Thiago Antônio Moretti de Andrade

Chitosan-alginate membranes accelerate wound healing.

The purpose of this study was to evaluate the efficacy of chitosan-alginate membrane to accelerate wound healing in experimental cutaneous wounds. Two wounds were performed in Wistar rats by punching (1.5 cm diameter), treated with membranes moistened with saline solution (CAM group) or with saline only (SL group). After 2, 7, 14, and 21 days of surgery, five rats of each group were euthanized and reepithelialization was evaluated. The wounds/scars were harvested for histological, flow cytometry, neutrophil infiltrate, and hydroxyproline analysis. CAM group presented higher inflammatory cells recruitment as compared to SL group on 2(nd) day. On the 7(th) day, CAM group showed higher CD11b(+) level and lower of neutrophils than SL group. The CAM group presented higher CD4(+) cells influx than SL group on 2(nd) day, but it decreased during the follow up and became lower on 14(th) and 21(st) days. Higher fibroplasia was noticed on days 7 and 14 as well as higher collagenesis on 21(st) in the CAM group in comparison to SL group. CAM group showed faster reepithelialization on 7(th) day than SL group, although similar in other days. In conclusion, chitosan-alginate membrane modulated the inflammatory phase, stimulated fibroplasia and collagenesis, accelerating wound healing process in rats.

Hyaluronidase Modulates Inflammatory Response and Accelerates the Cutaneous Wound Healing

Hyaluronidases are enzymes that degrade hyaluronan an important constituent of the extracellular matrix. They have been used as a spreading agent, improving the absorption of drugs and facilitating the subcutaneous infusion of fluids. Here, we investigated the influence of bovine testes hyaluronidase (HYAL) during cutaneous wound healing in in vitro and in vivo assays. We demonstrated in the wound scratch assay that HYAL increased the migration and proliferation of fibroblasts in vitro at low concentration, e.g. 0.1 U HYAL enhanced the cell number by 20%. HYAL presented faster and higher reepithelialization in in vivo full-thickness excisional wounds generated on adult Wistar rats back skin already in the early phase at 2nd day post operatory compared to vehicle-control group. Wound closured area observed in the 16 U and 32 U HYAL treated rats reached 38% and 46% compared to 19% in the controls, respectively. Histological and biochemical analyses supported the clinical observations and showed that HYAL treated wounds exhibited increased granulation tissue, diminished edema formation and regulated the inflammatory response by modulating the release of pro and anti-inflammatory cytokines, growth factor and eicosanoids mediators. Moreover, HYAL increased gene expression of peroxisome proliferator-activated receptors (PPAR) γ and PPAR β/δ, the collagen content in the early stages of healing processes as well as angiogenesis. Altogether these data revealed that HYAL accelerates wound healing processes and might be beneficial for treating wound disorders.

The vegetal biomembrane in the healing of chronic venous ulcers

BACKGROUND: The vegetal biomembrane has been used to treat cutaneous ulcers. OBJECTIVES: To assess the role of the vegetal biomembrane on the chronic venous ulcers treatment compared to treatment with collagenase cream. METHODS: Fourteen patients were selected to be treated with vegetal biomembrane and 7 with Fibrase®(CONTROL), followed clinically and photographically by the Wound Healing Index by ImageJ during 120 days and biopsied on the 1stand 30thdays for histological examination. RESULTS: The vegetal biomembrane was better in promoting healing of the ulcers, especially on the inflammatory phase, confirmed by abundant exudation and wound debridement than the CONTROL group, on the 30thday. There was a greater tendency to angiogenesis followed by re-epithelialization with highest wound healing index on the 90thand 120thdays. CONCLUSION: A combined analysis of clinical and histopathological findings suggests that the vegetal biomembrane acted as a factor inducing wound healing, especially on the inflammatory phase, confirmed by abundant exudation of the lesions promoting the transformation of the microenvironment of the chronic venous ulcers, and also stimulating angiogenesis and subsequent re-epithelialization.

Development of lamellar gel phase emulsion containing marigold oil (Calendula officinalis) as a potential modern wound dressing

Appropriate therapeutics for wound treatments can be achieved by studying the pathophysiology of tissue repair. Here we develop formulations of lamellar gel phase (LGP) emulsions containing marigold (Calendula officinalis) oil, evaluating their stability and activity on experimental wound healing in rats. LGP emulsions were developed and evaluated based on a phase ternary diagram to select the best LGP emulsion, having a good amount of anisotropic structure and stability. The selected LGP formulation was analyzed according to the intrinsic and accelerated physical stability at different temperatures. In addition, in vitro and in vivo studies were carried out on wound healing rats as a model. The LGP emulsion (15.0% marigold oil; 10.0% of blend surfactants and 75.0% of purified water [w/w/w]) demonstrated good stability and high viscosity, suggesting longer contact of the formulation with the wound. No cytotoxic activity (50-1000 μg/mL) was observed in marigold oil. In the wound healing rat model, the LGP (15 mg/mL) showed an increase in the leukocyte recruitment to the wound at least on days 2 and 7, but reduced leukocyte recruitment after 14 and 21 days, as compared to the control. Additionally, collagen production was reduced in the LGP emulsion on days 2 and 7 and further accelerated the process of re-epithelialization of the wound itself. The methodology utilized in the present study has produced a potentially useful formulation for a stable LGP emulsion-containing marigold, which was able to improve the wound healing process.

