Topical Treatment Of Wounds Research Articles

Heparin-Based Coacervate of FGF2 Improves Dermal Regeneration by Asserting a Synergistic Role with Cell Proliferation and Endogenous Facilitated VEGF for Cutaneous Wound Healing.

Effective wound healing requires complicated, coordinated interactions and responses at protein, cellular, and tissue levels involving growth factor expression, cell proliferation, wound closure, granulation tissue formation, and vascularization. In this study, we develop a heparin-based coacervate consisting of poly(ethylene argininylaspartate digylceride) (PEAD) as a storage matrix, heparin as a bridge, and fibroblast growth factor-2 (FGF2) as a cargo (namely heparin-FGF2@PEAD) for wound healing. First, in vitro characterization demonstrates the loading efficiency and control release of FGF2 from the heparin-FGF2@PEAD coacervate. The following in vivo studies examine the wound healing efficiency of the heparin-FGF2@PEAD coacervate upon delivering FGF2 to full-thickness excisional skin wounds in vivo, in comparison with the other three control groups with saline, heparin@PEAD as vehicle, and free FGF2. Collective in vivo data show that controlled release of FGF2 to the wounds by the coacervate significantly accelerates the wound healing by promoting cell proliferation, stimulating the secretion of vascular endothelial growth factor (VEGF) for re-epithelization, collagen deposition, and granulation tissue formation, and enhancing the expression of platelet endothelial cell adhesion molecule (CD31) and alpha-smooth muscle actin (α-SMA) for blood vessel maturation. In parallel, no obvious wound healing effect is found for the control, vehicle, and free FGF2 groups, indicating the important role of the coavervate in the wound healing process. This work designs a suitable delivery system that can protect and release FGF2 in a sustained and controlled manner, which provides a promising therapeutic potential for topical treatment of wounds.

Treatment for diabetic ulcer wounds using a fern tannin optimized hydrogel formulation with antibacterial and antioxidative properties

Ethnopharmacological relevanceBlechnum orientale Linn. (B. orientale) is a fern traditionally used by the natives as a poultice to treat wounds, boils, ulcers, blisters, abscesses, and sores on the skin. Aim of the studyTo investigate the wound healing ability of a concentrated extract of B. orientale in a hydrogel formulation in healing diabetic ulcer wounds. Materials and methodsThe water extract from the leaves of B. orientale was separated from the crude methanolic extract and subjected to flash column chromatography techniques to produce concentrated fractions. These fractions were tested for phytochemical composition, tannin content, antioxidative and antibacterial activity. The bioactive fraction was formulated into a sodium carboxymethylcellulose hydrogel. The extract-loaded hydrogels were then characterized and tested on excision ulcer wounds of streptozotocin-induced diabetic rats. Wound size was measured for 14 days. Histopathological studies were conducted on the healed wound tissues to observe for epithelisation, fibroblast proliferation and angiogenesis. All possible mean values were subjected to statistical analysis using One-way ANOVA and post-hoc with Tukey’s T-test (P<0.05). ResultsOne fraction exhibited strong antioxidative and antibacterial activity. The fraction was also highly saturated with tannins, particularly condensed tannins. Fraction W5–1 exhibited stronger antioxidant activity compared to three standards (α-Tocopherol, BHT and Trolox-C). Antibacterial activity was also present, and notably bactericidal towards Methicillin-resistant Staphylococcus aureus (MRSA) at 0.25mg/ml. The extract-loaded hydrogels exhibited shear-thinning properties, with high moisture retention ability. The bioactive fraction at 4% w/w was shown to be able to close diabetic wounds by Day 12 on average. Other groups, including controls, only exhibited wound closure by Day 14 (or not at all). Histopathological studies had also shown that extract-treated wounds exhibited re-epithelisation, higher fibroblast proliferation, collagen synthesis, and angiogenesis. ConclusionThe ethnopharmacological effects of using B. orientale as a topical treatment for external wounds was validated and was also significantly effective in treating diabetic ulcer wounds. Thus, B. orientale extract hydrogel may be presented as a potential treatment for diabetic ulcer wounds.

