A biocomplex to repair experimental critical size defects associated with photobiomodulation therapy

Abstract Background: The association of scaffolds to repair extensive bone defects can contribute to their evolution and morphophysiological recomposition. The incorporation of particulate biomaterials into three-dimensional fibrin bioproducts together with photobiomodulation therapy (PBM) has potential and can improve regenerative medicine procedures. The objective of this experiment was to evaluate the effects of PBM therapy on critical size defects filled with xenogenic bone substitute associated with fibrin biopolymer. Methods: A critical defect of 8 mm was performed in 36 Wistar male adult rats that were divided into four groups. Groups BC and BC-PBM were defined as controls with defects filled by a clot (without or with PBM, respectively) and groups XS and XS-PBM that comprised those filled with biocomplex Bio-OssTM in association with fibrin biopolymer. PBM was applied immediately after the surgery and three times a week every other day, with the parameters: wavelength of 830 nm, energy density 6.2 J/cm2, output power 30 mW, beam area of 0.116 cm2, irradiance 0.258,62 W/cm2, energy/point 0.72 J, total energy 2.88 J. Fourteen and 42 days after the surgery, animals were euthanatized and subjected to microtomography, qualitative and quantitative histological analysis. Results: The BC-PBM and XS-PBM groups had a similar evolution in the tissue repair process, with a higher density of the volume of new formed bone in relation to the groups without PBM (p = 0.04086; p = 0.07093, respectively). Intense vascular proliferation and bone deposition around the biomaterial particles were observed in the animals of the groups in which biocomplex was applied (XS and XS-PBM). Conclusion: PBM therapy allowed an improvement in the formation of new bone, with a more organized deposition of collagen fibers in the defect area. Biocomplex favored the insertion and permanence of the particulate material in bone defects, creating a favorable microenvironment for accelerate repair process.

A biocomplex to repair experimental critical size defects associated with photobiomodulation therapy

The association of scaffolds to repair extensive bone defects can contribute to their evolution and morphophysiological recomposition. The incorporation of particulate biomaterials into three-dimensional fibrin bioproducts together with photobiomodulation therapy (PBM) has potential and can improve regenerative medicine procedures. The objective of this experiment was to evaluate the effects of PBM therapy on critical size defects filled with xenogenic bone substitute associated with fibrin biopolymer. Methods: A critical defect of 8 mm was performed in 36 Wistar male adult rats that were divided into four groups. Groups BC and BC-PBM were defined as controls with defects filled by a clot (without or with PBM, respectively) and groups XS and XS-PBM that comprised those filled with biocomplex Bio-OssTM in association with fibrin biopolymer. PBM was applied immediately after the surgery and three times a week every other day, with the parameters: wavelength of 830 nm, energy density 6.2 J/cm2, output power 30 mW, beam area of 0.116 cm2, irradiance 0.258,62 W/cm2, energy/point 0.72 J, total energy 2.88 J. Fourteen and 42 days after the surgery, animals were euthanatized and subjected to microtomography, qualitative and quantitative histological analysis. Results: The BC-PBM and XS-PBM groups had a similar evolution in the tissue repair process, with a higher density of the volume of new formed bone in relation to the groups without PBM (p = 0.04086; p = 0.07093, respectively). Intense vascular proliferation and bone deposition around the biomaterial particles were observed in the animals of the groups in which biocomplex was applied (XS and XS-PBM). Conclusion: PBM therapy allowed an improvement in the formation of new bone, with a more organized deposition of collagen fibers in the defect area. Biocomplex favored the insertion and permanence of the particulate material in bone defects, creating a favorable microenvironment for accelerate repair process.(AU)

Comparative study between standard and inside-out vein graft techniques on sciatic nerve repair of rats. Muscular and functional analysis

