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Objective: Antiseptics are widely used in wound management to prevent or treat wound infections, and have been shown to have antibiofilm efficacy. The objective of this study was to assess the effectiveness of a polyhexamethylene biguanide (PHMB)-containing wound cleansing and irrigation solution on model biofilm of pathogens known to cause wound infections compared with a number of other antimicrobial wound cleansing and irrigation solutions., Method: Staphylococcus aureus and Pseudomonas aeruginosa single-species biofilms were cultured using microtitre plate and Centers for Disease Control and Prevention (CDC) biofilm reactor methods. Following a 24-hour incubation period, the biofilms were rinsed to remove planktonic microorganisms and then challenged with wound cleansing and irrigation solutions. Following incubation of the biofilms with a variety of concentrations of the test solutions (50%, 75% or 100%) for 20, 30, 40, 50 or 60 minutes, remaining viable organisms from the treated biofilms were quantified., Results: The six antimicrobial wound cleansing and irrigation solutions used were all effective in eradicating Staphylococcus aureus biofilm bacteria in both test models. However, the results were more variable for the more tolerant Pseudomonas aeruginosa biofilm. Only one of the six solutions (sea salt and oxychlorite/NaOCl-containing solution) was able to eradicate Pseudomonas aeruginosa biofilm using the microtitre plate assay. Of the six solutions, three (a solution containing PHMB and poloxamer 188 surfactant, a solution containing hypochlorous acid (HOCl) and a solution containing NaOCl/HOCl) showed increasing levels of eradication of Pseudomonas aeruginosa biofilm microorganisms with increasing concentration and exposure time. Using the CDC biofilm reactor model, all six cleansing and irrigation solutions, except for the solution containing HOCl, were able to eradicate Pseudomonas aeruginosa biofilms such that no viable microorganisms were recovered., Conclusion: This study demonstrated that a PHMB-containing wound cleansing and irrigation solution was as effective as other antimicrobial wound irrigation solutions for antibiofilm efficacy. Together with the low toxicity, good safety profile and absence of any reported acquisition of bacterial resistance to PHMB, the antibiofilm effectiveness data support the alignment of this cleansing and irrigation solution with antimicrobial stewardship (AMS) strategies.

A wound offers an ideal environment for the growth and proliferation of a variety of microorganisms which, in some cases, may lead to localised or even systemic infections that can be catastrophic for the patient; the development of biofilms exacerbates these infections. Over the past few decades, there has been a progressive development of antimicrobial resistance (AMR) in microorganisms across the board in healthcare sectors. Such resistant microorganisms have arisen primarily due to the misuse and overuse of antimicrobial treatments, and the subsequent ability of microorganisms to rapidly change and mutate as a defence mechanism against treatment (e.g., antibiotics). These resistant microorganisms are now at such a level that they are of grave concern to the World Health Organization (WHO), and are one of the leading causes of illness and mortality in the 21st century. Treatment of such infections becomes imperative but presents a significant challenge for the clinician in that treatment must be effective but not add to the development of new microbes with AMR. The strategy of antimicrobial stewardship (AMS) has stemmed from the need to counteract these resistant microorganisms and requires that current antimicrobial treatments be used wisely to prevent amplification of AMR. It also requires new, improved or alternative methods of treatment that will not worsen the situation. Thus, any antimicrobial treatment should be effective while not causing further development of resistance. Some antiseptics fall into this category and, in particular, polyhexamethylene hydrochloride biguanide (PHMB) has certain characteristics that make it an ideal solution to this problem of AMR, specifically within wound care applications. PHMB is a broad-spectrum antimicrobial that kills bacteria, fungi, parasites and certain viruses with a high therapeutic index, and is widely used in clinics, homes and industry. It has been used for many years and has not been shown to cause development of resistance; it is safe (non-cytotoxic), not causing damage to newly growing wound tissue. Importantly there is substantial evidence for its effective use in wound care applications, providing a sound basis for evidence-based practice. This review presents the evidence for the use of PHMB treatments in wound care and its alignment with AMS for the prevention and treatment of wound infection.