LL37 loaded nanostructured lipid carriers (NLC): A new strategy for the topical treatment of chronic wounds

The LL37 is a human antimicrobial peptide which not only has a broad spectrum of antimicrobial activity, but it has also been proved to modulate wound healing by participating in angiogenesis, epithelial cell migration and proliferation, and immune response. In this work, LL37 has been encapsulated in nanostructured lipid carriers (NLCs), produced by the melt-emulsification method, in order to improve its effectiveness. The characterisation of the NLC-LL37 showed a mean size of 270nm, a zeta potential of −26mV and an encapsulation efficiency of 96.4%. The cytotoxicity assay performed in Human Foreskin Fibroblasts demonstrated that the NLC-LL37 did not affect cell viability. Moreover, the in vitro bioactivityassay evidenced that the peptide remained active after the encapsulation, since the NLC-LL37 reversed the activation of the macrophages induced by LPS in the same way as the LL37 in solution. In addition, the in vitro antimicrobial assay revealed the NLC-LL37 activity against Escherichia coli. The effectiveness of the nanoparticles was assessed in a full thickness wound model indb/dbmice. The data demonstrated that NLC-LL37 significantly improved healing compared to the same concentration of the LL37 solution in terms of wound closure, reepithelisation grade and restoration of the inflammatory process. Overall, these findings suggest a promising potential of the NLC-LL37 formulation for chronic wound healing.

Towards next generation maggot debridement therapy: transgenic Lucilia sericata larvae that produce and secrete a human growth factor.

BackgroundDiabetes and its concurrent complications impact a significant proportion of the population of the US and create a large financial burden on the American health care system. FDA-approved maggot debridement therapy (MDT), the application of sterile laboratory-reared Lucilia sericata (green bottle fly) larvae to wounds, is a cost-effective and successful treatment for diabetic foot ulcers and other medical conditions. Human platelet derived growth factor-BB (PDGF-BB) is a secreted dimeric peptide growth factor that binds the PDGF receptor. PDGF-BB stimulates cell proliferation and survival, promotes wound healing, and has been investigated as a possible topical treatment for non-healing wounds. Genetic engineering has allowed for expression and secretion of human growth factors and other proteins in transgenic insects. Here, we present a novel concept in MDT technology that combines the established benefits of MDT with the power of genetic engineering to promote healing. The focus of this study is to create and characterize strains of transgenic L. sericata that express and secrete PDGF-BB at detectable levels in adult hemolymph, whole larval lysate, and maggot excretions/ secretions (ES), with potential for clinical utility in wound healing.ResultsWe have engineered and confirmed transgene insertion in several strains of L. sericata that express human PDGF-BB. Using a heat-inducible promoter to control the pdgf-b gene, pdgf-b mRNA was detected via semi-quantitative PCR upon heat shock. PDGF-BB protein was also detectable in larval lysates and adult hemolymph but not larval ES. An alternative, tetracycline-repressible pdgf-b system mediated expression of pdgf-b mRNA when maggots were raised on diet that lacked tetracycline. Further, PDGF-BB protein was readily detected in whole larval lysate as well as larval ES.ConclusionsHere we show robust, inducible expression and production of human PDGF-BB protein from two conditional expression systems in transgenic L. sericata larvae. The tetracycline-repressible system appears to be the most promising as PDGF-BB protein was detectable in larval ES following induction. Our system could potentially be used to deliver a variety of growth factors and anti-microbial peptides to the wound environment with the aim of enhancing wound healing, thereby improving patient outcome in a cost-effective manner.

Pomegranate seed oil: Effect on 3-nitropropionic acid-induced neurotoxicity in PC12 cells and elucidation of unsaturated fatty acids composition

Background: Seed oils are used as cosmetics or topical treatment for wounds, allergy, dandruff, and other purposes. Natural antioxidants from plants were recently reported to delay the onset or progress of various neurodegenerative conditions. Over one thousand cultivars of Punica granatum (Punicaceae) are known and some are traditionally used to treat various ailments.Aim: The effect of pomegranate oil on 3-nitropropionic acid- (3-NP) induced cytotoxicity in rat pheochromocytoma (PC12) neuronal cells was analyzed in this study. Furthermore, the analysis of unsaturated fatty acid composition of the seed oil of pomegranate by gas chromatography-electron impact mass spectrometry (GC-MS) was done.Results: GC-MS study showed the presence of 6,9-octadecadiynoic acid (C18:2(6,9)) as a major component (60%) as 4,4-dimethyloxazoline derivative. The total extractable oil with light petroleum ether by Soxhlet from the dry seed of P. granatum was 4–6%. The oil analyzed for 48.90 ± 1.50 mg gallic acid equivalents/g of oil, and demonstrated radical-scavenging-linked antioxidant activities in various in vitro assays like the DPPH (2,2-diphenyl-l-picrylhydrazyl, % IP = 35.2 ± 0.9%), ABTS (2,2′-azinobis(3-ethylbenzothiazoline-6-sulfonic acid), % IP 2.2 ± 0.1%), and β-carotene bleaching assay (% IP = 26 ± 3%), respectively, which could be due the possible role of one methylene interrupted diynoic acid system for its radical-scavenging/antioxidant properties of oil. The oil also reduced lipid peroxidation, suppressed reactive oxygen species, extracellular nitric oxide, lactate/pyruvate ratio, and lactase dehydrogenase generated by 3-NP- (100 mM) induced neurotoxicity in PC12 cells, and enhanced the levels of enzymatic and non-enzymatic antioxidants at 40 μg of gallic acid equivalents.Conclusion: The protective effect of pomegranate seed oil might be due to the ability of an oil to neutralize ROS or enhance the expression of antioxidant gene and the exact mechanism of action yet to be elucidated.

