Polymeric Materials for Hemostatic Wound Healing

Hemorrhage is one of the greatest threats to life on the battlefield, accounting for 50% of total deaths. Nearly 86% of combat deaths occur within the first 30 min after wounding. While external wound injuries can be treated mostly using visual inspection, abdominal or internal hemorrhages are more challenging to treat with regular hemostatic dressings because of deep wounds and points of injury that cannot be located properly. The need to treat trauma wounds from limbs, abdomen, liver, stomach, colon, spleen, arterial, venous, and/or parenchymal hemorrhage accompanied by severe bleeding requires an immediate solution that the first responders can apply to reduce rapid exsanguinations from external wounds, including in military operations. This necessitates the development of a unique, easy-to-use, FDA-approved hemostatic treatment that can deliver the agent in less than 30 s and stop bleeding within the first 1 to 2 min at the point of injury without application of manual pressure on the wounded area.

Evaluation of wound healing potential of a sea cucumber (Actinopyga mauritiana) extract in mice (Mus musculus)

Sea cucumbers are a marine source with biological activities that have been used in food as well as medicine in many Asian countries. Actinopyga mauritiana is one of the sea cucumber species with limited research about its bioactive activities. In this study, the wound healing activity of A. mauritiana extract in the form of cream, gel, and serum formulations in mice was investigated. The histopathology test was performed to evaluate the fibroblast and collagen dense levels in wound healing. Phytochemical screening has been carried out by the qualitative test of alkaloids, flavonoids, glycosides, steroids, and saponins compounds. The A. mauritiana ethanol extract (SCAE) was added into cream, gel and serum formulations with various concentrations (3, 6, and 9%) and applied to the wounded area of mice. The wound healing activities and histopathology results indicated that serum 9%-SCAE performed the highest decrease of wound length 0.55 ± 0.32 compared to other groups with a density level of fibroblast and collagen are 10.00 ± 1.00 and 10.67 ± 0.00, respectively. To the best of our knowledge, this is the first report on the wound healing activity of A.Mauritiana, which demonstrated promising therapeutic agents for wound healing and cosmetics applications in the future.

Oleuropein multicompartment nanovesicles enriched with collagen as a natural strategy for the treatment of skin wounds connected with oxidative stress

Aim: Collagen-enriched transfersomes, glycerosomes and glytransfersomes were specifically tailored for skin delivery of oleuropein. Methods: Vesicles were prepared by direct sonication and their main physicochemical and technological properties were measured. Biocompatibility, protective effect and promotion of the healing of a wounded cell monolayer were tested in vitro using fibroblasts. Results: Vesicles were mainly multicompartment, small (∼108 nm), slightly polydispersed (approximately 0.27) and negatively charged (~-49 mV). Oleuropein was incorporated in high amounts (approximately 87%) and vesicles were stable during four months of storage. In vitro studies confirmed the low toxicity of formulations (viability ≥95%), their effectiveness in counteracting nitric oxide generation and damages caused by free oxygen radicals, especially when collagen glytransfersomes were used (viability ~100%). These vesicles also promoted the regeneration of a wounded area by promoting the proliferation and migration of fibroblasts. Conclusion: Collagen-enriched vesicles are promising formulations capable of speeding up the healing of the wounded skin.

Antimicrobial Photodinamic Therapy Combined with Laser Photobiomodulation in the Treatment of Skin Wounds in a Dog (Canis lupus familiaris)