Aims: We evaluated a novel disinfectant (VR) and seven comparators (disinfectants A–G) against resistant pathogens common in healthcare settings. Methods and Results: VR at different dilutions, along with commercial disinfectants A–G, was tested against surrogate viruses, and resistant bacterial and fungal pathogens. Surrogate viruses had an initial concentration of ~1 × 108 mL−1, and bacterial and fungal isolates had an initial concentration of ~1 × 106 mL−1 on Siliconee surfaces. After the application of VR or a comparator disinfectant, surfaces were tested for the reduction in microbial loads after 30 s and 5 min wet exposures, and after a 24 h dry residue exposure. Sterile deionized water was used as a control. The VR at a concentration of 4.68% was superior to all comparator disinfectants against most pathogens in wet and dry testing. The VR at 7.8% concentration showed the highest pathogen-reduction rate among all comparator disinfectants when tested against all pathogens. Conclusions: Overall, the novel VR disinfectant was the most effective disinfectant in both wet and dry residue states against the range of tested pathogens. Significance and Impact of the Study: VR is a broadly effective disinfectant combination for use in high-risk settings, particularly those in which intervals between applications of disinfectant can be lengthy or inconsistent. [ABSTRACT FROM AUTHOR]

The presented article describes the method of synthesizing new ionic liquid based on a biguanide cation and a tiocyanate or benzoate anion with antimicrobial properties. The structure of obtained new ionic liquid was confirmed by infrared spectroscopy. Additionally, the article describes a simple method of producing an antibacterial textile materials and PE-based film with the addition of an ionic liquid. [ABSTRACT FROM AUTHOR]

Background: Progressively increasing number of eye surgeries forces the development of simple-to-use, effective methods to reduce the risk of postoperative endophthalmitis. We wondered whether the eyelid margin wipes containing 0,1% polyhexamethylene biguanide (PHMB) (HexaClean, VERCO, Poland) influence the reduction of bacterial flora localized in the conjunctival sac and whether it can be used for prophylaxis before the cataract surgery. MATERIAL AND METHODS: 95 patients before the cataract surgery were included in the study. The conjunctival swab was collected from patients twice -- before using eye wipes and after 5 days of eye wipes usage. The swabs were plated on microbiological enriched media and incubated under aerobic and microaerophilic conditions for 24-48 hours at 35°C ± 2°C. Then the identification of microorganisms was carried out using classic microbiological methods and tests. RESULTS: Bacterial strains were isolated from the conjunctival sac in 84% of patients before using the eye wipes. The largest group of isolated pathogens was Gram-positive cocci, and these were mainly methicillin-sensitive and methicillin-resistant coagulase-negative staphylococci, which accounted for 72% of isolated strains. When the eye wipes were used, the bacterial flora was eliminated from the conjunctival sac in 54% of patients. A reduction in isolated strains and decreased variety of bacteria was observed in another 22% of patients. CONCLUSION: These results indicate that the application of eyelid wipes with polyhexanide reduces a significant amount of the conjunctival sac microbiota, which may prevent inflammation after cataract surgery. [ABSTRACT FROM AUTHOR]

Objective: The primary aim of this research was to investigate the combination effect of polyhexamethylene biguanide (PHMB) and low-frequency contact ultrasonic debridement (LFCUD) on the bacterial load in hard-to-heal wounds in adults, compared with ultrasonic debridement alone. Secondary outcomes included wound healing, quality of life (QoL) and pain scores. Method: In this single-blinded, randomised, controlled trial participants were randomised to two groups. All participants received LFCUD weekly for six weeks, plus six weeks of weekly follow-up. The intervention group received an additional 15-minute topical application of PHMB post-LFCUD, at each dressing change and in a sustained dressing product. The control group received non-antimicrobial products and the wounds were cleansed with clean water or saline. Wound swabs were taken from all wounds for microbiological analysis at weeks 1, 3, 6 and 12. Results: A total of 50 participants took part. The intervention group (n=25) had a lower bacterial load at week 12 compared with the control group (n=25) (p<0.001). There was no difference in complete wound healing between the groups (p=0.47) or wound-related QoL (p=0.15). However, more wounds deteriorated in the control group (44%) compared with the intervention group (8%, p=0.01). A higher proportion of wounds reduced in size in the intervention group (61% versus 12%, p=0.019). Pain was lower in the intervention group at week six, compared with controls (p=0.04). Conclusion: LFCUD without the addition of an antimicrobial agent such as PHMB, cannot be recommended. Further research requires longer follow-up time and would benefit from being powered sufficiently to test the effects of multiple covariates. [ABSTRACT FROM AUTHOR]

