Assessment of the use of LED phototherapy on bone defects grafted with hydroxyapatite on rats with iron-deficiency anemia and nonanemic: a Raman spectroscopy analysis.

This study aimed to assess bone repair in defects grafted or not with hydroxyapatite (HA) on healthy and iron-deficiency anemia (IDA) rats submitted or not to LED phototherapy (LED-PT) by Raman spectroscopy. The animals were divided in eight groups with five rats each: Clot; Clot + LED; IDA + Clot; IDA + LED; Graft; Graft + LED; IDA + Graft; and IDA + Graft + LED. When appropriated, irradiation with IR LED (λ850 ± 10 nm, 150 mW, CW, Φ = 0.5 cm(2), 16 J/cm(2), 15 days) was carried out. Raman shifts: ∼ 960 [symmetric PO4 stretching (phosphate apatite)], ∼ 1,070 [symmetric CO3 stretching (B-type carbonate apatite)], and ∼ 1,454 cm(-1) [CH2/CH3 bending in organics (protein)] were analyzed. The mean peak values for ∼ 960, ∼ 1,070, and ∼ 1,454 cm(-1) were nonsignificantly different on healthy or anemic rats. The group IDA + Graft + LED showed the lowest mean values for the peak ∼ 960 cm(-1) when compared with the irradiated IDA group or not (p ≤ 0.001; p ≤ 0.001). The association of LED-PT and HA-graft showed lowest mean peak at ∼ 1,454 cm(-1) for the IDA rats. The results of this study indicated higher HA peaks as well as a decrease in the level of organic components on healthy animals when graft and LED phototherapy are associated. In the other hand, IDA condition interfered in the graft incorporation to the bone as LED phototherapy only improved bone repair when graft was not used.

Effects of imiquimod and low-intensity laser (λ660 nm) in chemically induced oral carcinomas in hamster buccal pouch mucosa.

Squamous cell carcinoma (SCC) is the most common neoplasm of the oral cavity. It is aggressive, highly proliferative, and metastatic. This study aimed to evaluate the effect of LLLT and imiquimod on DMBA chemically induced lesions on the oral mucosa of hamsters. SCCs were induced on 25 hamsters. Animals of G1 (control 1) were killed and the presence of tumors confirmed; G2 (control 2) suffered no interventions for additional 4 weeks; animals of G3 (laser treatment) were irradiated (λ660 nm, 50 mW, CW, Ø=3 mm, 0.07 cm(2), 714.2 mW/cm(2), 133 s, 95 J/cm(2), 6.65 J) at every other day for 4 weeks; animals of G4 (imiquimod treatment) received 5 % imiquimod three times a week for 4 weeks; and animals of G5 (imiquimod and laser treatment) received both treatments for the same period. Samples were taken and underwent histological analysis by light microscopy and were investigated using immunohistochemistry for S-100(+) dendritic cells. In G1, G2, and G3, the evaluations showed malignant tumors and the absence of S-100(+) dendritic cells in the tumor stroma. In G4, 60 % of the animals had no malignant tumors, and S-100(+) dendritic cells were present in the stroma of the tumors as well as dysplasia. In G5, 40 % of the animals presented SCC, with scarce or no S-100(+) dendritic cells. The imiquimod treatment played a direct effect on SCC, demonstrated by the increased number of S-100(+) dendritic cells, which could suggest an important role of immune surveillance against neoplastic proliferation. Furthermore, its association with laser needs to be further investigated.

Effect of LED phototherapy (λ700 ± 20 nm) on TGF-ß expression during wound healing: an immunohistochemical study in a rodent model.

