Photobiomodulation (PBM) has demonstrated positive effects on the muscle repair process. The aim of the study was to evaluate the effects of infrared PBM using different light sources—low-level laser (LLL) at 780 nm (40 or 70 mW, 10 J/cm², 0.4 J) or LED at 850 nm (40 or 70 mW, 0.13 J/cm², 0.4 J)—and dosimetric parameters on the proliferation and migration of muscle cells. The results showed that LLL 40 mW and 70 mW, with the same radiation exposure, led to an increase in proliferation after 24 h, but no differences at 48 and 72 h. Cells irradiated with LED 70 mW exhibited an increase in proliferation in comparison to the control group and 40mW after 24 and 48 h, but not at 72 h. Moreover, cell migration was greater in comparison to the control after 6 and 24 h, and no differences were found at 12 h when LLL was used with an output power of 70 mW. Furthermore, no differences were found at 6 and 12 h with the 70 mW output power-LED, but an increase was observed in the cell migration after 24 h. In conclusion, PBM using different light sources and dosimetric parameters was able to modulate the proliferation of C2C12 myoblasts, but only PBM at 70 mW was able to modulate the migration of these cells.

Cancer is a chronic disease responsible for millions of deaths annually. Its multifaceted profile, with diverse types and anatomical locations, complicates treatment, often limited to surgery, radiotherapy, and chemotherapy. These treatments are frequently associated with increased tumor aggressiveness and recurrence, highlighting the urgent need for new, less invasive therapies. Recent studies suggest that blue light (BL; 450–470 nm) may offer anti‐tumor and pro‐apoptotic effects, making it a promising alternative for cancer treatment. However, its cellular and molecular mechanisms remain unclear. This qualitative systematic review, conducted in accordance with PRISMA guidelines, analyzed 37 in vitro and in vivo studies published between 2002 and 2024, retrieved from databases including MEDLINE/PubMed, EMBASE, and LILACS, with a focus on the effects of photobiomodulation (PBM) with blue light (450–470 nm) in pre‐clinical cancer models. BL demonstrated anti‐tumor potential by reducing cell viability, proliferation, migration, and invasion, as well as increasing ROS production and inducing apoptosis. In animal models, BL also inhibited tumor growth, metastasis, and improved survival. Despite the encouraging findings, considerable methodological heterogeneity and insufficient reporting of dosimetric parameters compromise the reproducibility and comparability of results across studies. These findings underscore the therapeutic potential of BL in oncology and highlight the need for standardized protocols to support clinical translation.

Background/Objectives: Cerebral palsy (CP) is a non-progressive, permanent syndrome of childhood, with approximately 80% of patients exhibiting spasticity. Untreated spasticity can cause pain, structural changes in bones, muscles, and nerves negatively impacting quality of life and functionality. Photobiomodulation (PBM) has demonstrated biological effects such as tissue regeneration, muscle relaxation, inflammation reduction, and pain relief. The objective of this pilot study is to evaluate the action of PBM on the spasticity of the medial and lateral right gastrocnemius muscles of children and adolescents with spastic cerebral palsy. Methods: This single-blinded, randomized, controlled trial evaluated PBM’s effect on gastrocnemius spasticity in children and adolescents with CP. The study presents pilot preliminary results from twelve children and adolescents (7–16 years) with spastic CP who were randomized into two groups: active PBM (850 nm, 100 mW, 1.5 J/point, 2 points, weekly for 8 weeks) or placebo (same protocol, device off). Both groups received standard rehabilitation exercises. Outcomes were assessed using the Modified Ashworth Scale (MAS), Pediatric Evaluation of Disability Inventory (PEDI), Gross Motor Function Classification System (GMFCS), and ankle range of motion before and after the intervention (8 weeks). Results: MAS and all outcomes improved significantly over time in both groups. No significant differences were found between groups for all outcomes. The PBM effect size on MAS improvement (ANOVA, Analysis of Vari, η² = 0.171) suggests modest but positive benefits. PBM did not worsen spasticity, and no adverse effects were reported. Conclusion: This study represents a pioneering effort in evaluating a safe PBM protocol for the spastics gastrocnemius in children and adolescents with CP. This protocol, used as an adjunct to physiotherapy, demonstrated no short-term adverse effects and no participant dropouts. Future studies should explore this PBM protocol in patients with less severe GMFCS levels, those with minimally preserved functionality, or those with contraindications to physiotherapeutic exercises.

Introduction Obesity has become a worldwide public health problem and is directly linked to loss of quality of life, complications and comorbidities. One of them is chronic pain, especially in the knees, which increases significantly and proportionally with weight gain. In patients with severe obesity, with indication for bariatric surgery, the presence of chronic pain disables and often prevents their participation in a pre-surgical rehabilitation programme. As an analgesic therapy, photobiomodulation (PBM) has been studied with safety, efficacy, well-tolerated used and low costs. Thus, this study aims to evaluate the use of PBM for the treatment of chronic knee pain in obese patients undergoing a pre-surgical rehabilitation programme for bariatric surgery. Methods and analyses This is a double-blinded, randomised, placebo-controlled clinical, superiority, trial protocol. The PBM will be applied in bilateral knees and lumbar paraspinal points levels referring to the roots of innervation of the knee. The outcomes evaluated will be pain intensity, functionality, quality of life and clinical signs of neurological sensitization of chronic knee pain pathways. Ethics and dissemination This protocol has already been approved by the Comitê de Ética em Pesquisa do Hospital das Clínicas da Universidade Federal de Goiás/EBSERH—Ethics Committee and it is following SPIRIT guidelines. The results will be statistically analysed and subsequently published in peer-reviewed journals. Trial registration number Clinical Trials Platform (https://clinicaltrials.gov/) with the number NCT05816798.