Evaluation by fractal dimension of muscle regeneration after photobiomodulation

Bárbara Menezes De Oliveira,Pedro Rocha Tenorio,Carlos Eduardo Assumpção De Freitas,Francis Lopes Pacagnelli,Raisa De Jesus Dutra Dias,Gabriela Alves De Lima Moschini

doi:10.1590/1980-5918.033.ao39

Bárbara Menezes De Oliveira, Pedro Rocha Tenorio + Show 4 more

Open Access

https://doi.org/10.1590/1980-5918.033.ao39

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Abstract

Abstract Introduction: Many treatment modalities are used for muscle tissue recovery. Photobiomodulation is a modality that can be employed to improve the quality of tissue repair. The use of fractal dimension (FD) is an innovative methodology in the quantitative evaluation of treatment efficacy. Objective: Use FD as a quantitative analysis method to evaluate the effect of photobiomodulation of 904 nanometers (nm) in the initial phase of the muscle regeneration process. Method: Thirty male Wistar rats were divided into three groups: Control Group (CG), Injured and Untreated Group (IUT), and Injured and Treated Group (IT). Muscle injury was induced by cryoinjury in the central region of the anterior tibial (AT) belly of the left posterior limb. This was performed by an iron rod that was previously immersed in liquid nitrogen. Applications started 24 hours after the injury and occurred daily for five days. They were performed at two points in the lesion area. The rats were euthanized on the seventh day. The AT muscles were removed and frozen in liquid nitrogen. Then, the histological sections were stained using the Hematoxylin-Eosin (HE) technique and submitted to FD analysis performed by the box-counting method using ImageJ software. The Kolmogorov-Smirnov test was used for data normality, and the Kruskall-Wallis test and Dunn's post-test were used for group comparison (p<0.05%). Results: Differences between IT and IUT groups were statistically significant, and it was possible to observe the reduction of fractability with p=0.0034. Conclusion: FD is a useful tool for the analysis of skeletal muscle disorganization in the initial phase of regeneration and confirms the potentially beneficial effects of photobiomodulation to this process.

Highlights

Many treatment modalities are used for muscle tissue recovery
Use fractal dimension (FD) as a quantitative analysis method to evaluate the effect of photobiomodulation of 904 nanometers in the initial phase of the muscle regeneration process
Thirty male Wistar rats were divided into three groups: Control Group (CG), Injured and Untreated Group (IUT), and Injured and Treated Group (IT)

Summary

Introduction

Many treatment modalities are used for muscle tissue recovery. Photobiomodulation is a modality that can be employed to improve the quality of tissue repair. Objective: Use FD as a quantitative analysis method to evaluate the effect of photobiomodulation of 904 nanometers (nm) in the initial phase of the muscle regeneration process. Muscle injury was induced by cryoinjury in the central region of the anterior tibial (AT) belly of the left posterior limb This was performed by an iron rod that was previously immersed in liquid nitrogen. Applications started 24 hours after the injury and occurred daily for five days They were performed at two points in the lesion area. They are commonly caused by injuries or strains [1, 2]. Injuries to muscles account for approximately 90% of medical procedures in the country This is worrying from an epidemiological point of view, and in relation to the health system. Such procedures are often expensive and performed by the public health system (Sistema Único de Saúde, SUS) [3]

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