Tendon disease and rupture are common in patients with diabetes and these are exacerbated by poor healing. although nanoscale changes in diabetic tendon are linked to increased strength and stiffness. The resistance to mechanical damage of a tissue may be measured using fatigue testing but this has not been carried out in diabetic tendon, although the toughness of diabetic bone is known to be reduced. The aim of this study was to measure the static fatigue behaviour of tendons from a streptozotocin (STZ)-induced rat model of diabetes, hypothesising that diabetes causes tendon to show lower resistance to mechanical damage than healthy tendon. Diabetic (n=3, 12 weeks post-STZ) and age-matched control (n=3) adult male Sprague Dawley rats were culled, tails harvested and stored at −80ºC. Following defrosting, fascicles (5 per animal) were carefully dissected, mean diameter measured using an optical micrometer and mounted in a Bose Biodynamics test machine using custom grips in a PBS bath. Static fatigue testing at 30 MPa to failure enabled both elastic modulus (initial ramp) and steady state creep rate (gradient at creep curve inflexion) to be measured. Data are reported as median ± interquartile range and pw0.05 using a Mann-Whitney U test was taken as significant.Introduction
Materials and Methods
Platelet Rich Plasma (PRP) has been shown to have positive effect in tendon regeneration in in-vitro and limited in-vivo animal studies. We aim to study PRP use in acute Achilles tendon rupture (ATR) regeneration in a purposely designed clinical trial. This is a prospective double-arm patient-blinded randomized controlled trial. ATR patients were randomized into PRP treatment or control groups. Non-operatively treated patients received PRP or control injection in clinic. In operatively treated patients, PRP gel was applied in the ruptured gap during percutaneous repair. Standard rehabilitation protocol was used and patients were followed up for 24 weeks. ATR, VISA-A and FAOS scores were used as subjective outcome measures. Functional ultrasound Elastography (FUSE) was performed at each follow-up to assess the mechanical properties of tendons. PRP analysis and tendon needle-biopsy were performed to study the histological differences during healing in both groups.Purpose
Methods
The use of platelet-rich concentrate (PRC) to enhance the healing response in tendon repair is currently an area of considerable interest. Activated platelets release a cocktail of growth factors and ECM regulating molecules. Previous work suggests that tenocytes are activated by contact with these clot-derived molecules. Our studies on tenocytes and PRC aim to establish the direct molecular and functional effects of PRC on tenocytes and to support the clinical research on Achilles tendon repair taking place within our group. We hypothesise that applying PRC to human tenocytes in culture will increase proliferation rate and survival by activating relevant signalling pathways. Using a centrifugation method, PRC was extracted from fresh human whole blood. The PRC was immediately clotted and left in medium overnight to release biological factors (at least 95% of presynthesized growth factors are secreted in the first hour of activation)1. Human tenocytes derived from explanted healthy hamstring were used for up to three passages. Cells were treated with varying concentrations of PRC-conditioned medium and assessed for viable cell number (Alamar Blue™ fluorescence) and proliferation (Ziva™ Ultrasensitive BrdU assay) after 72hrs. For western blotting, cells were treated with 10% PRC for 5 or 30 minutes. Antibodies to P-ERK and P-Akt detected the active protein state on the blot, followed by membrane stripping and re-probing with pan antibodies. Quantification was achieved by densitometry using Visionworks software v. 6.7.1.Introduction
Materials and Methods