Abstract Purpose: To compare the functional result of standart vein grafts and inside-out vein graft technique on sciatic nerve repair. Methods: We used 24 male Wistar rats divided into 4 groups: control group (CG), standard vein graft group (SVG), Inside-out vein graft group (IOVG) and denervated Group (DG). SVG, IOVG and DG underwent total section of the sciatic nerve, SVG and IOVG however underwent nerve repair surgery using a graft with normal jugular vein and inside-out jugular vein, respectively. Histological analysis of the soleus and Extensor Digitorum Longus (EDL), and Sciatic Functional Index were used to compare the results after 6 weeks. Results: Both grafts acted favorably in muscle recovery and improved functionality; They were similar in all parameters, however, in more points SVG achieved similar to the CG, in the other hand IOVG more times was similar to DG. Fact that makes the graft with normal vein the most viable option between the two options. Conclusion: Both types of grafts acted beneficially wherein the graft normal vein has proved to be the best option

Electrical stimulation attenuates morphological alterations and prevents atrophy of the denervated cranial tibial muscle / Eletroestimulação atenua alterações morfológicas e previne atrofia do músculo tibial cranial desnervado

ABSTRACT Objective To investigate if electrical stimulation through Russian current is able to maintain morphology of the cranial tibial muscle of experimentally denervated rats. Methods Thirty-six Wistar rats were divided into four groups: the Initial Control Group, Final Control Group, Experimental Denervated and Treated Group, Experimental Denervated Group. The electrostimulation was performed with a protocol of Russian current applied three times per week, for 45 days. At the end, the animals were euthanized and histological and morphometric analyses were performed. Data were submitted to statistical analysis with a significance level of p<0.05. Results The Experimental Denervated Group and the Experimental Denervated and Treated Group had cross-sectional area of smaller fiber compared to the Final Control Group. However, there was significant difference between the Experimental Denervated Group and Experimental Denervated and Treated Group, showing that electrical stimulation minimized muscle atrophy. The Experimental Denervated and Treated Group and Initial Control Group showed similar results. Conclusion Electrical stimulation through Russian current acted favorably in maintaining morphology of the cranial tibial muscle that was experimentally denervated, minimizing muscle atrophy.

RESUMO Objetivo Investigar se a estimulação elétrica pela corrente russa é capaz de manter a morfologia do músculo tibial cranial de ratos desnervados experimentalmente. Métodos Foram utilizados 36 ratos Wistar, distribuídos em quatro grupos: Grupo Controle Inicial, Grupo Controle Final, Grupo Experimental Desnervado Tratado, Grupo Experimental Desnervado. A eletroestimulação foi realizada com um protocolo de corrente russa aplicada três vezes por semanas, durante 45 dias. Ao final, os animais foram eutanasiados e, em seguida, foram realizadas as análises histológica e morfométrica. Os dados foram submetidos à análise estatística, com nível de significância de p<0,05. Resultados Os Grupos Experimental Desnervado e o Grupo Experimental Desnervado Tratado apresentaram área de secção transversal da fibra menor quando comparados ao Grupo Controle Final. Entretanto, constatou-se diferença significativa entre o Grupo Experimental Desnervado e o Grupo Experimental Desnervado Tratado, mostrando que a estimulação elétrica minimizou atrofia muscular. Ainda, observou-se que o Grupo Experimental Desnervado Tratado apresentou resultados semelhantes ao Grupo Controle Inicial. Conclusão A estimulação elétrica por meio da corrente russa foi favorável na manutenção da morfologia do músculo tibial cranial desnervado experimentalmente, minimizando a atrofia muscular.

Efeito da associação da laserterapia com a natação no reparo morfológico do nervo isquiático e na recuperação funcional de ratos submetidos à axonotmese / Efecto de la asociación entre la laserterapia y la natación en la recuperación morfológica del nervio isquiático y en la recuperación funcional de ratas sometidas a axonotmesis / Effect of the laser therapy in association with swimming for a morphological nerve repair and functional recovery in rats submitted to sciatic axonotmesis