Background: Reduction of accidental contamination of the near-patient environment has potential to reduce acquisition of healthcare-associated infection(s). Although medical gloves should be removed when soiled or touching the environment, compliance is variable. The use of antimicrobial-impregnated medical gloves could reduce the horizontal-transfer of bacterial contamination between surfaces.Aim: Determine the activity of antimicrobial-impregnated gloves against common hospital pathogens: Streptococcus pyogenes, carbapenem-resistant E.coli (CREC), MRSA and ESBL-producing Klebsiella pneumoniae.Methods: Fingerpads (~1cm2) of PHMB-treated and untreated gloves were inoculated with 10 μL (~104 colony-forming-units [cfu]) of test-bacteria prepared in heavy-soiling (0.5%BSA), blood or distilled-water (no-soiling) and sampled after 0.25, 1, 10 or 15 min contact-time. Donor surfaces (~1cm2 computer-keys) contaminated with wet/dry inoculum were touched with the fingerpad of treated/untreated gloves and subsequently pressed onto recipient (uncontaminated) computer-keys.Results: Approximately 4.50log10cfu of all bacteria persisted after 15 min on untreated gloves regardless of soil-type. In the absence of soiling, PHMB-treated gloves reduced surface-contamination by ~4.5log10cfu (>99.99%) within 10 min of contact-time but only ~2.5log10 (>99.9%) and ~1.0log10 reduction respectively when heavy-soiling or blood was present. Gloves became highly-contaminated (~4.52log10-4.91log10cfu) when handling recently-contaminated computer-keys. Untreated gloves contaminated "recipient" surfaces (~4.5log10cfu) while PHMB-treated gloves transferred fewer bacteria (2.4-3.6log10cfu). When surface contamination was dry, PHMB gloves transferred fewer bacteria (0.3-0.6log10cfu) to "recipient" surfaces than untreated gloves (1.0-1.9log10; P < 0.05).Conclusions: Antimicrobial-impregnated gloves may be useful in preventing dissemination of organisms in the near-patient environment during routine care. However they are not a substitute for appropriate hand-hygiene procedures. [ABSTRACT FROM AUTHOR]

In our previous work, we have attempted to develop a novel bacterial nanocellulose wound dressing which composed of both polyhexamethylene biguanide (PHMB) as an antimicrobial agent and sericin as an accelerative wound healing component. The loading sequence and concentration of PHMB and sericin were optimized to provide the wound dressing with the most effective antimicrobial activity and enhanced collagen production. In this study, further in vitro, in vivo, and clinical studies of this novel wound dressing were performed to evaluate its safety, efficacy, and applicability. For the in vitro cytotoxic test with L929 mouse fibroblast cells, our novel dressing was not toxic to the cells and also promoted cell migration as good as the commercially available dressing, possibly due to the component of sericin released. When implanted subcutaneously in rats, the lower inflammation response was observed for the novel dressing implanted, comparing to the commercially available dressing. This might be that the antimicrobial PHMB component of the novel dressing played a role to reduce infection and inflammation reaction. The clinical trial patch test was performed on the normal skin of healthy volunteers to evaluate the irritation effect of the dressing. Our novel dressing did not irritate the skin of any volunteers, as characterized by the normal levels of erythema and melanin and the absence of edema, papule, vesicle, and bullae. Then, the novel dressing was applied for the treatment of full-thickness wounds in rats. The wounds treated with our novel dressing showed significantly lower percentage of wound size and higher extent of collagen formation mainly due to the activity of sericin. We concluded that our novel bacterial nanocellulose incorporating PHMB and sericin was a safe and efficient wound dressing material for further investigation in the wound healing efficacy in clinic. [ABSTRACT FROM AUTHOR]

High-pressure laminates (HPLs) are durable, resistant to environmental effects and good cost-benefit decorative surface composite materials with special properties tailored to meet market demand. In the present work, polyhexamethylene biguanide (PHMB) was incorporated for the first time into melamine-formaldehyde resin (MF) matrix on the outer layer of HPLs to provide them antimicrobial properties. Chemical binding of PHMB to resin matrix was detected on the surface of produced HPLs by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). Antimicrobial evaluation tests were carried out on the ensuing HPLs doped with PHMB against gram-positive Listeria innocua and gram-negative Escherichia coli bacteria. The results revealed that laminates prepared with 1.0 wt % PHMB in MF resin were bacteriostatic (i.e., inhibited the growth of microorganisms), whereas those prepared with 2.4 wt % PHMB in MF resin exhibited bactericidal activity (i.e., inactivated the inoculated microorganisms). The results herein reported disclose a promising strategy for the production of HPLs with antimicrobial activity without affecting basic intrinsic quality parameters of composite material. [ABSTRACT FROM AUTHOR]

