A standardized wound infection model for antimicrobial testing of wound dressings in vitro.

To investigate the effectiveness of antimicrobial agents against wound infections, experiments using either 2D cultures with planktonic microorganisms or animal infection models are frequently carried out. However, the transferability of the results to human skin is limited by the lack of complexity of the 2D models or by the poor translation of the results from animal models. Hence, there is a need for wound infection models capable of assessing antimicrobial agents. In this study, an easily standardized wound infection model was established. This model consists of a mechanically wounded human skin model on a collagen matrix infected with various clinically relevant bacteria. Infection of the model led to recognition of the pathogens and induction of an inflammatory response. The untreated infection spread over time, causing significant tissue damage. By applying an antimicrobial-releasing wound dressing, the bacterial load could be reduced and the success of the treatment could be further measured by a decrease in the inflammatory reaction. In conclusion, this wound infection model can be used to evaluate new antimicrobial therapeutics as well as to study host-pathogen interactions.

Clinical Experience Using a Monofilament Fiber Cleansing and Debriding Technology for Various Skin Conditions.

BACKGROUND: Gentle skin cleansing and exfoliation and the use of moisturizers as an adjunct to medical treatment should be part of the prevention, treatment, and maintenance of cutaneous conditions such as acne vulgaris (acne) psoriasis, and xerosis. A monofilament fiber debriding technology (MFDT) is used for effective, safe, and rapid skin cleansing and exfoliation and debris, slough, and biofilm removal. The current review addresses the clinical experience using MFDT for various cutaneous conditions that require cleansing or exfoliation or both and how to combine it with medical treatment. METHODS: A literature review explored clinical insights into the role of skin cleansing and exfoliation for patients with various dermatological conditions. The searches yielded 29 publications, 7 guidelines/algorithms, 13 reviews, 8 clinical studies, and one in vitro study. RESULTS: Mechanical cleansing using a device can be helpful; however, avoid injury of the skin as it may result in thickening of the epidermis leading to hyperkeratosis and disruption of the skin barrier. Clinical experience with MFDT for acne, psoriasis, atopic dermatitis, and xerosis is discussed. Additionally, MFDT was used to exfoliate hyperkeratosis, actinic keratosis, and traumatic skin tattoos. CONCLUSIONS: Mechanical cleansing using MFDT was shown to be safe and beneficial for skin cleansing and exfoliation of various cutaneous conditions; however, only anecdotal evidence or small studies are available to support its use for these conditions. J Drugs Dermatol. 2022;21(11):1173-1180. doi:10.36849/JDD.6261.

Bacterial Cellulose-Adaptation of a Nature-Identical Material to the Needs of Advanced Chronic Wound Care.

Modern wound treatment calls for hydroactive dressings. Among the variety of materials that have entered the field of wound care in recent years, the carbohydrate polymer bacterial cellulose (BC) represents one of the most promising candidates as the biomaterial features a high moisture-loading and donation capacity, mechanical stability, moldability, and breathability. Although BC has already gained increasing relevance in the treatment of burn wounds, its potential and clinical performance for "chronic wound" indications have not yet been sufficiently investigated. This article focuses on experimental and clinical data regarding the application of BC within the indications of chronic, non-healing wounds, especially venous and diabetic ulcers. A recent clinical observation study in a chronic wound setting clearly demonstrated its wound-cleansing properties and ability to induce healing in stalling wounds. Furthermore, the material parameters of BC dressings obtained through the static cultivation of Komagataeibacter xylinus were investigated for the first time in standardized tests and compared to various advanced wound-care products. Surprisingly, a free swell absorptive capacity of a BC dressing variant containing 97% moisture was found, which was higher than that of alginate or even hydrofiber dressings. We hypothesize that the fine-structured, open porous network and the resulting capillary forces are among the main reasons for this unexpected result.

Treatment of Impetigo in the Pediatric Population: Consensus and Future Directions.

BACKGROUND: Impetigo is a common contagious superficial bacterial skin infection. Treatment of localized lesions can be achieved through topical antibiotics. Oral antibiotics are reserved for extensive disease. Increasing antimicrobial resistance to existing therapies have raised concerns. Antimicrobial stewardship, achieved through the responsible use of antibiotics, is an important measure to re-duce bacterial resistance. This review highlights treatment options for impetigo and shares consensus statements to help guide the management of impetigo in the pediatric population. OBJECTIVE: An expert panel of dermatologists and pediatricians convened in February 2019 to establish evidence-based consensus on the management of impetigo in the pediatric patient population. METHODS: The consensus was created in accordance with the Appraisal of Guidelines, Research and Evaluation (AGREE) II instrument. Prior to the consensus meeting, a systematic literature review was conducted, with the selected literature deemed clinically relevant to the consensus statements. Statements were further refined and assessed systematically following established standards. The consensus process consisted of a modified Delphi approach. The consensus was established through a minimal 75% “agree” rate. RESULTS: Thirteen consensus statements were developed addressing clinical challenges, existing treatment options and their limita-tions, and new therapeutic alternatives. CONCLUSION: Bacterial resistance to antimicrobials commonly used in treating impetigo has been reported. Antimicrobial stewardship is critical to optimize patient outcomes and to prevent the development of resistance. Healthcare providers should be aware of local resistance patterns in impetigo to help guide therapy. The use of newer safe and effective topical antibiotic alternatives as a first-line treatment should be an important step in antimicrobial stewardship.J Drugs Dermatol. 2020;19(3): doi:10.36849/JDD.2020.4679.