Measurements in wound healing with observations on the effects of topical agents on full thickness dermal incised wounds

IntroductionA multitude of topical wound treatments are used today. Although it is well established that the micro-environment of healing wounds can be altered to improve healing, it is difficult to measure the subtle differences in outcome where therapies are compared. MethodWe compared wound healing properties between four different topical agents in surgically incised wounds in a pig model. The four topical agents, 5% Povidone-Iodine cream, 1% Silver-Sulphadiazine, 2% Mupirocin, and 1% Silver-Sulphadiazine plus 1mg/100g recombinant-human epithelial growth factor (EGF) were randomly assigned to four test animals each. Test agents were compared to each other and to untreated controls. We investigated existing and new methodologies of measurement of wound healing: clinical and histological visual scoring systems, immuno-histochemistry, and computerized image analysis of the wounds on days 3, 7, and 28. ResultsAll agents were found to have improved healing rates with better cellular architecture. Healing was faster, histological appearance resembled normal architecture sooner, clinical appearance improved, mitotic activity was stimulated and more collagen was deposited in comparison to the wounds with no agents. EGF-treated wounds showed an increased rate of epithelisation, but the rate of healing did not correlate well with evaluation of cosmetic outcome. ConclusionTopical agents improve all aspects of wound healing. The addition of a human recombinant EGF to Silver-Sulphadiazine increases epithelial growth and amounts of collagen in the regenerating wounds at day 7.

In vivo wound healing activity of gels containing Cecropia pachystachya leaves.

To evaluate the in-vivo wound healing and in-vitro antioxidant activity of gels containing the ethyl acetate extract of Cecropia pachystachya (ECP) 2% and 5%, and to perform the chemical fingerprint of ECP by HPLC-DAD. The wound healing activity of the gels was evaluated for 21 days, using the excision model in rats followed by histopathological and histomorphometric analysis. The in-vitro antioxidant effect of ECP was investigated using 1-diphenyl-2-picrylhydrazyl, reducing power, β-carotene bleaching and thiobarbituric acid reactive substances assays. Also, a HPLC analysis was performed to identify the chemical markers orientin, iso-orientin and chlorogenic acid. The group of animals treated with ECP 5% presented oedema and inflammatory infiltrate with less intensity than the other groups. Both ECP 2% and 5% gels showed less neovascularization and cellularity, and better tissue repair when compared to the control, which showed a younger and homogeneous tissue. This study had demonstrated that the ECP gels promoted the acceleration of the healing process when compared to the control group. Wound contraction, angiogenesis, epithelialization and the collagen deposition support further evaluation of C. pachystachya leaves in the topical treatment and management of skin wounds.

In vitro Cytotoxicity and Anti-herpes Simplex Virus Type 1 Activity of Hydroethanolic Extract, Fractions, and Isolated Compounds from Stem Bark of Schinus terebinthifolius Raddi.

