Osteoarthritis ( OA ) is a degenerative disease characterized by progressive destruction of articular cartilage, subchondral bone remodeling, joint space narrowing and osteophyte formation , which induces to the emergence of pain conditions and functional losses in affected individuals . Thus , it becomes important to develop technologies capable of treating and prevent the evolution of OA. Currently, low-level laser therapy ( LLLT) and chitosan has demonstrated positive effects on cartilage metabolism. However, the mechanisms of action and the effects of the combination of both treatments still require elucidation. Thus , the aim of this study is to evaluate the viability of chitosan, the LLLT and the combination of both therapy, by evaluating the biological responses induced by the treatments, through in vitro studies. Also, assess by testing in vivo the effects of chitosan and LLLT (associated or not) in an experimental model of OA induced by anterior cruciate ligament transection (ACLT). For this reason, tests of cell viability and interaction of chitosan and LLLT (associated or not) (P = 30 mW, D = 10 J / cm 2 and J = 0.3 GaAlAs 808 nm) will be performed. For in vivo tests, will be used 160 male Wistar rats, divided into 4 groups : control group; OA treated with chitosan; OA irradiated with LLLT ; OA treated with chitosan and irradiated with LLLT . The treatments will be started 21 days after ACLT surgery and will be performed for 30 and 60 days . Laser GaAlAs 808 nm will be used; P=50 mW; D=50 J/cm2; E=1.4 J, 3 times per week for two points in the medial and lateral joint line of the knee. For evaluation and comparison of treatment effects analyzes of cytokines in synovial fluid, micro-CT, morphological and morphometric analyzes of cartilage (cellularity, thickness, chondrocytes density and proteoglycan content), protein expression of interleukin (IL-1², IL-4 e IL-10), collagen type 2 , alpha 1 ( COL2A1 ) and gene expression of COL2A1, MMP-2, MMP-9 IL-1², TNF-±. It is expected that the results of this project will bring significant contribution in elucidating the mechanisms of action of chitosan , the LLLT and the combination of both in an experimental model of OA, which culminate in the development of safer and more effective therapeutic techniques to be employed in the treatment osteodegenerative diseases.
News published in Agência FAPESP Newsletter about the scholarship: