Photobiomodulation and photodynamic therapy applied after electrocauterization for skin healing optimization in rats.

Photobiomodulation-PBM and Photodynamic Therapy-PDT have been used to induce healing. However, the effects of these therapies on skin-lesions induced by electrocautery are unknown, aiming at more favorable clinical and esthetic results. Electrocauterization was done in 78-female Wistar-rats using a system that includes an electrocautery and red-LED. The groups were: No injury, Injury, Injury + ALA (topical 5-aminolevulinic acid application), Injury + LED and Injury + ALA + LED (topical ALA application followed by photoactivation with LED). After 2nd, 7th and 14th days post-injury, immuno-histomorphometric analyses (inflammatory infiltrate, blood vessels, fibroblasts, eschar/epidermal thickness, IL-10 and VEGF) and biochemical assays of MPO (neutrophil), NAG (macrophage), nitrite, DCF (H2 O2 ), carbonyl (membrane's damage), sulfhydryl (membrane's integrity), SOD, GSH, hydroxyproline and re-epithelialization area were performed. The Injury + LED and Injury + ALA + LED groups controlled inflammation and oxidative stress, favoring angiogenesis, fibroblasts proliferation and collagen formation. Therefore, the PBM or PDT was effective in tissue formation with thinner eschar and epidermis, resulting in less scarring after electrocauterization.

Intra-articular treatment with hyaluronic acid associated with gold nanoparticles in a mechanical osteoarthritis model in Wistar rats.

This study aimed to evaluate the effects of intra-articular treatment with hyaluronic acid (HA) associated with GNPs in a mechanical model of osteoarthritis induced by median meniscectomy (MM). Fifty Wistar rats (2 months weighing between 250 and 300 g) were used, divided into five groups of 10 animals each: Sham, osteoarthritis (OA), OA + HA, OA + gold nanoparticles (GNPs), and OA + HA + GNPs. Intra-articular treatment was started 30 days after the model was induced, with a frequency of 2 weeks for 60 days. Fifteen days after the last application, the animals were euthanized with the removal of the joint tissue for biochemical and histological analysis. The model used was able to mimic osteoarthritis, characterized by the presence of high levels of proinflammatory cytokines, oxidative stress, and degeneration of joint surfaces (Grade III, according to SCORE OARSI). The isolated use of HA or GNPs provided beneficial results to the joint; however, only the group subjected to the association between HA and GNPs showed the attenuation of oxidative stress and reduced proinflammatory markers, with a simultaneous increase in levels of anti-inflammatory cytokines and growth factors. Upon histological analysis, only the OA + HA + GNPs group achieved the restoration of the thickness of the joint cartilage with reduced damage and return to the intact joint surface. The results found demonstrated that the association of GNPs with HA was able to reverse the deleterious effects caused by the model by inhibiting the progressive degeneration of joint surfaces, representing a promising treatment for osteoarthritis.

Effects of Percutaneous Collagen Induction Therapy Associated with Hyaluronic Acid on Inflammatory Response, Oxidative Stress, and Collagen Production.

Percutaneous collagen induction (PCI) is an alternative treatment for skin dysfunctions, it aims to stimulate collagen production by encouraging normal wound healing that occurs after any trauma by inducing microlesions; also it may be potentiated with the association with drugs such as hyaluronic acid (HA). Our objective was to evaluate the effects of PCI associated with hyaluronic acid (0.9%) on inflammatory process, oxidative stress, and collagen production in rat epidermis. For the study, 36 adult Wistar rats were randomly divided into 6 groups (n = 6): Control; PCI 0.5; PCI 1.0; HA; PCI 0.5 + HA; and PCI 1.0 + HA. The animals were anesthetized, trichotomized, and the application of therapies was performed once; After 7 days, the animals were euthanized for removal of the skin region. Levels of pro-inflammatory (IL1, IL6, TNFα), anti-inflammatory (IL4 and IL10) cytokines and growth factors (FGF, TGFß) were evaluated, besides oxidative stress parameters and histological analysis. In combination groups, there is a decrease in TNFα compared with the control and PCI groups in contrast to a significant increase in anti-inflammatory cytokines and growth factors. Oxidant and oxidative damage levels showed a significant decrease in PCI + HA groups in relation to PCI groups while antioxidant defense increased in PCI + HA groups compared with the control group. The number of fibroblasts was increased in the PCI 1.0 group in relation to the control, HA, and PCI 0.5. The number of blood vessels and collagen area was increased in groups PCI and PCI + HA compared with the HA group. We conclude that the combination of PCI with HA is able to accelerate the acute inflammatory process, reducing its deleterious effects and anticipating the chronic response, contributing to tissue repair.

Effects of the Association between Photobiomodulation and Hyaluronic Acid Linked Gold Nanoparticles in Wound Healing.

Healing is the process responsible for restoring the integrity of the body's internal or external structures when they rupture. Photobiomodulation (PBM) stands out as one of the most efficient resources in the treatment of epithelial lesions, as well as hyaluronic acid (HA), which has been emerging as a new molecule for the treatment of dermal and epidermal lesions. The biological application of gold nanoparticles (GNPs) shows promising results. This study aimed to investigate the possible anti-inflammatory and antioxidant effects of the association between PBM and GNPs-linked HA in an epithelial lesion model. Fifty Wistar rats were randomly distributed in the Control Group (CG); (PBM); (PBM + HA); (PBM + GNPs); (PBM + GNPs-HA). The animals were anesthetized, trichotomized, and induced to a surgical incision in the dorsal region. Topical treatment with HA (0.9%) and/or GNPs (30 mg/kg) occurred daily associated with 904 nm laser irradiation, dose of 5 J/cm2, which started 24 h after the lesion and was performed daily until the seventh day. The levels of proinflammatory (IL1 and TNFα), anti-inflammatory (IL10 and IL4) and growth factors (FGF and TGFß) cytokines and oxidative stress parameters were evaluated, besides histological analysis through inflammatory infiltrate, fibroblasts, new vessels, and collagen production area. Finally, for the analysis of wound size reduction, digital images were performed and subsequently analyzed by the IMAGEJ software. The treated groups showed a decrease in proinflammatory cytokine levels and an increase in anti-inflammatory cytokines. TGFß and FGF levels also increased in the treated groups, especially in the combination therapy group (PBM + GNPs-HA). Regarding the oxidative stress parameters, MPO, DCF, and Nitrite levels decreased in the treated groups, as well as the oxidative damage (Carbonyl and Thiol groups). In contrast, antioxidant defense increased in the groups with the appropriate therapies proposed compared to the control group. Histological sections were analyzed where the inflammatory infiltrate was lower in the PBM + GNPs-HA group. The number of fibroblasts was higher in the PBM and PBM + HA treated groups, whereas collagen production was higher in all treated groups. Finally, in the analysis of the wound area contraction, the injury group presented a larger area in cm2 compared to the other groups. Taken together, these results allow us to observe that the combination of PBM + GNPs-HA optimized the secretion of anti-inflammatory cytokines, proliferation and cell differentiation growth factors, and made an earlier transition to the chronic phase, contributing to the repair process.