Background:Herpes simplex virus type 1 (HSV-1) is associated with orofacial infections and is transmitted by direct contact with infected secretions. Several efforts have been expended in the search for drugs to the treatment for herpes. Schinus terebinthifolius is used in several illnesses and among them, for the topical treatment of skin wounds, especially wounds of mucous membranes, whether infected or not.Objective:To evaluate the cytotoxicity and anti-HSV-1 activity of the crude hydroethanolic extract (CHE) from the stem bark of S. terebinthifolius, as well as its fractions and isolated compounds.Materials and Methods:The CHE was subjected to bioguided fractionation. The anti-HSV-1 activity and the cytotoxicity of the CHE, its fractions, and isolated compounds were evaluated in vitro by SRB method. A preliminar investigation of the action of CHE in the virus–host interaction was conducted by the same assay.Results:CHE presented flavan-3-ols and showed anti-HSV-1 activity, better than its fractions and isolated compounds. The class of substances found in CHE can bind to proteins to form unstable complexes and enveloped viruses, as HSV-1 may be vulnerable to this action. Our results suggest that the CHE interfered with virion envelope structures, masking viral receptors that are necessary for adsorption or entry into host cells.Conclusion:The plant investigated exhibited potential for future development treatment against HSV-1, but further tests are necessary, especially to elucidate the mechanism of action of CHE, as well as preclinical and clinical studies to confirm its safety and efficacy.SUMMARY Crude hydroethanolic extract (CHE) presents promising activity against herpes simplex virus type 1 (HSV 1), with selectivity index (SI) = 22.50CHE has flavan-3-ols in its composition, such as catechin and gallocatechinThe fractions and isolated compounds obtained from CHE by bioguided fractionation are less active than the CHE against HSV-1CHE interferes with viral entry process in the host cell and acts directly on the viral particle. Abbreviations used: HSV: Herpes simplex virus, CHE: Crude hydroethanolic extract, WF: Water fraction, AF: Ethyl-acetate fraction, MPLC: Medium-performance liquid chromatography, TLC: Thin-layer chromatography, NMR: Nuclear magnetic resonance, ESI-MS: Electrospray ionization mass spectrometry, SRB: Sulforhodamine B, CPE: Cytopathic effect, CC50: 50% cytotoxic concentration, EC50: 50% effective concentration, PBS: Phosphate-buffered saline.

MODERN TREATMENT METHODS OF THE CHRONIC WOUNDS

The author gives a review of published data on the problem of terminology and classification of chronic wounds, as well as an overview of methods for the topical treatment of wounds with illustrations from his own clinical practice.

BANEOTSIN® (POWDER, OINTMENT) – PERSPECTIVE FOR USE IN COMPLEX SURGICAL TREATMENT OF PURULONECROTIC DISEASES OF THE LOWER EXTREMITIES IN PATIENTS WITH DIABETIC FOOT SYNDROME

Objective – to improve the results of the topical medical treatment of wounds in patients with various forms of diabetic foot syndrome (DFS). Materials and methods. A comparative in vitro study of the antimicrobial and osmotic activity of Baneotsin® and ointments on the basis of polyethylene glycol was done. The subject of the clinical study were 18 patients with DFS. Out of these patients 8 (44.4 %) had the neuro-ischemic form and 10 (55.6 %) had the neuropathic form. According to depth and prevalence of purulonecrotic process, in 3 (16.7 %) cases there was indicated Stage II of the process according to Wagner, in 9 (50.0 %) cases – Stage III and in 6 (33.3 %) patients – Stage IV. All patients had type 2 diabetes of severe treatment, on insulin. Average age of the patients was 61.3 ± 1.4 years. The average rate of glycated hemoglobin of patients on ad- mission to hospital was 8.4 ± 1.3 %. After radical surgical treatment of purulent foci with careful removal of all necrotic tissue all patients had surgical wounds treated with 0.2 % solution of Lavasept®. 3 (16.7 %) patients with the ulcer surface without obvious signs of perifocal inflammation had bandage with Baneotsin® powder after treatment, and after 4–5 days after detecting signs of wound process during the transition to phase II the treatment was continued under the bandage with ointment Baneotsin®. In 10 (55.6 %) cases (in the results of microbiological tests were found aerobic and obligate anaerobes) the treatment of postoperative wound was done under the bandages with 5 % Dioxydine ointment for 2–3 days. 5 (27.8 %) patients (without clinical and bacteriological data of obligate anaerobes) were treated with ointment of Levomekol immediately after the operation. After 7–10 days, the patients were discharged to the outpatient treatment phase with recommendations to continue treatment with bandages with Baneotsin® powder (for 4–5 days) and then with ointment Baneotsin®. Systemic antibiotic therapy at the hospital stage of treatment lasting more than 7 days, was used only in 4 (22.2 %) cases. Results. In patients with trophic anabrosis (3 (16.7 %) persons) it was managed to heal the defects by secondary intention in the period of up to 1 month after surgical treatment. The other wounds were prepared to run the final stage of treatment – the plastic reconstruction of the foot in the period from 10–14 days to 1 month. High ablations and fatal cases in the researched group of patients were not recorded. Conclusion. Application of the algorithm of topical drug treatment of wounds with Baneotsin® powder and ointment, polyethylene glycol based ointments having different osmotic activity, depending on the severity and extent of purulent process in soft tissues, lets to avoid the prescription of long-term systemic antibiotic therapy and to accelerate the transition of purulonecrotic wounds in the phase II of wound process.

