Effects of 780-nm Low-Level Laser Therapy with a Pulsed Gallium Aluminum Arsenide Laser on the Healing of a Surgically Induced Open Skin Wound of Rat

Tailoring photobiomodulation to enhance tissue regeneration

Photobiomodulation (PBM), the use of biocompatible tissue-penetrating light to interact with intracellular chromophores to modulate the fates of cells and tissues, has emerged as a promising non-invasive approach to enhancing tissue regeneration. Unlike photodynamic or photothermal therapies that require the use of photothermal agents or photosensitizers, PBM treatment does not need external agents. With its non-harmful nature, PBM has demonstrated efficacy in enhancing molecular secretions and cellular functions relevant to tissue regeneration. The utilization of low-level light from various sources in PBM targets cytochrome c oxidase, leading to increased synthesis of adenosine triphosphate, induction of growth factor secretion, activation of signaling pathways, and promotion of direct or indirect gene expression. When integrated with stem cell populations, bioactive molecules or nanoparticles, or biomaterial scaffolds, PBM proves effective in significantly improving tissue regeneration. This review consolidates findings from in vitro, in vivo, and human clinical outcomes of both PBM alone and PBM-combined therapies in tissue regeneration applications. It encompasses the background of PBM invention, optimization of PBM parameters (such as wavelength, irradiation, and exposure time), and understanding of the mechanisms for PBM to enhance tissue regeneration. The comprehensive exploration concludes with insights into future directions and perspectives for the tissue regeneration applications of PBM.

Use of adipose derived stem cells accelerates the healing process in third-degree burns

INTRODUCTION

Burns are defined as a traumatic injury, usually of thermal origin, that affects the epithelial and adjacent tissue and is classified according to the depth reached. Tissue repair involved in this type of injury is often a challenge both due to its severity and the multiplicity of complications. Regenerative medicine has focused on the use of low-level laser photobiomodulation therapy (LLLT) and adipose-derived stem cells (ADSC), especially in the early stages of the process, to promote better healing and shorten repair time. Therefore, aim of this study was to evaluate the action of LLLT (660 nm) and ADSC in the repair process of burned skin tissue and investigate the association of the techniques (LLLT and ADSC).

MATERIALS AND METHODS

An in vivo study was carried out using 96 rats (Wister) with a scald burn model at a temperature of 95ºC, exposing the animal's back for 14 s. Animals were randomized into seven groups and three periods, five, 14 and 21 days. The groups included GC: Control group, ADSC-: Group treated with CD49d negative cells, ADSC+ : Group treated with positive CD49d cells, CULT: Group treated with conventional isolation cells, LLLT: Group treated only with LLLT Low Power Laser, ADSC-LLLT: Group treated with CD49d negative cells and LLLT. ADSC+LLLT: Group treated with positive CD49d cells and LLLT. The groups treated with LLLT (660 nm; 5 J/cm2) received irradiation three times a week, on alternate days for five, 14 and 21 days, according to the time of biopsy. ADSC-treated groups received one to three applications of the cells in a total volume of 1000 μL starting soon after the surgical debridement of the burn. Photographic monitoring was carried out at 5, 14 and 21 days after the beginning of the experiment to assess the degree of lesion contraction. Macroscopic, morphometric and histopathological analyzes were performed.

RESULTS

We showed significant re-epithelialization as well as an improvement in the healing process in the ADSC+, LLLT and ADSC+LLLT groups. We observed effects in the reduction of the inflammatory phase, increase in angiogenesis, decrease in oedema, greater collagen deposition, and better organization of the extracellular matrix compared to the other treatments. Moreover, the immunomagnetic separation of ADSC cells through the expression of the CD49d protein proved to be a useful means to obtain a more homogeneous population of cells with a role in tissue regeneration compared to the ADSC- and CULT groups.

CONCLUSION

In conclusion, the association of ADSC+ with LLLT was effective in accelerating the burn repair process, stimulating cell proliferation and formation of more normal skin tissue.

