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Background: Cutaneous mucormycoses, mainly due to Lichtheimia (Absidia), have occurred on several occasions in the Burn Unit of the University Hospital of Lille, France., Aim: To investigate the potential vector role of non-sterile bandages used to hold in place sterile gauze used for wound dressing., Methods: Mycological analysis by conventional culture, Mucorales real-time polymerase chain reaction (qPCR), and Lichtheimia species-specific qPCR were performed on eight crepe and six elasticized bandages that were sampled on two independent occasions in March 2014 and July 2016. Characteristics of the seven Lichtheimia mucormycoses which occurred in burn patients between November 2013 and July 2016 were also collected to assess the epidemiological relationship between potentially contaminated bandages and clinical infections., Findings: One Lichtheimia corymbifera strain was isolated from a crepe bandage by culture, and Lichtheimia spp. qPCR was positive in six out of eight crepe and four out of six elasticized bandages. Using species-specific qPCR, Lichtheimia ramosa, Lichtheimia ornata, and L. corymbifera were identified in six out of ten, five out of ten, and four out of ten bandages, respectively. In patients with mucormycosis, L. ramosa and L. ornata were present in five and two cases, respectively., Conclusion: Our data support the utility of Mucorales qPCR for epidemiological investigations, the potential role of these bandages in cutaneous mucormycoses in burn patients in our centre, and, consequently, the need for sterile bandages for the dressing of extensive wounds., (Copyright © 2018 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.)

This review aims to evaluate the antimicrobial efficacy of calcium hydroxide against endodontic pathogens when used for 7 days or longer. A systematic electronic literature search was performed in the PubMed, Embase and EBSCO Dentistry & Oral Sciences Source databases using appropriate key words to identify investigations written in the English language that examined the association between the contact time of intracanal calcium hydroxide dressing and its antimicrobial properties. There were no exclusions based on study design. The search yielded 6993 publications. After duplicate removal, 5913 publications were identified and 11 studies met the inclusion criteria. Results showed that the antimicrobial effect of calcium hydroxide for contact times ranging between seven and 45 days is comparable. Two studies demonstrated contradictory findings when exposure was extended to more than 45 days. Future studies are warranted to investigate and optimise calcium hydroxide application for longer periods and identify the potential benefits of its use in clinical settings., (© 2017 Australian Society of Endodontology Inc.)

Topical silver agents and dressings are used to control infection and promote healing in chronic wounds, but reviews published from 2006 to 2011 found heterogeneous results regarding their effectiveness. A scoping review was conducted to examine the extent, range, and nature of research activity surrounding chronic wound care that employed silver-impregnated dressings; identify research gaps in the existing literature; and summarize the evidence to provide recommendations for future clinical studies. Ten (10) electronic databases and additional sources were screened from their inception to May 2016; search terms for the different databases included but were not limited to silver, chronic, complications, wound, ulcer, and sore. English-language articles that compared silver dressings with an alternate treatment in adults with chronic wounds and that reported clinical outcome measures were included. Of 222 full-text reviewed studies, 27 were included for qualitative analysis. Qualitative analysis was guided by key findings identified among the included studies that were analyzed in aggregate form where appropriate. In comparative analyses of the 26 studies that investigated wound healing, 15 revealed significantly positive wound healing outcomes with silver treatments versus 9 that did not; the remaining 2 failed to provide statistical values of significance. Of 17 studies that presented data on microbiology, 3 reported significant microbial load improvement for silver dressings, 9 noted nonsignificant findings, and 4 provided no statistical values. Pain, adverse events, and treatment cost were included in 5, 7, and 3 studies, respectively, with heterogeneous findings. The heterogeneous evidence regarding the impact of silver dressings on clinical outcomes may be related to differences in the silver treatments themselves, heterogeneous intervention strategies, study designs, outcomes, and measures. Well-designed clinical studies with multiple outcome parameters are necessary to determine the optimal type and use of silver-dressings in chronic wounds.

The purpose of this study was to investigate incidence rates and levels of microbial contamination in open-but-unused portions of wound dressings stored in home settings. Portions of wound dressings were collected at up to four home visits for 104 clients undertaking wound management within their home. A control sample and stored sample was collected on each home visit and sent for pathology testing to identify levels of microbial contamination. The stored open-but-unused wound dressings were managed according to a written protocol. Of the tested samples (n = 776), 6% of control samples and 7% of test samples had microbial contamination. From regression analysis, the stored samples were more likely to have microbial contamination than control samples, but results were not statistically significant. In comparing occasions of storage and handling across four home visits, after adjusting for sample group and dressing type, none of the home visit occasion regressions were statistically significant. In conclusion, storage of open-but-unused portions of wound dressings kept in home settings does not appear to increase the rate of microbial contamination compared to newly opened wound dressings., (© 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.)

Migration of fibroblasts into wound area is a critical phenomenon in wound healing process. We used an appropriate system to fabricate an electrospun bioactive scaffold with controlled release of PDGF-BB in order to induce migration of primary skin fibroblast cells. First of all, protein-loaded chitosan nanoparticles based on ionic gelation interaction between chitosan and sodium tripolyphosphate were prepared. Then polycaprolactone electrospun fibers containing chitosan nanoparticles or PDGF-BB-loaded chitosan nanoparticles were prepared. Cellular attachment and morphology of cells seeded on scaffolds with or without PDGF-BB were evaluated by using a fluorescence microscope and scanning electron microscopy. Cells were well-oriented 72 h after seeding on the scaffolds containing PDGF-BB. The mean aspect ratio of populations on scaffold containing PDGF-BB-loaded chitosan nanoparticles was significantly greater than those on the scaffold containing chitosan nanoparticles but no PDGF-BB. Furthermore, the Arp2 gene, which is involved in cell protrusion formation, showed about three times more expression at mRNA level, in cells seeding on PDGF-BB-containing scaffold compared to cells seeding on scaffold containing only chitosan nanoparticles, using Real Time PCR test. Finally, under agarose migration assay results demonstrated that cells' chemotaxic behavior was more toward scaffold containing PDGF-BB compared to the PDGF-BB alone or FBS group. In addition, in terms of distance, the cell mass could grow faster, in response to scaffold containing PDGF-BB compared to FBS or PDGF-BB alone; however, the number of migrating cells might be the same or significantly higher in the latter groups.

This study focused on the synthesis and comprehensive characterization of environmentally friendly hydrogel membranes based on carboxymethyl cellulose (CMC) for wound dressing and skin repair substitutes. These new CMC hydrogels were prepared with two degrees of functionalization (DS=0.77 and 1.22) and chemically crosslinked with citric acid (CA) for tuning their properties. Additionally, CMC-based hybrids were prepared by blending with polyethylene glycol (PEG, 10wt.%). The results demonstrated that superabsorbent hydrogels (SAP) were produced with swelling degree typically ranging from 100% to 5000%, which was significantly dependent on the concentration of CA crosslinker and the addition of PEG as network modifier. The spectroscopical characterizations indicated that the mechanism of CA crosslinking was mostly associated with the chemical reaction with CMC hydroxyl groups and that PEG played an important role on the formation of a hybrid polymeric network. These hydrogels presented very distinct morphological features depended on the degree of crosslinking and the surface nanomechanical properties (e.g., elastic moduli) were drastically affected (from approximately 0.08GPa to 2.0GPa) due to the formation of CMC-PEG hybrid nanostructures. These CMC-based hydrogels were cytocompatible considering the in vitro cell viability responses of over 95% towards human embryonic kidney cells (HEK293T) used as model cell line., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Wound dressings require good antiseptic properties, mechanical strength and, more trustably, natural material ingredients. Antimicrobial properties of cerium ions and chitosan are known and alginate based wound dressings are commercially available. In this study, the advantages of these materials were combined and alginate films were crosslinked with cerium(III) solution and chitosan added cerium(III) solution. Films were characterized by Fourier transform infrared spectroscopy (FTIR), light transmittance, scanning electron microscopy (SEM), swelling experiments, water vapor transmittance tests, and mechanical stretching tests. The antibacterial and physical properties of the films were compared with those of conventional calcium alginate films. Both cerium ion crosslinked and cerium ion-chitosan crosslinked alginate films gained antibacterial activity against Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria. Cerium alginate-chitosan films showed high resistance to being deformed elastically. Results show that cerium alginate-chitosan films can be flexible, ultraviolet-protecting, and antibacterial wound dressings., (Copyright © 2017 Elsevier B.V. All rights reserved.)