THE USE OF THE NEGATIVE PRESSURE WOUND THERAPY SYSTEM FOR PATIENTS WITH COMPLICATED BONE INJURIES

The article presents a successful experience of complex multi-stage surgical treatment of a severe open comminuted fracture of the humerus with large detachment and crushing of the soft tissues of the upper limb. Special attention was paid to approaches to performance of staged surgical treatment and preparation of the wound to plastic closing, state-of-art treatment methods that include negative pressure wound therapy (NPWT), treatment of wounds with a "pulsating liquid jet", use of noninvasive means for the topical treatment of wounds. The whole complex of the proposed surgical and conservative methods allowed transferring of the wound process from the complicated to the normal category, reposition and closing of the fracture area with fully functional soft tissues, complete elimination of the extensive injury of the upper extremity in a functionally active region, to a greater extent at the expense of local surrounding tissues, as well as achievement of the good functional and cosmetic effect.

Gallium-Loaded Dissolvable Microfilm Constructs that Provide Sustained Release of Ga(3+) for Management of Biofilms.

The persistence of bacterial biofilms in chronic wounds delays wound healing. Although Ga(3+) can inhibit or kill biofilms, precipitation as Ga(OH)3 has prevented its use as a topical wound treatment. The design of a microfilm construct comprising a polyelectrolyte film that releases noncytotoxic concentrations of Ga(3+) over 20 d and a dissolvable micrometer-thick film of polyvinylalcohol that enables facile transfer onto biomedically important surfaces is reported. By using infrared spectroscopy, it is shown that the density of free carboxylate/carboxylic acid and amine groups within the polyelectrolyte film regulates the capacity of the construct to be loaded with Ga(3+) and that the density of covalent cross-links introduced into the polyelectrolyte film (amide-bonds) controls the release rate of Ga(3+) . Following transfer onto the wound-contact surface of a biologic wound dressing, an optimized construct is demonstrated to release ≈0.7 μg cm(-2) d(-1) of Ga(3+) over 3 weeks, thus continuously replacing Ga(3+) lost to precipitation. The optimized construct inhibits formation of P. aeruginosa (two strains; ATCC 27853 and PA01) biofilms for up to 4 d and causes pre-existing biofilms to disperse. Overall, this study provides designs of polymeric constructs that permit facile modification of the wound-contacting surfaces of dressings and biomaterials to manage biofilms.

PH manipulation as a novel strategy for treating mucormycosis.

Mucormycosis is a fatal fungal disease caused by several organisms within the order Mucorales. In recent years, traumatic injury has emerged as a novel risk factor for mucormycosis. Current antifungal therapy is ineffective, expensive, and typically requires extensive surgical debridement. There is thus a pressing need for safe prophylactic treatment that can be rapidly and easily applied to high-risk patients, such as those with major trauma injuries. Acetic acid has been used as a topical treatment for burn wounds for centuries and has proven activity against Gram-negative bacteria. Here, we demonstrate that acetic acid is also highly effective against major pathogenic groups of Mucorales, even at very low concentrations (0.3%). This antifungal effect is not seen with other acids, such as hydrochloric and lactic acid, suggesting that acetic acid activity against Mucorales spores is not solely evoked by low environmental pH. In agreement with this, we demonstrate that the antifungal activity of acetic acid arises from a combination of its ability to potently lower intracellular pH and from pH-independent toxicity. Thus, dilute acetic acid may offer a low-cost, safe, prophylactic treatment for patients at risk of invasive mucormycosis following traumatic injury.

Antimicrobial activity of customary medicinal plants of the Yaegl Aboriginal community of northern New South Wales, Australia: a preliminary study.

BackgroundThis study is a collaboration between Macquarie University researchers and the Yaegl Aboriginal Community of northern NSW, Australia to investigate the antimicrobial potential of plants used in the topical treatment of wounds, sores and skin infections. Based on previously documented medicinal applications, aqueous and aqueous ethanolic extracts of Alocasia brisbanensis, Canavalia rosea, Corymbia intermedia, Hibbertia scandens, Ipomoea brasiliensis, Lophostemon suaveolens and Syncarpia glomulifera and the aqueous extracts of Smilax australis and Smilax glyciphylla were tested against common wound pathogens, including antibiotic resistant bacterial strains.MethodsPlant material was prepared as aqueous extractions modelled on customary preparations and using 80% aqueous ethanol. Extracts were assayed against a selection of clinically relevant Gram positive (Streptococcus pyogenes and sensitive and resistant strains of Staphylococcus aureus) and Gram negative (Pseudomonas aeruginosa, Escherichia coli and Salmonella typhimurium) bacteria and a fungus (Candida albicans) using disc diffusion and MTT microdilution methods. Viability of treated microorganisms was determined by subculturing from microdilution assays.ResultsThe extracts of Corymbia intermedia, Lophostemon suaveolens and Syncarpia glomulifera had promising levels of antimicrobial activity (MIC 31–1,000 µg/mL) against both antibiotic sensitive and resistant Staphylococcus aureus as well as the fungus Candida albicans (clinical isolate).ConclusionAqueous and 80% aqueous ethanolic extracts of Lophostemon suaveolens, Corymbia intermedia and Syncarpia glomulifera exhibited promising levels of antimicrobial activity against a range of both antibiotic sensitive and resistant strains of microorganisms. This is the first report of antimicrobial activities for C. intermedia and L. suaveolens and the leaves of S. glomulifera. This study demonstrates the value of customary knowledge in the identification of new sources of antimicrobial treatments.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-015-1258-x) contains supplementary material, which is available to authorized users.