Evaluation of photobiomodulation effect on cesarean-sectioned wound healing: a clinical study

The effects of low-level laser on the wound healing and burn injuries have been previously examined to demonstrate some satisfactory results. Despite there are a few articles available to study photobiomodulation (PBM) effects on the pain relief of cesarean sectioned wound, however no systematic examination has been carried out so far regarding its healing. Here, the aim of this clinical study was to evaluate PBM effect on the cesarean-sectioned wound healing. PBM effects of semiconductor lasers are investigated at 658 and 660 nm with 100, 150 and 350 mW output powers on 40 patients. Due to the global increasing number of cesarean sections, we have decided to investigate the effect of laser as a reliable technique to recover the wounds fast. We considered women as the target group who had their first delivery giving the birth of their children by cesarean section. We selected patients are who treated by laser therapy using indium gallium aluminum phosphide (InGaAlP) semiconductor linear scanning type with beam cross section of 12 cm2 and the output power of 100 mW at 658 nm exposing a therapeutic dose of 2 J/cm2. The purpose is to accelerate the healing process of the wounds after delivery as an intervention group against the people who chose the conventional methods (using ointments, pills, etc.) to heal their cesarean sectioned wounds as the control group. Regarding the wounds of these two groups, the questionnaires were filled by patients to assess the severity of pain from visual analogue scale (VAS) based on the healing of wounds from redness, edema, ecchymosis, discharge, and distance between the two edges of the wound (REEDA) scale in the early hours after surgery and the post-treatment follow-up on the third, seventh, and the tenth days. The data collected by these questionnaires were analyzed using statistical package for social science)SPSS( as a statistical software to give out the comparative histograms. This study reports a clinical examination of PBM under intervention group of 40 patients ranging 18-40 years old with body mass index (BMI) of 29-36, during post-cesarean surgery to elucidate successful healing of the wounds and scars against conventional methods which considered as control group. Comparison of mean REEDA scores on the third day (p = 0.035), seventh day (p = 0.03), and tenth day (p = 0.02) after delivery exhibits that the two groups benefit a statistically significant difference with each other. For instance, the mean wound healing score in the intervention group was almost half of the mean wound healing score on the tenth day in the control group (1.09 ± 0.586 vs. 2.25 ± 0.422). The post-cesarean follow-up indicates that the patients treated by the laser therapy (intervention group) encounter better recovery than the control group.

NIR irradiation of human buccal fat pad adipose stem cells and its effect on TRP ion channels

The effect of near infrared (NIR) laser irradiation on proliferation and osteogenic differentiation of buccal fat pad-derived stem cells and the role of transient receptor potential (TRP) channels was investigated in the current research. After stem cell isolation, a 940 nm laser with 0.1 W, 3 J/cm² was used in pulsed and continuous mode for irradiation in 3 sessions once every 48 h. The cells were cultured in the following groups: non-osteogenic differentiation medium/primary medium (PM) and osteogenic medium (OM) groups with laser-irradiated (L +), without irradiation (L -), laser treated + Capsazepine inhibitor (L + Cap), and laser treated + Skf96365 inhibitor (L + Skf). Alizarin Red staining and RT-PCR were used to assess osteogenic differentiation and evaluate RUNX2, Osterix, and ALP gene expression levels. The pulsed setting showed the best viability results (P < 0.05) and was used for osteogenic differentiation evaluations. The results of Alizarin red staining were not statistically different between the four groups. Osterix and ALP expression increased in the (L +) group. This upregulation abrogated in the presence of Capsazepine, TRPV1 inhibitor (L + Cap); however, no significant effect was observed with Skf96365 (L + Skf).

An Evaluation of the Effects of Photobiomodulation Therapy on the Peri-Implant Bone Healing of Implants with Different Surfaces: An In Vivo Study

(1) Background: This study evaluates the effects of photobiomodulation (PBM) therapy on the peri-implant bone healing of implants with a machined surface (MS) and treated surface (TS). (2) Methods: Topographic characterization of the surfaces (scanning electron microscopy [SEM]- energy dispersive X-ray spectroscopy [EDX]) was performed before and after implant removal. Twenty rabbits were randomly divided into four groups: MS and TS groups (without PBM therapy) and LMS and LTS groups (with PBM therapy). After implant placement, the stability coefficient (ISQ) was measured. In the periods of 21 and 42 days, the ISQ was measured again, followed by biomechanical analysis. (3) Results: The surfaces of the TS implants showed topographic differences compared with MS implants. The ISQ values of the LMS were statistically significant when compared with those of the MS at 42 days (p < 0.001). The removal torque values of the LMS were statistically significant when compared with those of the MS at 21 days (p = 0.023) and 42 days (p = 0.023). For SEM, in general, the LMS, TS and LTS presented high bone tissue coverage when compared to MS. (4) Conclusions: The PBM therapy modulated the osseointegration process and was evidenced mainly on the machined surface.