Curativo de biomembrana vegetal e hipersensibilidade

BACKGROUND: The natural biomembrane of latex extracted from Hevea brasiliensis has been used as a dressing for skin ulcers. OBJECTIVES: To evaluate how safe the natural biomembrane is in relation to hypersensitivity to latex when used as a dressing. METHODS: We selected patients with skin ulcers, forming the following groups: control - low occupational exposure to latex (n = 17); latex-exposed control - high occupational exposure (n = 14); ulcerated, using the natural biomembrane (n = 13); ulcerated control, not using the natural biomembrane (n = 14); and new cases (n = 9), assessed before and after 3 months of using the natural biomembrane. All patients underwent clinical and epidemiological evaluation for latex hypersensitivity and specific IgE (UniCap®), and the control and latex-exposed control groups underwent the patch test. RESULTS: Hypersensitivity was positive in 64.7% of the patients in the control group, 71.4% of the patients in the latex-exposed control group, 61.5% of the ulcerated using the natural biomembrane, 35.7% of the ulcerated control, and only 22 , 2% of the new cases. In the patch test of the control and latex-exposed control groups, only one individual in the control group (low contact) showed erythema in the first reading, which became negative in the second. The mean contact with latex in the latex-exposed control group was 3.42 hours / day. In the fluoroimmunoenzymatic assay, most of the sera was classified as zero (range 0-6). No serum was rated above 2, which is not considered significant for hypersensitivity (classification > 4). CONCLUSION: The natural biomembrane proved to be safe as a dressing, for it did not induce hypersensitivity reactions among the volunteers who underwent the patch test or among users of the natural biomembrane, as it was clinically and immunologically demonstrated by IgE levels.

Struthanthus vulgaris ointment prevents an over expression of inflammatory response and accelerates the cutaneous wound healing

ETHNOPHARMACOLOGICAL RELEVANCE Struthanthus vulgaris (Vell.) Mart. (Loranthaceae) has been largely used in traditional folk medicine in Brazil as an anti-inflammatory agent and to treat various skin disorders, including wounds. AIMS OF THE STUDY To investigated the influence of 5% Struthanthus vulgaris ointment during cutaneous wound healing in rats. MATERIALS AND METHODS Twenty Wistar rats were used in each group according the daily treatment, S. vulgaris 5% ointment (SV 5%) and vehicle control groups. Four full thicknesses wounds were punched in back side skin of each animal, and five animals were sacrificed after 2, 7, 14 and 21 days after surgery for histological, immunological and biochemical analysis. RESULTS A significant wound closured area in the S. vulgaris 5% group of about 38% and 35% as compared to 19% and 21% in the control group was observed after 2 and 5 days, respectively. Histological and biochemical analysis of the skin biopsies showed that S. vulgaris treated wounds exhibited increased granulation tissue and regulated the inflammatory response by modulating the release of pro and anti-inflammatory cytokines like IL-1α, TNF-α and IL-10, nitric oxide and, growth factors like TGF-β. Moreover, S. vulgaris showed a marked and robust increase in the deposition and organization of collagen fibers in the wounds, and improve the quality of the scar tissue. CONCLUSIONS Altogether these data revealed that S. vulgaris seems to prevent an over expression of inflammation and accelerates wound epithelialization and might be beneficial for treating healing disorders.

Phototherapy promotes healing of cutaneous wounds in undernourished rats

BACKGROUND Various studies have shown that phototherapy promotes the healing of cutaneous wounds. OBJECTIVE To investigate the effect of phototherapy on healing of cutaneous wounds in nourished and undernourished rats. METHODS Forty rats, 20 nourished plus 20 others rendered marasmus with undernourishment, were assigned to four equal groups: nourished sham, nourished Light Emitting Diode treated, undernourished sham and undernourished Light Emitting Diode treated. In the two treated groups, two 8-mm punch wounds made on the dorsum of each rat were irradiated three times per week with 3 J/cm2 sq cm of combined 660 and 890nm light; wounds in the other groups were not irradiated. Wounds were evaluated with digital photography and image analysis, either on day 7 or day 14, with biopsies obtained on day 14 for histological studies. RESULTS Undernourishment retarded the mean healing rate of the undernourished sham wounds (p < 0.01), but not the undernourished Light emission diode treated wounds, which healed significantly faster (p < 0.001) and as fast as the two nourished groups. Histological analysis showed a smaller percentage of collagen in the undernourished sham group compared with the three other groups, thus confirming our photographic image analysis data. CONCLUSION Phototherapy reverses the adverse healing effects of undernourishment. Similar beneficial effects may be achieved in patients with poor nutritional status.