New single dose interactive extracellular matrix (ECM) mimicking nanofibrous wound dressings based on polylactic acid (PLA) and cellulose acetate (CA) were developed, characterized and investigated for wound treatment. The antimicrobial agent, thymoquinone (TQ) was selected and incorporated into the scaffolds for preventing common clinical infections, and to accelerate the rate of wound closure and re-epithelialization. The newly fabricated TQ-loaded PLA/CA wound dressings offered many advantages such as mimicking the ECM via the 3D nanofibrous structure, and promoted the cell proliferation due to the hydrophilicity and bioactivity of CA. The wound dressings also prevented the bacterial infection in the early stages due to presence of TQ, and maintained the minimum possible bacterial load in the wound area through the sustained release of the drug for 9days. In vivo assessment demonstrated that TQ-loaded PLA: CA (7:3) scaffolds significantly promoted the wound healing process by increasing re-epithelialization and controlling the formation of granulation tissue. The obtained results suggest that the developed TQ-loaded PLA/CA nanofibrous mats could be ideal for wound dressing applications., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In the present article, we propose a simple Antibiofilm Dressing's Activity Measurement (A.D.A.M.) test that allows to check in vitro a dressing's suitability against biofilm-related wound infections. To perform the test, three agar discs are covered with biofilm formed by the tested pathogen after which they are assembled one over another in the form of an agar plug and placed in the well of a 24-well plate. The top disc is covered with the analyzed dressing and the entire set is incubated for 24h. During this time, the investigated antimicrobial substance is released from the dressing and penetrates to subsequent biofilm-covered agar discs. Biofilm reduction is measured using 2,3,5-triphenyl-2H-tetrazolium chloride (TTC) spectrometric assay and the results are compared to untreated control samples (agar plug covered with biofilm and without the dressing/or with a passive dressing placed on the top disc). Furthermore, in order to standardize the differences in penetrability of the drugs released from active dressings the results can be expressed as a dimensionless value referred to as the Penetrability Index. In summary, A.D.A.M. test is simple, cheap, can be performed practically in every clinical laboratory and takes no more time than routine microbiological diagnostics. Apart from measuring the released drug's activity, the A.D.A.M. test allows to assess drug penetrability (across three agar discs), reflecting real wound conditions, where microbes are frequently hidden under the necrotic tissue or cloth. In conclusion, the A.D.A.M. test produces a high volume of data that, when analyzed, can provide a researcher with a valuable hint concerning the applicability of active dressings against specific biofilm pathogens in a particular setting., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The current study was aimed to develop a transparent wound dressing comprised of bacterial cellulose (BC) and poly (2-hydroxyethyl methacrylate) (PHEMA) hydrogel coated with silver (Ag) nanoparticles. Briefly, different concentrations of BC whiskers (BCWs) were added into the HEMA solution to form PHEMA/BCWs hydrogel with volume ratio of monomer HEMA and BCWs as 7:3 and 1:1. The addition of BCWs into PHEMA matrix improved its equilibrium water content and light transmittance about 20%-40% and 10%, respectively. The Young's modulus for PHEMA was found to be 0.72MPa, which was improved to 0.57MPa and 0.50MPa for PHEMA/BCWs 7:3 and PHEMA/BCWs 1:1, respectively. Further, immersion of PHEMA/BCWs hydrogel in the AgNO 3 and NaBH 4 solutions bestowed it with antibacterial property and produced inhibition zones of 0.5±0.15cm and 0.25±0.15cm against Escherichia coli and Staphylococcus aureus, respectively. Similarly, PHEMA/BCWs prepared with 0.001M AgNO 3 and 0.001M NaBH 4 solutions showed 99% and 90% reduction in colony forming unit (CFU) for E. coli and S. aureus, respectively, after 24h. The PHEMA/BCWs/Ag hydrogel facilitated the growth of NIH3T3 fibroblast, showing their low toxicity. These results demonstrate the suitability of PHEMA/BCWs/Ag hydrogel for its application as potential transparent wound dressing material for skin repair., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this work, hydrogel membranes were developed based on poly vinyl alcohol (PVA), starch (St), and chitosan (Cs) hydrogels with nano Zinc oxide (nZnO). PVA/St/Cs/nZnO hydrogel membranes were prepared by freezing-thawing cycles, and the aqueous PVA/St solutions were prepared by dissolving PVA in distilled water. After the dissolution of PVA, starch was mixed, and the mixture was stirred. Then, chitosan powder was added into acetic acid, and the mixture was stirred to form a chitosan solution. Subsequently, Cs, St and PVA solutions were blended together to form a homogeneous PVA/St/Cs ternary blend solution. Measurement of Equilibrium Swelling Ratio (ESR), Water Vapor Transmission Test (WVTR), mechanical properties, scanning electron microscopy (SEM), MTT [3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide] assay, antibacterial studies, in vivo wound healing effect and histopathology of the hydrogel membranes were then performed. The examination revealed that the hydrogel membranes were more effective as a wound dressing in the early stages of wound healing and that the gel could be used in topic applications requiring a large spectrum of antibacterial activity; namely, as a bandage for wound dressing.

Background: Polymicrobial communities colonize all wounds, and biofilms are hypothesized to be a key link to the chronic state and stalled healing. Molecular methods offer greater insight when studying microbial ecology in chronic wounds, as only a small fraction of wound bacteria are cultured by currently available methods and studies have shown little agreement between culture and molecular based approaches. Some interventions, like dressings with oxidized silver, are reported to help the stalled wounds move to a normal healing trajectory but the underlying mechanisms are difficult to measure. One hypothesis is that the use of topical antimicrobial dressings targets the wound microbiome and reduces bioburden., Objectives: Our objective was to determine if culture-independent molecular methods could be used to identify the microbial composition in chronic wounds, and measure the microbiome over time when a topical antimicrobial dressing is used to reduce bioburden., Methods: Patients with chronic wounds defined as >6 weeks in duration and not taking systemic antibiotics were recruited to participate. A wound contact layer containing silver oxynitrate was applied immediately after routine sharp debridement material was collected and swabs of the wound bed taken. Next-generation sequencing of the bacterial 16S rRNA gene in each specimen was used to measure the microbiome., Results: Distinct bacterial communities were observed between swab and debridement samples, highlighting spatial differences and the importance of sampling consistency. The microbial communities appeared to be similar between different diabetes statuses, but different among the three wound categories included., Conclusions: Culture-independent methods can be applied to measure the microbiome of chronic wounds even when a topical antimicrobial dressing is applied to the wound.

Opportunistic bacteria that cause life-threatening infections are still a central problem associated with a healthcare setting. Bacteriophage capsid immobilization on nanostructured polymers maximizes its tail exposure and looks promising in applications toward skin-infections as alternative to antibiotics standardly used. The main goal of this work was to investigate the covalent immobilization of vB_Pae_Kakheti25 bacteriophage capsid on polycaprolactone (PCL) nanofibers (non-woven textile), as a potential effective antimicrobial, laundry resistant and non-toxic dressing for biomedical use. Surface analyses showed that the immobilization of vB_Pae_Kakheti25 bacteriophage capsid on PCL nanofibres oriented bacteriophage tails to interact with bacteria. Furthermore, antimicrobial assays showed a very effective 6 log bacterial reduction, which was equivalent to 99.9999%, after immediate and 2 hours of contact, even following 25 washing cycles (due to covalent bond). The activity of PCL-vB_Pae_Kakheti25 against P. aeruginosa was immediate and its reduction was complete., (Copyright © 2017 Elsevier Inc. All rights reserved.)