The Combined Effect of Photobiomodulation and Curcumin on Acute Skin Wound Healing in Rats

Introduction: Abnormal wound repair is a cause for considerable expense, as well as patient morbidity and mortality. Here, we investigated the combined impact of photobiomodulation (PBM) and curcumin on a rat experimental model of an acute skin wound. Methods: A round full-thickness wound was created on the back of each rat. We divided the rats into the following four groups. Group one was the control group. Group two received pulse wave (PW) PBM at a dose of 890 nm, 80 Hz, and 0.2 J/cm². Group 3 received 40 mg/kg curcumin by gastric gavage and group 4 were treated with PWPBM + curcumin. We measured the wound area on days 4, 7, and 15, and performed microbiological and tensiometric examinations. Results: There was markedly improved wound contraction in the curcumin (7.5 ± 0.57; P =0.000), PBM (8.5 ± 1.2; P =0.000), and PBM + curcumin (14.5 ± 4.3; P =0.002) groups relative to the control group (25 ± 6). PBM (100 ± 7.3; P =0.005), and PBM + curcumin (98 ± 6; P =0.005) groups meaningfully improved tensile strength relative to the control group (61 ± 8.2). On day 15, the PBM (10 ± 5; P =0.000), curcumin (14 ± 4.5, P =0.000), and PBM + curcumin (27.3 ± 8.3; P =0.000) groups meaningfully decreased microbial flora relative to the control group (95 ± 6). Conclusion: We concluded that the PBM and PBM + curcumin groups meaningfully accelerated wound healing of the acute skin wound in the rats. The results of the PBM group were statistically more effective than the curcumin alone and PBM + curcumin-treated groups.

Comparison Of The Efficacy Of Two Laser Types In Healing Of Full-Thickness Wound: An Experimental Study

The aim of the study ― To investigate the effectiveness of pulsed laser with high intensity and laser with low intensity on a full-thickness wound in rats and to compare the effects of both laser types. Material and Methods ― Forty-five adult male rats were utilized in the present study. After anesthesia, wound of five cm2 was produced on dorsal aspect in each rat; then, the rats were randomly classified into three groups as follows: high power pulsating laser group (A) which received Nd: YAG laser with 1064 nm wavelength, low power laser group (B) which received GaAlAs laser with 830 nm wavelength, and control group (C) which received no treatment. Laser lights in groups (A) and (B) were introduced at an intensity of five joules per cm2 with a total energy of 25 joules for each wound area through the use of a scanning method and at a rate of 3 sessions per week for three weeks. Results ― At the end of treatment, better wound healing in form of more wound contraction and higher healing rate was elicited in both laser groups in comparison to wound healing in the control group, and there were no significantly different effects between both laser types. Conclusion ― At the intensity of five joules/cm2, both low-intensity and pulsating high-intensity lasers speed up the healing of the wound in rats, and there are no significant differences between their effects.

Stereological and gene expression examinations on the combined effects of photobiomodulation and curcumin on wound healing in type one diabetic rats

We examined the effects of photobiomodulation (PBM) independently and combined with curcumin on stereological parameters and basic fibroblast growth factor (bFGF), hypoxia-inducible factor-1α (HIF-1α), and stromal cell-derived factor-1α (SDF-1α) gene expressions in an excisional wound model of rats with type one diabetes mellitus (T1DM). T1DM was induced by an injection of streptozotocin (STZ) in each of the 90 male Wistar rats. One round excision was generated in the skin on the back of each of the 108 rats. The rats were divided into six groups (n = 18 per group): control (diabetic), untreated group; vehicle (diabetic) group, which received sesame oil; PBM (diabetic) group; curcumin (diabetic) group; PBM + curcumin (diabetic) group; and a healthy control group. On days 4, 7, and 15, we conducted both stereological and quantitative real-time PCR (qRT-PCR) analyses. The PBM and PBM + curcumin groups had significantly better inflammatory response modulation in terms of macrophages (P < .01), neutrophils (P < .001), and increased fibroblast values compared with the other groups at day 4 (P < .001), day 7 (P < .01), and day 15 (P < .001). PBM treatment resulted in increased bFGF gene expression on days 4 (P < .001) and 7 (P < .001), and SDF-1α gene expression on day 4 (P < .001). The curcumin group had increased bFGF (P < .001) expression on day 4. Both the PBM and PBM + curcumin groups significantly increased wound healing by modulation of the inflammatory response, and increased fibroblast values and angiogenesis. The PBM group increased bFGF and SDF-1α according to stereological and gene expression analyses compared with the other groups. The PBM and PBM + curcumin groups significantly increased the skin injury repair process to more rapidly reach the proliferation phase of the wound healing in T1DM rats.

