Ultra-low-level laser therapy

Emerging near-infrared targeting diagnostic and therapeutic strategies for ischemic cardiovascular and cerebrovascular diseases

Ischemic cardiovascular and cerebrovascular diseases (ICCDs), including thrombosis, ischemic stroke and atherosclerosis, represent a significant threat to human health, and there is an urgent requirement for the implementation of emerging diagnostic and therapeutic approaches to improve symptoms and prognosis. As a promising noninvasive modality offering high spatial and temporal resolution with favorable biocompatible properties, near-infrared (NIR) light has demonstrated a vast and profound potential in the biomedical field in recent years. Meanwhile, nanomedicine carriers are undergoing rapid development due to their high specific surface area, elevated drug loading capacity, and unique physicochemical properties. The combination of NIR light with targeted nanoprobes modified with different functional components not only maintains the high penetration depth of NIR irradiation in biological tissues but also significantly enhances the targeting specificity at the lesion site. This strategy allows for the realization of on-demand drug release and photothermal effects, thus inspiring promising avenues for the diagnosis and treatment of ICCDs. However, the clinical translation of NIR imaging and therapy is still hindered by significant obstacles. The existing literature has provided a comprehensive overview of the advancements in NIR-based nanomedicine research. However, there is a notable absence of reviews that summarize the NIR-mediated targeting strategies against ICCDs in imaging and therapy. Therefore, this review concludes the application of the emerging targeting probes combined with NIR radiation for ICCDs classified by molecular targets, analyzes the current challenges, and provides improvement strategies and prospects for further clinical translation. STATEMENT OF SIGNIFICANCE: Ischemic cardiovascular and cerebrovascular diseases (ICCDs) represent a significant threat to human health. Recently, near-infrared (NIR) light combined with targeting probes have been employed for the diagnosis and treatment of ICCDs, offering exceptional advantages including rapid feedback, high penetration depth, on-demand drug release, and favorable biocompatibility. However, there is a notable absence of reviews that summarize the NIR light-mediated targeting strategies for the imaging and therapy of ICCDs. Therefore, this review summarizes the emerging targeting probes combined with NIR light classified by molecular targets, and the proposes potential improvement strategies for clinical translation. This review elucidates the potential and current status of NIR-based techniques in ICCDs, while also serving as a reference point for additional targeted therapeutic strategies for ICCDs.

Phototherapy for age-related brain diseases: Challenges, successes and future

Brain diseases present a significant obstacle to both global health and economic progress, owing to their elusive pathogenesis and the limited effectiveness of pharmaceutical interventions. Phototherapy has emerged as a promising non-invasive therapeutic modality for addressing age-related brain disorders, including stroke, Alzheimer's disease (AD), and Parkinson's disease (PD), among others. This review examines the recent progressions in phototherapeutic interventions. Firstly, the article elucidates the various wavelengths of visible light that possess the capability to penetrate the skin and skull, as well as the pathways of light stimulation, encompassing the eyes, skin, veins, and skull. Secondly, it deliberates on the molecular mechanisms of visible light on photosensitive proteins, within the context of brain disorders and other molecular pathways of light modulation. Lastly, the practical application of phototherapy in diverse clinical neurological disorders is indicated. Additionally, this review presents novel approaches that combine phototherapy and pharmacological interventions. Moreover, it outlines the limitations of phototherapeutics and proposes innovative strategies to improve the treatment of cerebral disorders.

Effect of 650 nm laser photobiomodulation therapy on the HT-7 (shenmen) acupoint in the Mus musculus model of Parkinson's disease

Background

Parkinson's disease is one of the neurodegenerative conditions that impacts 1-2% of the world's population. The only effective therapy for this condition today is to restore the biochemical function of the diseased dopamine neurons by giving them Levodopa or L-3,4-dihydroxyphenylalanine (l-DOPA). The risk of progenitor stem cells, though, is the growth of teratomas or the uncontrolled growth of cells. As a result, an alternative or additional method is needed, such as photobiomodulation therapy using a laser diode. In this research, male mice (Mus musculus), which were used as models for Parkinson's disease in an in vivo paraquat study, to determine the optimal dose of photobiomodulation therapy and a laser diode was used as a treatment.

Methods

The three sample groups are Group P-L- (control group, induced by 0.9% NaCl), Group P + L- (only caused by paraquat), and Group P + L+. (Treatment group, treated by paraquat and photobiomodulation therapy with a laser diode). Photobiomodulation treatment doses of 0.14 J, 0.29 J, 0.37 J, 0.76 J, 1.14 J, and 1.52 J were used in the P+L+ subgroups (6 groups). The laser diode generated a continuous wave with a wavelength of 658 nm, a beam spot of 2.10 mm, and an output power of 15.42 mW. After treatment, the histopathology results of each sample were inspected under a microscope.