RESUMO As lesões de nervos periféricos ocorrem frequentemente e, de modo geral, causam perda funcional impactando de forma negativa na vida do paciente. O objetivo do estudo foi verificar a eficiência da associação da laserterapia e natação em ratos acometidos por axonotmeses. A amostra foi composta por 50 ratos da linhagem Wistar. Foram divididos em 5 grupos, sendo: grupo controle (GC); grupo controle cirúrgico (GCC); grupo experimental laser (GEL); grupo experimental natação (GEN) e grupo experimental laser associado à natação (GELAN). O nervo foi esmagado em um segmento de 5 mm de comprimento próximo a trifurcação do nervo isquiático, feito com uma pinça durante 60 segundos. Foi utilizado o laser infravermelho AsGa (904 nm) com energia irradiada de 0,4 J na primeira semana, 0,8 J na segunda semana e 1,2 J na terceira e quarta semana. Para avaliação funcional (IFC), os animais foram imobilizados, e a região plantar das patas foram pintadas com tinta de carimbo. Esse procedimento foi repetido duas vezes com cada animal. Foi realizada a morfometria (áreas, diâmetros e espessuras das fibras, axônios e bainha de mielina) dos nervos com mensuração de 220 fibras por animal de cada grupo. Pudemos observar que os grupos GEL e GEN, em todas as variáveis morfométricas estudadas, obtiveram os melhores resultados, quando comparados com os outros grupos (GC, GCC e GELAN), mas não apresentou diferença estatisticamente significante entre eles. Na análise funcional observou-se que o grupo GELAN obteve o melhor resultado quando comparado com os outros grupos (GCC, GEL e GEN) e quando comparados os grupos GEL e GEN entre eles não houve diferença estatisticamente significante. A conclusão foi que os grupos GEL e GEN obtiveram os melhores resultados morfométricos, enquanto o GELAN apresentou o melhor resultado funcional. Portanto, pode-se concluir que a associação destes recursos favoreceu a recuperação funcional desses animais.

RESUMEN Las lesiones de los nervios periféricos frecuentemente ocurren, y generalmente ocasionan pérdida funcional, lo que les causa daño a la vida de los pacientes. En este artículo se propone a verificar la eficacia de la asociación de la laserterapia y de la natación en ratas sometidas a axonotmesis. El muestro se compuso de 50 ratas Wistar. Se las dividieron en 5 grupos: grupo control (GC); grupo control quirúrgico (GCQ); grupo experimental láser (GEL); grupo experimental natación (GEN) y grupo experimental láser asociado con la natación (GELAN). Se aplastó con una pinza durante 60 segundos el nervio en un segmento de 5 mm de extensión cerca de la trifurcación del nervio isquiático. Se empleó el láser infrarrojo AsGa (904 nm) con energía irradiada de 0,4 J en la primera semana, 0,8 J en la segunda y 1,2 J en la tercera y cuarta semanas. Para la evaluación funcional (IFC), se los inmovilizaron los animales y se los pintó con tinta estampilla la región plantar de las patas. Se repitió dicho procedimiento dos veces en cada animal. Se realizó la morfometría (áreas, diámetros y espesuras de las fibras, axónios y vaina de mielina) de los nervios con mensuración de 220 fibras por cada animal de cada grupo. Se notó que los grupos GEL y GEN, en todas las variables morfométricas estudiadas, presentaron los mejores resultados, en comparación con los otros grupos (GC, GCQ y GELAN), sin embargo no presentó diferencia estadísticamente significativa entre ellos. En el análisis funcional se observó que el grupo GELAN tuvo el mejor resultado en comparación con otros grupos (GCQ, GEL y GEN), y al comparar los grupos GEL y GEN no presentaron diferencia estadísticamente significativa. Se concluyó que los grupos GEL y GEN tuvieron mejores resultados morfométricos, mientras que el GELAN presentó el mejor resultado funcional. Por lo que se concluye que la asociación de dichos recursos les favoreció la recuperación funcional de dichos animales.