Searching for methods to predict septic complications in surgical patients

Aim. To assess the significance of acute stage reactants as the marker for purulent complications in surgical patients.Methods. We analyzed the results of treatment of 228 patients with purulent and inflammatory diseases of soft tissues, treated in 2011-2014. Acute phase reactants: C-reactive protein, albumin and fibrinogen were measured starting from the day of admission and surgical treatment and during the next 7 days. The control group (112 patients) included patients whowere treated conventionally by gauze bandage with water-soluble ointments and antiseptic solutions and broad-spectrum antibiotics. In the study group (116 patients) topical treatment of wounds was performed using «Poliderm» bandages.Results. Application of the «Poliderm» combined dressing reduced the wounds clearance term from 4.3±0.5 to 3.2±0.4 days, active inflammation term from 8.8±1.3 to 6.4±0.7 days, epithelialization of the wound from 10.1±0.8 to 8.4±0.6 days. C-reactive protein level was 87.3±4.3 g/l at the day of admission and decreased by day 7 to 34.13±1.2 g/l, compared to 51.83±3.6 g/l on the 7th day in the control group. Albumin level was 42.73±3.7 g/l in the study group with further decrease to 40.33±1.7 g/l on the 2nd and subsequent increase up to 45.13±1.3 g/l on the day 7. Patients of the control group had albumin level decreased on the 2nd and 3rd days with further increase up to 41.73±2.1 g/l on the day 7. At the treatment start, leukocyte intoxication index was 5.923±0.4 in the main group and 5.873±0.3 in the control group. On the 2nd day, this parameter decreased to 5.12 in the main group and to 5.41 in the control group.Conclusion. Measuring the levels of acute phase reactants (C-reactive protein, albumin, etc.) allows to assess the clinical course of a purulent and inflammatory disease, to register the good treatment effect on the 1-2nd day of treatment, even before the significant clinical changes, changes in the body temperature, white blood cell counts, erythrocyte sedimentation rate.

Development and in vitro evaluation of lipid nanoparticle-based dressings for topical treatment of chronic wounds

This research addresses the development and in vitro evaluation of lipid nanoparticle (NP)-based dressings to optimize the delivery of human recombinant epidermal growth factor (rhEGF) for the topical treatment of chronic wounds. The systems investigated were rhEGF-loaded solid lipid nanoparticles (rhEGF-SLN) and rhEGF-loaded nanostructured lipid carriers (rhEGF-NLC) formulated in wound dressings comprising either semi-solid hydrogels or fibrin-based solid scaffolds. Following detailed characterisation of the NP, in vitro diffusion cell experiments (coupled with dermatopharmacokinetic measurements), together with confocal microscopic imaging, conducted on both intact skin samples, and those from which the barrier (the stratum corneum) had been removed, revealed that (a) the particles remained essentially superficially located for at least up to 48h post-application, (b) rhEGF released on the surface of intact skin was unable to penetrate to the deeper, viable layers, and (c) sustained release of growth factor from the NP “drug reservoirs” into barrier-compromised skin was observed. There were no significant differences between the in vitro performance of rhEGF-SLN and rhEGF-NLC, irrespective of the formulation employed. It is concluded that, because of their potentially longer-term stability, the fibrin-based scaffolds may be the most suitable approach to formulate rhEGF-loaded lipid nanoparticles.

Nod-like receptor protein-3 inflammasome plays an important role during early stages of wound healing.