Result

In Parkinson's disease-affected mice, paraquat has been shown to reduce the number of neurons. According to the results of the histopathological examination, photobiomodulation therapy using a laser diode (P + L+) on the HT-7 (Shenmen) may raise the quantity of neurons and the proportion of healthy cells in the mouse brain.

Conclusion

The effective radiated energy of the photobiomodulation therapy using laser diode treatment on the muscle musculus cell model of Parkinson's disease is 0.76 J.

Effect of preemptive photobiomodulation associated with nimesulide on the postsurgical outcomes, oxidative stress, and quality of life after third molar surgery: a randomized, split-mouth, controlled clinical trial

OBJECTIVE

The aim of this study is to compare the effect of photobiomodulation with low-level laser therapy (LLLT) and nimesulide on inflammatory parameters, biomarkers of oxidative stress and inflammation, and quality of life after lower third molar (L3M) surgery.

MATERIAL AND METHODS

A randomized, two-factor, triple-blind, controlled, split-mouth clinical trial was performed with 40 volunteers who required bilateral L3M removal. Patients were allocated depending on the use or not of 100 mg nimesulide 1 hbefore surgery, as well as the use or not of LLLT in the preoperative period.

RESULTS

Pain peaks occurred after 6 h (nimesulide-placebo [N-P] group) and 8 h (nimesulide group). In the N-P group, LLLT resulted in significantly lower mean pain scores than the subgroup without LLLT after 4 h (p = 0.009) and 6 h (p = 0.048). As for edema, a shorter distance between the mandibular angle and the outer canthus of the eyes after 7 days (p = 0.037) and a smaller cumulative effect (p = 0.036) were observed in the N-P group associated with LLLT. A direct effect between LLLT (p = 0.047) and a reduction in the mean scores of overall dissatisfaction with quality of life was detected.

CONCLUSIONS

Preemptive use of nimesulide only delayed peak pain. LLLT reduced edema, trismus, and contributed to a better perception of quality of life. Nimesulide inhibits peroxidation by increasing GSH and stopping neutrophil migration. The benefit of the association of both strategies was not superior to the use of LLLT alone.

CLINICAL RELEVANCE

Translational study with impact on clinical-surgical protocols involving L3M surgery related to pharmacological and non-pharmacological methods.

Analysis of the psychopathological profile, quality of life, and cost-effectiveness of oral lichen planus patients treated with photobiomodulation

OBJECTIVES

To evaluate the effect of PBM on the psychological profile and quality of life of patients with oral lichen planus (OLP) in comparison to corticoid and to investigate the cost-effectiveness of both treatments.

MATERIALS AND METHODS

Patients were randomized into two groups: Control (clobetasol propionate 0.05%) and Photobiomodulation (660 nm, 100mW, 177 J/cm², 5 s, 0.5 J) twice a week for 30 days. The Hospital Anxiety and Depression Scale (HADS) and OHIP-14 were used in different treatment time points and at follow-up. The cost-effectiveness was calculated using the improvement in OHIP-14 after treatment.

RESULTS

OLP patients showed detected levels of anxiety, depression, and poor quality of life at baseline. No improvement in anxiety and depression was noticed after treatments. However, PBM and corticoid significantly improved the quality of life of OLP patients, considering the OHIP-14-T and the physical pain domain. The treatment with corticoid was more cost-effective than PBM.

CONCLUSIONS

Psychological distress was not improved after both treatments and PBM is as effective as corticoids in promoting a better quality of life in OLP patients, despite its higher cost.

CLINICAL RELEVANCE

This study highlights the need for additional therapeutic interventions in OLP patients, to early recognize and to manage the alterations in their psychological profile. Moreover, PBM is an effective therapy in OLP patient's quality of live and although it was a more expensive, the advantage of being a minimally invasive therapy associated with no side effects must be considered in clinical practice, especially in those patients with refractory disease.

TRIAL REGISTRATION

This study is registered at ClinicalTrials.gov; the registration number is NCT03320460, registered in 17/10/2017.

