Low level laser therapy increases angiogenesis in a model of ischemic skin flap in rats mediated by VEGF, HIF-1α and MMP-2

Abstract

It is known that low level laser therapy is able to improve skin flap viability by increasing angiogenesis. However, the mechanism for new blood vessel formation is not completely understood. Here, we investigated the effects of 660 nm and 780 nm lasers at fluences of 30 and 40 J/cm2 on three important mediators activated during angiogenesis. Sixty male Wistar rats were used and randomly divided into five groups with twelve animals each. Groups were distributed as follows: skin flap surgery non-irradiated group as a control; skin flap surgery irradiated with 660 nm laser at a fluence of 30 or 40 J/cm2 and skin flap surgery irradiated with 780 nm laser at a fluence of 30 or 40 J/cm2. The random skin flap was performed measuring 10 × 4 cm, with a plastic sheet interposed between the flap and the donor site. Laser irradiation was performed on 24 points covering the flap and surrounding skin immediately after the surgery and for 7 consecutive days thereafter. Tissues were collected, and the number of vessels, angiogenesis markers (vascular endothelial growth factor, VEGF and hypoxia inducible factor, HIF-1α) and a tissue remodeling marker (matrix metalloproteinase, MMP-2) were analyzed. LLLT increased an angiogenesis, HIF-1α and VEGF expression and decrease MMP-2 activity. These phenomena were dependent on the fluences, and wavelengths used. In this study we showed that LLLT may improve the healing of skin flaps by enhancing the amount of new vessels formed in the tissue. Both 660 nm and 780 nm lasers were able to modulate VEGF secretion, MMP-2 activity and HIF-1α expression in a dose dependent manner.

Biophysical Approaches for Oral Wound Healing: Emphasis on Photobiomodulation

“…36 Similarly, it has been shown that PBM (both 660 and 780 nm) improves the healing of skin flaps by enhancing the amount of new vessels formed in the tissue by modulating vascular endothelial growth factor (VEGF) secretion and HIF1a expression in a dose-dependent manner. 66 PBM has also been shown to rescue dendritic atrophy in the brain by upregulating brain-derived neurotrophic factor (BDNF) expression through induction of CREB. 67 Overall, the controlled expression and activity of transcriptional factors in response to laser-generated cellular stress are capable of coordinating a broad range of beneficial responses.…”

A prospective case series evaluating the safety and efficacy of the Klox BioPhotonic System in venous leg ulcers

“…22 It has also been shown that PBM events may also regulate vascular endothelial growth factor, enhancing the formation of new vessels and improving the healing of skin. 23 In summary, light treatments can lead to modulation of transcription factors capable of coordinating a wide range of beneficial responses in wound healing.…”

<b>Interaction between low level laser therapy and anesthesia in wistar rats

“…Values found for the limb withdrawal threshold (in grams) for the pressure performed on the plantar surface (Plantar) and close to the incision (Local) in the pre-injury (Pre) times, 10 (10') and 60 (60') minutes of awakening. Discussion LLLT is a useful tool for the therapeutic field, aiming tissue repair (Bossini et al, 2012;Cury et al, 2013;Hussein, Alfars, Falih, & Hassan, 2011;Vasilenko et al, 2010), anti-inflammatory effects (Chen, Huang, Sharma, & Hamblin, 2011;Marcos et al, 2011) and analgesia (Chow et al, 2007;Chow, Johnson, Lopes-Martins, & Bjordal, 2009;Chow, Armati, Laakso, Bjordal, & Baxter, 2011;Eslamian, Shakouri, Ghojazadeh, Nobari, & Eftekharsadat, 2012;Rayegani et al, 2011;Yan et al, 2011). However, Aras et al (2010), in a review study, indicate a possible dubious effect of low power laser associated with anesthetics, since it can help or hinder the effects of anesthesia.…”

“…Low level laser therapy (LLLT) has been widely used in clinical practice because it is not invasive, painless, easily administered (Bjordal et al, 2008), and has beneficial effects for the irradiated tissues, such as activation of microcirculation (Maegawa, Itoh, Hosokawa, Yaegashi, & Nishi, 2000), vasodilation production (Plass, Wieselthaler, Podesser, & Prusa, 2012) and neovascularization (Cury et al, 2013). LLLT modulates several biological processes, increasing mitochondrial respiration and ATP synthesis (Karu, 1999), changing enzymatic reactions by inhibiting the synthesis and release of prostaglandins (Marcos et al, 2011), besides producing analgesia via release of beta-endorphin (Meireles et al, 2012) and changes in nerve conduction (Chow, David, & Armati, 2007;Yan, Chow, & Armati, 2011).…”