The molecular systemic and local effects of intratendinous injection of Platelet Rich Plasma in tendinosis: preliminary results on a rat model with ELISA method

Abstract

showed no significant modification of their biological markers at D7, D13, D18 and D25 (p>0.22). Comparison of immunological sample tendon markers of PRPT+, PST+ and T+ groups also showed no significant modification of markers at D7, D13, D18 and D25 (p>0.16) considering each biological marker and also all subgroups confounded. Conclusion: our study strongly suggests that a single intratendinous US-guided injection of PRP in Achilles and patellar T+ doesn't increase biological markers such as growth factors compared to a control group in mid-term and long-term follow-up. KEY WORDS: tendinosis, rat, platelet, PRP, ELISA.Key Points: our goal was to assess the systemic and local molecular effect of intratendinous injection of PRP in tendinosis. We used patellar and Achilles tendinosis in a rat model with adequate controls. We precisely defined platelet, leukocyte concentrations in PRP, on a large cohort. We evaluated PRP biological molecular systemic and local effects. We provide strong evidence that PRP didn't increase biological markers, particularly growth factors, in serum and tendon dosages in PRP treated tendinosis compared to placebo group in mid-term and longterm follow-up. IntroductionTendinosis (T+) is a very common and disabling condition, resulting in impairment of quality of life. Indeed, T+ of the rotator cuff is the most common musculoskeletal cause of shoulder pain in the general population, mainly women between 40 and 65 year old in Europe whereas Achille's T+ affects 5-6% of the general population, especially young men in North America. In most cases, this condition progresses to a disabling pain or tendon rupture 1,2 . The healthy tendon is composed of type 1 collagen and a few elastic fibers, within a ground substance containing cells (tenocytes and tenoblasts) and water. In case of T+, histology mainly shows thinned and disorganized collagen fibers and increased interfibrillar glycosaminoglycans deposition with production of prostaglandins [PGE2, Interleukines (IL6, IL1B), cyclooxygenase (COX2) and matrix metalloproteinase SummaryPurpose: the aim of our study was thus to quantify the effect of Platelet Rich Plasma (PRP) injection on systemic and local growth factors and to identify molecular markers in a rat model of patellar and Achilles tendinosis treated with PRP. Material and method: twenty two rats were used for the study. Two healthy rats were used as control (T-). We induced tendinosis (T+) in 20 rats (80 tendons by injecting under ultrasonography (US) guidance Collagenase 1® (day 0 = D0, patellar=40 and Achilles=40). At D3, these 20 rats with tendinosis were separated in treatment by either PRP (PRPT+, n=28), physiological serum (PST+, n=28, control) USguided intratendinous injection, or without no PRP or PS (T+, n=24, control of natural evolution of tendinopathy). Follow-up at D7, D13, D18 and D25 using serum sample and local tendon removal with ELISA technics and comparison between the 3 groups were performed. Results: during biological follow up, comparison of all serum samples of P...

Efficacy of autologous leukocyte-reduced platelet-rich plasma therapy for patellar tendinopathy in a rat treadmill model

“…As the animal model for the patellar tendinopathy, it was suggested that a model prepared using a repetitive running exercise on a rodent treadmill machine pathophysiologically reproduced well an actual tendinopathy compared to the collagenase-induced model, since there was no inflammation reaction in/around the tendon in actual tendinopathy although the inflammation was observed in/around the tendon in the collagenase-induced tendinopathy and the clinical tendinopathy was pathogenetically induced with the over-use and/or over-load stress like a repetitive running exercise for a long distance [18][19][20][21] . The previous basic researches described above and also the current animal study 22 were performed using the collagenase-induced model and there was no examination, which examined the therapeutic effect of PRP for the tendinopathy in an animal model prepared using a repetitive running exercise on a rodent treadmill machine to our knowledge at the present. We have experienced to make this animal model and have examined the study using the rat tendinopathy model prepared by a repetitive running exercise 23 .…”