This work demonstrated the successful application of N-halamine technology for wound dressings rendered antimicrobial by facile and inexpensive processes. Four N-halamine compounds, which possess different functional groups and chemistry, were synthesized. The N-halamine compounds, which contained oxidative chlorine, the source of antimicrobial activity, were impregnated into or coated onto standard non-antimicrobial wound dressings. N-halamine-employed wound dressings inactivated about 6 to 7 logs of Staphylococcus aureus and Pseudomonas aeruginosa bacteria in brief periods of contact time. Moreover, the N-halamine-modified wound dressings showed superior antimicrobial efficacies when compared to commercially available silver wound dressings. Zone of inhibition tests revealed that there was no significant leaching of the oxidative chlorine from the materials, and inactivation of bacteria occurred by direct contact. Shelf life stability tests showed that the dressings were stable to loss of oxidative chlorine when they were stored for 6 months in dark environmental conditions. They also remained stable under florescent lighting for up to 2 months of storage. They could be stored in opaque packaging to improve their shelf life stabilities. In vitro skin irritation testing was performed using a three-dimensional human reconstructed tissue model (EpiDerm™). No potential skin irritation was observed. In vitro cytocompatibility was also evaluated. These results indicate that N-halamine wound dressings potentially can be employed to prevent infections, while at the same time improving the healing process by eliminating undesired bacterial growth., Competing Interests: The authors declare no conflict of interest.

Silk fibroin materials have shown some success in wound dressing applications; however, their use for this purpose remains limited by a complex production process and wasted sericin. In the present study, Bombyx mori cocoon materials are used because the protective function of the silkworm cocoon resembles the manner in which the skin protects the human body. A series of silkworm cocoon sol-gel film (SCSF) wound dressings are prepared by immersion in a CaCl 2 -ethanol-H 2 O solution for different treatment times. The accelerated wound-healing capabilities of SCSFs are systematically evaluated. Among them, the SCSF sample immersed for 90min exhibits stronger biocompatibility and antibacterial performance compared to other SCSFs. SCSF-90 also exhibits excellent transparency, a high swelling ratio, and good extensibility. Furthermore, in vivo experiments indicate that SCSF-90 can significantly accelerate the healing rate of wounds in New Zealand white rabbits, compared to the standard Mepitel ® dressing, and histological examinations reveal that SCSF-90 aided in the successful reconstruction of intact and thickened epidermis. These results demonstrate that the proposed approach may be utilized in the design of antibacterial materials with promising applications in wound dressing., (Copyright © 2017 Elsevier B.V. All rights reserved.)

This study aims to develop new antibacterial hydrogel wound dressings composed of poly(aminoethyl) modified chitosan (PAEMCS). FTIR, 1 H NMR, and elemental analysis demonstrated that PAEMCS was successfully synthesized via grafting poly(aminoethyl) groups onto hydroxyl groups on chitin first, and removing acetyl groups from the grafted polymer afterward. XRD and TGA implied its well-defined crystallinity and thermostability. Furthermore, a series of hydrogels were fabricated under the participation of dipotassium hydrogen phosphate (DHP). The gelation tests suggested that the higher concentration of PAEMCS or DHP was beneficial to the formation of hydrogels. The pH values of hydrogels at 37°C were all in the range of 7.12-7.50. The rheological tests indicated that PAEMCS-based hydrogels were of lower DHP addition and higher elasticity than CS-based hydrogels to achieve the same gelation temperature under the same polymer's concentration. Additionally, the swelling, anti-bacteria, and cytotoxicity experiments showed that PAEMCS-based hydrogels possessed excellent hygroscopicity, high antibacterial activity against E. coli, S. aureus, or S. epidermidis, and good cytocompatibility toward L929 cells or HUVECs, respectively. All the results implied that PAEMCS-based hydrogels not only maintained inherent multiple properties of chitosan but also possessed excellent antibacterial activity, and might be promising antibacterial hydrogel dressings used in wound therapy., (Copyright © 2017 Elsevier B.V. All rights reserved.)

In this study, three kinds of antiseptics which were 0.05% chlorhexidine, 0.2% polyhexamethylene biguanide (PHMB), or 200 ppm silver nanoparticle was introduced to incorporate in the sericin-based scaffold to produce the antimicrobial dressing for the treatment of infected chronic wound. The effects of antiseptic incorporation on the stability, release of sericin, and short-term and long-term (6 months) antimicrobial activity of the sericin dressing against gram-negative and gram-positive bacteria were investigated. We showed that the incorporation of each antiseptic did not have significant effect on the internal morphology (pore size ~ 73-105 μm), elasticity (Young's modulus ~ 200-500 kPa), and the sericin release behavior of the sericin-based dressing. The release of sericin from the dressing was prolonged over 120 h and thereafter. Comparing among three antiseptics, 0.05% chlorhexidine incorporated in the sericin dressing showed the highest immediate and long-term (6 months) antimicrobial effect (largest inhibition zone) against most bacteria either gram-positive or gram-negative bacteria. The in vivo safety test following ISO10993 standard (Biological evaluation of medical devices - Part 6: Tests for local effects after implantation) confirmed that the sericin dressing incorporating 0.05% chlorhexidine did not irritate to tissue, comparing with the commercial material used generally in clinic (Allevyn®, Smith & Nephew). We suggested the sericin dressing incorporating 0.05% chlorhexidine for the treatment of infected chronic wound. Chlorhexidine would reduce the risk of infection while the sericin may promote wound healing.

Recent studies in wound dressing applications offer new therapies and promote wound healing process. The aim of this study was to develop Hypericum perforatum (St John's Wort) oil incorporated chitosan films for wound dressing applications. H. perforatum oil as a potential therapeutic agent was encapsulated in chitosan film to achieve a better wound dressing material. Oil incorporated chitosan films were successfully prepared by solvent casting method in different oil concentrations (0.25-1.5%v/v). Water vapor permeability (WVP), mechanical test, swelling behavior and surface hydrophobicity were performed in order to characterize the prepared films. Antimicrobial test was performed by disc diffusion method and the growth inhibition effects of the films including different amount of H. perforatum oil were investigated on Escherichia coli and Staphylococcus aureus. WVP increased with oil incorporation and the highest value was obtained for 0.25% oil concentration.The highest strain value was obtained in 0.25% oil content films although tensile stress decreased with increasing oil content. H. perforatum oil incorporated films had antimicrobial effect on both microorganisms. Chitosan based films had no cytotoxic effects on NIH3T3fibroblast cells and provided a good surface for cell attachment and proliferation. The results showed that the H. perforatum incorporated chitosan films seems to be a potential and novel biomaterial for wound healing applications., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The compatibility of a 2% chlorhexidine gluconate/70% isopropyl alcohol (CHG/IPA) skin preparation with a gum mastic liquid adhesive (GMLA) and liquid adhesive remover (LAR) was assessed in healthy volunteers. Twenty subjects completed test material combination with microbial sampling at 3- and 7-day time points. Mean log10 reductions from baseline for normal flora were assessed. There was no significant difference in reduction of normal flora on skin prepped with CHG/IPA versus skin prepped with CHG/IPA followed by GMLA or LAR. The conclusion of the study was that the use of GMLA or LAR with CHG/IPA does not affect the antiseptic effectiveness of CHG/IPA.

