Abstract Introduction Tendinopathy, a disease involving tendon inflammation and damage, results in considerable productivity and economic losses for the patient and the society. Currently available diagnosis/ treatment monitoring modalities are less efficacious and highly subjective, underlying the need for better tools. Previously, we have shown that Fourier Transform Infrared (FTIR) spectroscopy has potential in tendinopathy diagnosis/ monitoring, when combined with multivariate statistical analysis. The current study explores the spectral range that gave the best results in statistical analysis, to discover protein secondary structures associated with tendon injury and recovery that can act as markers of disease. Methods Animals (n=60) underwent a surgery in which Achilles tendon were injured by dropping a 20g weight. Rats were divided into three groups (n=20) – control (C), Achilles tendon injury (I) and Achilles tendon injury treated with amniotic membrane fragment treated (T). FTIR spectra were obtained from each group 3, 7, 14, and 28 days post injury/ treatment. Results Triple helix, β-turn, and disordered structure levels differ between control, injured and treated tendons over the time period studied. Parallel β-sheets increase steadily over time in treated tendons compared to control and injured. Conclusion Combined analysis of Triple helix, β- sheets, β-turn, and disordered structure levels may be useful for tendinopathy diagnosis and treatment monitoring. However, further studies in this area are required to confirm the findings.

Abstract Purpose: To evaluate the effect of human amniotic membrane (hAM) fragment on inflammatory response, proliferation of fibroblast and organization of collagen fibers in injured tendon. Methods: Sixty rats were divided into 3 groups: C - surgical procedures without tendon lesion and with simulation of hAM application; I - surgical procedures, tendon injury and simulation of hAM application; T - surgical procedures, tendon injury and hAM application. These groups were subdivided into four experimental times (3, 7, 14 and 28 days). The samples underwent histological analysis and ATR-FTIR spectroscopy. Results: Histological analysis at 14 days, the T group showed collagen fibers with better alignment. At 28 days, the I group presented the characteristics described for the T group at 14 days, while this group presented aspects of a mature connective tissue. FT-IR analysis showed a clear distinction among the three groups at all experimental times and groups T and I presented more similarities to each other than to group C. Conclusion: Acute injury of tendon treated with human amniotic membrane fragment showed a faster healing process, reduction in inflammatory response, intense proliferation of fibroblasts and organization of collagen fibers.