Antimicrobial approaches are valuable in controlling the development of buccal diseases, but some antibacterial agents have a short duration of activity. Therefore, the development of prolonged delivery systems would be advantageous. Liquid crystalline systems comprising monoolein ( GMO)/water have been considered to be a potential vehicle to deliver drugs to the buccal mucosa because of the phase properties that allow for controlled drug release as well as its mucoadhesive properties. Therefore, the aim of this study was to develop a GMO/water system for the slow release of poly(hexamethylene biguanide) hydrochloride ( PHMB) on the buccal mucosa and test the properties of this system with regard to swelling, release profile, antimicrobial activity, and strength of mucoadhesion, with the overall goal of treating buccal infections. The tested systems were capable of modulating drug release, which is controlled by diffusion of the drug throughout the system. Furthermore, PHMB appeared to improve the mucoadhesive properties of the system and may synergistically act with the drug to promote antimicrobial activity against S. mutas and C. albicans, indicating that liquid crystals may be suitable for the administration of PHMB on the buccal mucosa. Therefore, this system could be proposed as a novel system for mucoadhesive drug delivery. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 103:3914-3923, 2014 [ABSTRACT FROM AUTHOR]

Abstract: An effective amount of the antiseptic agent PHMB cannot simply be placed on the surface of titanium alloys where hydrocarbons were removed by different purification procedures. Pre-treatment of Ti6Al4V specimen with 5% H2O2 in 24 h results in extra introduced –OH and –COOH groups as well as an adsorbed water film on the surface, which provide the base for the subsequent formation of a relatively stable and multi-layered PHMB film. The superficially adhering PHMB film produces no adverse effects on MG63 cells within a 48 h-cell culture, but promotes the initial attachment and spreading of the osteoblasts on the modified Ti6Al4V surface within 15 min. After direct bacterial inoculation of the active sample, the PHMB film reacts antimicrobially against Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and Gram-negative strains (Pseudomonas aeruginosa, Escherichia coli) after surface contact. The bactericidal efficacy is only slightly reduced after using of the same specimen for re-testing the antibacterial activity. MG63 cells adhere and proliferate within 48 h on a PHMB film-containing Ti6Al4V surface, which has been pre-contaminated with S. aureus. Bacterial biofilms were only revealed in controls without PHMB. [Copyright &y& Elsevier]

Negative pressure wound therapy with instillation ( NPWTi) is increasingly used as an adjunct therapy for a wide variety of infected wounds. However, the effect of NPWTi on mature biofilm in wounds has not been determined. This study assessed the effects of NPWTi using saline or various antimicrobial solutions on mature Pseudomonas aeruginosa biofilm using an ex vivo porcine skin explant biofilm model. Treatment consisted of six cycles with 10-minute exposure to instillation solution followed by 4 hours of negative pressure at −125 mm Hg over a 24-hour period. NPWTi using saline reduced bacterial levels by 1-log (logarithmic) of 7-log total colony-forming units ( CFUs). In contrast, instillation of 1% povidone iodine (2-log), L-solution (3-log), 0·05% chlorhexidine gluconate (3-log), 0·1% polyhexamethylene biguanide (4-log), 0·2% polydiallyldimethylammonium chloride (4-log) and 10% povidone iodine (5-log), all significantly reduced ( P < 0·001) total CFUs. Scanning electron micrographs showed disrupted exopolymeric matrix of biofilms and damaged bacterial cells that correlated with CFU levels. Compared with previous studies assessing microbicidal effects of topical antimicrobial dressings on biofilms cultured on porcine skin explants, these ex vivo model data suggest that NPWTi with delivery of active antimicrobial agents enhances the reduction of CFUs by increasing destruction and removal of biofilm bacteria. These results must be confirmed in human studies. [ABSTRACT FROM AUTHOR]

The effective management of bacterial bioburden is an essential element of wound care. Recent years have seen the increased use of topical antimicrobial dressings to control colonisation and infection, yet there is concern that some may inhibit wound healing and may have systemic sequelae (World Union of Wound Healing Societies (WUWHS), 2008). This article focuses on the safety and effectiveness of PHMB, an antimicrobial compound that is relatively underused in the UK, and argues that it is an effective option for the management of bacterial colonisation and infection. [ABSTRACT FROM AUTHOR]