Curcuma longa (turmeric) has a long history of use in medicine as a treatment for inflammatory conditions. The primary active constituent of turmeric and the one responsible for its vibrant yellow color is curcumin. Curcumin is used for treatment of wound and inflammation. It had antimicrobial and antioxidant property. It has low intrinsic toxicity and magnificent properties like with comparatively lesser side-effects. Cotton cloth is one of the most successful wound dressings which utilize the intrinsic properties of cotton fibers. Modern wound dressings, however, require other properties such as antibacterial and moisture maintaining capabilities. In this study, conventional cotton cloth was coated with Curcumin composite for achieving modern wound dressing properties. Curcumin nanocomposite is characterized. The results show that coated cotton cloth with Curcumin nanocomposite has increased drying time (74%) and water absorbency (50%). Furthermore, they show antibacterial efficiency against bacterial species present in wounds., (Copyright © 2017 Elsevier B.V. All rights reserved.)

The microbial infection and growth of fibroblasts are the critical factors for the effective wound healing. The natural polymer-based dressing membranes may mimic extracellular matrix to support the survival, proliferation and differentiation of fibroblasts. The present study deals with the preparation of chitosan/titanium dioxide (CS/TiO 2 ) composite membranes with different degree of TiO 2 incorporation, and their characterization in terms of morphology, ultrastructure, thermal behavior and mechanical properties with SEM, FTIR, XRD and tensile strength analyses. The data demonstrated the formation of strong O-Ti-O bonding between TiO 2 and CS resulting in superior porosity, mechanical strength, crystallinity and flexibility of the composite membranes. Further, the cyto-compatibility, proliferation, oxidative stress, cell cycle and apoptosis analyses of fibroblast L929 cells demonstrated the enhanced proliferation and survival, and decreased oxidative stress and apoptosis in L929 cells grown on CS/TiO 2 membrane incorporated with 025% TiO 2 . Next, we measured the significant up-regulation in the expression of fibroblast-markers in L929 cells cultured on CS/TiO 2 (0.25%) membrane. Furthermore, the CS/TiO 2 composite membranes exhibited a superior antibacterial activity against Staphylococcus aureus. Taken together, the data confirmed that CS/TiO 2 (0.25%) membrane improved the growth, survival and functional integrity of fibroblasts, and exerted antibacterial activity which may be utilized as potential dressing materials., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Purpose: Dressings containing chlorhexidine gluconate (CHG) are increasingly used in clinical environments for prevention of infection at central venous catheter insertion sites. Increased tolerance to this biocide in staphylococci is primarily associated with the presence of qacA/B and smr genes., Methodology: We used a culture-independent method to assess the prevalence of these genes in 78 DNA specimens recovered from the skin of 43 patients at catheter insertion sites in the arm that were covered with CHG dressings., Results: Of the 78 DNA specimens analysed, 52 (67 %) possessed qacA/B and 14 (18 %) possessed smr; all samples positive for smr were also positive for qacA/B. These prevalence rates were not statistically greater than those observed in a subsample of specimens taken from non-CHG treated contralateral arms and non-CHG-dressing exposed arms. A statistically greater proportion of specimens with greater than 72 h exposure to CHG dressings were qac-positive (P=0.04), suggesting that the patients were contaminated with bacteria or DNA containing qacA/B during their hospital stay. The presence of qac genes was not positively associated with the presence of DNA specific for Staphylococcusepidermidis and Staphylococcusaureus in these specimens., Conclusion: Our results show that CHG genes are highly prevalent on hospital patients' skin, even in the absence of viable bacteria.

Infection remains the most common and significant complication after high-energy fractures. The Bioburden Study is a multicenter, prospective, observational cohort study of wound bacterial bioburden and antibiotic care in severe open lower extremity fractures. The aims of this study are to (1) characterize the contemporary extremity wound "bioburden" at the time of definitive wound closure; (2) determine the concordance between polymerase chain reaction results and hospital microbiology; (3) determine, among those who develop deep infections, the concordance between the pathogens at wound closure and at deep infection; and (4) compare the probability of deep infection between those who did and did not receive an appropriate course of antibiotics based on bioburden at the time of wound closure. To address these aims, sites collected tissue samples from severe lower extremity injuries at the time of wound closure and at first surgery for treatment of a deep infection, nonunion, flap failure, amputation, or other complications (because these surgeries may be due to undetected infection). Otherwise, if no further surgical treatment occurred, participants were followed for 12 months. The study was conducted at 38 US trauma centers and has enrolled 655 participants aged 18-64 years. This is the first large multi-institutional study evaluating the wound bioburden of severe open tibia fractures and correlating this bioburden with the risk of wound complications after definitive soft tissue closure.

Wound infections, particularly of chronic wounds, pose a substantial challenge for designing antimicrobial dressings that are both effective against pathogens, and do not interfere with wound healing. Due to their broad-spectrum antimicrobial and immunomodulatory activities, naturally-occurring antimicrobial peptides (AMPs) are promising alternative treatments. However, their cytotoxicity at high concentrations and poor stability hinders their clinical use. To mitigate these undesirable properties, we investigated the effects of tethering human AMP cathelicidin LL37 to collagen, one of the main extracellular matrix proteins in wound sites, secreted by fibroblasts, and in commercially-available wound dressings. The active domain of human AMP cathelicidin, LL37, and two chimeric peptides containing LL37 fused to collagen binding domains (derived from collagenase - cCBD-LL37 or fibronectin - fCBD-LL37) were synthesized and adsorbed to PURACOL® type I collagen scaffolds. After 14days, 73%, 81% and 99% of LL37, cCBD-LL37 and fCBD-LL37, respectively, was retained on the scaffolds and demonstrated undiminished antimicrobial activity when challenged with both Gram-positive and Gram-negative bacterial strains. Loaded scaffolds were not cytotoxic to fibroblasts despite retaining peptides at concentrations 24 times higher than the reported cytotoxic concentrations in solution. These findings indicate that biopolymer-tethered AMPs may represent a viable alternative for preventing and treating wound infection while also supporting tissue repair., Statement of Significance: Over 6.5million people annually in the United States suffer chronic wounds; many will become infected with antibiotic-resistant bacteria. Treatments used to prevent and fight infection are toxic and may hinder wound healing. AMPs are broad-spectrum antimicrobials that also promote healing; however, their instability and toxicity are major challenges. To overcome treatment gaps, we functionalized collagen scaffolds with chimeric antimicrobial peptides (AMPs) with collagen binding domains to create antimicrobial and non-cytotoxic scaffolds that may promote healing. This is the first report of CBD-mediated delivery of AMPs onto collagen scaffolds that demonstrates no cytotoxicity toward fibroblasts. This study also suggests that retention of antimicrobial activity is CBD-dependent, which provides foundations for fundamental studies of CBD-AMP mechanisms and clinical explorations., (Copyright © 2016. Published by Elsevier Ltd.)

