Optimization of Photobiomodulation Dose in Biological Tissue by Adjusting the Focal Point of Lens

Photobiomodulation therapy (PBMT) in skeletal muscle regeneration: A comprehensive review of mechanisms, clinical applications, and future directions

Photobiomodulation therapy (PBMT) emerged as a significant non-invasive method of stimulating regeneration of the skeletal muscle tissue. This review considers the pathophysiologic and molecular mechanisms of muscle repair, with a focus on the imperative of inflammation resolution, activation of satellite cells, mitochondrial ATP generation, and angiogenesis, with consideration of the role of PBMT. We systematically evaluate preclinical and clinical studies, highlighting the translational gaps caused by differences between controlled experimental models and the complex, heterogeneous nature of human muscle injuries. Variability in PBMT parameters-such as wavelength, fluence, and pulse mode-and the lack of standardized protocols are identified as major barriers to consistent therapeutic outcomes. Furthermore, we discuss the effects of PBMT in acute and chronic muscle injury models and provide an in-depth analysis of laser parameters to elucidate dose-response relationships. Future directions for research involve the application of real-time biofeedback devices, the utilization of artificial intelligence-based individualized therapeutic approaches, as well as the integration of photobiomodulation therapy with nanotechnology, biomaterials, and multiple mechanical stimulation methods. In concusion, while PBMT has significant potential for muscle regeneration therapies, its clinical application requires more complete mechanistic validation, rigorous standardization, and interdisciplinary technological development.

Use of quantum hyperlight technology in photobiomodulation on stem cells: an experimental in vitro study

Human umbilical cord matrix Wharton's jelly mesenchymal stem cells (WJ-MSCs) are commonly utilized in regenerative medicine due to their therapeutic benefits. However, the microenvironmental stress present in patients with hyperglycemia can significantly reduce mesenchymal stem cell (MSC) viability under high-glucose conditions in the body, ultimately reducing their therapeutic effectiveness. Enhancing the survival rate of MSCs following cell transplantation remains a crucial challenge. This study investigates whether Quantum Hyperlight (QHL) can counteract the detrimental effects of high glucose (HG), thereby improving MSC survival, proliferation, and mitochondrial function. We aimed to evaluate the effect of QHL on cellular viability, proliferation, and mitochondrial activity in WJ-MSCs exposed to HG. MSCs were cultured in a medium containing normal glucose (NG) (1 g/L) and HG (4.5 g/L). MSCs in the HG medium were exposed to QHL for 90 s or 180 s with an energy density of 2.4 Joules/cm2/minute and an average power density of 40 mW/cm2. Then, proliferating cell nuclear antigen (PCNA), MTT assays, and Mitotracker Green staining were performed to evaluate cell viability and proliferation. The viability of MSCs was significantly increased in the QHL-treated groups (84% in QHL-90 s and 86% in QHL-180 s) compared to the untreated HG group (65%, p < 0.001). PCNA expression in QHL-90 s and QHL-180 s groups showed significant increases (p < 0.001) compared to the untreated HG group. MitoTracker staining intensity was significantly higher in the QHL-treated groups compared to the untreated HG group (p < 0.001). The HG environment reduced viability, proliferation, and mitochondrial staining. In the context of the NG environment, MSCs exhibited notable differences. However, the viability, proliferation, and mitochondrial staining rates of MSCs were significantly higher in the HG conditions when treated with QHL compared to the group that did not receive QHL. This study introduces QHL as a novel approach to enhance the therapeutic potential of WJ-MSCs under HG conditions, demonstrating its ability to improve cellular viability, proliferation, and mitochondrial activity. This study highlights its potential as a pretreatment to improve clinical outcomes in regenerative medicine.

Assessment of photobiomodulation by a 660-nm diode laser on the reversal of soft tissue anesthesia in children: A randomized controlled clinical trial

BACKGROUND

Soft tissue anesthesia (STA) following inferior alveolar nerve block (IANB) anesthesia lasts 3-5 h. It is important to reverse STA after treatment to prevent soft tissue injury (STI).

AIM

This study evaluated photobiomodulation using a 660 nm diode laser on STA reversal and its impact on STI following IANB anesthesia.

DESIGN

A randomized controlled clinical trial was conducted on 32 children, aged 5-8 years, allocated into the test and control groups. Anesthesia was administered; the operative procedure was performed followed by exposure to laser. STA reversal was monitored through lip tapping, current perception threshold (CPT) tests, and paediatric Functional Assessment Battery.

RESULTS

The test group showed significantly faster recovery to normal sensation following exposure to laser than the control group which did not undergo any reversal (p < .0001), with a median time of 115 and 60 min according to lip tapping and CPT tests, respectively. The test group also showed significantly faster recovery to normal function (p = .016). The incidence of STI in the form of redness was significantly higher in the control group (p = .022).

CONCLUSION

Photobiomodulation using a 660 nm diode laser can be considered as an efficient approach to minimize STA and STI after dental interventions.

The effect of bone remodeling with photobiomodulation in dentistry: a review study

Photobiomodulation (PBM) has been emerging as a promising alternative therapy in dentistry. However, various parameters of PBM are used in different studies, and there is limited cumulative data on PBM for improving bone formation in clinical trials. The aim of this review was to evaluate the effectiveness of PBM in the process of bone remodeling in dentistry using randomized controlled trials. Initially, a total of 1,011 articles published from January 2008 to December 2021 were retrieved from five electronic databases (PubMed, Scopus, Cochrane Library, EMBASE, and CINAHL). After a two-step review, nine articles met the inclusion criteria. The parameter of PBM, group, treatment sessions, assessment times and outcomes of the included studies were reviewed. Eighty-nine percent of the studies revealed positive effects on bone formation between the laser group and the control group. Only one article reported that light-emitting diode did not significantly enhance osteogenesis. Additionally, the present study shows that Gallium aluminum arsenide of near infrared (NIR) laser with continuous mode is the most commonly used form of PBM. The biostimulatory effects are dependent on several parameters, with wavelength and dose being more important than others. Based on this review, it is suggested that the NIR range and an appropriate dose of PBM could be used to increase the efficiency of stimulating bone healing and remodeling. However, standardization of treatment protocols is needed to clarify therapeutic strategies in dentistry.