Photo-infrared pulsed bio-modulation (PIPBM): a novel mechanism for the enhancement of physiologically reparative responses

Cationic Iridium(III) Complexes with Benzothiophene-Quinoline Ligands for Deep-Red Light-Emitting Electrochemical Cells

Three new cationic cyclometalated iridium(III) complexes equipped with differently substituted benzo[b]thiophen-2-ylquinoline cyclometalating ligands and with a sterically demanding tert-butyl-substituted 2,2'-bipyridine ancillary ligand were synthesized and structurally characterized by NMR and X-ray diffraction techniques. To tune the electronic properties of such complexes, the quinoline moiety of the cyclometalating ligands was kept pristine or equipped with electron-withdrawing phenyl and -CF₃ substituents, leading to complexes 1, 2, and 3, respectively. A complete electrochemical and photophysical investigation, supported by density functional theory calculations, permits a deep understanding of their electronic properties. The emission of all complexes arises from ligand-centered triplet states in the spectral range between 625 and 950 nm, with excited-state lifetimes between 2.10 and 6.32 μs at 298 K. The unsubstituted complex (1) exhibits the most blue-shifted emission in polymeric matrix at 298 K (λ_max = 667 nm, photoluminescence quantum yield (PLQY) = 0.25 and τ = 5.32 μs). The phenyl-substituted complex (2) displays the highest photoluminescent quantum yields (up to 0.30 in polymeric matrix), while the CF₃-substituted counterpart (3) shows the most red-shifted emission, peaking at approx. 720 nm, but with lower quantum yields (e.g., 0.10 in polymeric matrix at 298 K). Complexes 1 and 2 were tested in single-layer nondoped light-emitting electrochemical cells (LEECs), using a nozzle-printing technique; both devices display deep-red electroluminescence with an external quantum efficiency close to 20%.

Biological effects and medical applications of infrared radiation

Infrared (IR) radiation is electromagnetic radiation with wavelengths between 760nm and 100,000nm. Low-level light therapy (LLLT) or photobiomodulation (PBM) therapy generally employs light at red and near-infrared wavelengths (600-100nm) to modulate biological activity. Many factors, conditions, and parameters influence the therapeutic effects of IR, including fluence, irradiance, treatment timing and repetition, pulsing, and wavelength. Increasing evidence suggests that IR can carry out photostimulation and photobiomodulation effects particularly benefiting neural stimulation, wound healing, and cancer treatment. Nerve cells respond particularly well to IR, which has been proposed for a range of neurostimulation and neuromodulation applications, and recent progress in neural stimulation and regeneration are discussed in this review. The applications of IR therapy have moved on rapidly in recent years. For example, IR therapy has been developed that does not actually require an external power source, such as IR-emitting materials, and garments that can be powered by body heat alone. Another area of interest is the possible involvement of solar IR radiation in photoaging or photorejuvenation as opposites sides of the coin, and whether sunscreens should protect against solar IR? A better understanding of new developments and biological implications of IR could help us to improve therapeutic effectiveness or develop new methods of PBM using IR wavelengths.

Photobiomodulation of human adipose-derived stem cells using 810nm and 980nm lasers operates via different mechanisms of action

Photobiomodulation (PBM) using red or near-infrared (NIR) light has been used to stimulate the proliferation and differentiation of adipose-derived stem cells. The use of NIR wavelengths such as 810nm is reasonably well accepted to stimulate mitochondrial activity and ATP production via absorption of photons by cytochrome c oxidase. However, the mechanism of action of 980nm is less well understood. Here we study the effects of both wavelengths (810nm and 980nm) on adipose-derived stem cells in vitro. Both wavelengths showed a biphasic dose response, but 810nm had a peak dose response at 3J/cm² for stimulation of proliferation at 24h, while the peak dose for 980nm was 10-100 times lower at 0.03 or 0.3J/cm². Moreover, 980nm (but not 810nm) increased cytosolic calcium while decreasing mitochondrial calcium. The effects of 980nm could be blocked by calcium channel blockers (capsazepine for TRPV1 and SKF96365 for TRPC channels), which had no effect on 810nm. To test the hypothesis that the chromophore for 980nm was intracellular water, which could possibly form a microscopic temperature gradient upon laser irradiation, we added cold medium (4°C) during the light exposure, or pre-incubated the cells at 42°C, both of which abrogated the effect of 980nm but not 810nm. We conclude that 980nm affects temperature-gated calcium ion channels, while 810nm largely affects mitochondrial cytochrome c oxidase.

"Quantum Leap" in Photobiomodulation Therapy Ushers in a New Generation of Light-Based Treatments for Cancer and Other Complex Diseases: Perspective and Mini-Review

OBJECTIVE

Set within the context of the 2015 International Year of Light and Light-Based Technologies,and of a growing and aging world population with ever-rising healthcare needs, this perspective and mini-review focuses on photobiomodulation (PBM) therapy as an emerging, cost-effective, treatment option for cancer (i.e., solid tumors) and other complex diseases, particularly, of the eye (e.g., age-related macular degeneration, diabetic retinopathy, glaucoma, retinitis pigmentosa) and the central nervous system (e.g., Alzheimer's and Parkinson's disease).

BACKGROUND DATA

Over the last decades, primary and secondary mechanisms of PBM have been revealed. These include oxygen-dependent and oxygen-independent structural and functional action pathways. Signal and target characteristics determine biological outcome, which is optimal (or even positive) only within a given set of parameters.