In spite of developing new drugs and modern formulations, the treatments of chronic fungal infections are still challenging. Fibrous wound dressings are new suggestions for the treatment of chronic superficial infections. In the present study, we formulated an antifungal agent, terbinafine hydrochloride (TFH), which is a hydrophobic drug, in wound dressings prepared by electrospun polycaprolactone, polycaprolactone/gelatin (50:50 w/w) and gelatin. To obtain more water-stable meshes, the preparations were treated by glutaraldehyde and their properties were determined before and after treatment. The morphology of fibrous meshes was observed by scanning electron microscopy. Drug loading efficiency and release rate were measured by high performance liquid chromatography (HPLC) and the release rate was monitored for 144h. Antifungal tests were performed on Trichophyton mentagrophytes, Aspergillus fumigatus and Candida albicans cultured on Muller-Hinton agar. The toxicity of the meshes was measured after 24h and 14days by MTT assay. Terbinafine loading of polycaprolactone/gelatin (50:50) was 100% and it released the highest amount of TFH too. In antifungal tests, all samples were able to hinderT. mentagrophytes and A. fumigatus but not C. albicans growth among them, polycaprolactone fibers made the largest inhibition zone. In MTT assay, none of prepared samples showed toxicity against L929 cells. Teken together, the prepared TFH-loaded PCL/gelatin electrospun meshes were able to release TFH slowly and in a steady state in time. With respect to no obvious cytotoxicity in MTT assay and stong antifungal activity toward T. mentagrophytesin vitro, these TFH-based meshes could be considered as potential candidates in clinical application as wound dressing for treatment of chronic dermatophytosis., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Wound care treatment is a serious issue faced by the medical staffs due to its variety and complexity. Wound dressings are typically used to manage the various types of wounds. In this study, polyurethane (PU) fibers containing mupirocin (Mu), a commonly used antibiotic in wound care, were fabricated via electrospinning technique. The aim of this study was to develop biomedical electrospun fiber scaffolds for preventing wound infections with good compatibility and to demonstrate their applications as anti-infective burn wound dressings. The surface morphology of fibers was obtained by scanning electron microscopy. FT-IR spectra, water vapor transmission rate, and drug release study in vitro were tested to demonstrate the fiber scaffold characteristic. The prepared PU/Mu composite scaffolds had satisfactory antibacterial activity especially against Staphylococcus aureus. The cell studies revealed that the scaffolds were biocompatible and safe for cell attachment. Histological and immunohistochemical examinations were performed in rats, and the results indicated the histological analysis of tissue stained with H&E showed no obvious inflammation reaction. The results indicated that the electrospun scaffolds were capable of loading and delivering drugs, and could be potentially used as novel antibacterial burn wound dressings.

Copper ion (Cu 2+ ) incorporated microporous chitosan-polyethylene glycol films were developed as a multipotent wound dressing material. The mechanical properties, swelling behavior and moisture permeability of hydrogel films with varying Cu 2+ concentration and the release of Cu 2+ from films were evaluated. The results revealed the enhanced mechanical stability of films with increasing Cu 2+ concentration without compromising moisture permeability and absorption capability of wound exudates. Microporous surface and swollen micropores in hydrated conditions were confirmed from morphological analysis. Degradation studies in lysozyme and H 2 O 2 demonstrated increasing stability of films with increasing Cu 2+ concentration up to 30days. Antibacterial tests revealed superiority in inhibiting biofilm formation in comparison to chitosan films. In vitro drug release, MTT assays and cell adhesion tests demonstrated the efficiency of Cu 2+ incorporated hydrogels in sustained drug release and antibacterial activity with excellent keratinocyte cell response., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Novel nanocomposite hydrogel wound dressings on the basis of egg white and polyvinyl alcohol, as matrix, and natural Na-montmorillonite clay, as reinforcing agent, were prepared and their performances on wound healing investigated in vitro and in vivo. In vitro cytotoxicity assay revealed non-cytotoxic activity and excellent biocompatibility level of prepared nanocomposite hydrogel wound dressings. The bacterial penetration assay showed the prepared nanocomposite hydrogel wound dressings are excellent barriers against microorganisms and could protect the wound from infection during the wound healing. In vivo animal study showed that the wound healing process was considerably faster in wounds covered with nanocomposite hydrogel wound dressings compared to the conventional wound dressing, i.e. sterile gauze, due to creation of a moist environment on the wound surface and faster migration rate of the epidermal cells. The mechanical properties of healed wounds with nanocomposite hydrogel wound dressings were better than those control wounds covered with sterile gauze due to their better collagen formation ability as a result of created moist healing condition as well as the presence of egg white, as a source of proteins, in their structures.

Reconstituted cellulose films were generated using residual bacterial cellulose membranes mechanically defibrillated (RBC fibrils) recycled following wound dressing production via a dry-cast process. Arabinogalactan (AG) extracted from Pereskia aculeata leaves and/or a xyloglucan (GHXG) from Guibourtia hymenifolia seeds were incorporating into the RBC at various compositions, and new films were created using the same process. Biocomposite properties were evaluated by scanning electron microscopy, contact angle (CA), and X-ray diffraction measurements. The attachment and proliferation of murine L929 fibroblasts on RBC and RBC/Hydrocolloids (HD) were also evaluated. RBC films with 20-30% GHXG replacement improved film stability and the inclusion of HD increased microfiber aggregation and reduced porous regions. Changes in the hydrophilic characteristics were also observed and owing to the adhesion effect the inclusion of HD on RBC led to a statistically significant effect of the mechanical properties of films. The RBC/AG films supported L929 adhesion similar to that observed for commercial bacterial cellulose, indicating their potential use for biomedical applications., (Copyright © 2016. Published by Elsevier Ltd.)

Objective: This study was designed to evaluate the antibacterial activity of a wound dressing which combines polyacrylate fibres and a silver lipido-colloid matrix (UrgoClean Ag, silver polyabsorbent dressing), against biofilm of methicillin-resistant Staphylococcus aureus (MRSA)., Method: Samples of silver polyabsorbent dressing and the neutral form of this dressing (UrgoClean) were applied to biofilms of MRSA formed on a collagen I-coated surface, cultured for 24 hours. Different exposure times were tested (1, 2, 4 and 7 days) without dressing change. The biofilm reduction was quantified by using culture methods and by confocal laser scanning microscopy experiments., Results: The application of the silver polyabsorbent dressing resulted in a significant decrease of the biofilm population by a log reduction of 4.6, after 24 hours of exposure. Moreover, the antibiofilm activity was maintained for 7 days with reduction values up to 4 log (reduction of biofilm superior to 99.99%). The application of the neutral dressing also induced a significant reduction of the concentration of sessile cells after 1 day (about 0.90 log). The results obtained with this neutral form of the dressing showed that the polyacrylate fibres were able to exert a mechanical disruption of the biofilm architecture., Conclusion: These in vitro experiments demonstrated that silver polyabsorbent dressing was able to strongly reduce the biofilm of MRSA. The antibiofilm mechanism of this dressing can be explained by a dual action of the polyabsorbent fibres (based on ammonium polyacrylate polymer around an acrylic core) which induced a mechanical disruption of the biofilm matrix and/or a sequestration of sessile cells, and the diffusion of silver ions which produced bactericidal activity., Declaration of Interest: This study was supported by Laboratoires Urgo (Dijon). P. Janod is an employee of Laboratoires Urgo. The company had no influence on the experimental design and the interpretation of the results.

The objective of this study was to develop novel hydrogel films based on carboxyl-modified hypromellose-crosslinked chitosan for potential wound dressing. Hypromellose (HPMC) was grafted with succinic acid to yield hypromellose succinate (HPMCS), and then the reinforced hydrogel films of HPMCS-crosslinked chitosan (HPMCS-CS) were prepared through amide bond formation using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) and N- hydroxysuccinimide (NHS) as a catalyst. Compared to that of blend film, mechanical properties of HPMCS-CS hydrogel films were significantly enhanced both in dry and swollen state. To assess the applicability of HPMCS-CS hydrogel films as wound dressing, the swelling behavior, water vapor transmission rate (WVTR), oxygen permeability, biocompatibility (cytotoxicity and hemolysis), in vitro drug release and bactericidal properties were analyzed. The results indicated that HPMCS-CS hydrogel films with good biocompatibility possess high swelling ratio, proper WVTR, and oxygen permeability, which might accelerate tissue regeneration. Meanwhile, gentamycin sulfate release from drug-loaded HPMCS-CS hydrogel films were sustained, which would help to protect wound from infection., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Wound healing is a dynamic process that normally follows a predictable cascade of events. A common cause of delayed wound healing or wound dehiscence is increased colonization with microbes, often leading to infection. Infection may impede the healing process by inducing an undesirable inflammatory response. Systemic antibiotics and topical antiseptics are mainstays of treatment, but their adverse side effects and the potential for emergence of resistant microbial strains have led to a search for alternative approaches for control of bioburden., Cases: We describe two neonates and one 10-year-old girl who experienced delayed wound healing treated with a nonmedicated dressing that exploits bacterial cell-surface hydrophobic interactions via a dressing with a fatty acid (dialkylcarbamoylchloride [DACC]) coating. This dressing was used in a colonized, unstageable occipital pressure injuries, an infected stage 4 pressure injury over a vertebra, and a dehisced surgical sternal wound. Complete closure was achieved in all wounds within 2 to 4 weeks., Conclusion: We employed a DACC-coated dressing that provides bacteriostatic activity without creating cytotoxicity or an inflammatory response.