The Nod-like receptor protein (NLRP)-3 inflammasome/IL-1β pathway is involved in the pathogenesis of various inflammatory skin diseases, but its biological role in wound healing remains to be elucidated. Since inflammation is typically thought to impede healing, we hypothesized that loss of NLRP-3 activity would result in a downregulated inflammatory response and accelerated wound healing. NLRP-3 null mice, caspase-1 null mice and C57Bl/6 wild type control mice (WT) received four 8 mm excisional cutaneous wounds; inflammation and healing were assessed during the early stage of wound healing. Consistent with our hypothesis, wounds from NLRP-3 null and caspase-1 null mice contained lower levels of the pro-inflammatory cytokines IL-1β and TNF-α compared to WT mice and had reduced neutrophil and macrophage accumulation. Contrary to our hypothesis, re-epithelialization, granulation tissue formation, and angiogenesis were delayed in NLRP-3 null mice and caspase-1 null mice compared to WT mice, indicating that NLRP-3 signaling is important for early events in wound healing. Topical treatment of excisional wounds with recombinant IL-1β partially restored granulation tissue formation in wounds of NLRP-3 null mice, confirming the importance of NLRP-3-dependent IL-1β production during early wound healing. Despite the improvement in healing, angiogenesis and levels of the pro-angiogenic growth factor VEGF were further reduced in IL-1β treated wounds, suggesting that IL-1β has a negative effect on angiogenesis and that NLRP-3 promotes angiogenesis in an IL-1β-independent manner. These findings indicate that the NLRP-3 inflammasome contributes to the early inflammatory phase following skin wounding and is important for efficient healing.

Honey as a topical treatment for wounds.

Honey is a viscous, supersaturated sugar solution derived from nectar gathered and modified by the honeybee, Apis mellifera. Honey has been used since ancient times as a remedy in wound care. Evidence from animal studies and some trials has suggested that honey may accelerate wound healing. The objective of this review was to assess the effects of honey compared with alternative wound dressings and topical treatments on the of healing of acute (e.g. burns, lacerations) and/or chronic (e.g. venous ulcers) wounds. For this update of the review we searched the Cochrane Wounds Group Specialised Register (searched 15 October 2014); The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 9); Ovid MEDLINE (1946 to October Week 1 2014); Ovid MEDLINE (In-Process & Other Non-Indexed Citations 13 October 2014); Ovid EMBASE (1974 to 13 October 2014); and EBSCO CINAHL (1982 to 15 October 2014). Randomised and quasi-randomised trials that evaluated honey as a treatment for any sort of acute or chronic wound were sought. There was no restriction in terms of source, date of publication or language. Wound healing was the primary endpoint. Data from eligible trials were extracted and summarised by one review author, using a data extraction sheet, and independently verified by a second review author. All data have been subsequently checked by two more authors. We identified 26 eligible trials (total of 3011 participants). Three trials evaluated the effects of honey in minor acute wounds, 11 trials evaluated honey in burns, 10 trials recruited people with different chronic wounds including two in people with venous leg ulcers, two trials in people with diabetic foot ulcers and single trials in infected post-operative wounds, pressure injuries, cutaneous Leishmaniasis and Fournier's gangrene. Two trials recruited a mixed population of people with acute and chronic wounds. The quality of the evidence varied between different comparisons and outcomes. We mainly downgraded the quality of evidence for risk of bias, imprecision and, in a few cases, inconsistency.There is high quality evidence (2 trials, n=992) that honey dressings heal partial thickness burns more quickly than conventional dressings (WMD -4.68 days, 95%CI -5.09 to -4.28) but it is unclear if there is a difference in rates of adverse events (very low quality evidence) or infection (low quality evidence).There is very low quality evidence (4 trials, n=332) that burns treated with honey heal more quickly than those treated with silver sulfadiazine (SSD) (WMD -5.12 days, 95%CI -9.51 to -0.73) and high quality evidence from 6 trials (n=462) that there is no difference in overall risk of healing within 6 weeks for honey compared with SSD (RR 1.00, 95% CI 0.98 to 1.02) but a reduction in the overall risk of adverse events with honey relative to SSD. There is low quality evidence (1 trial, n=50) that early excision and grafting heals partial and full thickness burns more quickly than honey followed by grafting as necessary (WMD 13.6 days, 95%CI 9.82 to 17.38).There is low quality evidence (2 trials, different comparators, n=140) that honey heals a mixed population of acute and chronic wounds more quickly than SSD or sugar dressings.Honey healed infected post-operative wounds more quickly than antiseptic washes followed by gauze and was associated with fewer adverse events (1 trial, n=50, moderate quality evidence, RR of healing 1.69, 95%CI 1.10 to 2.61); healed pressure ulcers more quickly than saline soaks (1 trial, n= 40, very low quality evidence, RR 1.41, 95%CI 1.05 to 1.90), and healed Fournier's gangrene more quickly than Eusol soaks (1 trial, n=30, very low quality evidence, WMD -8.00 days, 95%CI -6.08 to -9.92 days).The effects of honey relative to comparators are unclear for: venous leg ulcers (2 trials, n= 476, low quality evidence); minor acute wounds (3 trials, n=213, very low quality evidence); diabetic foot ulcers (2 trials, n=93, low quality evidence); Leishmaniasis (1 trial, n=100, low quality evidence); mixed chronic wounds (2 trials, n=150, low quality evidence). It is difficult to draw overall conclusions regarding the effects of honey as a topical treatment for wounds due to the heterogeneous nature of the patient populations and comparators studied and the mostly low quality of the evidence. The quality of the evidence was mainly downgraded for risk of bias and imprecision. Honey appears to heal partial thickness burns more quickly than conventional treatment (which included polyurethane film, paraffin gauze, soframycin-impregnated gauze, sterile linen and leaving the burns exposed) and infected post-operative wounds more quickly than antiseptics and gauze. Beyond these comparisons any evidence for differences in the effects of honey and comparators is of low or very low quality and does not form a robust basis for decision making.