Background: Laser photobiomodulation has been used in the treatment of various injuries and diseases. This promotes modulation of the inflammatory process, edema reduction and devitalized tissue regeneration. The advantages of Antimicrobial photodynamic therapy are its easy application and the absence of side effects. Other advantages are the cost of the therapy, minimal damage to animal tissue, the broad spectrum of action, and efficiency against strains resistant to antimicrobials. The aim of this study was to report the clinical and their resolution in a female dog with a traumatic, infected wound treated with laser phototherapy as an alternative therapy method.Case: A 3-year-old bitch Border Collie, weighing 18 kg, from the municipality of Ilhéus, Bahia, Brazil, waspresented for examination with a history of traumatic laceration of the left thoracic member. On the anamnesis, it was reported that the patient presented with laceration of the left thoracic member. The wound was cleaned and an antibiotic [30 mg/kg of 12/12 h] and anti-inflammatory [0.1 mg/kg every 24 h were prescribed, both for 5 days]. Twenty-four h after the surgical procedure, there was dehiscence of the sutures, with daily topical therapy based on zinc oxide for secondary intention healing. Upon physical examination, the wound was found to be contaminated with swollen and erythematous edges, an ulcerated area with devitalized tissue, serous exudate, and 8.8 cm2 of wounded area. Given the macroscopic characteristics of the lesion, phototherapy was associated with conventional therapy until complete healing of the wound, with three weekly applications at 48 h intervals. Initially, the wound was cleaned with saline solution at 0.9% and a single treatment with aPDT was scheduled due to the high degree of contamination. The dosimetry parameters of irradiation were calculated according to the wounded area with a diode laser of 0.1W of power, continuous emission, spot area of 0.028 cm2, and energy of 9 J per application point. A gauze imbibed with 1 mL of methylene blue aqueous solution (300 μM), which was the photosensitizer was applied to the lesion, with a pre-irradiation time of 5 min, after which it was irradiated with red laser (RL) (λ = 660nm) for 90 s per point, using the sweeping technique. The edge of the lesion was irradiated with infrared laser (IRL) (λ = 808 nm), total energy of 5 J, using the technique of specific points and 1 J of energy/point. After aPDT, low-intensity laser therapy (LILT) sessions were set up with RL and IRL, with energies of 0.5 J/point and 1 J/point, respectively. The wound was cleaned daily, protected with a bandage, and clinically evaluated until complete regression.Discussion: In the present case, methylene blue was used as a photosensitizer, but it is noteworthy that, apparently, each microorganism responds differently to photosensitizers. Thus, the therapy becomes specific for each application, for example: the type of photosensitizer, its concentration, pre-irradiation time, type of light used in photosensitization, wavelength, energy, power, mode delivery of light. Thus, for the best result, the specific protocol in each application should be used Low-intensity laser therapy is an easily executed technique with effective results. The use of PDT associated with photobiomodulation therapy enabled rapid healing of the cutaneous wound, in addition to an improvement in clinical signs and pain caused by the lesion. The technique proved to be an efficient alternative in the treatment of wounds, whether used in isolation or associated with conventional therapy. Keywords: methylene blue, healing, wound, photobiomodulation, low-level laser.Título: Terapia fotodinâmica antimicrobiana combinada com a fotobiomodulação a laser no tratamento de ferida cutânea em cão (Canis lupus familiaris).

High-throughput method for detection and quantification of lesions on leaf scale based on trypan blue staining and digital image analysis

Background Field-grown leafy vegetables can be damaged by biotic and abiotic factors, or mechanically damaged by farming practices. Available methods to evaluate leaf tissue damage mainly rely on colour differentiation between healthy and damaged tissues. Alternatively, sophisticated equipment such as microscopy and hyperspectral cameras can be employed. Depending on the causal factor, colour change in the wounded area is not always induced and, by the time symptoms become visible, a plant can already be severely affected. To accurately detect and quantify damage on leaf scale, including microlesions, reliable differentiation between healthy and damaged tissue is essential. We stained whole leaves with trypan blue dye, which traverses compromised cell membranes but is not absorbed in viable cells, followed by automated quantification of damage on leaf scale. Results We present a robust, fast and sensitive method for leaf-scale visualisation, accurate automated extraction and measurement of damaged area on leaves of leafy vegetables. The image analysis pipeline we developed automatically identifies leaf area and individual stained (lesion) areas down to cell level. As proof of principle, we tested the methodology for damage detection and quantification on two field-grown leafy vegetable species, spinach and Swiss chard. Conclusions Our novel lesion quantification method can be used for detection of large (macro) or single-cell (micro) lesions on leaf scale, enabling quantification of lesions at any stage and without requiring symptoms to be in the visible spectrum. Quantifying the wounded area on leaf scale is necessary for generating prediction models for economic losses and produce shelf-life. In addition, risk assessments are based on accurate prediction of the relationship between leaf damage and infection rates by opportunistic pathogens and our method helps determine the severity of leaf damage at fine resolution.