The effects of 808-nm near-infrared laser light irradiation on actin cytoskeleton reorganization in bone marrow mesenchymal stem cells

Tailoring the cell organelles and thus changing cell homeostatic behavior has permitted the discovery of fascinating metabolic features enabling enhanced viability, differentiation, or quenching inflammation. Recently, photobiomodulation (PBM) has been accredited as an effective cell manipulation technique with promising therapeutic potential. In this prospective, in vitro results revealed that 808-nm laser light emitted by a hand-piece with a flat-top profile at an irradiation set up of 60 J/cm2 (1 W, 1 W/cm²; 60 s, continuous wave) regulates bone marrow stromal cell (BMSC) differentiation toward osteogenesis. Considering the importance of actin cytoskeleton reorganization, which controls a range of cell metabolic activities, comprising shape change, proliferation and differentiation, the aim of the current work is to assess whether PBM therapy, using a flat-top hand-piece at higher-fluence irradiation on BMSCs, is able to switch photon signals into the stimulation of biochemical/differentiating pathways involving key activators that regulate de novo actin polymerization. Namely, for the first time, we unearthed the role of the flat-top hand-piece at higher-fluence irradiation on cytoskeletal characteristics of BMSCs. These novel findings meet the needs of novel therapeutically protocols provided by laser treatment and the manipulation of BMSCs as anti-inflammatory, osteo-inductive platforms.

Postoperative Analgesic Effects of Laserpuncture and Meloxicam in Bitches Submitted to Ovariohysterectomy

Background: This prospective, randomised and blind study investigated the efficacy of laserpuncture for postoperative pain management in dogs. Method: Sixteen bitches were sedated with acepromazine and randomly treated before ovariohysterectomy with meloxicam 0.2 mg·kg⁻¹ intramuscular or laserpuncture (wavelength 904 mm, frequency 124 Hz, potency 10 Joules, 100 s in each acupoint). Anaesthesia was performed with propofol, isoflurane/O₂, and fentanyl. The Glasgow Composite Measure Pain Scale (GCMPS) and Dynamic Interactive Visual Analog Scale (DIVAS) were used to evaluate postoperative pain before and for 24 h after surgery. Morphine was administrated as rescue analgesia when pain scores were ≥3.33 (GCMPS). Differences between treatments, time points, and amount of rescue analgesia between groups were investigated by the Mann–Whitney test and the area under the curve (AUC) for GCMPS, Friedman, and Chi-squared tests, respectively (p < 0.05). Results: Dogs treated with laserpuncture presented lower GCMPS AUC for 24 h and lower GCMPS scores at 2 and 4 h postoperatively (p = 0.04). Three dogs treated with meloxicam required postoperatively rescue analgesia against none treated with laserpuncture. Conclusions: In this preliminary study, laserpuncture mitigated postoperative pain in dogs following ovariohysterectomy, and the technique is a promising adjunct to perioperative pain management in dogs undergoing soft tissue surgery.

Ultra-Low-Level Laser Therapy and Acupuncture Libralux: What Is so Special?

Background: Contrary to the most credited theories on laser therapy that see power/energy as the major factors to its effectiveness, a technique using an extremely low power/energy laser stimulation to treat musculoskeletal pain and dysfunction is proposed. The stimulus consists of a 20 s train of modulated pulses with an average power below 0.02 mW and is applied on sequences of acupuncture points selected according to the impaired segment of the patient’s body. Methods: Modifications on the extracellular soft tissue matrix and on the “fascia” were sonographically demonstrated. Laboratory and clinical tests confirmed the effectiveness. Results: Responses similar to those experienced in acupuncture were observed. The device—a CE Class IIa certified medical device named Libralux—affords a clinically proven effectiveness exceeding 80% in the treatment of musculoskeletal conditions and associated motor dysfunctions. An average of just three application sessions was generally sufficient to overcome the dysfunction. Conclusions: The development of the method is supported by over 20 years of R&D activities, with a range of experiments discussed in several papers published in indexed peer-reviewed journals. A few considerations regarding the possible physiological action mechanisms involved are proposed in this paper.

Laser Acupuncture in Open-Angle Glaucoma Treatment: A Retrospective Study of Eye Blood Flow

Patients with glaucoma can show blood flow anomalies at the eye vessel level. A causal relationship is reasonably expected, but so far, it has not been demonstrated. Traditional Chinese medicine indicates that acupuncture can promote specific blood perfusion in specific body districts. Ninety-eight patients with open-angle glaucoma were treated with an ultralow light-level laser, according to a specific acupuncture protocol, and their blood flow was measured before and after a six-week treatment cycle. Doppler measurements showed significant modifications in both pulsatility and resistivity indexes. The most relevant outcome of this study is that the applied treatment demonstrated its effectiveness not only in vasodilation but also in perfusion control that seems to restore appropriate functionality. The protocol therefore should be investigated in future controlled studies and perhaps in other blood perfusion-related pathologies.