Purpose: The role of bacteria in meibomian gland dysfunction is unclear, yet contamination of compresses used as treatment may exacerbate this condition. This study therefore determined the effect of heating on bacteria on two forms of compress., Methods: Cotton flannels and MGDRx EyeBags (eyebags) were inoculated by adding experimental inoculum (Staphylococcus aureus, Streptococcus pyogenes, Pseudomonas aeruginosa; one species for each set of 3 eyebags and flannels). One of each were then randomised in to 3 groups: no heating (control); therapeutic (47.4±0.7°C); or sanitisation (68±1.1°C). After treatment, bacteria cell numbers were calculated. The experiment was repeated in triplicate., Results: There was a statistically significant difference between each treatment with the eyebag for S. aureus (control=7.15±0.11logC/ml, therapeutic heating=5.24±0.59logC/ml, sanitisation heating=3.48±1.43logC/ml; P<0.001) and S. pyogenes (7.36±0.13, 5.73±0.26, 4.75±0.54; P<0.001). P. aeruginosa also showed a significant reduction (P<0.001) from control (6.39±0.34) to therapeutic (0.33±0.26) and sanitisation (0.33±0.21), but the latter were similar (P=1.000). For the flannels, there was significant difference between each treatment for S. aureus (6.89±0.46, 3.96±1.76, 0.42±0.90; P<0.001). For S. pyogenes, there was a significant reduction (P<0.001) from control (7.51±0.10) to therapeutic (5.91±0.62) and sanitisation (5.18±0.8), but the latter were similar (P=0.07). For P. aeruginosa, there was a significant difference (P<0.001) from control (7.15±0.36) to sanitisation (5.83±0.44); but not to therapeutic (6.84±0.31) temperatures (P=0.07)., Conclusions: Therapeutic heating produces a significant reduction in bacteria on the eyebags, but only sanitisation heating appears effective for flannels. However, patients should be advised to heat the eyebag to sanitisation temperatures on initial use., (Copyright © 2015 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)

Thin layers of chitosan (positively charged)/sodium hyaluronate (negatively charged)/nonwoven fabrics were constructed by polyelectrolyte multilayer pad-dry-cure technique. Pure chitosan (CS) was isolated from shrimp shell and immobilized onto nonwoven fabrics (NWFs) using citric acid (CTA) as cross linker and solvent agents through a pad-dry-cure method. The prepared thin layer of chitosan citrate/nonwoven fabrics (CSCTA/NWFs) were consequently impregnated with hyaluronan (CSCTA/HA/NWFs) in the second path through a pad-dry-cure method. Chitosan/hyaluronan/nonwoven fabrics wound dressing was characterized by different techniques such as FTIR-ATR, TGA and SEM. The antibacterial activity and the cytotoxicity of the dressing sheets were evaluated against Escherichia coli (E. coli) and Streptococcus aureus (S. aureus), mouse fibroblast (NIH-3T3) and keratinocytes (HaCaT) cell lines, respectively. The cell-fabrics interaction was also investigated using fluorescence microscope, based on live/dead staining assay of 3T3 cells. The healing properties of the new wound dressing were evaluated and compared with the control sample., (Copyright © 2016 Elsevier B.V. All rights reserved.)

We describe a new wound dressing technology that can actively generate an inorganic germicide agent, in situ, within the wound pad. The technology provides real time control over the quantitative, spatial and temporal delivery of the germicide. The identity of the germicide is hypochlorous acid (HClO). The HClO is produced in a flexible wound pad, made of a composite of thin (micrometer scale) layers of various materials, with different electrochemical properties that enhance HClO production. Active control over the production of HClO is achieved by control of the pH and of the electric potential across the layers. The effectiveness of the Active HClO Pad (AHClOP) concept is demonstrated in a study on sterilization of E. coli in a deep wound contamination simulating gel. The performance of the AHClOP is compared with that of four commercial wound dressings. Results show that the AHClOP can sterilize throughout the gel, while the commercial dressings cannot.

Wound dressings play an important role in a patient's recovery from health problems, as unattended wounds could lead to serious complications such as infections or, ultimately, even death. Therefore, wound dressings since ancient times have been continuously developed, starting from simple dressings from natural materials for covering wounds to modern dressings with functionalized materials to aid in the wound healing process and enhance tissue repair. However, understanding the nature of a wound and the subsequent healing process is vital information upon which dressings can be tailored to ensure a patient's recovery. To date, much progress has been made through the use of nanomedicine in wound healing due to the ability of such materials to mimic the natural dimensions of tissue. This review provides an overview of recent studies on the physiology of wound healing and various wound dressing materials made of nanofibers fabricated using the electrospinning technique.

Objective: To date only planktonic bacteria have been shown to bind irreversibly to dialkyl carbamoyl chloride (DACC)-coated Cutimed Sorbact dressings. Therefore, this study was designed to determine whether bacterial biofilm bound to the DACC-coated dressing in vitro., Method: Samples of DACC-coated dressings and uncoated control dressings (supplied by BSN medical Ltd, Hull) were placed in contact with plastic coverslips on which biofilms of either Pseudomonas aeruginosa or methicillin-resistant Staphylococcus aureus (MRSA) had been cultivated for 24 hours. Dressing samples were examined by scanning electron microscopy to detect the presence of biofilm., Results: Pseudomonas aeruginosa biofilm bound avidly to both DACC-coated and uncoated dressing samples. MRSA bound more extensively to DACC-coated dressings than to uncoated samples., Conclusion: Biofilms of two different test bacteria bound to dressings in vitro with the DACC-coating on the dressings enhancing the binding of MRSA biofilm., Declaration of Interest: This study was supported by BSN medical Ltd (Hull). The company had no influence on the experimental design or the interpretation of the results.

Objective: To compare a superabsorbent polymer dressing (DryMax Extra; DME), an antibacterial absorbent polymer dressing (Sorbact absorption dressing; SB) and an antibacterial superabsorbent polymer dressing (Sorbion Sachet S; SSS) activity against Pseudomonas aeruginosa biofilms., Method: A 3D acellular synthetic soft tissue (ASST) allowing biofilm formation, was prepared and inoculated with Pseudomonas aeruginosa, before the application of dressings. The dressings DME, with and without a silver net, and two benchmark dressings SB and SSS were tested. After 24 hours' incubation, qualitative assessment by visual screening of the soft tissue and bacterial burden assessment in the dressings and acellular soft tissue model were performed., Results: DME combined with a silver net gave a distinct and wide colourless zone of inhibition while partial zones of inhibition were seen for DME, SSS and SB. Compared with the tissues exposed to the other dressings, those exposed to SB and the bacterial control appeared green and opaque. In descending order, the most visual growth was seen in bacterial control, followed by SB, SSS, and DME. The bacterial load was equivalent for all dressings without an antimicrobial substance in both ASST (around log 10) and dressing (around log 11). The bacterial load for DME combined with a silver net, in comparison to DME alone was significantly reduced, with log 3.6 in dressings and log 4.2 in ASST., Conclusion: The removal of bacteria by DME was equivalent to SB and SSS. Furthermore, DME limited the production of the green colour, indicative of Pyocyanin. If extrapolated to a wound, the ability of DME to absorb Pseudomonas aeruginosa and limit Pyocyanin levels in the wound might lead to reduced virulence.

