In vitro evaluation of the antimicrobial effectiveness and moisture binding properties of wound dressings

Fabrication of gelatin-based antibacterial bilayer wound dressing using direct writing and electrospinning methods

Fabricating a fibrous well-ordered wound dressing for accelerating full-thickness wounds is a desirable treatment vector. Here, through modifications in the material extrusion device and adding a pneumatic-based injection, a material extrusion method for gelatin was introduced with the ability to fabricate 3D structure with repeat layers to support cell activity for the under layer. Furthermore, in the upper layer, the co-electrospinning of PU with gelatin was designed to simultaneously exploit the oxygen permeability and mechanical stability of PU with regenerative properties and collagen-like structure of gelatin. Moreover, zinc oxide nanoparticles (ZnO) was added into the 3D-printed under layer to synergistically benefit from the antibacterial properties of ZnO and the excellent biocompatibility of gelatin. The controllable porosity of the under layer, enabled through the additive manufacturing method, was adjusted to mimic the extracellular matrix of natural tissue with around (127.28 ± 20.70) μm pore size after swelling with smooth fibers. S. aureus, E. coli, Bacillus subtilis, and Pseudomonas with inhibition zone diameters at ∼ 2.14 cm and ∼ 1.96 cm, ∼ 4.01 cm, and ∼ 2.24 cm, respectively. Moreover, the scaffold showed great biocompatibility toward fibroblast cells after 7 days of cell culture with ∼ 89 % cell viability.

Ceramic Dressings-A New Non-Pharmacological Therapeutic Option in the Management of Chronic Wounds?

A new ceramic dressing, free from active antimicrobial or pharmaceutical agents, uses physical binding mechanisms for its absorption capacities and bacterial-binding properties. The purpose of this study was to evaluate wound healing, bacterial-related retention, and diagnostic properties of ceramic dressings in patients with stagnated chronic wounds.

METHODS

In this monocentric, intra-individually controlled, prospective study, patients with conservatively treated refractory chronic wounds were enrolled. One week before the start of the application with ceramic dressing, it was ensured during a screening phase that chronic wounds showed less than a 10% reduction in wound size. During the 4-week ceramic dressing treatment wound size measurements, wound scoring, measurement of wound exudate amount, wound swabs, and ceramic dressing sonication (low-intensity ultrasound) were carried out. The sonication fluid of the removed ceramic dressing was used for analysis of bacterial retention and compared to wound swabs.

RESULTS

A total of 20 patients with a mean age of 64.6 years (±26.2) and 21 chronic wounds were included in this study. After a 4-week treatment, a significant reduction of median wound size from 1178 mm2 (range 104-6300) to 751.5 mm2 (range 16-4819) and better total wound scores were observed (p < 0.001). The sensitivity of bacteria detection was 90.7% in the sonication fluid from the ceramic dressings, while only 76.9% in the conventional wound swabs.

CONCLUSION

The new ceramic dressing seems to have a positive impact on wound healing in chronic wounds. Bacteria-binding characteristics of the investigated ceramic dressing, in combination with its debridement, absorption, and detoxification properties, could contribute to its healing abilities. Based on those results, the investigated ceramic dressing seems to be a promising new treatment option for chronic wounds without the use of any active antimicrobial or pharmacological agents. Moreover, ceramic dressings can also be considered for microbiological diagnostic purposes.

An Overview of Recent Developments in the Management of Burn Injuries

According to the World Health Organization (WHO), around 11 million people suffer from burns every year, and 180,000 die from them. A burn is a condition in which heat, chemical substances, an electrical current or other factors cause tissue damage. Burns mainly affect the skin, but can also affect deeper tissues such as bones or muscles. When burned, the skin loses its main functions, such as protection from the external environment, pathogens, evaporation and heat loss. Depending on the stage of the burn, the patient's condition and the cause of the burn, we need to choose the most appropriate treatment. Personalization and multidisciplinary collaboration are key to the successful management of burn patients. In this comprehensive review, we have collected and discussed the available treatment options, focusing on recent advances in topical treatments, wound cleansing, dressings, skin grafting, nutrition, pain and scar tissue management.

In vivo and in vitro studies of a propolis-enriched silk fibroin-gelatin composite nanofiber wound dressing

In this study, electrospun nanofibers (NFs) used in trauma dressings were prepared using silk fibroin (SF) and gelatin (GT) as materials and highly volatile formic acid as the solvent, with three different concentrations of propolis extracts (EP), which were loaded through a simple process. The resulting samples were characterized by surface morphology, scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), contact angle meter, water absorption, degradation rate, and mechanical property tests. The incorporation of propolis improved its antibacterial properties against Escherichia coli, and Staphylococcus aureus, compared to those of the silk gelatin nanofiber material (SF/GT) alone. In vitro biocompatibility assays showed that SF/GT-1%EP had good cytocompatibility and hemocompatibility. In addition, it can also significantly promote the migration of L929 cells. SF/GT-1%EP was applied to a mouse model of full thickness skin defects, and it was found to significantly promote wound healing. These results indicate that the SF/GT-EP nanofiber material has good biocompatibility, migrating-promoting capability, antibacterial properties, and healing-promoting ability, providing a new idea for the treatment of full thickness skin defects.