Photobiomodulation with polychromatic light increases zone 4 survival of transverse rectus abdominis musculocutaneous flap

OBJECTIVE

The aim of this study was to evaluate the effect of relatively novel approach of application of polychromatic light waves on flap survival of experimental musculocutaneous flap model and to investigate efficacy of this modality as a delay procedure to increase vascularization of zone 4 of transverse rectus abdominis musculocutaneous (TRAM) flap.

METHODS

Twenty-one Wistar rats were randomized and divided into 3 experimental groups (n = 7 each). In group 1 (control group), after being raised, the TRAM flap was sutured back to its bed without any further intervention. In group 2 (delay group), photobiomodulation (PBM) was applied for 7 days as a delay procedure, before elevation of the flap. In group 3 (PBM group), the TRAM flap was elevated, and PBM was administered immediately after the flap was sutured back to its bed for therapeutic purpose. PBM was applied in 48 hours interval from 10 cm. distance to the whole abdominal wall both in groups 2 and 3 for one week. After 7 days of postoperative follow-up, as the demarcation of necrosis of the skin paddle was obvious, skin flap survival was further evaluated by macroscopic, histological and microangiographic analysis.

RESULTS

The mean percentage of skin flap necrosis was 56.17 ± 23.68 for group 1, 30.92 ± 17.46 for group 2 and 22.73 ± 12.98 for group 3 PBM receiving groups 2 and 3 revealed less necrosis when compared to control group and this difference was statistically significant. Vascularization in zone 4 of PBM applied groups 2 and 3 was higher compared to group 1 (P = 0.001). Acute inflammation in zone 4 of group 1 was significantly higher compared to groups 2 and 3 (P = 0.025). Similarly, evaluation of zone 1 of the flaps reveled more inflammation and less vascularization among the samples of the control group (P = 0.006 and P = 0.007, respectively). Comparison of PBM receiving two groups did not demonstrate further difference in means of vascularization and inflammation density (P = 0.259).

CONCLUSION

Application of PBM in polychromatic fashion enhances skin flap survival in experimental TRAM flap model both on preoperative basis as a delay procedure or as a therapeutic approach. Lasers Surg. 51:538-549, 2019. © 2019 Wiley Periodicals, Inc.

Improvement in infected wound healing in type 1 diabetic rat by the synergistic effect of photobiomodulation therapy and conditioned medium

We investigated the effects of photobiomodulation therapy (PBMT) and conditioned medium (CM) of human bone marrow mesenchymal stem cells (hBM-MSC) individually and/or in combination on the stereological parameters and the expression of basic fibroblast growth factor (bFGF), hypoxia-inducible factor (HIF-1α), and stromal cell-derived factor-1α (SDF-1α) in a wound model infected with methicillin-resistant Staphylococcus aureus (MRSA) in diabetic rats. CM was provided by culturing hBM-MSCs. Type 1 diabetes mellitus (T1DM) was induced in 72 rats, divided into four groups, harboring 18 rats each: group 1 served as a control group, group 2 received PBMT, group 3 received CM, and group 4 received CM + PBMT. On days 4, 7, and 15, six animals from each group were euthanized and the skin samples were separated for stereology examination and gene expression analysis by real-time polymerase chain reaction. In the CM + PBMT, CM, and PBMT groups, significant decreases were induced in the number of neutrophils (1460 ± 93, 1854 ± 138, 1719 ± 248) and macrophages (539 ± 69, 804 ± 63, 912 ± 41), and significant increases in the number of fibroblasts (1073 ± 116, 836 ± 75, 912 ± 41) and angiogenesis (15 230 ± 516, 13 318 ± 1116, 14 041 ± 867), compared with those of the control group (2690 ± 371, 1139 ± 145, 566 ± 90, 12 585 ± 1219). Interestingly, the findings of the stereological examination in the CM + PBMT group were statistically more significant than those in the other groups. In the PBMT group, in most cases, the expression of bFGF, HIF-1α, and SDF-1α, on day 4 (27.7 ± 0.14, 28.8 ± 0.52, 27.5 ± 0.54) and day 7 (26.8 ± 1.4, 29.6 ± 1.4, 28.3 ± 1.2) were more significant than those in the control (day 4, 19.3 ± 0.42, 25.5 ± 0.08, 22.6 ± 0.04; day 7, 22.3 ± 0.22, 28.3 ± 0.59, 24.3 ± 0.19) and other treatment groups. The application of PBMT + CM induced anti-inflammatory and angiogenic activities, and hastened wound healing process in a T1 DM model of MRSA infected wound.