Characterization of a novel standardized human three-dimensional skin wound healing model using non-sequential fractional ultrapulsed CO2 laser treatments.

At present, there is no standardized in vitro human skin model for wound healing. Therefore, our aim was to establish and characterize an in vitro/ex vivo three-dimensional (3D) wound healing model, which we employed to analyze the effects of dexpanthenol on wound healing and gene regulation. The novel human 3D skin wound healing model using scaffold and collagen 3D organotypic skin equivalents was irradiated with a non-sequential fractional ultrapulsed CO2 laser. These standardized injured full-thickness skin equivalents enable qRT-PCR, microarray, and histological studies analyzing the effect of topically or systemically applied compounds on skin wound healing. These human laser-irradiated skin models were found to be appropriate for in vitro wound healing analysis. Topical treatment of skin wounds with a 5% dexpanthenol water-in-oil emulsion or two different 5% dexpanthenol oil-in-water emulsions clearly enhanced wound closure compared to laser-irradiated untreated control models. To find out whether this positive effect is caused by the active substance dexpanthenol, laser-irradiated skin models were cultured in calciumpantothenate containing medium (20 μg/ml) compared to skin equivalents cultured without calciumpantothenate. 3D models cultured in calciumpantothenate revealed considerably faster wound closure compared to the control models. Quantitative RT-PCR studies showed enhanced mRNA expression of MMP3, IL1α, keratin-associated protein 4-12 (KRTAP4-12), and decreased expression of S100A7 in laser-irradiated skin models cultured in medium containing calciumpantothenate. This novel standardized human 3D skin wound healing model proves useful for topical pharmacological studies on wound healing and reveals new insights into molecular mechanisms of dexpanthenol-mediated effects on wound healing. In addition, these novel 3D model systems can be used to monitor ex vivo effects of various laser systems on gene expression and morphology of human skin.

Topical fentanyl stimulates healing of ischemic wounds in diabetic rats.

Topically applied opioids promote angiogenesis and healing of ischemic wounds in rats. We examined if topical fentanyl stimulates wound healing in diabetic rats by stimulating growth-promoting signaling, angiogenesis, lymphangiogenesis and nerve regeneration. We used Zucker diabetic fatty rats that develop obesity and diabetes on a high fat diet due to a mutation in the Leptin receptor. Fentanyl blended with hydrocream was applied topically on ischemic wounds twice daily, and wound closure was analyzed regularly. Wound histology was analyzed by hematoxylin and eosin staining. Angiogenesis, lymphangiogenesis, nerve fibers and phospho-platelet derived growth factor receptor-β (PDGFR-β) were visualized by CD31-, lymphatic vessel endothelium-1, protein gene product 9.5- and anti-phospho PDGFR-β-immunoreactivity, respectively. Nitric oxide synthase (NOS) and PDGFR-β signaling were analyzed using Western immunoblotting. Fentanyl significantly promoted wound closure as compared to phosphate-buffered saline (PBS). Histology scores were significantly higher in fentanyl-treated wounds, indicative of increased granulation tissue formation, reduced edema and inflammation, and increased matrix deposition. Fentanyl treatment resulted in increased wound angiogenesis, lymphatic vasculature, nerve fibers, nitric oxide, NOS and PDGFR-β signaling as compared to PBS. Phospho-PDGFR-β co-localized with CD31 co-staining for vasculature. Topically applied fentanyl promotes closure of ischemic wounds in diabetic rats. Increased angiogenesis, lymphangiogenesis, peripheral nerve regeneration, NO and PDGFR-β signaling are associated with fentanyl-induced tissue remodeling and wound healing.