Pilot study of minimally adherent silver dressings for acute surgical wounds

Background and Aims

Minimally adherent silver dressings (SILVER MASD) are antimicrobial, nonirritating, provide a moist wound healing environment, and low cost. The purpose of this pilot, single-center, non-blinded randomized controlled trial was to quantify the outcomes of acute surgical wounds treated with MASD versus standard of care (SoC) dressings.

Methods

Thirty-two patients with acute wounds were randomized 1:1 to be treated with MASD once weekly or SoC following surgical excision of skin and/or subcutaneous tissue between September 13, 2016 and November 28, 2017. The outcome variables included clinical infection, time to wound closure, and pain scores at dressing changes. Two independent, one-sided sample t-tests were performed to assess statistical significance.

Results

There was no difference in wound healing between SILVER MASD and SoC. Dressing changes were less painful for wounds managed with MASD silver dressings.

Conclusions

The results of this study suggest that MASD are not less effective in wound healing compared to SoC while also providing the benefit of decreased pain at dressing changes. Therefore, minimally adherent silver dressings can and should be considered a viable option in the management of acute surgical wounds.

Manufacturing of Zinc Oxide Nanoparticle (ZnO NP)-Loaded Polyvinyl Alcohol (PVA) Nanostructured Mats Using Ginger Extract for Tissue Engineering Applications

In this research, as an alternative to chemical and physical methods, environmentally and cost-effective antimicrobial zinc oxide nanoparticles (ZnO NP) were produced by the green synthesis method. The current study focuses on the production of ZnO NP starting from adequate precursor and Zingiber officinale aqueous root extracts (ginger). The produced ZnO NP was loaded into electrospun nanofibers at different concentrations for various tissue engineering applications such as wound dressings. The produced ZnO NPs and ZnO NP-loaded nanofibers were examined by Scanning Electron Microscopy (SEM) for morphological assessments and Fourier-transform infrared spectrum (FT-IR) for chemical assessments. The disc diffusion method was used to test the antimicrobial activity of ZnO NP and ZnO NP-loaded nanofibers against three representatives strains, Escherichia coli (Gram-negative bacteria), Staphylococcus aureus (Gram-positive bacteria), and Candida albicans (fungi) microorganisms. The strength and stretching of the produced fibers were assessed using tensile tests. Since water absorption and weight loss behaviors are very important in tissue engineering applications, swelling and degradation analyses were applied to the produced nanofibers. Finally, the MTT test was applied to analyze biocompatibility. According to the findings, ZnO NP-loaded nanofibers were successfully synthesized using a green precipitation approach and can be employed in tissue engineering applications such as wound dressing.

Practical extended use of antimicrobial silver (PExUS)

BACKGROUND

Antimicrobial silver has had a role in wound antisepsis throughout history and, with the rise in acquired antibiotic resistance, silver dressings are once again commonly used. Issues with silver dressings include the important environmental consideration of nanoparticle manufacture, and the significant financial cost of these products. One solution to these problems may be to adopt an opened-but-unused model of wound care whereby dressing materials are used in piecemeal fashion and excess stored in between dressing changes. Due to a lack of literature on the topic, this project was designed with the aim of testing the antimicrobial efficacy of available silver dressings during storage after opening.

METHODS

Four commonly used silver dressings were tested for antimicrobial activity using a zone of inhibition assay against clinically important pathogens. The assay was performed on opening of dressings and repeated over 3 months in storage at 4, 25 or 37°C. Analysis was performed using repeated measures ANOVA. Swab cultures were taken at each simulated dressing change to detect microbial contamination of the dressings during storage.

RESULTS

There was no effect of time or storage temperature on the zone of inhibition over the 12 week test period. No swabs taken returned culture consistent with microbial contamination of stored dressings.

CONCLUSION

Opened silver dressings maintain antimicrobial activity for at least 12 weeks in storage and are resistant to contamination. An opened-but-unused model for wound care is likely to improve cost-effectiveness while preserving effectiveness and safety.

Does exudate viscosity affect its rate of absorption into wound dressings?