An improvement in acute wound healing in mice by the combined application of photobiomodulation and curcumin-loaded iron particles

Here, we examined the combined effect of pulse wave photobiomodulation (PBM) with curcumin-loaded superparamagnetic iron oxide (Fe₃O₄) nanoparticles (curcumin), in an experimental mouse model of acute skin wound. Thirty male adult mice were randomly allocated into 5 groups. Group 1 was served as the control group. Group 2 was a placebo and received distilled water, as a carrier of curcumin. Group 3 received laser (890 nm, 80 Hz, 0.2 J/cm²). Group 4 received curcumin by taking four injections around the wound. Group 5 received laser + curcumin. One full-thickness excisional round wound was made on the back of all the mice. On days 0, 4, 7, and 14, bacterial flora, wound surface area, and tensile strength were examined and microbiological examinations were performed. In case of wound closure, the two-way ANOVA shows that wound surface area of entire groups decreased progressively. However, the decrease in laser + curcumin and laser groups, and especially data from laser + curcumin group were statistically more significant, in comparison with the other groups (F statistics = 2.28, sig = 0.019). In terms of microbiology, the two-way ANOVA showed that laser, and laser + curcumin groups have statistically a lower bacterial count than the curcumin, control, and carrier groups (F statistics = 35, sig = 0 = 000). Finally, the one-way ANOVA showed that laser + curcumin, curcumin, and curcumin significantly increased wound strength, compared to the control and carrier groups. Furthermore, laser + curcumin significantly increased wound strength, compared to the control, laser, and curcumin groups (LSD test, p = 0.003, p = 0.002, and p = 0.005, respectively). In conclusion, curcumin nanoparticles, pulse wave laser, and pulse wave laser + curcumin nanoparticles accelerate wound healing, through a significant increase in wound closure rate, as well as wound strength, and a significant decrease in Staphylococcus aureus counts. Furthermore, the statistical analysis of our data suggests that the combined treatment of pulse wave laser + curcumin nanoparticles enhances the wound closure rate, and wound strength, compared to the laser and curcumin nanoparticles alone.

Stereological and molecular studies on the combined effects of photobiomodulation and human bone marrow mesenchymal stem cell conditioned medium on wound healing in diabetic rats

We investigated the effects of conditioned medium (CM) from human bone marrow mesenchymal stem cells (h BMMSC)s and pulse wave photobiomodulation (PW PBM), applied alone or in combination, on the stereological parameters and gene expression of some growth factors, during wound healing in a streptozotocin (STZ)-induced rat model of type one diabetes mellitus (T1DM). T1DM was induced in 72 rats and two incisions were made in each animal. The rats were assigned to one of four groups: a control (placebo) group, a Laser group (890 nm, 80 Hz, 0.2 J/cm²); a CM group, and a combined CM + Laser group. On post-surgical days 4, 7, and 15, skin samples were extracted for stereology and reverse transcription PCR (RT-PCR) analyses of gene expression of basic fibroblast growth factor (bFGF), hypoxia-inducible factor (HIF-1α), and stromal cell-derived factor-1α (SDF-1α). The stereological examinations of the proximal and distal wounds revealed significantly enhanced healing in all the treated groups, compared to the control group. The extent of healing was significantly greater in the CM + Laser group than in the other treatment groups. The RT-PCR results also indicated greater gene expression in the CM + Laser and Laser groups than in the CM and control groups. Application of CM and PW PBM, alone or in combination accelerated the process of wound healing in T1DM rats. The results of combined application of CM and PW PBM, indicated a synergistic effect, and the combination treatment was statistically more effective than single applications of CM or PW PBM.