OBJECTIVE: The aim of the present investigation was to evaluate transforming growth factor ß (TGF-ß) expression on cutaneous wounds in rodents treated or not treated with LED light. BACKGROUND: TGF-ß is a multifunctional cytokine that presents a central action during tissue repair. Although several studies both in vitro and in vivo have shown that LED phototherapy influences tissue repair, a full understanding of the mechanisms involved in its usage, such as in the modulation of some growth factors, remains unclear. MATERIALS AND METHODS: Under general anesthesia, 24 young adult male Wistar rats weighing 200-250 g had one excisional wound created on the dorsum of each, and were randomly distributed into two groups: G0 (Control) and G1 (LED, λ700 ± 20 nm, 16 mW, SAEF = 5 J/cm(2), Illuminated Area = 2 cm(2), 8 mWcm(2), 626 s) Each group was subdivided into three subgroups according to the animal death timing (2, 4, and 6 days). LED phototherapy started immediately after surgery and was repeated every other day during the experimental time. Following animal death, specimens were removed, routinely processed to wax, cut and immunomarked with polyclonal anti-TGF-ß, and underwent histological analysis by light microscopy. The mean area of expression of each group was calculated. The data were statistically analyzed using ANOVA and Tukey's test. RESULTS: The area of the expression of TGF-ß on LED-irradiated animals was significantly smaller than on controls at day 2 (p = 0.013). No significant difference was found at later times. It is concluded that the use of LED light, at these specific parameters, caused an inhibition of the expression of TGF-ß at an early stage of the healing process.

Polarized light (λ400-2000 nm) on third-degree burns in diabetic rats: immunohistochemical study.

AIM: The aim of this study was to evaluate with light microscopy the healing process of third-degree burns on diabetic rats treated with polarized light (λ400-2000 nm, 20 or 40 J/cm(2)/session, 40 mW/cm(2), 2.4 J/cm(2)/min, 5.5-cm beam diameter). BACKGROUND: Uncontrolled diabetes mellitus causes severe disruption of the body's metabolism, including healing. Polarized light sources have been shown to be effective in improving healing in many situations. ANIMALS AND METHODS: Diabetes mellitus was induced with streptozotocin (60 mg/kg) in 45 male Wistar albino rats, and a third-degree burn (1.5 by 1.5 cm) was created on the dorsum of each animal under general anesthesia. The animals were randomly distributed into three groups: control, 20 J/cm(2), and 40 J/cm(2). Each group was then divided into three subgroups based on time of death (7, 14, 21 d). Phototherapy (20 or 40 J/cm(2) per session) was carried out immediately after the burning and repeated daily until the day before death. Following animal death, specimens were removed, embedded in paraffin, sectioned, and stained with hematoxylin and eosin (HE) or Sirius Red or immunomarked with CK AE1/AE3 antibody. Qualitative and semiquantitative analyses were performed under light microscopy. The results were statistically analyzed. RESULTS: The animals treated with 20 J/cm(2) showed significant differences with regard to revascularization and re-epithelialization. Although the 40 J/cm(2) group showed stimulation of fibroblastic proliferation as an isolated feature, no other difference from the control was observed. CONCLUSION: Our results suggest that the use of polarized light at 20 J/cm(2) effectively improves the healing of third-degree burns on diabetic animals at both early and late stages of repair.

Laser light may improve the symptoms of oral lesions of cicatricial pemphigoid: a case report.

OBJECTIVE: The aim of this work is to report the handling of a patient suffering from cicatricial pemphigoid (CP) treated with laser phototherapy (LPT) and systemic steroids. BACKGROUND DATA: CP is a group of rare chronic autoimmune blistering diseases that predominately affect the mucous membranes and occasionally the skin. The gingiva is most commonly involved, followed by the palate and the buccal mucosa. High-dosage systemic steroids are widely used for its treatment. LPT has been shown to improve wound healing and relieve pain. Its efficacy depends on the amount of energy delivered to the tissue, exposure time, and delivery method. MATERIALS AND METHODS: A white 47-y-old man with CP who used systemic steroids for the previous 5 y was examined at our clinic. Extra- and intraoral examination revealed classic signs of the condition. LPT (GaAlAs diode laser, 660 nm wavelength, 30 mW, continuous wave, diameter approximately 3 mm, 60 J/cm(2) per session) was used in association with the steroids. LPT was performed in a punctual contact manner every other day on the oral mucosa. Maintenance of the treatment was carried out weekly because interruption of the LPT resulted in the recurrence of the lesions. At the time that this report was written, the patient had been undergoing twice weekly treatments for 6 months without signs of lesion recurrence. CONCLUSION: Concomitant use of systemic steroids and LPT showed a positive effect on controlling oral CP lesions and on improving both oral health and the quality of life of the patient.