Treatment for neuropathic pain and chronic inflammation using LASER in animal models

The ST36 (Zusanli) acupuncture point is used to treat inflammatory processes, pain and gastrointestinal disturbs. For this reason, the aim of the present study was to evaluate the antinociceptive effect of Low-level Laser Treatment (LLLT) on ST36 acupoint using models of chronic nociception and inflammation. Male Swiss mice were treated with LLLT on ST36 30 minutes before the mechanical allodynia (von Frey) performed on the partial sciatic nerve ligation (PSNL) method and Complete Freund's Adjuvant (CFA). The results demonstrated that application of LLLT on ST36 inhibited the mechanical allodynia response induced by PSNL and CFA, with total reversion at 30 minutes after application. Long-term treatment of animals with LLLT on the same acupoint, once a day, also reduced the PNSL and CFA-induced mechanical allodynia response during 8 days of treatment. As conclusion, the results demonstrated that photonic stimulus on ST36 with LLLT produces antinociceptive effect in chronic models of nociception and inflammation. These findings suggest that LLLT may constitute an important therapeutic alternative to control chronic pain.

Low-level ultrahigh-frequency and ultrashort-pulse blue laser irradiation enhances osteoblast extracellular calcification by upregulating proliferation and differentiation via transient receptor potential vanilloid 1

BACKGROUND AND OBJECTIVE

Low-level laser irradiation (LLLI) exerts various biostimulative effects, including promotion of wound healing and bone formation; however, few studies have examined biostimulation using blue lasers. The purpose of this study was to investigate the effects of low-level ultrahigh-frequency (UHF) and ultrashort-pulse (USP) blue laser irradiation on osteoblasts.

STUDY DESIGN/ MATERIALS AND METHODS

The MC3T3-E1 osteoblast cell line was used in this study. Following LLLI with a 405 nm newly developed UHF-USP blue laser (80 MHz, 100 fs), osteoblast proliferation, and alkaline phosphatase (ALP) activity were assessed. In addition, mRNA levels of the osteoblast differentiation markers, runt-related transcription factor 2 (Runx2), osterix (Osx), alkaline phosphatase (Alp), and osteopontin (Opn) was evaluated, and extracellular calcification was quantified. To clarify the involvement of transient receptor potential (TRP) channels in LLLI-induced biostimulation, cells were treated prior to LLLI with capsazepine (CPZ), a selective inhibitor of TRP vanilloid 1 (TRPV1), and subsequent proliferation and ALP activity were measured.

RESULTS

LLLI with the 405 nm UHF-USP blue laser significantly enhanced cell proliferation and ALP activity, compared with the non-irradiated control and LLLI using continuous-wave mode, without significant temperature elevation. LLLI promoted osteoblast proliferation in a dose-dependent manner up to 9.4 J/cm² and significantly accelerated cell proliferation in in vitro wound healing assay. ALP activity was significantly enhanced at doses up to 5.6 J/cm² , and expression of Osx and Alp mRNAs was significantly increased compared to that of the control on days 3 and 7 following LLLI at 5.6 J/cm² . The extent of extracellular calcification was also significantly higher as a result of LLLI 3 weeks after the treatment. Measurement of TRPV1 protein expression on 0, 3, and 7 days post-irradiation revealed no differences between the LLLI and control groups; however, promotion of cell proliferation and ALP activity by LLLI was significantly inhibited by CPZ.

CONCLUSION

LLLI with a 405 nm UHF-USP blue laser enhances extracellular calcification of osteoblasts by upregulating proliferation and differentiation via TRPV1. Lasers Surg. Med. 50:340-352, 2018. © 2017 Wiley Periodicals, Inc.

Laser acupuncture-induced analgesic effect and molecular alterations in an incision pain model: a comparison with electroacupuncture-induced effects

Low-level laser acupuncture (LLLA) produces photobiomodulation through acupuncture point and is an alternative to low-level laser therapy. Although the analgesic effect of LLLA on chronic pain has been proven, its effect on acute postincisional pain has yet to be investigated. A plantar incision (PI) model was used to mimic human postsurgical pain. Male adult rats received GaAlAs laser irradiation at the right ST36 acupoint immediately after operation and on the following 4 days. Three laser treatment groups (two red laser groups with a 30- or 15-min treatment duration and one 30-min near-infrared laser group) were compared with sham LLLA and naive groups and an electroacupuncture (EA) group (separate study). Behavioral withdrawal thresholds of both hind paws were measured before and after incision. Expression of mitogen-activated protein kinases (p-ERK and p-p38), inducible nitric oxide synthase (iNOS), and tumor necrosis factor (TNF) in the spinal cord was analyzed. All three LLLA treatments attenuated post-PI tactile allodynia in the ipsilateral paw, but only the 30-min red laser treatment affected the contralateral paw and had similar efficacy to that of EA. All laser treatments barely reduced heat hyperalgesia in both hind paws. At 3 days after PI, the 30-min red laser group showed reversed increases of PI-induced p-ERK, p-p38, and iNOS but not TNF expression in the spinal cord. Repetitive LLLA treatments ameliorated PI-induced mechanical pain. The inhibition of multiple sensitization signals highlights the unique clinical role of LLLA. Thus, LLLA is an alternative to EA as an adjuvant for postoperative pain control.