Clinical and immunological evaluation after BCG-id vaccine in leprosy patients in a 5-year follow-up study

Introduction The use of bacillus Calmette–Guérin (BCG) has long been considered a stimulus for immune reactivity in leprosy household contacts. Probably, the combination of multidrug therapy with BCG could facilitate the clearance of leprosy bacilli in the host, reduce relapse rates, and shorten the duration of skin-smear positivity. Methods To investigate the mechanism of action of BCG, a study involving 19 leprosy patients, eleven multibacillary (MB) and eight paucibacillary, was performed to assess the in vitro production of interleukin (IL)-10, interferon (IFN)-γ, tumor necrosis factor (TNF)-α, IL-6, and IL-17 in the supernatant of peripheral blood mononuclear cells, before and 30 days after inoculation with BCG intradermally (BCG-id). Peripheral blood mononuclear cells isolated by Ficoll–Hypaque gradient were cultivated with Concanavalin-A (Con-A), lipopolysccharides (LPS), or BCG. The supernatant was collected for ELISA quantification of cytokines. The immunohistochemistry of IFN-γ, IL-1, IL-10, IL-12, transforming growth factor (TGF)-β, and TNF-α was carried out in biopsies of skin lesions of leprosy patients before and 30 days after inoculation of BCG-id. These patients were followed up for 5 years to assess the therapeutic response to multidrug therapy, the occurrence of leprosy reactions, and the results of bacterial index and anti-PGL-1 serology after the end of treatment. Results The results showed increased production of cytokines after BCG-id administration in MB and paucibacillary leprosy patients. There was statistically higher levels of TNF-α (P = 0.017) in MB patients and of IL-17 (P = 0.008) and IFN-γ (P = 0.037) in paucibacillary patients. Immunohistochemical staining, especially for TNF-α, was more intense in biopsies of MB leprosy patients taken after BCG-id administration, probably for induction of innate human immunity. The clinical evaluation suggests that BCG-id is able to induce a more effective therapeutic response, with reduction of the number and the intensity of leprosy reactions. Conclusion These results suggest that BCG-id induces activation of the initial phase of immunocellular activity: innate human immunity (increase in TNF-α, IL-12 and macrophage activation). Therefore, we conclude that the use of BCG-id could be indicated as an adjuvant to multidrug therapy in treatment of leprosy patients.

Clinical and immunohistopathological aspects of venous ulcers treatment by Low-Intensity Pulsed Ultrasound (LIPUS) ☆

The immunological mechanisms that are triggered by Low-Intensity Pulsed Ultrasound (LIPUS) in wound healing are unknown. In the present study, experimental groups were used to assess the treatment of chronic venous ulcers with 30mW/cm(2) SATA peripheral LIPUS three times per week compared to a daily treatment of 1% silver sulfadiazine (SDZ). The ulcers of the SDZ group (n=7) (G1) and LIPUS group (n=9) (G2) were photographed five times three months, and the images were analyzed using ImageJ software to quantify the total area (S), fibrin/sphacel area (yellow) and granulation area (red). The healing process was evaluated by the wound healing rate (WHR), granulation tissue rate (GTR) and fibrin/sphacel tissue rate (FTR). The ulcers were biopsied on days 1 and 45 and stained for collagen fiber quantification (picrosirius) and CD68(+) protein and VEGF (vascular endothelial growth factor) expression using HRP-streptavidin (horseradish peroxidase-streptavidin). On day 90, G2 had a mean 41% decrease in the ulcer area, while no decrease was observed in G1 (p<0.05). An increased tendency toward positive labeling of collagen fibers and VEGF (p>0.05) was observed in G2 compared to G1, and the number of CD68(+) cells was greater in G2 than in G1 (p<0.05). LIPUS presents superior activity compared to SDZ in stimulating the inflammatory and proliferative (angiogenesis and collagenesis, respectively) phases of chronic venous wound healing.

Wound healing modulation by a latex protein-containing polyvinyl alcohol biomembrane

In a previous study, we performed the chemical characterization of a polyvinyl alcohol (PVA) membrane supplemented with latex proteins (LP) displaying wound healing activity, and its efficacy as a delivery system was demonstrated. Here, we report on aspects of the mechanism underlying the performance of the PVA-latex protein biomembrane on wound healing. LP-PVA, but not PVA, induced more intense leukocyte (neutrophil) migration and mast cell degranulation during the inflammatory phase of the cicatricial process. Likewise, LP-PVA induced an increase in key markers and mediators of the inflammatory response (myeloperoxidase activity, nitric oxide, TNF, and IL-1β). These results demonstrated that LP-PVA significantly accelerates the early phase of the inflammatory process by upregulating cytokine release. This remarkable effect improves the subsequent phases of the healing process. The polyvinyl alcohol membrane was fully absorbed as an inert support while LP was shown to be active. It is therefore concluded that the LP-PVA is a suitable bioresource for biomedical engineering.