Effect of Low-Level Laser Therapy in an Experimental Model of Osteoarthritis in Rats Evaluated Through Raman Spectroscopy

Abstract

Objective: This work aimed to investigate the biochemical changes associated with low-level laser therapy (LLLT) using 660 and 780 nm, on a well-established experimental model of osteoarthritis (OA) in the knees of rats with induced collagenase, using histomorphometry and Raman spectroscopy. Materials and methods: Thirty-six Wistar rats were divided into four groups: control (GCON, n = 9), collagenase without treatment (GCOL, n = 9), collagenase with LLLT 660 nm treatment (G660, n = 8), and collagenase with LLLT 780 nm treatment (G780, n = 10). LLLT protocol was: 30 mW power output, 10 sec irradiation time, 0.04 cm 2 spot size, 0.3 J energy, 0.75 W/cm 2 irradiance, and 7.5 J/cm 2 fluence per session per day, during 14 days. Then, knees were withdrawn and submitted to histomorphometry and Raman spectroscopy analysis. Principal components analysis (PCA) and Mahalanobis distance were employed to characterize the spectral findings. Results: Histomorphometry revealed a significant increase in the amount of collagen III for the group irradiated with 660 nm. The Raman bands at 1247, 1273, and 1453 cm -1 (from principal component score PC2), attributed to collagen type II, and 1460 cm -1 (from PC3), attributed to collagen type III, suggested that the LLLT causes acceleration in cellular activity, especially on the cells that repair cartilage, accelerating the breakdown of cartilage destroyed by collagenase and stimulating the fibroblast to synthesize repairing collagen III. Conclusions: LLLT accelerated the initial breakdown of cartilage destroyed by collagenase and stimulated the fibroblast to synthesize the repairing collagen III, suggesting a beneficial effect of LLLT on OA.

Comparison of Low-Level Laser versus Intra-Articular Corticosteroid Therapy for Temporomandibular Joint Corticosteroid Therapy for Temporomandibular Joint Osteoarthritis in Rats Osteoarthritis in Rat

“…26 Also, LLL therapy has been shown to accelerate the initial breakdown of cartilage destroyed by collagenase and to stimulate fibroblasts to produce collagen type III. 27 In this way, LLL therapy may exert its beneficial effects in OA.…”

Articular Cartilage Regeneration: An Update of Possible Treatment Approaches

“…As well, the application of appropriately timed biophysical stimuli when engineering neocartilage [7] , and one less well studied related topic, examining upstream factors that can be harnessed to protect articular cartilage may help to avert progressive cartilage deterioration and degradation, and/or to produce functional cartilage. As well, the possible use of multiple, rather than single therapeutic strategies to attenuate the disease process [15] , including joint protection efforts in the face of attempts to stimulate neocartilage might prove especially helpful, as might careful mechanical or electrical stimulation of the affected osteoarthritic joint or both [102][103][104][105][106][107][108][109][110][111][112] .…”

“…Others are, eliminating or reducing any obvious structural deformities, maximizing muscle and joint function, careful placement of any implants, and in recognition of the structure of the diseased tissue, possible enzymatic control to reduce immunogenic responses [64] . The use of weight-bearing activities that match the repair tissue biomechanical properties [65] , pulsed electromagnetic fields and other remedies to quell pain, and joint swelling, in addition to harnessing the multilineage differentiation capacity of osteoarthritis multipotent progenitor cells [42] , or mixing adult and juvenile cartilage fragments [67] and introducing early exercise loading following graft implantation [102] , laser therapy [104][105][106][107][108] , may also favor the initiation of desirable chondrocyte reparative processes.…”

“…4. Efforts to examine and integrate promising physical modalities into the cartilage repair paradigm, such as laser light applications, ultrasound, pulsed electromagnetic fields, electrical stimulation, active and passive exercises [102][103][104][105][106][107][108][109][110][111][112][113][114][115] .…”

Physical Stimulations for Bone and Cartilage Regeneration

“…Studies also indicate that low energy light could directly stimulate chondrogenesis. LLLT using 660 and 780 nm wavelengths benefits the regeneration of OA by accelerating the initial breakdown of cartilage, destroyed by collagenase, and stimulating fibroblasts to synthesize the repairing collagen III [245]. UV irradiation is also normally used on engineered cartilage.…”