The effect of light-emitting diode (590/830 nm)-based low-level laser therapy on posttraumatic edema of facial bone fracture patients

PURPOSE

Posttraumatic edema in facial bone fracture patients may interfere with the operation field and delay the schedule. Thus, swiftly reducing the edema alleviates patient discomfort and advances the operation date. Ice packing and compression bandages are often used for such a purpose, but such methods are often inconvenient for the face. In this study, we aim to analyze the effect of light-emitting diode (LED) (590/830 nm)-based low-level laser therapy (LLLT) in posttraumatic edema in facial bone fracture patients.

MATERIALS AND METHODS

We conducted a prospective cohort study of 40 patients who were admitted to a single institution for facial bone fracture. The patients were divided into two groups of 20 each, treated either with LLLT or with sham treatment light. We used an LLLT device that consists of planar LED-based arrays with double wavelengths 590 nm and 830 nm. The patients were treated with either true or sham light from posttraumatic day 1-5, twice a day. After each treatment, the volume of a patient's face was measured with a 3-dimensional camera. We analyzed and compared the changes in facial edema. The Wilcoxon rank sum test was conducted for statistical comparison of the two groups, and significance was set to the level of p < 0.05.

RESULTS

The sex ratio and mean age of the two groups were of little difference. The fracture sites included the nasal bone, orbital wall, zygomaticomaxillary bone, mandible, and frontal sinus. Mechanisms of injury included fall, assault, traffic accident, sports, and gunshot. The total operation rate of both groups was equal to 85%. Our analysis showed a 16.5% reduction of edema in the LLLT group and 7.3% in the sham light group. The edema reduction was statistically significantly greater in the LLLT group than in the sham light group (p < 0.047).

CONCLUSION

LED-based LLLT is recently receiving attention worldwide for its cost-effectiveness and large coverage area compared to traditional laser therapy. Recent studies support its effectiveness in various areas such as wound healing, skin rejuvenation, and pain alleviation. In this study, we treated facial bone fracture patients with LED-based LLLT, and showed its effectiveness in reducing posttraumatic edema.

Amblyopia: Can Laser Acupuncture be an Option?

This paper describes the results of the treatment of amblyopia in young patients using an unconventional laser-acupuncture technique. After obtaining satisfactory results in the treatment of a 14-year-old amblyopic girl, the treatment was applied to 13 amblyopic children aged 3-11 years, with an encouraging outcome. An ultralow-light-intensity laser with a square-wave modulated emission was applied over a sequence of acupuncture points. Each session lasted < 15 minutes, and the treatment was performed once a week in 6-week cycles. Patients were followed for several years to evaluate the long-term results and/or to extend the treatment. All except two of the treated patients showed a rapid increase in visual acuity after several treatment sessions. Some required retreatment for regressions in visual acuity. The need for medium-term treatment cycles seems, however, to suggest that results may not be stable for all individuals. Although acupuncture has already been proved to be effective in the treatment of amblyopia, the results reported in this paper suggest that laser acupuncture at ultra-low-light-intensity levels can provide similar, if not better, results to conventional acupuncture stimulation, but with higher patient compliance.

Prevention of Thyroidectomy Scars in Asian Adults With Low-Level Light Therapy

BACKGROUND

Abnormal wound-healing after thyroidectomy with a resulting scar is a common dermatologic consultation. Despite many medical and surgical approaches, prevention of postoperative scars is challenging.

OBJECTIVE

This study validated the efficacy and safety of low-level light therapy (LLLT) using an 830/590 nm light-emitting diode (LED)-based device for prevention of thyroidectomy scars.

METHODS AND MATERIALS

Thirty-five patients with linear surgical suture lines after thyroidectomy were treated with 830/590 nm LED-LLLT. Daily application of 60 J/cm (11 minutes) for 1 week starting on postoperative day 1 was followed by treatment 3 times per week for 3 additional weeks. The control group (n = 15) remained untreated. Scar-prevention effects were evaluated 1 and 3 months after thyroidectomy with colorimetric evaluation using a tristimulus-color analyzer. The Vancouver Scar Scale (VSS) score, global assessment, and a subjective satisfaction score (range: 1-4) were also determined.

RESULTS

Lightness (L*) and chrome values (a*) decreased significantly at the 3-month follow-up visit in the treatment group compared with those of controls. The average VSS and GAS scores were lower in the treatment group, whereas the subjective score was not significantly different.

CONCLUSION

Light-emitting diode based LLLT treatment suppressed the formation of scars after thyroidectomy and could be safely used without noticeable adverse effects.