OBJECTIVE

Exudate is a vital component of healing wounds. There are differences between acute and chronic exudate, with the latter seen as highly toxic to the healing environment. Wound exudate assessment is not easy for clinicians. The viscosity of wound fluid/exudate is as important as its quantity. Wound fluid viscosity increases when it contains more protein. As wound dressings exhibit a variety of fluid-handling mechanisms, it is important to understand how they interact with the different exudate types, which may alter the wound/dressing interface. This knowledge will ensure a healing wound environment that is beneficial, not one that leaves harmful exudate on the wound surface. This study aimed to evaluate if the viscosity of exudate affected absorption time in four wound dressing types.

METHODS

This study evaluated the viscosities of two solutions and their effect on the absorption times of four dressing types. The viscosities of the solutions were calculated using Ostwald viscometers, then 2 ml of each of these liquids was applied to each of the four dressing types and repeated 10 times for each dressing, as per British Standards Institution requirements. The parameters for temperature and frequency were applied, and the absorption times recorded. A two-way repeated analysis of variance (ANOVA) was conducted to examine if exudate viscosity and dressing type, or their interaction, affected the absorption time.

RESULTS

The results indicated that the viscosity of the solution alone had a significant effect on absorption time (p<0.01), and that the combined effect of dressing type and viscosity also affected absorption (p<0.01). The type of dressing alone was found to have a significant effect on absorption time (p<0.01). When looking at the between-subject effects of the dressings (between the four types) the only non-significant finding was between two dressings-the superabsorbent and the moderate (foam) absorbing dressing (p=0.097). All other dressings had a between-subject effect of (p<0.01).

CONCLUSION

A significant difference in absorption times was found in this investigation of dressing types and viscosity of test solutions. The greater the viscosity of the fluid, the longer it took for it to be absorbed into all dressing types tested. This delay was not determined simply by the dressing or by the viscosity of the fluid, but likely to be a combination of the mode of action of the dressing, its pore size and particulate composition of the exudate, all of which require further investigation.

The effect of a silver hydrogel sheet dressing on postsurgical incision healing after foot and ankle surgery

Introduction

Silver hydrogel dressings are antimicrobial dressings with the potential to aid post-surgical healing. The purpose of this study is to evaluate the effects of a silver hydrogel dressing on postoperative scarring and complications.

Methods

40 foot and ankle patients (48.43 ± 16.82 years) were included in the study with 20 patients in each group. Postoperatively, the treatment group was treated with a silver hydrogel sheet dressing, and the control group was treated with a standard petroleum-based dressing. Follow-up was performed at two, six, and 12 weeks. Postoperative scarring and complications were evaluated and compared between groups. Scarring was evaluated using the Patient and Observer Scar Assessment Scale (POSAS). Scar length and width were measured using digital calipers and used to compute scar area.

Results

The treatment group demonstrated statistically significant improvements in the POSAS observer score and observer opinion at six and 12 weeks (p < 0.001). Additionally, patient reported pain was significantly lower for the treatment group than the control group at 12 weeks (p < 0.001). Patient reported itch declined across time for both groups (p < 0.001) with significantly less itching reported by the treatment group (p = 0.027). Scar area was also significantly lower for the treatment group than the control group at six weeks and 12 weeks (p ≤ 0.002). Neither group experienced any postoperative complications.

Conclusion

These results suggest that the inherent properties of the silver hydrogel dressing may improve postsurgical scarring.

Lay Summary

Surgical incisions result in scar, which can present both cosmetic and rehabilitation concerns after foot or ankle surgery. It is standard to use a petroleum-based dressing on incisions after surgery, however, advancements in incisional dressings have been made over the past 20 years. One such advancement is silver-impregnated hydrogel sheet dressings which have been shown to maintain a moist wound environment conducive to healing, while decreasing the chance of infection through its antimicrobial properties. This paper evaluates scar healing after foot or ankle surgery in patients treated with either the standard petroleum-based dressing, or the silver hydrogel sheet dressing. Patients who were treated with the silver hydrogel dressing had less itching and pain, as well as a smaller scar area than patients in the standard dressing group. Therefore, our results suggest that the silver hydrogel dressing may improve scarring after surgery.

Antimicrobial silver dressings: a review of emerging issues for modern wound care

Skin is an important barrier to pathogenic microorganisms and plays a critical role in a ctivation of innate immune responses. When the skin barrier is breached following wounding or burn injury, pathogens can invade and complicate healing with infection resulting in delayed healing and symptomatic scarring. Wound infection is a significant problem after burn injury and in patients with chronic wounds. Antimicrobial silver has had a significant role in wound antisepsis throughout history and, given the rise in community acquired antibiotic resistance, silver dressings are now commonly used to combat wound infection. The multi-modal mechanism of action, low potential for toxicity and formation of microbial resistance makes silver dressings suitable tools against a wide array of clinically important microbes. There are, however, a number of issues with silver dressings including a conflicting evidence base, the important environmental consideration of nanoparticle manufacture, and the significant cost of these products. One solution may be to adopt an 'opened-but-unused' means of wound care whereby bulk dressing materials are used piecemeal and stored in between dressing changes to increase the cost-effectiveness and reduced wastage. There is, however, little literature on this topic and so in vitro and clinical research must be performed to consider the efficacy of active ingredient dressings in wound care including silver dressings once opened and stored.