Abstract: Liposomes or oil-in-water emulsions containing egg yolk phosphatidylcholine (EPC) were combined with aqueous polyhexamethylene biguanide hydrochloride (PHMB). The bactericidal activity of these preparations against Pseudomonas aeruginosa and Staphylococcus aureus as well as their cytotoxicity on cultured murine fibroblasts (L929 cells) was then assayed for either 30min or 60min in the presence of cell culture medium containing 10% fetal bovine serum as surrogate for wound fluid. We used two assay designs: in the first bactericidal activity and cytotoxicity were determined in separate experiments; in the second both were determined in one experiment. Combining PHMB and EPC containing o/w emulsions or liposomes protects mammalian cells without neutralizing the antiseptic effect. From all tested combinations the o/w emulsions containing 0.05% PHMB proved to be superior in this respect to the aqueous preparation. [Copyright &y& Elsevier]

Over the past two decades a body of evidence has been generated to support the traditional use of water in cleansing wounds, with studies showing that the use of clean water does not increase the risk of infection or delay healing. However, recent advances in the understanding of wound management have encouraged reforms and led to the development of wound cleansing agents that have the potential to improve clinical outcomes. This article draws on in vitro and in vivo evidence including comparative studies of patients with acute and chronic wounds to consider the evidence supporting alternatives to water in wound cleansing. [ABSTRACT FROM AUTHOR]

Unlike the native surface of the implant material (Ti6Al4V), oxidation with H2O2 leads to increased binding of the effective antimicrobial agent poly(hexamethylene) biguanide [PHMB]. However, treating with NaOH instead results in an even higher PHMB mass coverage. After oxidation with H2O2, strong differences in the PHMB adsorption capability between polished and corundum-blasted surfaces appear, indicating a roughness dependence. After NaOH treatment, no such effect was observed. The wetting properties of specimens treated with either H2O2 or NaOH prior to PHMB exposure clearly varied. To unravel the nature of this interaction, widespread in silico and in vitro experiments were performed. Methods: By X-ray photoelectron spectroscopy, scanning electron microscopy, water contact angle measurements and MD simulations, we characterized the interplay between the polycationic antimicrobial agent and the implant surface. A theoretical model for PHMB micelles is tested for its wetting properties and compared to carbon contaminated TiO2. In addition, quantitation of anionic functional group equivalents, the binding properties of PHMB with blocked amino end-group, and the ability to bind chlorhexidine digluconate (CHG) were investigated. Ultimately, the capability of osteoblasts to build calcium apatite, and the activity of alkaline phosphatase on PHMB coated specimens, were determined. Results: Simulated water contact angles on carbon contaminated TiO2 surfaces and PHMB micelle models reveal little influence of PHMB on the wetting properties and point out the major influence of remaining and recovering contamination from ambient air. Testing PHMB adsorption beyond the critical micelle concentration and subsequent staining reveals an island-like pattern with H2O2 as compared to an evenly modified surface with NaOH. Both CHG and PHMB, with blocked amino end groups, were adsorbed on the treated surfaces, thus negating the significant influence of PHMB's terminal groups. The ability of osteoblasts to produce calcium apatite and alkaline phosphatase is not negatively impaired for PHMB mass coverages up to 8 μg/specimen. Conclusion: Differences in PHMB adsorption are triggered by the number of anionic groups and carbon contaminants, both of which depend on the specimen pre-treatment. With more PHMB covering, the implant surface is protected against the capture of new contamination from the ambient air, thus building a robust antimicrobial and biocompatible surface coating. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) hydrogels are among the most efficient materials already being used for the treatment of complex wounds. The moist environment provided by the BC dressing is a key feature assuring efficient wound recovery. Improving the dressings´ moisture-holding ability facilitates its application and leads to an economically preferable extended wear time. To produce materials with reduced moisture loss, BC dressings were impregnated with a secondary hydrophilic component: alginate. The feasibility of an industrial fabrication of this composite was evaluated on pilot scale equipment. It was shown that the procedure can easily be scaled up without significantly increasing the manufacturing time. The resultant composite possessed improved water-retention properties, providing a smooth dressing exchange as demonstrated by a wound-imitating model. The new materials were moreover shown to be compatible with an antimicrobially active compound, which assures their efficiency in the treatment of highly colonized wounds. Unlabelled Image • Pilot scale fabrication of bacterial cellulose/alginate wound dressings was tested. • New dressings possess improved water-retention properties. • The dressings have reduced affinity to the wound tissue. • The dressings can be enhanced by incorporation of a cationic antimicrobial agent. [ABSTRACT FROM AUTHOR]