Anti-inflammatory effect of laser acupuncture in ST36 (Zusanli) acupoint in mouse paw edema

Low-level laser therapy (LLLT) in acupuncture is a low-power laser applied to acupoints for providing luminous energy, capable to produce photobiological induction that results in biochemical, bioelectric, and bioenergetic effects. ST36 (Zusanli) is a point of acupuncture commonly used for treatment of several pathological alterations, such as inflammation, acute pain, and gastrointestinal disorders. In this study, we evaluated the anti-inflammatory effect of LLLT (830 nm, 4 J/cm(2)) in ST36 acupoint through the model of carrageenan-induced paw edema in mice and the possible mechanisms involved. Female Swiss mice were treated with LLLT in ST36 before the paw edema induction, which was measured by means of a digital micrometer and the temperature through a high-resolution digital thermograph. After this, the levels of reactive oxygen species (ROS), lipid hydroperoxides (LOOH), and reduced glutathione (GSH) were quantified. In another set of experiments, the paw edema was induced by bradykinin, histamine, and prostaglandin E2 (PGE2). LLLT in ST36 acupoint significantly inhibited the edema formation for 4 h after the carrageenan injection and reduced the paw temperature in 10 %. Furthermore, LLLT also reduced the levels of ROS (55 %) and LOOH (50 %) but, however, did not alter the GSH levels. LLLT in ST36 reduced the paw edema induced by bradykinin (30 min, 6 %, 60 min, 7 %), histamine (30 min, 11 %), and PGE2 (90 min, 10 %, 120 min, 16 %). In conclusion, these results prove that LLLT in ST36 acupoint produces a relevant anti-inflammatory effect, reducing edema, temperature, and free radicals levels in mice paw.

Biolite: A Patented Ultra-Low-Level Laser-Therapy Device for Treating Musculoskeletal Pain and Associated Impairments

After an excursus on state-of-the-art knowledge for low-level laser therapy (LLLT), Biolite, a patented ultra-low-level laser therapy device used to treat musculoskeletal pain and associated impairments, is presented. The application protocols include short stimulation of sequences of acupuncture points. The observed effects seem, however, to be far from those that might be expected after acupuncture. The primary effect seems more likely to be an extracellular soft-tissue matrix reaction. The development of the technique, the studies performed, and the evidence collected over > 10 years suggest that specifically modulated laser light can interact with human tissues at light fluences well under those previously considered as being capable of having any effect. Musculoskeletal pain very often becomes an autonomous dysfunction that is independent of the original injury and that can be effectively treated using specific peripheral acupuncture-like stimulation. Because such acupuncture is capable of reducing motor control "interferences" from noxious stimuli, it can improve motor control performance, thereby reducing the risk of falls in the elderly individuals. The proposal of acupuncture-derived protocols to be applied by Western physiotherapists using an ultra-low-level laser therapy device is a further "bridge" between two different, and sometimes very different, clinical worlds to better serve our patients.

In vitro exposure to very low-level laser modifies expression level of extracellular matrix protein RNAs and mitochondria dynamics in mouse embryonic fibroblasts

Background

Low-level lasers working at 633 or 670 nm and emitting extremely low power densities (Ultra Low Level Lasers - ULLL) exert an overall effect of photobiostimulation on cellular metabolism and energy balance. In previous studies, it was demonstrated that ULLL pulsed emission mode regulates neurite elongation in vitro and exerts protective action against oxidative stress.

Methods

In this study the action of ULLL supplied in both pulsed and continuous mode vs continuous LLL on fibroblast cultures (Mouse Embryonic Fibroblast-MEF) was tested, focusing on mitochondria network and the expression level of mRNA encoding for proteins involved in the cell-matrix adhesion.

Results

It was shown that ULLL at 670 nm, at extremely low average power output (0.21 mW/ cm²) and dose (4.3 mJ/ cm²), when dispensed in pulsed mode (PW), but not in continuous mode (CW) supplied at both at very low (0.21 mW/cm²) and low levels (500 mW/cm²), modifies mitochondria network dynamics, as well as expression level of mRNA encoding for selective matrix proteins in MEF, e.g. collagen type 1α1 and integrin α5.

Conclusions

We suggest that pulsatility, but not energy density, is crucial in regulating expression level of collagen I and integrin α5 in fibroblasts by ULLL.