Photo-Crosslinked Gelatin-Based Hydrogel Films to Support Wound Healing

Gelatin is used widely in the biomedical field, among other for wound healing. Given its upper critical solution temperature, crosslinking is required. To this end, gelatin is chemically modified with different photo-crosslinkable moieties with low (32-34%) and high (63-65%) degree of substitution (DS): gelatin-methacrylamide (gel-MA) and gelatin-acrylamide (gel-AA) and gelatin-pentenamide (gel-PE). Next to the more researched gel-MA, it is especially interesting and novel to compare with other gelatin-derived compounds for the application of wound healing. An additional comparison is made with commercial dressings. The DS is directly proportional to the mechanical characteristics and inversely proportional to the swelling capacity. Gel-PE shows weaker mechanical properties (G' < 15 kPa) than gel-AA and gel-MA (G' < 39 and 45 kPa, respectively). All derivatives are predominantly elastic (recovery indices of 89-94%). Gel-AA and gel-MA show excellent biocompatibility, whereas gel-PE shows a significantly lower initial biocompatibility, evolving positively toward day 7. Overall, gel-MA shows to have the most potential to be applied as wound dressing. Future blending with gel-AA to improve the curing kinetics can lead to dressings able to compete with current commercial dressings.

Synthesis of Poly(ε-caprolactone) Diacrylate for Micelle-Cross-Linked Sodium AMPS Hydrogel for Use as Controlled Drug Delivery Wound Dressing

This study focuses on the synthesis of poly(ε-caprolactone) diacrylate (PCLDA) for the fabrication of micelle-cross-linked sodium AMPS wound dressing hydrogels. The novel synthetic approach of PCLDA is functionalizing a PCL diol with acrylic acid. The influences of varying the PCL diol/AA molar ratio and temperature on the suitable conditions for the synthesis of PCLDA are discussed. The hydrogel was synthesized through micellar copolymerization of sodium 2-acrylamido-2-methylpropane sulfonate (Na-AMPS) as a basic monomer and PCLDA as a hydrophobic association monomer. In this study, an attempt was made to develop new hydrogel wound dressings meant for the release of antibacterial drugs (ciprofloxacin and silver sulfadiazine). The chemical structures, morphology, porosity, and water interaction of the hydrogels were characterized. The hydrogels' swelling ratio and water vapor transmission rate (WVTR) showed a high swelling capacity (4688-10753%) and good WVTR (approximately 2000 g·m^-2·day^-1), which can be controlled through variation of the PCLDA concentration. The mechanical property results confirmed that PCLDA improved the mechanical properties of the hydrogel; the stress increased from 37 to 68 kPa, and the strain increased from 198 to 360% with increasing PCLDA (0-30% wt of Na-AMPS). These hydrogels presented no cytotoxicity based on over 70% cell viability responses (L929 fibroblasts) using an in vitro 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Additionally, the drug release mechanism, kinetic models, and antibacterial activity were determined. The results demonstrated that antibiotics were released from the hydrogel with a Fickian diffusion mechanism and antibacterial activity against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus). Based on the results obtained, and bearing in mind that further progress still needs to be made, the fabricated hydrogels show considerable potential for meeting the stringent property requirements of hydrogel wound dressings.

Antimicrobial stewardship of antiseptics that are pertinent to wounds: the need for a united approach

Long before the nature of infection was recognized, or the significance of biofilms in delayed healing was understood, antimicrobial agents were being used in wound care. In the last 70 years, antibiotics have provided an effective means to control wound infection, but the continued emergence of antibiotic-resistant strains and the documented antibiotic tolerance of biofilms has reduced their effectiveness. A range of wound dressings containing an antimicrobial (antibiotic or non-antibiotic compound) has been developed. Whereas standardized methods for determining the efficacy of non-antibiotic antimicrobials in bacterial suspension tests were developed in the early twentieth century, standardized ways of evaluating the efficacy of antimicrobial dressings against microbial suspensions and biofilms are not available. Resistance to non-antibiotic antimicrobials and cross-resistance with antibiotics has been reported, but consensus on breakpoints is absent and surveillance is impossible. Antimicrobial stewardship is therefore in jeopardy. This review highlights these difficulties and in particular the efficacy of current non-antibiotic antimicrobials used in dressings, their efficacy, and the challenges of translating in vitro efficacy data to the efficacy of dressings in patients. This review calls for a unified approach to developing standardized methods of evaluating antimicrobial dressings that will provide an improved basis for practitioners to make informed choices in wound care.