P046 Vitamin D decreases PDIA3 and prevents the enhanced migration of fibroblasts from stricturing Crohn’s disease

Background Fibrosis is a common complication in Crohn’s disease (CD) patients and fibroblasts play an important role in the fibrogenic process. Low vitamin D (VD) levels and a defective VD-signalling pathway have been reported in CD. VD signals through both vitamin D receptor (VDR) and protein disulfide-isomerase A3 (PDIA3) and we have previously demonstrated that VDR protein levels are reduced in fibroblasts isolated from CD patients and that VD increased VDR expression in these cells (A-2080; ECCO 2019). We aim to analyse here the effect of VD on both PDIA3 protein levels and migration in CD fibroblasts. Methods We used intestinal fibroblasts isolated from surgical resections of the damaged mucosa of CD patients with stricturing behaviour (B2). Control fibroblasts were obtained from the non-damaged intestine of patients with colorectal cancer. Fibroblasts were treated with VD (100 nM) or its vehicle for 24 h and PDIA3 protein levels were measured by Western Blot. In the wound healing analysis, a single scraping was done in the centre of the fibroblasts monolayer and FBS-free medium was added to the cells, which allows us to determine the ability of fibroblasts to migrate and close the wound. Photos were taken at 0, 24 and 48 h. Results of wound healing were expressed as the percentage of the wound at each time point for the maximal wounded area (time 0, 100%). Statistical significance was measured by ANOVA or t-test. Results No significant differences in PDIA3 protein levels were detected between control and CD fibroblasts but VD significantly decreased PDIA3 expression in CD fibroblasts (Figure 1A). In the wound healing assay, we detected that CD-B2 fibroblasts migrate faster than control cells, resulting in a reduced wounding area, 48 h later (Figure 1B). Treatment of these CD-B2 cells with VD decreased their migration rate, and 48 h later cells exhibited a higher and significant wounding area than vehicle-treated cells (Figure 1C). Conclusion Vitamin D decreased PDIA3 expression and prevented the accelerated migration detected in intestinal fibroblasts from B2-CD patients which suggest an anti-fibrotic effect of VD mediated by a direct effect of this hormone on intestinal fibroblasts.

ANTI-INFECTIVE EFFECTIVENESS OF ASCORBIC ACID IN THE ORAL MUCOSA OF GUINEA PIGS

Objective:To know the anti-infective effectiveness of ascorbic acid, after a linear incision in the mucosa of the mandibular antero-inferior segment of the oral cavity of the guinea pigs, housed in the vivarium of the Biology Center of the Central University of Ecuador. Materials and methods:This study is experimental in-vivo and longitudinal, where an incision was made in the mucosa of the mandibular anteroinferior segment of the oral cavity in guinea pigs, three groups of 10 guinea pigs were formed, Group C, received mega doses ( 1.42 ml / 214.2 mg) which contained high amounts of ascorbic acid, Group B received normal doses (0.095 ml / 14.25 mg) and group Aor control group did not receive ascorbic acid, this dose was applied one day before, during, and one day after the incision. The clinical evaluation was performed at 24 and 72 hours post incision, a sample was taken by swab from the wounded area at 72 hours for the planting of bacterial cultivation. Results: The clinical examination shows that at 24 hours in group C, 0% bleeding, edema, and erythema, and 100% epithelial junction, while in group B, 30% bleeding, 50% edema, 50% erythema and 100% epithelial junction and in group A50% bleeding, 40% edema, 40% erythema and 20% epithelial junction; at 72 hours the results in group C and B showed better healing percentages in relation to group A, in this group some guinea pigs still showed bleeding edema and erythema in the wounded area. Conclusion: It is determined that the guinea pigs who received mega doses of ascorbic acid presented a better result in the process of healing after clinical examination at 24 and 72 hours and the swab exam shows a lower amount of bacterial colonization, thus demonstrating the effectiveness of ascorbic acid in mega doses of infectious processes.