The effect of combined photobiomodulation and curcumin on skin wound healing in type I diabetes in rats

The purpose of the present scientific study was to analyze the effects of combined pulsed wave Photobiomodulation (PW PBM) and Curcumin on the microbial flora; in addition, the tensiometrical wounds properties for type one diabetes mellitus (TIDM) in an experimental animal model. TIDM induction was performed in thirty rats. In the entire animals, one full-thickness excision was implemented on their backs. Randomly, the divisions of rats into 5 groups took place. The primary group was considered as the control group and did not receive any treatment. The secondary group (placebo) received sesame oil by gastric gavage. The third group received PWPBM (890 nm, 80 Hz, 0.2 J/cm²). The fourth group received curcumin (40 mg/kg, which was dissolved in sesame oil) by gastric gavage. Eventually, the fifth group received PW PBM + curcumin. Precisely, on day 7, microbiological examinations, and on the 15th day microbiological and tensiometrical examinations were conducted. The data were analyzed by statistical tests. PW PBM, significantly exacerbated tensiometrical properties of the TIDM repairing wound. PW PBM, curcumin, and PWPBM + curcumin significantly decreased colony forming units compared to the control and the placebo groups indeed. It was remarkably attained that PW PBM significantly accelerated the process of wound healing in the STZ-induced TIDM. The PW PBM was statistically more compelling compared to the curcumin and PWPBM + curcumin. PW PBM, curcumin, and PWPBM + curcumin significantly decreased colony forming units compared to the control and placebo groups.

The effect of combined photobiomodulation and metformin on open skin wound healing in a non-genetic model of type II diabetes

This study intended to examine the combined influences of photobiomodulation (PBM) and metformin on the microbial flora and biomechanical parameters of wounds in a non-genetic model of type II diabetes mellitus (TII DM). We induced a non-genetic model of TII DM in 20 rats by feeding them a 10% fructose solution for 2weeks followed by an injection of streptozotocin (STZ, 40mg/kg). After 21days from the injection of STZ, we induced one full-thickness skin wound in each of the diabetic rats. We randomly divided the rats into four groups: i) placebo; ii) pulsed wave laser (890nm, 80Hz, 0.324J/cm²); iii) metformin; and iv) laser+metformin. Rats received daily intraperitoneal injections of metformin (50mg/kg). On days 7and 15 we inspected the microbial flora of each wound. On day 15 we obtained a standard sample from each healing wound for biomechanical analyses. PBM significantly decreased colony-forming units (CFUs) 7days after wound infliction compared to the placebo group (LSD test, p=0.012). Metformin significantly enhanced the biomechanical property (stress high load) of the wounds compared to the placebo group (LSD test, p=0.028). We observed the same significant result for PBM compared to the placebo group (LSD test, p=0.047). PBM significantly accelerated the wound healing process and significantly reduced CFUs of bacteria in a non-genetic rat model of TII DM.

Effect of low-level laser therapy on bisphosphonate-treated osteoblasts

BACKGROUND

This study investigates the effect of alendronate-treated osteoblasts, as well as the effect of low-level laser therapy (LLLT) on the alendronate-treated osteoblasts. Bisphosphonate decreases the osteoblastic activity. Various treatment modalities are used to enhance the bisphosphonate-treated osteoblasts; however, there were no cell culture studies conducted using a low-level laser.

METHODS

Human fetal osteoblastic (hFOB 1.19) cells were treated with 50 μM alendronate. Then, they were irradiated with a 1.2 J/cm2 low-level Ga-Al-As laser (λ = 808 ± 3 nm, 80 mW, and 80 mA; spot size, 1 cm2; NDLux, Seoul, Korea). The cell survivability was measured with the MTT assay. The three cytokines of osteoblasts, receptor activator of nuclear factor κB ligand (RANKL), osteoprotegerin (OPG), and macrophage colony-stimulating factor (M-CSF) were analyzed.

RESULTS

In the cells treated with alendronate at concentrations of 50 μM and higher, cell survivability significantly decreased after 48 h (p < 0.05). After the applications of low-level laser on alendronate-treated cells, cell survivability significantly increased at 72 h (p < 0.05). The expressions of OPG, RANKL, and M-CSF have decreased via the alendronate. The RANKL and M-CSF expressions have increased, but the OPG was not significantly affected by the LLLT.

CONCLUSIONS

The LLLT does not affect the OPG expression in the hFOB cell line, but it may increase the RANKL and M-CSF expressions, thereby resulting in positive effects on osteoclastogenesis and bone remodeling.