Alginate, gelatin, and carboxymethyl cellulose coated nonwoven fabrics containing antimicrobial AgNPs for skin wound healing in rats

Nonwoven fabrics containing silver nanoparticles (AgNPs) are widely utilized to assist management of infected wounds and those at risk of infection. However, such materials have varied responses due to their chemical nature. Herein we investigated the correlation between the concentration of AgNPs taken up by nonwoven viscose material and antibacterial activity in a simulated wound fluid model against two bacterial models (i.e., Escherichia coli and Staphylococcus aureus). Thereafter, the developed nonwoven viscose containing AgNPs were independently coated with two polyacid carbohydrate polymers (i.e., carboxymethyl chitosan (CMCs), alginate (ALG)), and gelatin (GEL) protein in order to study their influence on the physical and biological attributes in vitro and in vivo. Intensive characterizations were utilized to monitor the physicochemical features of the developed nonwoven viscose. The results demonstrated that higher concentrations of AgNPs were taken up by viscose fabric whilewhile increasing AgNPs in the colloidal solution during padding process. Overall, the treated nonwoven fabric with and without polymers' coatings showed remarkable antibacterial activity against two bacterial models in vitro. As well as they achieved high and speed wound recovery in rats which was almost similar to commercial dermazin treatment. Therefore, it validates excellent nonwoven dressing clinically relevant to the wound type and condition.

Chlorhexidine Gel Use in the Oral District: A Systematic Review

Chlorhexidine compounds and their different formulations have been investigated several times, especially in the dentistry field. Chlorhexidine application for mouth rinsing immediately underwent oral contraindications, linked to the possibility of causing pigmentation to the teeth or relating to possible cytotoxic events after oral surgery. The positive effects, however, are considerable and its topical antiseptic action has been widely demonstrated by in vitro and clinical research. That’s the reason for its large application in different fields of dentistry. The aim of this study is to collect all the literature regarding the use of chlorhexidine gel in dentistry and all the numerous applications. The initial search on search engines obtained 232 results; then, following the application of the inclusion criteria there were 24 selected articles. The chlorhexidine gel appliance in the dental daily practice is direct to oral surgery, conservative endodontics, prevention and prophylaxis. The use of chlorhexidine has shown some positive effects, also in the case of systemic diseases prevention. Surely, this topical medicine used both professionally and prescribed for home use, can be considered a great help for the prevention of several oral pathologies with systemic implications too.

Cornstarch-based wound dressing incorporated with hyaluronic acid and propolis: In vitro and in vivo studies

The unique physicochemical and functional characteristics of starch-based biomaterials and wound dressings have been proposed for several biomedical applications. Film dressings of cornstarch/hyaluronic acid/ ethanolic extract of propolis (CS/HA/EEP) were prepared by solvent-casting and characterized by attenuated total reflectance/Fourier transform infrared spectroscopy, scanning electron microscopy, gas chromatography/mass spectrometry, light transmission, opacity measurements, EEP release, equilibrium swelling, and in vitro and in vivo evaluations. The CS/HA/0.5%EEP film dressing exhibited higher antibacterial activity against Staphylococcus aureus (2.08 ± 0.14 mm), Escherichia coli (2.64 ± 0.18 mm), and Staphylococcus epidermidis (1.02 ± 0.15 mm) in comparison with the CS, CS/HA, and CS/HA/0.25%EEP films. Also, it showed no cytotoxicity for the L929 fibroblast cells. This wound dressing could effectively accelerate the wound healing process at Wistar rats' skin excisions. These results indicate that enrichment of cornstarch wound dressings with HA and EEP can significantly enhance their potential efficacy as wound dressing material.

Novel Bacterial Cellulose-Poly (Acrylic Acid) Hybrid Hydrogels with Controllable Antimicrobial Ability as Dressings for Chronic Wounds

This investigation examines the combination of poly (acrylic acid) (PAA) and bacterial cellulose (BC) nanofibers to synthesize hydrogel hybrid composites used for wound dressing application. Amoxicillin (AM) was also grafted onto the composites for drug release. Fourier transform infrared analysis and scanning electron microscopy conducted revealed the structure and porosity of the composite being developed, as well as the successful fabrication of BC-PAA composites. The results of mechanical testing and hygroscopicity revealed that the composite shows higher stability than hydrogels which are currently used worldwide, albeit with a slight reduction in swelling capabilities. However, the composite was revealed to be responsive to a rise in pH values with an increase in composite swelling and drug release. These results together with their morphological characteristics suggest that BC-PAA hydrogel hybrid composite is a promising candidate for wound dressing application.