ABSTRACT The peripheral nerve injuries occur frequently and generally cause functional loss impacting negatively on patient's life. The objective this study was to verify the efficiency of the combination of laser therapy and swimming in rats affected by axonotmesis. The sample was comprised of 50 Wistar rats and it was divided into 05 groups: Control Group; Surgical Control Group; Laser Experimental Group; Swimming Experimental Group and Laser Experimental combined with Swimming Group. The nerve was crushed into a 5 mm-long segment next to the sciatic nerve trifurcation with a pair of forceps for 60 seconds. The GaAs infrared laser (904nm) was used with energy radiated 0,4J the first week, the second week 0,8J and 1,2J in the third and fourth week. For functional (FCI) evaluation, the animals were immobilized and the plantar region of their paws were painted with ink stamp. The procedure was repeated twice to each animal. The nerve morphometry (areas, diameters and thicknesses of the fibers, axons and myelin sheath) was performed with the measurement of 220 fibers per animal in each group . We can see that the GEL and GEN groups , obtained the best results when compared with the other groups (GC, GCC and GELAN) in all morphometric variables studied, but no statistically significant difference was found between them. In functional analysis, it was observed that the gelan group obtained the best results when compared with the other groups (GCC , GEN and GEL) and when the GEL and GEN groups were compared, there was no statistically significant difference between them. Was conclued the GEL and GEN groups havd the best morphometric results, while the GELAN showed the best functional outcome. Therefore, it can be concluded that the combination of these features favoured the functional recovery of the animals.

Efeito da corrente alternada simétrica sinusoidal na musculatura estriada esquelética desnervada experimentalmente / Effect of sinusoidal alternated current in experimentally denerved skeletal striated muscle

Introdução: A utilização da estimulação elétrica (EE) no tratamento de músculos desnervados tem sido muito estudada, pois auxilia na reinervação tardia e minimiza a atrofia muscular. Objetivo: Neste estudo, avaliamos a EE através da corrente alternada simétrica sinusoidal na manutenção dos aspectos morfológicos dos músculos Extensor longo dos dedos (EDL) e Sóleo desnervados experimentalmente. Método: Quarenta ratos da linhagem wistar foram divididos em quatro grupos experimentais (n=10): Em grupo controle inicial (GCI), controle Final (GCF), desnervado (GD), e em desnervado e estimulado (GDE). A aplicação EE no músculo EDL e sóleo teve início 48 horas após a lesão nervosa, sendo aplicada três vezes por semana durante quarenta e cinco dias. Cortes transversais foram corados com HE para a mensuração da morfometria das fibras musculares. Para a análise estatística foi utilizado a análise de variância (one-way - ANOVA) seguido pelo teste de tukey (p < 0,05). Resultados: Os animais do grupo D e DE apresentaram uma diminuição da área de secção transversal (AST) quando comparadas ao CF. Porém o grupo DE minimizou a atrofia muscular, pois houve diferença estatisticamente significativa quando comparado ao D, tanto no músculo EDL quanto no sóleo. Conclusão: A EE foi eficiente na manutenção dos aspectos morfológicos dos músculos EDL e sóleo, minimizando a atrofia muscular. Podendo ser um tratamento útil para as lesões nervosas periféricas.

Introduction: the use of electrical stimulation (ES) in the treatment of denervated muscles has been studied as it assists in the late reinnervation and minimizes muscle atrophy. Purpose: this study assessed the ES through the symmetric sinusoidal alternating current in the maintenance of the morphological aspects of the experimentally denervated Extensor digitorum longus (EDL) and Soleus muscles. Method: Forty Wister rats were divided into four experimental groups (n = 10): initial control group ( ICG), final control group (FCG), denervated group (DG) and denervated and stimulated group (DSG). ES was first applied in the soleus and EDL muscle 48 hours after nerve injury, the applications took place three times per week for forty-five days. Cross-sections were stained with HE to perform the morphometric analysis of the muscle fibers. We used the analysis of variance (one-way - ANOVA) followed by the Tukey test (p < 0.05) for statistical analysis. Results: the animals belonging to group D and DE showed a decrease in the crosssectional area (CSA) when compared to FCG. However, the group DE had muscular atrophy minimized, as there was a statistically significant difference when compared to D, both for EDL and soleus muscles. Conclusion: the ES was effective in maintaining the morphological aspects of the EDL and soleus muscles, minimizing muscle atrophy. This may be a useful treatment for the peripheral nerve injuries.