METHODS

This study was a perspective and nonsystematic literature mini-review.

RESULTS

Studies support what we describe as a paradigm shift or "quantum leap" in the understanding and use of light and its interaction with water and other relevant photo-cceptors to restore physiologic function.

CONCLUSIONS

Based on existing evidence, it is argued that PBM therapy can raise the standard of care and improve the quality of life of patients for a fraction of the cost of many current approaches. PBM therapy can, therefore,benefit large, vulnerable population groups, including the elderly and the poor, whilehaving a major impact on medical practice and public finances.

Efficacy of LLLT in swelling and pain control after the extraction of lower impacted third molars

INTRODUCTION AND AIM

Low Level Laser Therapy (LLLT) can facilitate wound healing stimulating a more rapid resolution and an earlier start for the proliferation phase. The purpose of this study is to evaluate the effects of LLLT on postoperative pain and oedema following the removal of impacted lower third molars.

MATERIALS AND METHODS

Fifty-nine patients, who were to undergo surgical removal of their lower third molars, were studied. Patients were randomly allocated to one of three groups: 17 patients LLLT + traditional drug treatment17 patients traditional drug treatment as control group25 patients treated with LLLT only on one side+traditional drug treatment. The laser we have used for this study is a diode laser, GaAs, which delivers both in the infrared band at the wavelength of 910 nanometers (pulsed and superpulsed source), and in the visible (continuous source) at the wavelength of 650 nanometers (red). LLLT was performed just after the intervention and approximately 12 hours after surgery delivering 240 J in 15 minutes with theoretical fluence values of 480 J/cm(2) and 31 J/cm(2) for every minute of irradiation. We considered and signed with a label constant landmarks on both sides of the face of each patient; measurements were taken: before the surgery, after the surgery right after the 1st laser treatment, after approximately 24 hours after the 2(nd) laser treatment.

RESULTS

We collected all the values of the oedema measurements and the VAS reports and performed a statistical analysis by means One-way Analysis of Variance (ANOVA) test: for the evaluated values (X, Y, Z) an extremely significant difference was found with p values of 0.003 for Y at the first evaluation (pre-12 hours) and less than 0.001 for the other evaluations. A significant result was obtained for VAS recorded at hospital discharge (p<0.0001).

CONCLUSIONS

This study demonstrates that LLLT is effective on postoperative pain and oedema accelerating healing time and reducing patients distress.

Photobiomodulation of aqueous interfaces as selective rechargeable bio-batteries in complex diseases: personal view

OBJECTIVE

In this personal view, we propose that the modulation of the structure and function of water by light may come to embody a new mechanistic approach for the treatment of complex diseases.

BACKGROUND DATA

Long considered an innocuous medium, water has increasingly been found to be a key player in numerous mechanisms, including first-contact events in which cells decide between survival and apoptosis. Consequently, externally applied electromagnetic energy (light) may selectively target the organization of water to steer biological function.

METHODS

We survey light-water research with particular emphasis on the quasi-crystalline exclusion zone (EZ), part of the cell's aqueous interface that is just now beginning to be decoded. The current state of research, the technical challenges involved in obtaining evidence in biological systems, and some potential uses and implications of EZ water in medicine are presented.

RESULTS

Though existing data have not yet proven the role of EZ water in photobiomodulation, research shows that EZ water can store charge and can later return it in the form of current flow, with as much as 70% of the input charge being readily obtainable. Macroscopic separation of charges can be stable for days to weeks and has unusual electric potential. Water is, thus, an unexpectedly effective charge separation and storage medium.

CONCLUSIONS

We propose that the EZ may be selectively targeted in photobiomodulation as an efficient energy reservoir, which cells can use expeditiously to fuel cellular work, triggering signaling pathways and gene expression in the presence of injury-induced redox potentials.

Theoretic, experimental, clinical bases of the water oscillator hypothesis in near-infrared photobiomodulation

The objective of this review is to propose and document a role for the water oscillator in near-infrared (NIR) photobiomodulation. Greater understanding of the role of the water oscillator may add to a more-coherent description of central effects of NIR light on redox centers and key transmembrane enzymes such as cytochrome c oxidase (CcO). In addition, water provides a complementary pathway for absorption and transportation of NIR energy in photobiomodulation. Because of its unexpected potential, we propose terming it the "water oscillator paradox." Photobiologic mechanisms involved in the treatment of complex diseases are discussed in light of the present state of the art.

Irradiation at 634 nm releases nitric oxide from human monocytes

Previous studies have shown that irradiation at 634 nm decreases the release of extracellular reactive oxygen species (ROS) without affecting viability in human monocytes. Here, we examined the effect of irradiation at 634 nm on the release of nitric oxide (NO), activation of inducible nitric oxide synthase (iNOS) and endothelial NOS (eNOS), and release of intracellular ROS. Chemiluminescence assays were used to measure NO release, intracellular ROS, and adenosine triphosphate levels (to assess cell viability). Levels of iNOS and eNOS mRNA were analyzed using PCR. Irradiation resulted in elevated levels of NO but had no effect on iNOS or eNOS. Irradiation also caused a decrease in levels of intracellular ROS and had no effect on cell viability. Our studies indicate that irradiation at 634 nm releases NO, possibly from a preformed store, and reduces the production of intracellular ROS without affecting cell viability. Irradiation at 634 nm may have a wide range of clinical applications, including a reduction in oxidative stress-mediated injury in the vasculature.