Comparison of in vitro antibacterial activity of streptomycin-diclofenac loaded composite biomaterial dressings with commercial silver based antimicrobial wound dressings

Infected chronic wounds heal slowly, exhibiting prolonged inflammation, biofilm formation, bacterial resistance, high exudate and ineffectiveness of systemic antimicrobials. Composite dressings (films and wafers) comprising polyox/carrageenan (POL-CAR) and polyox/sodium alginate (POL-SA), loaded with diclofenac (DLF) and streptomycin (STP) were formulated and tested for antibacterial activity against 2 × 10⁵ CFU/mL of Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus representing infected chronic wounds and compared with marketed silver dressings. Minimum inhibitory concentration (MIC) showed higher values for DLF than STP due to non-conventional antibacterial activity of DLF. The DLF and STP loaded dressings were highly effective against E. coli, P. aeruginosa and S. aureus. POL-SA dressings were more effective against the three types of bacteria compared to POL-CAR formulations, while the DLF and STP loaded dressings showed greater antibacterial activity than the silver-based dressings. The films, showed greater antibacterial efficacy than both wafers and silver dressings. STP and DLF can act synergistically not only to kill the bacteria but also prevent their resistance and biofilm formation compared to silver dressings, while reducing chronic inflammation associated with infection.

A Randomized Controlled Trial on the Outcome in Comparing an Alginate Silver Dressing With a Conventional Treatment of a Necrotizing Fasciitis Wound

Necrotizing fasciitis (NF) is a high morbidity and mortality disease and also demands high economic resources. The standard treatment of NF is surgical debridement and proper dressing for wound bed preparation. The efficacy of silver alginate dressing can inhibit the growth of microorganisms and keep the environment clean for wound bed preparation. However an optimal dressing to manage such wounds has yet to emerge. NF patients who were admitted between April 2013 and May 2016 were randomized to have wound dressing using either silver dressing (Ag group) or normal saline solution gauze (NSS group). The 4 main outcomes for comparison between the 2 groups were the duration of wound bed preparation, total cost during hospital stay, the duration of hospital stay, and the pain score. Thirty-nine patients were included in the study: 19 patients in the NSS group and 20 patients in the Ag group. The mean duration of wound bed preparation in the NSS group was 31.87 days, and in Ag group it was 21.39 days, but this trend was not statistically significant ( P = .057). The mean cost of treatment in the NSS and Ag groups was not significantly different ( P = .434; US$3308.83 and US$2647.82, respectively). The duration of hospital days in the 2 groups was not significantly different either (29.19 days [NSS group] and 20.99 days [Ag group]; P = .222). The pain score was significantly lower in the Ag group than those in the NSS group. Although silver dressing seems to be expensive, the cost of total treatment during hospital stay and the duration of hospital stay were not significantly different between groups. However, the mean duration of wound bed preparation seems to trend favoring toward the silver dressing group.

Honey/PVA hybrid wound dressings with controlled release of antibiotics: Structural, physico-mechanical and in-vitro biomedical studies

Hydrogel/honey hybrids manifest an attractive design with an exclusive therapeutic property that promotes wound healing process. The greater the concentration of honey within the formulation, the better the biomedical properties that will be achieved. However, an increase in the percentage of honey can negatively affect the physico-chemical and mechanical properties of hybrid hydrogels. The need exists, therefore, to prepare wound dressings that contain high honey density with optimal biomedical, mechanical and physicochemical properties. In this study, a simple method for the preparation of a highly concentrated honey/PVA hybrid hydrogel with borax as the crosslinking agent is reported. Comprehensive evaluations of the morphology, swelling kinetics, permeability, bio-adhesion, mechanical characteristics, cytotoxicity, antibacterial property, cell proliferation ability and their controlling release properties were conducted as a function of crosslinking density. All the borax-induced hydrogels showed acceptable biocompatibility, and the incorporation of 1% borax in the hydrogel formulation produced optimal behaviours for wound addressing applications.

A photo-cleavable polyprodrug-loaded wound dressing with UV-responsive antibacterial property

A wound dressing with UV-responsive antibacterial property was prepared by loading a photo-cleavable polyprodrug (LHP) into poly(vinyl alcohol)/sodium alginate (PVA/SA) wound dressing to overcome the overuse of antibiotics.

Superior absorption and retention properties of foam-film silver dressing versus other commercially available silver dressing

BACKGROUND

The aim of this study is to investigate the physicochemical and structural properties of Medifoam®Silver and to compare with other commercially available silver-containing polyurethane (PU) foam dressing in vitro.