Background: Silver-containing negative-pressure wound therapy (NPWT) foam dressings should reduce the microbial load of infected surgical sites and thereby promote healing. The effects of silver and an experimental copper coating of NPWT dressings on the growth kinetics of methicillin-resistant Staphylococcus aureus (MRSA) were investigated with a focus on the importance of the initial bacterial load and the incubation time., Methods: Commercially available foam samples with and without silver coating were inoculated in vitro with six MRSA suspensions differing in bacterial concentration (1.85×10(3) to 1.85×10(8) colony-forming units per milliliter [CFU/mL]). In a second series, uncoated, silver-containing and experimental copper-coated foam samples were inoculated with one MRSA suspension (1.85×10(6) CFU/mL). The MRSA viable counts in the entrapped fluid were evaluated statistically after 1, 3, 7, and 14 d incubation., Results: Silver foam samples reduced MRSA counts by two decimal powers compared with the corresponding inocula. With respect to the uncoated samples, silver coating reduced MRSA concentrations by up to 7 logs, which was significant (p≤0.045) for all groups except the one with the highest MRSA concentration. The antibacterial effect of copper became apparent only after 7 d, but thereafter was far more pronounced than the effects of silver (p<0.01 after 14 d)., Conclusions: Antimicrobial-coated foam dressings showed significant in vitro antibacterial properties and thus could be advantageous in the treatment of MRSA-infected incisions.

The main goal of this investigation was the preparation of an antibacterial layer system for additional modification of wound dressings with atmospheric plasma. Furthermore, the modified wound dressings were checked on there bactericidal and cytotoxic activity. The layer system was applied by using a novel atmospheric pressure plasma chemical vapour deposition technique on a variety of textile substrates which are suitable as wound dressing materials. The layer system composed of silicon dioxide with in situ generated embedded silver nanoparticles. The bactericidal activity of the produced wound dressings was investigated against different bacteria like Staphylococcus aureus and Klebsiella pneumoniae while the cytotoxic potential of the coated wound dressings was verified using human keratinocytes. Even at low concentrations of silver precursor a strong antibacterial effect was observed in direct contact with S. aureus and K. pneumoniae. Furthermore, extractions produced from the coated textiles showed a good antibacterial effect. By means of optimised coating parameters a therapeutic window for those wound dressings could be identified. Consequently, the atmospheric pressure plasma chemical vapour deposition technique promise an effective and low cost modification of wound dressing materials.

Hydrogels were prepared using polyvinyl pyrrolidone (PVP) blended with carrageenan by gamma irradiation at different doses of 25 and 40 kGy. Gel fraction of hydrogels prepared using 10 and 15% PVP in combination with 0.25 and 0.5% carrageenan was evaluated. Based on gel fraction, 15% PVP in combination with 0.25% carrageenan and radiation dose of 25 kGy was selected for the preparation of hydrogels with nanosilver. Radiolytic synthesis of silver nanoparticles within the PVP hydrogel was carried out. The hydrogels with silver nanoparticles were assessed for antimicrobial effectiveness and physical properties of relevance to clinical performance. Fluid handling capacity (FHC) for PVP/carrageenan was 2.35 ± 0.39-6.63 ± 0.63 g/10 cm(2) in 2-24 h. No counts for Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Candida albicans were observed in the presence of hydrogels containing 100 ppm nanosilver after 3-6 h. The release of silver from hydrogels containing 100 ppm nanosilver was 20.42 ± 1.98 ppm/100 cm(2) in 24 h. Hydrogels containing 100 ppm nanosilver with efficient FHC demonstrated potential microbicidal activity (≥3 log10 decrease in CFU/ml) against wound pathogens, P. aeruginosa, S. aureus, E. coli, and C. albicans. PVP/carrageenan hydrogels containing silver nanoparticles can be used as wound dressings to control infection and facilitate the healing process for burns and other skin injuries.

Objective: To assess the effectiveness of a new, next-generation antimicrobial dressing (AQUACEL Ag+ dressing) in facilitating healing in a variety of hard-to-heal wounds that may have been compromised by infection and/or biofilm., Method: This was an international, multi-centred, real-life, non-randomised evaluation involving patients with a wide variety of slow-, non-healing or deteriorating chronic and acute wounds. There were no strict inclusion or exclusion criteria and the clinicians were asked to use their discretion in the selection of patients. The clinicians continued to use their standard protocol of care but replaced their existing primary wound-contact dressing with the next-generation antimicrobial dressing (NGAD) for up to 4 weeks. Clinicians could extend the treatment period if this was deemed clinically appropriate. Baseline assessments included wound bed characteristics, exudate level, indicators of wound biofilm, and signs and symptoms of infection. At the final assessment, the investigators reported the wound size, wound bed characteristics, and exudate level., Results: A total of 121 patients were recruited into the original evaluation, of which eight were excluded for incomplete data sets. Most wounds (73; 64%) were either venous leg ulcers (59; 52%) or diabetic foot ulcers (14; 12%). At baseline, the wounds of (26; 23%) patients were slowly improving, 65 were stagnant (58%) and 22 (19%) were deteriorating. Just under three-quarters (74%) of the wounds had suspected biofilm (criteria including failure of a wound to heal, lack of response to topical and systemic antimicrobial agents, or the presence of slimy substances on the wound surface). Following the evaluations, the average wound closure achieved for all wounds was 72.6%, 19 (17%) wounds healed, 47 (42%) achieved at least 90% wound closure, and 71 (63%) achieved at least 75% closure. The average treatment period was 4.1 weeks; 35 wounds were treated with the dressing for more than 4 weeks. Cost analysis indicated that potential antimicrobial dressing cost reductions of approximately 30% were realised using the NGAD., Conclusion: This real-life, non-randomised evaluation provides encouraging evidence that the NGAD may have a role to play in facilitating wound progression towards healing by helping to eliminate the biofilm barrier., Declaration of Interest: M. Walker, D. Metcalf, D. Parsons and P. Bowler are all employees of ConvaTec Ltd. Aysha Mendes da Mata is an independent writer and Annemarie Brown is an independent clinician, both received a fee and support from MA Healthcare to write up the evaluation using data supplied by ConvaTec.

We designed bilayer composites composed of an upper layer of titanium dioxide (TiO2)-incorporated chitosan membrane and a sub-layer of human adipose-derived extracellular matrix (ECM) sheet as a wound dressing for full-thickness wound healing. The dense and fibrous top layer, which aims to protect the wound from bacterial infection, was prepared by electrospinning of chitosan solution followed by immersion in TiO2 solution. The sponge-like sub-layer, which aims to promote new tissue regeneration, was prepared with acellular ECM derived from human adipose tissue. Using a modified drop plate method, there was a 33.9 and 69.6% reduction in viable Escherichia coli and Staphylococcus aureus on the bilayer composite, respectively. In an in vivo experiment using rats, the bilayer composites exhibited good biocompatibility and provided proper physicochemical and compositional cues at the wound site. Changes in wound size and histological examination of full-thickness wounds showed that the bilayer composites induced faster regeneration of granulation tissue and epidermis with less scar formation, than control wounds. Overall results suggest that the TiO2-incorporated chitosan/ECM bilayer composite can be a suitable candidate as a wound dressing, with an excellent inhibition of bacterial penetration and wound healing acceleration effects.

