Photobiomodulation with Pulsed and Continuous Wave Near-Infrared Laser (810 nm, Al-Ga-As) Augments Dermal Wound Healing in Immunosuppressed Rats

Abstract

Chronic non-healing cutaneous wounds are often vulnerable in one or more repair phases that prevent normal healing and pose challenges to the use of conventional wound care modalities. In immunosuppressed subject, the sequential stages of healing get hampered, which may be the consequences of dysregulated or stagnant wound inflammation. Photobiomodulation (PBM) or low-level laser (light) therapy (LLLT) emerges as a promising drug-free, non-invasive biophysical approach for promoting wound healing, reduction of inflammation, pain and restoration of functions. The present study was therefore undertaken to evaluate the photobiomodulatory effects of 810 nm diode laser (40 mW/cm2; 22.6 J/cm2) with pulsed (10 and 100 Hz, 50% duty cycle) and continuous wave on full-thickness excision-type dermal wound healing in hydrocortisone-induced immunosuppressed rats. Results clearly delineated that 810 nm PBM at 10 Hz was more effective over continuous and 100 Hz frequency in accelerating wound healing by attenuating the pro-inflammatory markers (NF-kB, TNF-α), augmenting wound contraction (α-SM actin), enhancing cellular proliferation, ECM deposition, neovascularization (HIF-1α, VEGF), re-epithelialization along with up-regulated protein expression of FGFR-1, Fibronectin, HSP-90 and TGF-β2 as compared to the non-irradiated controls. Additionally, 810 nm laser irradiation significantly increased CCO activity and cellular ATP contents. Overall, the findings from this study might broaden the current biological mechanism that could be responsible for photobiomodulatory effect mediated through pulsed NIR 810 nm laser (10 Hz) for promoting dermal wound healing in immunosuppressed subjects.

Light‐emitting diode irradiation using 660 nm promotes human fibroblast HSP90 expression and changes cellular activity and morphology

“…However, considering the other outcomes in current study such as MTT analysis showing the viability of the cells, it is highly probable that these cells are proliferating rather that dying. In line with other reports showing that light energy aided wound-healing [15,20,21], our results suggest that LEDs exert such an effect.…”

“…Increased HSP expression after irradiation has been previously documented [20,[22][23][24], including within fibroblasts [22]. Small HSPs such as HSP27 are thought to affect the synthesis of ATP and reactive oxygen species [22,25] and to play roles in various diseases.…”

A Comprehensive Analysis of Near‐Contact Photobiomodulation Therapy in the Host–Bacteria Interaction Model Using 3D‐Printed Modular LED Platform

“…It has been reported that pulsed wave (PW) light therapy can be more effective than continuous wave (CW) light therapy in some biological systems 26–28. To compare the efficacy of PBM therapy on anti‐inflammation activity in the LPS involved host–bacteria interaction model, we examined the cell viability and cytokine productions under low or high pulse frequency conditions (5 or 500 Hz; Figure 5 ).…”

Photobiomodulation Does Not Influence Maturation and Leads to Mild Improvements in Functional Healing of Mouse Achilles Tendons

“…PBM therapy can reduce rehabilitation time and improve treatment outcomes when implemented in physical therapy and outpatient clinics. 14–19 PBM therapy is the application of near-infrared light to increase cellular metabolism, including ATP 20 and collagen production 21,22 . PBM use in muscle can activate mitochondria, 23–25 yet it is unclear if the cellular mechanism of PBM is the same during tendon maturation and healing.…”