Lessons From Epithelialization: The Reason Behind Moist Wound Environment

Wound healing consists of multiple structured mechanism and is influenced by various factors. Epithelialization is one of the major aspect in wound healing and inhibition of this mechanism will greatly impair wound healing. Epithelialization is a process where epithelial cells migrate upwards and repair the wounded area. This process is the most essential part in wound healing and occurs in proliferative phase of wound healing. Skin stem cells which reside in several locations of epidermis contribute in the re-epithelialization when the skin is damaged. Epithelialization process is activated by inflammatory signal and then keratinocyte migrate, differentiate and stratify to close the defect in the skin. Several theories of epithelialization model in wound healing have been proposed for decades and have shown the mechanism of epidermal cell migration during epithelialization even though the exact mechanism is still controversial. This process is known to be influenced by the wound environment where moist wound environment is preferred rather than dry wound environment. In dry wound environment, epithelialization is known to be inhibited because of scab or crust which is formed from dehydrated and dead cells. Moist wound environment enhances the epithelialization process by easier migration of epidermal cells, faster epithelialization, and prolonged presence of proteinases and growth factors. This article focuses on the epithelialization process in wound healing, epithelialization models, effects of wound environment on epithelialization and epithelialization as the basis for products that enhance wound healing.

miR-222 represses expression of zipcode binding protein-1 and phospholipase C-γ1 in intestinal epithelial cells

Both zipcode binding protein-1 (ZBP1) and phospholipase C-γ1 (PLCγ1) are intimately involved in many aspects of early intestinal mucosal repair after acute injury, but the exact mechanisms that control their cellular abundances remain largely unknown. The present study shows that microRNA-222 (miR-222) interacts with the mRNAs encoding ZBP1 and PLCγ1 and regulates ZBP1 and PLCγ1 expression in intestinal epithelial cells (IECs). The biotinylated miR-222 bound specifically to the ZBP1 and PLCγ1 mRNAs in IECs. Ectopically expressed miR-222 precursor destabilized the ZBP1 and PLCγ1 mRNAs and consequently lowered the levels of cellular ZBP1 and PLCγ1 proteins. Conversely, decreasing the levels of cellular miR-222 by transfection with its antagonism increased the stability of the ZBP1 and PLCγ1 mRNAs and increased the levels of ZBP1 and PLCγ1 proteins. Overexpression of miR-222 also inhibited cell migration over the wounded area, which was partially abolished by overexpressing ZBP1 and PLCγ1. Furthermore, prevention of the increased levels of ZBP1 and PLCγ1 in the miR-222-silenced cells by transfection with specific small interfering RNAs targeting ZBP1 or PLCγ1 mRNA inhibited cell migration after wounding. These findings indicate that induced miR-222 represses expression of ZBP1 and PLCγ1 at the posttranscriptional level, thus inhibiting IEC migration during intestinal epithelial restitution after wounding.

Space Vector Pulse Width Modulation Method to Reducing a Switching Loss in Inverter

In This paper proposed an area space vector PWM technique that reduces switch victims of an electrical converter mainly efficiently by two-phase modulation technique. This technique chooses the most favorable one that minimizes a replacement switch (SW) defeat judgment supported lessening belongings in switch period allowing for section currents in numerous lessening patterns. This paper proposes an basic curved PWM technique . The planned technique created it attainable to scale back range of switch of the biggest or second major present section . And it will mechanically acclimatize to weight circumstances with varied power factors. Calculated switch wounded area unit condensed to regarding 50% by the planned technique.