METHODS

Surface and cross-section of four polyurethane foam dressings were assessed with field-emission scanning electron microscope. Thickness, density, tensile strength, elongation, absorption rate, absorption/retention capacity and water-vapor transmission (WVT) were measured to compare physical properties of various dressing materials.

RESULTS

Among four tested dressings, Medifoam®Silver has relatively uniform and smallest pore size in both surface and cross-section. In comparison of absorption properties with other dressing materials, Medifoam®Silver has rapid absorption rate, good absorption/retention capacity and good WVT value.

CONCLUSIONS

The data further suggests that Medifoam®Silver is a promising candidate for wound healing management.

A multi-centre clinical evaluation of reactive oxygen topical wound gel in 114 wounds

OBJECTIVE

This article reports the outcomes of the use of Surgihoney RO (SHRO), topical wound dressing in a multi-centre, international setting. The aims were to explore the clinical effects of SHRO, including a reduction in bacterial load and biofilm and improvement in healing in a variety of challenging non-healing and clinically infected wounds.

METHOD

This was a non-comparative evaluation, where both acute and chronic wounds with established delayed healing were treated with the dressing. Clinicians prospectively recorded wound improvement or deterioration, level of wound exudate, presence of pain, and presence of slough and necrosis. Analysis of this data provided information on clinical performance of the dressing. Semi-quantitative culture to assess bacterial bioburden was performed where possible.

RESULTS

We recruited 104 patients, mean age 61 years old, with 114 wounds. The mean duration of wounds before treatment was 3.7 months and the mean duration of treatment was 25.7 days. During treatment 24 wounds (21%) healed and the remaining 90 (79%) wounds improved following application of the dressing. No deterioration in any wound was observed. A reduction in patient pain, level of wound exudate and in devitalised tissue were consistently reported. These positive improvements in wound progress were reflected in the wound cultures that showed a reduction in bacterial load in 39 out of the 40 swabs taken. There were two adverse events recorded: a stinging sensation following application of the dressing was experienced by 2 patients, and 2 elderly patients died of causes unrelated to the dressing or to the chronic wound. These patients' wounds and their response to SHRO have been included in the analysis.

CONCLUSION

SHRO was well tolerated and shows great promise as an effective potent topical antimicrobial in the healing of challenging wounds.

DECLARATION OF INTEREST

Matthew Dryden has become a shareholder in Matoke Holdings, the manufacturer of Surgihoney RO, since the completion of this study. Keith Cutting is a consultant to Matoke Holdings.

Engineered honey: In vitro antimicrobial activity of a novel topical wound care treatment

Surgihoney is a novel engineered organic honey product for wound care. Its antimicrobial activity can be controlled and adjusted by the engineering process, allowing preparation of three different potencies, labelled Surgihoney 1-3. Susceptibility testing of a range of wound and ulcer bacterial isolates to Surgihoney by the disc diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determination, and time-kill measurements by time suspension tests were performed. Surgihoney demonstrated highly potent inhibitory and cidal activity against a wide range of Gram-positive and Gram-negative bacteria and fungi. MICs/MBCs were significantly lower than concentrations likely to be achieved in topical clinical use. The topical concentration of Surgihoney in wounds was estimated at ca. 500g/L. MICs/MBCs for Staphylococcus aureus were 32/125g/L for Surgihoney 1 and 0.12/0.25g/L for Surgihoney 3. Cidal speed depended on potency, being 48h for Surgihoney 1 and 30min for Surgihoney 3. Maintenance of the Surgihoney inoculum preparation for up to a week demonstrated complete cidal activity and no bacterial persistence. Surgihoney has wide potential as a highly active topical treatment combining the effects of the healing properties of honey with the potent antimicrobial activity of the engineered product for skin lesions, wounds, ulcers and cavities. It is highly active against multidrug-resistant bacteria. It is more active than other honeys tested and is comparable with chemical antiseptics in antimicrobial activity.

Antibacterial efficacy testing of a bioelectric wound dressing against clinical wound pathogens

Silver-based wound dressings have been developed for the control of bioburden in wounds. However, the popularity and extensive use of silver-based dressings has been associated with emerging microbial resistances to silver. In this study we examined in vitro antibacterial efficacy of a bioelectric dressing containing silver and zinc against various wound pathogens. Antibiotic-sensitive clinical wound isolates showed a 100% reduction in bacterial growth, except that Enterococcus faecalis isolate was shown to survive with a bacterial log₁₀ reduction rate of less than 10² CFU. We also investigated antibacterial efficacy against the extended spectrum β-lactamase (ESBL) bacteria, multidrug-resistant (MDR) bacteria, and methicillin-resistant Staphylococcus aureus (MRSA). The bioelectric dressing was effective in killing wound pathogens including ESBL, MDR, and MRSA in vitro. Furthermore, based on the primary results against E. faecalis, we carried out extensive studies against several nosocomial Enterococcus species including vancomycin-resistant species. Overall, the vancomycin-sensitive or -resistant Enterococcus species were resistant to this dressing at up to 48 h, except for the vancomycin-resistant Enterococcus raffinosus isolate only showing a 100% bacterial reduction at 48 h, but not at 24 h. The results demonstrated the effective bactericidal activity of a bioelectric dressing against antibiotic-sensitive and MDR strains, but Enterococcus species are bacteriostatic.