Low-level laser stimulation on adipose-tissue-derived stem cell treatments for focal cerebral ischemia in rats

This study investigated the effects of large-area irradiation from a low-level laser on the proliferation and differentiation of i-ADSCs in neuronal cells. MTT assays indicated no significant difference between the amount of cells with (LS+) and without (LS−) laser treatment (P > 0.05). However, immunofluorescent staining and western blot analysis results indicated a significant increase in the neural stem-cell marker, nestin, following exposure to low-level laser irradiation (P < 0.05). Furthermore, stem cell implantation was applied to treat rats suffering from stroke. At 28 days posttreatment, the motor functions of the rats treated using i-ADSCs (LS+) did not differ greatly from those in the sham group and HE-stained brain tissue samples exhibited near-complete recovery with nearly no brain tissue damage. However, the motor functions of the rats treated using i-ADSCs (LS−) remained somewhat dysfunctional and tissue displayed necrotic scarring and voids. The western blot analysis also revealed significant expression of oligo-2 in the rats treated using i-ADSCs (LS+) as well as in the sham group (P < 0.05). The results demonstrated that low-level laser irradiation exerts a positive effect on the differentiation of i-ADSCs and can be employed to treat rats suffering from ischemic stroke to regain motor functions.

830 nm light-emitting diode low level light therapy (LED-LLLT) enhances wound healing: a preliminary study

BACKGROUND AND AIMS

The application of light-emitting diodes in a number of clinical fields is expanding rapidly since the development in the late 1990s of the NASA LED. Wound healing is one field where low level light therapy with LEDs (LED-LLLT) has attracted attention for both accelerating wound healing and controlling sequelae. The present study evaluated LED-LLLT in 5 wounds of various etiologies.

SUBJECTS AND METHODS

There were 5 patients with ages ranging from 7 to 54 years, comprising 2 males and 3 females. The study followed 5 wounds, namely 2 acute excoriation wounds; 1 acute/subacute dog bite with infection; 1 subacute post-filler ulcerated wound with necrotic ischemic tissue and secondary infection; and 1 subacute case of edema and infection of the lips with herpes simplex involvement after an illegal cosmetic tattoo operation. All patients were in varying degrees of pain. All wounds were treated with multiple sessions (daily, every other day or twice weekly) using an LED-LLLT system (830 nm, CW, irradiance of 100 mW/cm(2) and fluence of 60 J/cm(2)) till improvement was achieved.

RESULTS

Full wound healing and control of infection and discomfort were achieved in all patients, with wound condition-mediated treatment periods ranging from 1 to 8 weeks. No recurrence of the herpes simplex case was seen in a 4-month follow-up.

CONCLUSIONS

830 nm LED-LLLT successfully brought about accelerated healing in wounds of different etiologies and at different stages, and successfully controlled secondary infection. LED-LLLT was easy and pain-free to apply, and was well-tolerated by all patients. The good results warrant the design of controlled studies with a larger patient population.

Orange-to-red tunable picosecond pulses by frequency doubling in a diode-pumped PPKTP waveguide

A compact picosecond all-room-temperature orange-to-red tunable laser source in the spectral region between 600 and 627 nm is demonstrated. The tunable radiation is obtained by second-harmonic generation in a periodically poled potassium titanyl phosphate (PPKTP) multimode waveguide using a tunable quantum-dot external-cavity mode-locked laser. The maximum second-harmonic output peak power of 3.91 mW at 613 nm is achieved for 85.94 mW of launched pump peak power at 1226 nm, resulting in conversion efficiency of 4.55%.

Treating balance disorders by ultra-low-level laser stimulation of acupoints

BACKGROUND

Balance disorders, a widespread problem in the senior population, are very often related to painful musculoskeletal disabilities and/or to degenerative neurologic pathologies. In a previous work, we investigated the beneficial effects of acupuncture such as laser photobiostimulation, regardless of the etiological origin of the balance dysfunction.

AIMS

Attention was focused on two individuals showing balance deficits with different etiologies. One healthy control individual was receiving treatment, one healthy control individual did not receive any treatment. Balance performances were measured before and after ultra-low-level laser (ULLL) stimulation as a basis for the design of further investigations.

METHODS

Romberg's parameters were measured on a force platform. Of the four tested individuals, one showed dizziness symptoms, one was affected by a mild form of Parkinson's disease, and two showed no dysfunction and were used as controls.

RESULTS

It was found that a ULLL stimulation of peripheral Traditional Chinese Medicine (TCM) acupuncture points can be effective, regardless of the pathology.

DISCUSSION

A specific clinical analysis of the stability of the beneficial result as a function of homogeneous groups of dysfunctional individuals is needed.

