich plasma (PRP), stem cells+platelet-rich plasma (SC+PRP), and control (eccentric training (ET)). After 4 weeks, the Achilles tendons were excised and subjected to biomechanical and histological analyses (Sirius red and hematoxylin-eosin staining). Results Biomechanical assessments revealed no differences among the groups in ultimate tensile strength or yield strength of the tendons (p = 0.157), but there were significant differences in the elastic modulus (MPa; p = 0.044) and maximum tensile deformation (p = 0.005). The PRP group showed the greatest maximum deformation, and the SC group showed the highest Young's modulus (elasticity) measurement. In histological analysis (hematoxylin-eosin and Sirius red staining), there were no differences among the groups. Conclusion PRP and SC+PRP yielded better biomechanical results than eccentric training, showing that these treatments offer better tend function outcomes. This theoretical rationale for the belief that cell therapies can serve as viable alternatives to current treatments chronic fibrotic opens the door for opportunities to continue this research.

Molecular and Structural Effects of Percutaneous Interventions in Chronic Achilles Tendinopathy

“…During the course of tendinopathy, the tendon has altered elastic properties and less tensile strength. The impact of PRP on mechanical properties is not well established in animal studies because the results are contradictory across studies: the parameters were either improved [ 37 , 39 , 41 ] or unchanged [ 36 , 42 ] ( Table 1 ).…”

“…A few studies on their use in animal models of tendinopathy are now available ( Table 3 ). Several types of stem cells have been used: bone marrow-derived MSC [ 41 , 57 ], adipose-derived stem cells (ASCs) [ 58 ], autologous tenocytes [ 59 ], and tendon-derived stem cells (TDSCs) [ 39 , 60 ]. After their injection, MSCs derived from bone marrow and autologous tenocytes were always present at the site of collagenase injury 6 or 8 weeks later and incorporated into the ECM [ 57 , 59 ].…”

“…Finally, some authors proposed injecting stem cells combined with PRP [ 39 , 41 ]. It was hypothesized that PRP may have the ability to promote tenocyte differentiation of stem cells and could potentiate their propensity to regenerate the tendon.…”

“…However, the little data available do not allow us to conclude whether there is a synergistic effect of the two treatments because the two studies available showed opposite results. The combined injection of TDSCs + PRP reduced histological lesions of tendinopathy and improved tensile strength compared to PRP, TDSCs or the control group [ 39 ] but the combined injection of bone marrow-derived stem cells + PRP did not improve histologic scores (morphology and density of tenocytes, neovascularization, inflammatory cell infiltrate, linearity and undulation of collagen fibers, and thickness) or the mechanical strength of Achilles tendons [ 41 ].…”

The Platelet Concentrates Therapy: From the Biased Past to the Anticipated Future

“…However, because PC derivatives are able to provide both growth factors and scaffolding materials, such as easily-degradable fibrin, the triangle can be rebuilt by adding the appropriate stem cells. According to this concept, bone marrow- and adipose-derived stem cells have been examined in several preclinical studies [ 16 , 35 , 36 , 37 ]. However, at the levels of clinical research and clinical practice, such combinational treatments are limited [ 38 , 39 ].…”