Effectiveness of 780 nm photobiomodulation as adjunct treatment for bone exposed fractures: A pilot study on radiograph, pain, and cytokines analysis.

The aim of this study was to evaluate the effectiveness of photobiomodulation with a 780 nm laser as an adjunct to surgical treatment in the regeneration of bone fractures. Twenty patients diagnosed with open fractures in the lower limbs were selected and randomly divided into two groups: control and LLLT. LLLT parameter: 780 nm, 0.04 cm2 of light beam diameter, 40 mW of power, 10 s per point, 0.4 J of energy, fluence of 10 J/cm2 and irradiance of 1 W/cm2. The evaluated data were: pain, using McGill scale, use of analgesics and anti-inflammatories, levels of cytokines TNF-α, IFN-γ, IL-1ß, IL-10, and IL-17, and bone level regeneration. Data were analyzed using Wilcoxon and Mann-Whitney tests (5%). We can conclude that LLLT was effective as an adjuvant in the bone fracture regeneration process, altered IL-1ß levels, reduced the use of analgesics and anti-inflammatories, reducing the pain pattern throughout the sessions.

Fluorescence spectroscopy of Candida albicans biofilms in bone cavities treated with photodynamic therapy using blue LED (450 nm) and curcumin.

Fluorescence spectroscopy may assisst in the diagnosis and control of infectious processes associated with bone lesions of the oral cavity. The aim of this study was to analyze, through fluorescence spectroscopy, Candida albicans biofilms formed in artificial bone cavities treated with photodynamic therapy (PDT) mediated with 450-nm blue light-emitting diode (LED) and curcumin. Another aim of this study was to analyze the existence of a correlation between the effectiveness of the photodynamic treatments and the fluorescence spectroscopy images. Artificial bone lesions (n = 40) were made in bovine bones and inoculated with standard suspensions of Candida albicans (ATCC 18804) for biofilm formation (14 days / 36 °C ± 1 °C). The 40 specimens were distributed among four experimental groups (n = 10): L-C- (control), L + C- (LED for 5 min), L-C+ (curcumin for 5 min), and L + C+ (PDT). Aliquots of 100 µL were collected from the bone cavities after treatments and were seeded in duplicate on Sabouraud dextrose agar for 24 h at 36 °C ± 1 °C and the colony-forming units (CFU/ mL) were counted. Before and after each treatment, the specimens were subjected to spectral fluorescence and the images were compared using the Image J program. The log10 CFU/mL were compared with Kruskal-Wallis and Dunn's Multiple Comparison post-test (significance level at 0.05). The fluorescence histogram values before and after treatment were compared using Wilcoxon test (95%).The correlation between Candida albicans log10 CFU/mL and the number of the fluorescence red pixels spectroscopy was verified using Spearman correlation test. The reduction of Candida albicans log10 CFU/mL in the L + C+ (PDT) group was the most relevant and the fluorescence spectroscopy was correlated to the microbiological result. It was concluded that there was a consistency between the number of Candida albicans log10 CFU/mL and the red pixel data of the fluorescence images, demonstrating that the fluorescence diagnostic device reflects the true microbiological condition of Candida albicans biofilms in the bone cavities during the pre-treatment and post-treatment, thus providing the clinician the ability to dynamically, simply, and instantaneously verify the performance of the treatment used.

Photoactivated resveratrol against Staphylococcus aureus infection in mice.

BACKGROUND: Among the pathogens, Staphylococcus aureus is the main causative agent of bacterial diseases in the world. In this context, antimicrobial photodynamic therapy (aPDT) appears as a promising tool by means of microbial inactivation with the use of light. aPDT is applied in treatments involving photosensitizers capable of generating oxygen free radicals. Thus, this work proposes the use of resveratrol as a photosensitizer. METHODS: In vitro tests were performed to determine the antibacterial activity of photoactivated resveratrol with blue LED light, as well as uric acid experiments for verification of singlet oxygen formation. Possible resveratrol structural changes were evaluated by HPLC. In the in vivo assays, the air pouch model was performed in mice for antimicrobial activity and cytokine production. RESULTS: The photoactivated resveratrol exhibited an increase in its antibacterial action and it is possibly brought about by the singlet oxygen formation. In the air pouch model, TNF-α and IL-17A cytokines were produced, diminishing the bacterial load, and consequently, reducing inflammation after 24 h of infection. Cellular number decrease in the inflammatory environment was associated with resolution of inflammation along with greater IL-10 production. CONCLUSION: It is the first time that resveratrol has been associated with aPDT. It was demonstrated in this work that resveratrol activated by blue LED light can be a promising photosensitizer. This compound, after the light stimulus, produces singlet oxygen, in addition to having effects on the immune system triggering TNF-α and IL-17A production, aiding in the clearance of several bacteria, including S. aureus.