The Effect of Combined Pulsed Wave Low-Level Laser Therapy and Human Bone Marrow Mesenchymal Stem Cell-Conditioned Medium on Open Skin Wound Healing in Diabetic Rats

OBJECTIVE

The nobility of this scientific study was to investigate the combined effects of pulsed wave low-level laser therapy (PWLLLT) and human bone marrow mesenchymal stem cell-conditioned medium (hBM-MSC-CM) on the biomechanical parameters of wounds in an experimental model for diabetes mellitus (DM).

BACKGROUND DATA

PWLLLT exhibited biostimulatory effects on wounds in diabetic animals. Secretomes can be administered into wounds by the use of BM-MSC-CM.

MATERIALS AND METHODS

Type I DM was induced in rats by streptozotocin (STZ). Two wounds were made on proximal and distal parts in the dorsal region of each rat. Rats were divided into four groups. The first group was considered as the control group. The second group received hBM-MSC-CM. The third group received PWLLLT. The fourth group received hBM-MSC-CM+LASER. hBM-MSC-CM was administrated twice intraperitoneally. The proximal wounds in the third and fourth groups were treated with a pulsed laser by 890 nm wavelength, 80 Hz frequency, and 0.2 J/cm(2) energy densities. On the 15th day, a standard sample from each healing wound was submitted for biomechanical examination. The data were analyzed by analysis of variance test.

RESULTS

PWLLLT and hBM-MSC-CM, alone or in combination, significantly increased biomechanical parameters within the healing wounds. However, PWLLLT was statistically more effective compared with the hBM-MSC-CM. In the third and fourth groups, the numbers of wound closures were significantly enhanced in proximal part, contrary to the control ones.

CONCLUSIONS

It was magnificently attained that PWLLLT significantly accelerated the wound healing process in the experimental model for STZ-induced type I DM rats.

Is there a protocol in experimental skin wounds in rats using low-level diode laser therapy (LLDLT) combining or not red and infrared wavelengths? Systematic review

A systematic review addressing experiments with healing of skin wounds in rats using LLDLT with different active means seeking to identify a pattern in adjustments such as laser wavelength, power and fluency and analysing wound healing parameters, such as wound area, presence of fibroblasts, angiogenesis, leukocyte infiltration, epithelial coverage and antibacterial effect. It was perceived that a protocol does not exist in view of the wide variation in the use of power (9 to 500 mW) and fluency (1 to 60 J/cm2); however, between the different wavelengths, the highlight was the combined use of red and infrared wavelengths showing better results than when used alone.

Histological and gene expression analysis of the effects of pulsed low-level laser therapy on wound healing of streptozotocin-induced diabetic rats

Diabetes mellitus (DM) is associated with poor wound healing. Studies have shown accelerated wound healing following pulsed low-level laser therapy (LLLT) in non-diabetic animals. The present study aims to evaluate the effect of pulsed LLLT on wound healing in streptozotocin-induced diabetic (STZ-D) rats. We divided 48 rats into two groups of non-diabetic and diabetic. Type 1 DM was induced in the diabetic rat group by injections of STZ. Two, full-thickness skin incisions were made on the dorsal region of each rat. One month after the STZ injection, wounds of the non-diabetic and diabetic rats were submitted to a pulsed, infrared 890-nm laser with an 80-Hz frequency and 0.2 J/cm(2) for each wound point. Control wounds did not receive LLLT. Animals were sacrificed on days 4, 7, and 15 post-injury for histomorphometry and reverse transcription polymerase chain reaction (RT-PCR) analyses of basic fibroblast growth factor (bFGF) gene expression. Pulsed LLLT significantly increased the numbers of macrophages, fibroblasts, and blood vessel sections compared to the corresponding control groups. Semi-quantitative analysis of bFGF gene expression at 48 h post-injury revealed a significant increase in gene expression in both non-diabetic and diabetic rats following LLLT (the ANOVA test). Pulsed LLLT at 0.2 J/cm(2) accelerated the wound healing process in both non-diabetic and diabetic rats as measured by histological characteristics and semi-quantitative bFGF gene expression.

Effect of pulsed Nd:YAG laser in the treatment of neuropathic foot ulcers in children with spina bifida: a randomized controlled study

OBJECTIVE

This study assessed the effects of pulsed Nd:YAG laser treatment of neuropathic foot ulcers in children with spina bifida.

BACKGROUND DATA

Children with spina bifida face increased risk for developing neuropathic foot ulcers.