Utilization of silver hydrogel sheet dressing on postsurgical incisions: a pilot study in foot and ankle surgery

Silver hydrogel dressings are antimicrobial, nonadherent, and have an absorptive capacity many times their weight. Fifty-nine (49.44 ± 16.85 years) foot and ankle patients with incisions >1 cm were prospectively enrolled to compare infection, scarring, and complication rates between the postoperative use of a silver hydrogel sheet (SHS) dressing and a standard petroleum-based (P) dressing. Overall, there were 5 (8.47%) infections; 4 (6.78%) superficial and 1 (1.69%) deep. The SHS group had 1 (3.45%) superficial infection, whereas the P group had 3 (10.00%) superficial infections and 1 (3.33%) deep infection. Infection incidence was similar for both groups (P = .37). However, in the P group, 3 (10.00%) patients developed wound dehiscence and 1 (1.69%) patient developed a fibrinous scab. Compared with SHS patients, the P patients had a greater incidence of incisional complications (1 [3.45%] vs 8 [26.67%], respectively; P = .03). The percent change in scar length was greater in the SHS group (18.04 ± 41.10%) when compared with the P group (2.00 ± 9.93%; P < .001) while the percent change in scar width was similar in the 2 groups (P = .19). The lower incidence of incisional complications and the greater reduction in scar length suggest that the inherent properties of the silver hydrogel dressing aid in postsurgical healing.

Use of Urgotul SSD to reduce bacteria and promote healing in chronic wounds

This product focus seeks to give an overview of the management of wound bioburden in relation to the use of antimicrobial dressings, according to recent guidelines and best practice statements. Identification of critical colonisation/localised infection and the role of biofilms is a key aspect of effective wound management. Silver antimicrobial dressings are efficient in reducing bacteria in wounds, but must be used appropriately to prevent overuse. Silver sulphadiazine has traditionally been used for the treatment of burns or Pseudomonas infection in leg ulceration, often in a cream formation. This article will be looking specifically at the effective use of Urgotul SSD in three critically colonised/non healing wounds.

Extremity Trauma, Dressings, and Wound Infection

The manner in which high-energy transfer limb injuries are dressed can alter the wound environment through manipulation of the bacterial burden, thus minimizing tissue degradation and influencing healing potential. Infection is the principal complication of such wounds, and antiseptic soaked gauze is accepted in early coverage of extremity wounds despite a lack of evidence to support this practice. There has been resurgence in the use of silver in acute wounds, through dressings manipulated to deliver sustained elemental silver to the wound interface. In vitro and in vivo experimentation of silver dressings are characterized however by methodological compromise, primarily through lack of similarity of models to the physiology of the healing wound. Results from in vitro studies caution against the use of silver because of evidence of cytotoxicity, but this is not reproduced in in vivo or clinical experimentation, leading to ambiguity. Review of silver dressing application in burns and chronic wound studies fails to support its use over other dressing systems. Similarly, evidence for the use of silver in acute limb wounds is lacking. This article provides a comprehensive overview of the use of silver dressings in acute wound care and highlights in particular the paucity of evidence regarding its routine use in extremity injury.

Synthesis and evaluation of novel absorptive and antibacterial polyurethane membranes as wound dressing

Preparation and evaluation of new polyurethane membranes for wound dressing application was considered in this work. The membranes were prepared through amine curing reaction of epoxy-terminated polyurethane prepolymers and an antibacterial epoxy-functional quaternary ammonium compound (glycidyltriehtylammonium chloride, GTEACl. To render the prepared membranes to be highly absorptive of wound exudates, poly (ethylene glycol) polyols were introduced into the polyurethane networks. Evaluation of biocompatibity via both MTT assay and direct contact with two different cell lines (fibroblast and epidermal keratinocytes) reveled that membranes with appropriate loading of GTEACl showed proper biocompatibility. Promising antibacterial activity of the prepared membranes against Staphylococcus aureus and Escherichia coli bacteria was confirmed by both agar diffusion and shaking flask methods. The membranes with balanced crosslink density and ionic groups' concentration possessed appropriate hydrophilicity and water vapor transmission rate; therefore, they could prevent the accumulation of exudates and decrease the surface inflammation in the wounded area.