Purposes: Sepsis caused by Gram-negative bacilli (GNB) is the most serious catheter-related bloodstream infection. However, the cause(s) of GNB propagation on the skin around needle or catheter insertion sites remain unclear. This observational study aimed to assess the differences in the microbial growth among various types of dressings used to cover injection sites, with a particular focus on GNB., Methods: We analyzed the bacterial populations on three types of surgical dressings; Tegaderm I.V. (semi-permeable, 27 sheets), IV3000 (highly permeable, 34 sheets) and Tegaderm CHG (chlorhexidine-impregnated, 26 sheets). The peripheral catheter site dressing was replaced every 3 days or when there was leakage or pain at the catheter site., Results: Bacterial growth was observed in all Tegaderm I.V. and IV3000 sheets and in only one (3.8%) Tegaderm CHG sheet. The GNB detection rate was significantly lower in the IV3000 group (2.9%) than in the Tegaderm I.V. group (63.0%). No GNB growth was identified in the Tegaderm CHG group., Conclusions: Semi-permeable dressings were insufficient to prevent GNB infections, whereas highly permeable or chlorhexidine-impregnated dressings could prevent GNB infections. Chlorhexidine-impregnated dressings can control almost all bacterial growth.

The ideal wound dressing would have properties that allow for absorption of exudates, and inhibition of microorganism for wound protection. In this study, we utilized an electrospinning (ELSP) technique to design a novel wound dressing. Chitosan (CTS) nanofibers containing various ratios of silver nanoparticles (AgNPs) were obtained. AgNPs were generated directly in the CTS solution by using a chemical reduction method. The formation and presence of AgNPs in the CTS/AgNPs composite was confirmed by x-ray diffraction (XRD), ultraviolet-visible spectroscopy (UV) and thermogravimetric analysis (TGA). The electrospun CTS/AgNPs nanofibers were characterized morphologically by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). These nanofibers were subsequently tested to evaluate their antibacterial activity against gram-negative Pseudomonas aeruginosa (P. aeruginosa) and gram-positive Methicillin-resistant Staphylococcus aureus (MRSA). Results of this antibacterial testing suggest that CTS/AgNPs nanofibers may be effective in topical antibacterial treatment in wound care., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Objective: The aim of this in vitro study was to demonstrate the binding capacity of multiple meticillin-resistant Staphylococcus aureus (MRSA) strains and compare the binding capacity to meticillin-sensitive Staphylococcus aureus., Method: The binding of Staphylococcus aureus to a surface was assessed by bioluminescent monitoring of the bacterial ATP levels. This assay can be used as an in vitro diagnostic model for bacteria binding in a critically colonised wound., Results: Eleven strains of Staphylococcus aureus were examined including MRSA, all of which efficiently and equally adhered to the dialkyl carbamoyl chloride (DACC)-coated dressing (Sorbact; Abigo Medical AB). The binding capacity was all in the same range 0.7-2.9 × 10⁶ CFU/cm². regardless of the antibiotic resistance properties of the specific strain., Conclusion: The decrease of wound bioburden of Staphylococcus aureus including MRSA is the result of the high binding capacity shown in this study and by earlier data. The findings in this study strengthen the held view that development of antibiotic resistance has minimal impact on the surface structures of the microorganisms in wounds.

Electrospun chitosan (CTS) nanofibers have been well known for use as a wound dressing in the biomedical field. Nevertheless, fatal bacterial infections are still a serious problem when CTS nanofibers are used for wound treatment. In this study, we designed a novel wound dressing based on blending the chitosan with polyurethane (CTS/PU) containing silver sulfadiazine (AgSD) in order to enhance both antibacterial activity and mechanical strength. This fiber sheet was produced using the electrospinning (ELSP) technique. The CTS/PU containing AgSD fiber sheet was characterized by energy-dispersive X-ray spectroscopy (EDX). The physicochemical properties of the CTS/PU/AgSD fiber sheets were also characterized by thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FT-IR). The electrospun fibers were morphologically characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). For an in vitro evaluation, the CTS/PU/AgSD fiber sheets were tested for their antibacterial activity against gram-negative Pseudomonas aeruginosa (P. aeruginosa), gram-positive Staphylococcus aureus (S. aureus) and Methicillin-resistant Staphylococcus aureus (MRSA). The results indicate that CTS/PU/AgSD fiber sheets have strong antimicrobial activity as displayed by inhibition of bacterial growth and prevention of infection during the healing process. These results indicate that this material would be good for use as a wound dressing material.

This study sought to determine if there was an increased risk for surgical site contamination during stockinette application for a lower extremity surgery draping technique. Utilizing a simulated, sterile surgical field, stockinettes were applied over 10 cadaver lower extremities that were contaminated with non-pathogenic Escherichia coli on the foot. Of those, five specimens were then disinfected with Chloroprep and another 5 did not undergo any disinfection. All the specimens in which the stockinette was applied over a non-prepped foot showed proximal contamination. No contamination occurred in any of the specimens where the foot was disinfected. Stockinette can be a source of surgical site contamination when placed over a non-prepared foot., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Objective: Mycobacterium ulcerans is the causative agent of Buruli ulcer disease, the third most common mycobacteriosis after tuberculosis and leprosy and an emerging public health threat in sub-Saharan Africa. The bacteria produce a diffusible cytotoxin called mycolactone, which triggers the formation of necrotic lesions in cutaneous and subcutaneous tissues. The principal aim of this study was to characterise the cell surface hydrophobicity of Mycobacterium ulcerans and determine if bacteria bind to dialkyl carbamoyl chloride (DACC)-coated dressings through hydrophobic interactions in vitro. Since mycolactone displays hydrophobic groups, a secondary aim was to compare mycolactone binding to hydrophobic and standard dressings., Methods: We used hydrophobic interaction chromatography to evaluate the cell surface hydrophobicity of Mycobacterium ulcerans, compared to that of other microorganisms colonising wounds. The binding of Mycobacterium ulcerans bacteria to DACC-coated and control dressings was then assessed quantitatively by measurement of microbial adenosine triphosphate (ATP), while that of mycolactone was evaluated by fluorescence spectroscopy., Results: Compared to Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, Mycobacterium ulcerans displayed the highest cell surface hydrophobicity, irrespective of the bacterial production of mycolactone. Mycobacterium ulcerans bacteria bound to DACC-coated dressings [corrected] better than untreated controls. Mycolactone did not bind stably to hydrophobic, nor standard dressings, in the conditions tested., Conclusion: Retention of Mycobacterium ulcerans and other wound pathogens to DACC-coated dressings may help reduce the bacterial load in Buruli ulcers and thereby improve healing. Dressings efficiently capturing mycolactone may bring an additional clinical benefit, by accelerating the elimination of the toxin during the course of antibiotic treatment.

Objectives: To evaluate the antimicrobial activity of a new, transparent composite film dressing, whose adhesive contains chlorhexidine gluconate (CHG), against the native microflora present on human skin., Methods: CHG-containing adhesive film dressings and non-antimicrobial control film dressings were applied to the skin on the backs of healthy human volunteers without antiseptic preparation. Dressings were removed 1, 4 or 7 days after application. The bacterial populations underneath were measured by quantitative cultures (cylinder-scrub technique) and compared with one another as a function of time., Results: The mean baseline microflora recovery was 3.24 log10 cfu/cm(2). The mean log reductions from baseline measured from underneath the CHG-containing dressings were 0.87, 0.78 and 1.30 log10 cfu/cm(2) on days 1, 4 and 7, respectively, compared with log reductions of 0.67, -0.87 and -1.29 log10 cfu/cm(2) from underneath the control film dressings. There was no significant difference between the log reductions of the two treatments on day 1, but on days 4 and 7 the log reduction associated with the CHG adhesive was significantly higher than that associated with the control adhesive., Conclusions: The adhesive containing CHG was associated with a sustained antimicrobial effect that was not present in the control. Incorporating the antimicrobial into the adhesive layer confers upon it bactericidal properties in marked contrast to the non-antimicrobial adhesive, which contributed to bacterial proliferation when the wear time was ≥4 days., (© The Author 2014. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy.)