ST36 laser acupuncture reduces pain-related behavior in rats: involvement of the opioidergic and serotonergic systems

Laser acupuncture is a modality of low-level light therapy used as an alternative to needling for the past three decades. Although it has proved effective for the treatment of various conditions, the mechanisms underlying its effects are not fully understood. To contribute to this understanding, this study was designed to (1) evaluate the antinociceptive effect of ST36 laser acupuncture (830 nm, 3 J/cm(2)) in rat models of acute nociception and (2) to investigate the opioidergic and serotonergic systems involvement in this effect. Our results demonstrate that ST36 laser acupuncture inhibited (36 ± 2 %) acetic acid-induced abdominal constrictions and both neurogenic (48 ± 7 %) and inflammatory (phase IIA 42 ± 8 % and phase IIB 83 ± 6 %) phases of formalin-induced nociceptive behavior. Moreover, the antinociceptive activity of laser irradiation in the acetic acid test was significantly reversed by preadministration of naloxone (1 mg/kg, nonselective opioid receptor antagonist), pindolol (1 mg/kg, subcutaneous; nonselective 5-HT 1A/B receptor antagonist), and ketanserin (1 mg/kg; selective 5-HT2A receptor antagonist) but not by ondansetron (1 mg/kg, selective 5-HT3 receptor antagonist). Taken together, our data demonstrate, for the first time, that (1) ST36 laser acupuncture elicited significant antinociceptive effect against acetic acid- and formalin-induced behavior in rats and that (2) this effect is mediated by activation of the opioidergic and serotonergic (5-HT1 and 5-HT2A receptors) systems.

The activation of directional stem cell motility by green light-emitting diode irradiation

Light-emitting diode (LED) irradiation is potentially a photostimulator to manipulate cell behavior by opsin-triggered phototransduction and thermal energy supply in living cells. Directional stem cell motility is critical for the efficiency and specificity of stem cells in tissue repair. We explored that green LED (530 nm) irradiation directed the human orbital fat stem cells (OFSCs) to migrate away from the LED light source through activation of extracellular signal-regulated kinases (ERK)/MAP kinase/p38 signaling pathway. ERK inhibitor selectively abrogated light-driven OFSC migration. Phosphorylation of these kinases as well as green LED irradiation-induced cell migration was facilitated by increasing adenosine triphosphate (ATP) production in OFSCs after green LED exposure, and which was thermal stress-independent mechanism. OFSCs, which are multi-potent mesenchymal stem cells isolated from human orbital fat tissue, constitutionally express three opsins, i.e. retinal pigment epithelium-derived rhodopsin homolog (RRH), encephalopsin (OPN3) and short-wave-sensitive opsin 1 (OPN1SW). However, only two non-visual opsins, i.e. RRH and OPN3, served as photoreceptors response to green LED irradiation-induced OFSC migration. In conclusion, stem cells are sensitive to green LED irradiation-induced directional cell migration through activation of ERK signaling pathway via a wavelength-dependent phototransduction.

Technical Parameters for Laser Acupuncture to Elicit Peripheral and Central Effects: State-of-the-Art and Short Guidelines Based on Results from the Medical University of Graz, the German Academy of Acupuncture, and the Scientific Literature

The scientific literature in the area of laser acupuncture is rather large; however, the actual mechanisms and effects have not yet been proven in detail. Since the early days of laser acupuncture, there are still many open questions concerning technical parameters of this innovative technique. In this paper, we report about the most important technical parameters (wavelength, output power, power density, energy density, dose range, and continuous or pulsed laser) for laser acupuncture and present quantitative results for optimal laser stimulation, which allow eliciting reproducible effects in the periphery and in the brain. There are several position statements on laser acupuncture and also several review articles in scientific literature concerning clinical effectiveness of laser acupuncture. For example, the Australian Medical Acupuncture College stated recently that "the optimal energy density for laser acupuncture and biostimulation, based on current clinical experience, is 4 J/cm(2)". However, our results of previous research studies and of this paper clearly show that dose must be adjusted according to the individual responses.

Sino-European transcontinental basic and clinical high-tech acupuncture studies-part 3: violet laser stimulation in anesthetized rats

The aim of this study was to determine the effect of violet laser stimulation on three acupuncture points in anesthetized rats and to test the hypothesis that violet laser light can modulate neurovegetative parameters like heart rate (HR), heart rate variability (HRV), and mean arterial blood pressure (MAP). Recordings were performed in 10 male anesthetized rats under three conditions in Beijing, and monitored with equipment from Graz, where also data analysis was performed. For stimulation a violet laser (emitted wavelength 405 nm, laser output 1 mW, continuous mode) was used. The electrocardiograms were recorded by an HRV Medilog AR12 system during laser acupuncture stimulation of the head, ear, and body (Baihui, "heart" ear acupoint, Zusanli). HR changed significantly only during (P = 0.013) and after (P = 0.038) stimulation at Baihui. Total HRV and the low frequency/high frequency ratio showed insignificant changes. There was an insignificant decrease in MAP after stimulation of Baihui acupoint. Violet laser stimulation offers a method to induce acute effects in HR and HRV in rats. Although the precise mechanism of this effect remains to be determined, alterations are significant. Violet laser stimulation on the Baihui acupoint could readily be translated to clinical studies.