METHODS

In a randomized controlled trial, 39 children and adolescents (ages 6-15 years) with spina bifida and stage III neuropathic foot ulcers were randomly assigned to the laser group or the placebo laser group. The former received pulsed Nd:YAG laser treatments (i.e., total energy of 300-350 J during three sessions/week) plus standard wound care, and the latter received sham laser treatments plus standard wound care. Wound size and wound appearance were assessed for all patients at the beginning of the treatment, after 5 weeks, and after 10 weeks.

RESULTS

The decrease in wound surface area at 5 and 10 weeks post- treatment was significantly greater in the laser group (i.e., 2.44 ± 0.33 and 0.29 ± 0.25 cm(2), respectively) than in the placebo group (i.e., 3.81 ± 0.18 and 3.24 ± 0.44 cm(2), respectively). Also, the decrease in the total score for the Pressure Sore Status Tool (PSST) at 5 and 10 weeks post-treatment was significantly different for the laser group (i.e., 32.76 ± 2.30 and 17.52 ± 1.66, respectively) than for the placebo group (i.e., 46.50 ± 2.12 and 38.11 ± 3.17, respectively).

CONCLUSIONS

Treatment with pulsed neodymium:yttrium aluminum garnet (Nd:YAG) laser combined with standard wound care decreases wound size and improves wound appearance for stage III neuropathic foot ulcers in children with spina bifida.

Comparative study of the effects of laser photobiomodulation and extract of Brassica oleracea on skin wounds in wistar rats: A histomorphometric study

The objective of this study was to investigate the effect of a photobiomodulation laser and Brassica oleracea on tissue morphology in skin wounds. The parameters analyzed were type I and III collagen fibers, and thickness and surface density of the epithelial tissue, as well as how quickly the wound closed. Five skin wounds 12mm in diameter were made on the backs of the animals, which were randomized into four groups (8 animals each). Saline Group: 0.9% saline solution; Ointment Group (extract of Cabbage, B. oleracea, 10% lanolin); Balsam Group (10% glycolic extract of B. oleracea emulsion oil); L60 Group (laser GaAsAl 60J/cm(2)). The applications were made daily during a 20-day treatment, and every 4 days tissue from different wounds was removed. The reduction in the size of the wounds on the 4th, 8th, 12th and 16th days was significantly greater in the treated groups compared to the control group. At all the time points analyzed, there was a greater proportion of collagen in the Balsam and L60 groups (p<0.05). There was also a greater proliferation of epithelial cells in the L60 and Balsam groups after 20 days of treatment (p<0.05). The healing extract and laser 60j/cm(2) exerted a great effect on collagen proliferation in stimulating scar tissue maturation.

Mechanisms of action for light therapy: a review of molecular interactions

Five decades after the first documented use of a laser for wound healing, research in light therapy has yet to elucidate the underlying biochemical pathways causing its effects. The aim of this review is to summarize the current research into the biochemical mechanisms of light therapy in order to better direct future studies. The implication of cytochrome c oxidase as the photoacceptor modulating light therapy is reviewed, as are the predominant hypotheses of the biochemical pathways involved in the stimulation of wound healing, cellular proliferation, production of transcription factors and other reported stimulatory effects.

Shining light on nanotechnology to help repair and regeneration

Phototherapy can be used in two completely different but complementary therapeutic applications. While low level laser (or light) therapy (LLLT) uses red or near-infrared light alone to reduce inflammation, pain and stimulate tissue repair and regeneration, photodynamic therapy (PDT) uses the combination of light plus non-toxic dyes (called photosensitizers) to produce reactive oxygen species that can kill infectious microorganisms and cancer cells or destroy unwanted tissue (neo-vascularization in the choroid, atherosclerotic plaques in the arteries). The recent development of nanotechnology applied to medicine (nanomedicine) has opened a new front of advancement in the field of phototherapy and has provided hope for the development of nanoscale drug delivery platforms for effective killing of pathological cells and to promote repair and regeneration. Despite the well-known beneficial effects of phototherapy and nanomaterials in producing the killing of unwanted cells and promoting repair and regeneration, there are few reports that combine all three elements i.e. phototherapy, nanotechnology and, tissue repair and regeneration. However, these areas in all possible binary combinations have been addressed by many workers. The present review aims at highlighting the combined multi-model applications of phototherapy, nanotechnology and, reparative and regeneration medicine and outlines current strategies, future applications and limitations of nanoscale-assisted phototherapy for the management of cancers, microbial infections and other diseases, and to promote tissue repair and regeneration.