Effect of helium/neon laser irradiation on nerve growth factor synthesis and secretion in skeletal muscle cultures

J Biomedical Materials Res

Huang

et al. 2013

This study proposes a biodegradable nerve conduit comprising 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linked gelatin annexed with β-tricalcium phosphate (β-TCP) ceramic particles (EDC-gelatin-TCP, EGT). For this study, the EGT-implant site in rats was irradiated using 660-nm GaAlAsP laser diodes (50 mW) for trigger point therapy to investigate the use of low-level laser (LLL) stimulation in the regeneration of a 15-mm transected sciatic nerve. Animals were divided into three groups: a control group undergoing autologous nerve graft (autograft); a sham-irradiated group (EGT), and an experimental group undergoing laser stimulation (EGT/LS). Two trigger points on the surgical incision along the sciatic nerve were irradiated transcutaneously for 2 min daily for 10 consecutive days. Twelve weeks after implantation, walking track analysis showed a significantly higher sciatic functional index (SFI; p < 0.05) and improved toe spreading development in the autograft and EGT/LS groups, compared to the EGT group. In the electrophysiological measurement, the mean recovery index (peak amplitude and area) of the compound muscle action potential curves in the autograft and EGT/LS groups showed significantly improved functional recovery than in the EGT group (p < 0.05). Compared with the EGT group, the autograft and EGT/LS groups showed a reduction in muscular atrophy. Histomorphometric assessments showed that the EGT/LS group had undergone more rapid nerve regeneration than the EGT group. Therefore, motor function, electrophysiological reaction, muscular reinnervation, and histomorphometric assessments demonstrate that LLL therapy can accelerate the repair of a 15-mm transected peripheral nerve in rats after being bridged with the EGT nerve conduit.

Section: Discussionmentioning

confidence: 54%

Neural regeneration in a novel nerve conduit across a large gap of the transected sciatic nerve in rats with low‐level laser phototherapy

J Biomedical Materials Res

Huang

et al. 2013

“…In this study, we applied the laser to the skin and muscle tissue; the areas we hypothesized contained increased levels of nerve growth factor. It has previously been shown that LLL therapy at a wavelength of 632 nm allows such a response [23]. LLL therapy appears to be an effective approach to accelerate the recovery of muscle fiber trophism.…”

Section: Discussionmentioning

confidence: 99%

Low-Level Laser-Accelerated Peripheral Nerve Regeneration within a Reinforced Nerve Conduit across a Large Gap of the Transected Sciatic Nerve in Rats

Evidence-Based Complementary and Alternative Medicine

Huang

et al. 2013

This study proposed a novel combination of neural regeneration techniques for the repair of damaged peripheral nerves. A biodegradable nerve conduit containing genipin-cross-linked gelatin was annexed using beta-tricalcium phosphate (TCP) ceramic particles (genipin-gelatin-TCP, GGT) to bridge the transection of a 15 mm sciatic nerve in rats. Two trigger points were irradiated transcutaneously using 660 nm of gallium-aluminum arsenide phosphide (GaAlAsP) via laser diodes for 2 min daily over 10 consecutive days. Walking track analysis showed a significant improvement in sciatic functional index (SFI) (P < 0.01) and pronounced improvement in the toe spreading ability of rats undergoing laser stimulation. Electrophysiological measurements (peak amplitude and area) illustrated by compound muscle action potential (CMAP) curves demonstrated that laser stimulation significantly improved nerve function and reduced muscular atrophy. Histomorphometric assessments revealed that laser stimulation accelerated nerve regeneration over a larger area of neural tissue, resulting in axons of greater diameter and myelin sheaths of greater thickness than that observed in rats treated with nerve conduits alone. Motor function, electrophysiological reactions, muscular reinnervation, and histomorphometric assessments all demonstrate that the proposed therapy accelerated the repair of transected peripheral nerves bridged using a GGT nerve conduit.

“…In this study, we applied the laser to the skin and muscle tissue, where we considered the we would find increased levels of nerve growth factor, which is a neurotropic factor secreted by skeletal muscles. It has been shown that LLL therapy at a wavelength of 632 nm allows such a response 32. Following radiation with red laser, we observed morphological changes in the mitochondria of the lymphocytes as well as the proliferation of mononuclear cells, responses that might be beneficial in the process of tissue repair 33, 34.…”

Section: Discussionmentioning

confidence: 77%

“…It has been shown that LLL therapy at a wavelength of 632 nm allows such a response. 32 Following radiation with red laser, we observed morphological changes in the mitochondria of the lymphocytes as well as the proliferation of mononuclear cells, responses that might be beneficial in the process of tissue repair. 33,34 The underlying mechanism of phototherapy in nerve regeneration has been proposed in in vitro studies showing that phototherapy induced massive neurite sprouting and outgrowth in cultured neuronal cells, 35 as well as Schwann cell proliferation.…”

Section: Morphometric Parametersmentioning

confidence: 90%

Effects of large‐area irradiated laser phototherapy on peripheral nerve regeneration across a large gap in a biomaterial conduit

J Biomedical Materials Res

Liu

2012

This paper proposes a novel biodegradable nerve conduit comprising 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) cross-linked gelatin, annexed with β-tricalcium phosphate (TCP) ceramic particles (EDC-Gelatin-TCP, EGT). In this study, the EGT-implant site in rats was irradiated using a large-area 660 nm AlGaInP diode laser (50 mW) to investigate the feasibility of laser stimulation in the regeneration of a 15-mm transected sciatic nerve. The animals were divided into three groups: a sham-irradiated group (EGT/sham); an experimental group undergoing low-level laser (LLL) therapy (EGT/laser); a control group undergoing autologous nerve grafts (autografts). Twelve weeks after implantation, walking track analysis showed a significantly higher sciatic functional index (p < 0.05) and improved toe spreading development in the EGT/laser and autograft groups than in the EGT/sham group. In electrophysiological measurement, both the mean peak amplitude and the area under the compound muscle action potential curves in the EGT/laser and autograft groups showed significantly improved functional recovery than the EGT/sham group (p < 0.05). Compared with the EGT/sham group, the EGT/laser and autograft groups displayed a reduction in muscular atrophy. Histomorphometric assessments revealed that the EGT/laser group had undergone more rapid nerve regeneration than the EGT/sham group. The laser-treated group also presented greater neural tissue area as well as larger axon diameter and thicker myelin sheath than the tube group without the laser treatment, indicating improved nerve regeneration. Thus, these assessments demonstrate that LLL therapy can accelerate the repair of a transected peripheral nerve in rats after being bridged with EGT conduit.