Use of a monofilament debridement pad in the treatment of acne vulgaris.

OBJECTIVE: Acne vulgaris (acne) presents with increased oil-sebum secretion and subsequent formation of comedones, papules, pustules and nodules. Skin cleansing is part of the daily routine to improve skin condition. A monofilament debridement pad has shown to be effective when used for wound debridement and skin cleansing in dermatological conditions. The pad may offer benefits when used for acne affected skin. METHODS: The in vitro cleansing capacity of the monofilament fibre pad was analysed and compared with commercially available cosmetic pads. For this purpose, a sebum model consisting of glass plates coated with an oil-red-stained layer of artificial sebum was used. To gain clinical experience a case series evaluated cleansing efficacy of the monofilament debridement pad in combination with polyhexanide and sodium-hypochlorite based solutions. Over a period of four months, seven individuals suffering from retentive moderate facial acne who visited the dermatology clinic for their acne used the pad as necessary, ranging from twice weekly to daily, dependent on the sensitivity of the patient's skin condition. RESULTS: The in vitro study exhibited a significantly better cleansing efficacy of the monofilament debridement pad compared with the cosmetic pads. After single use of the pad subject scores on sebum reduction revealed excellent/very good in 42.9% and acceptable in 57.1% of cases. After repeated use of the monofilament pads scores on sebum reduction of excellent/very good were given in 85.7% and acceptable in 14.3% of cases. Subject scored handling of the pad and comfort during use also received favourable ratings. CONCLUSION: These initial results show the potential of the monofilament debridement pad for cleansing of acne-prone and acne affected skin. More robust studies are needed to confirm these results.

Re-evaluation of polihexanide use in wound antisepsis in order to clarify ambiguities of two animal studies.

OBJECTIVE: Due to classification of the agent polihexanide (PHMB) in category 2 'may cause cancer' by the Committee for Risk Assessment of the European Chemicals Agency in 2011, the users of wound antiseptics may be highly confused. In 2017, this statement was updated, defining PHMB up to 0.1% as a preservative safe in all cosmetic products. In the interest of patient safety, a scientific clarification of the potential carcinogenicity of PHMB is necessary. METHODS: A multidisciplinary team (MDT) of microbiologists, surgeons, dermatologists and biochemists conducted a benefit-risk assessment to clarify the hazard of antiseptic use of PHMB. RESULTS: In two animal studies, from which the assessment of a carcinogenic risk was derived, PHMB was administered orally over two years in extremely high concentrations far above the NO(A)EL (no-observed-(adverse-) effect level) in rats and mice. Feeding in the NO(A)EL range resulted in no abnormal effects. In one male in the highest dose group of 4000ppm PHMB, an adenocarcinoma was found, which the author attributed to chronic inflammation of the colon with systemic atypical exposure. The increasing incidence of hemangiosarcomas highly probably resulted from increased endothelial proliferation, triggered by the exceedingly high dosage fed, because PHMB is not genotoxic and there is no evidence for epigenetic effects. DISCUSSION: It is well known that PHMB is not absorbed when applied topically. Considering the absence of genotoxicity and epigenetic effects together with the interpretation of the animal studies, it is the consensus of the multidisciplinary experts that a carcinogenic risk from PHMB-use for wound antisepsis can be ruled out. CONCLUSION: On this basis and considering their effectiveness, tolerability and clinical evidence, the indications for PHMB based wound antiseptics are justified.

Use of wet-to-moist cleansing with different irrigation solutions to reduce bacterial bioburden in chronic wounds.

OBJECTIVE:: The influence of different irrigation solutions, in conjunction with wet-to-moist cleansing, on the reduction of sessile, non-planktonic bacteria which colonise wounds, has not been investigated. In this study, the antibacterial effect of different irrigation solutions, during a 20-minute wet-to-moist cleansing, has been evaluated in chronic wounds. METHODS:: This study was designed as a prospective cohort study with 12 study arms and was conducted between June 2011 and April 2016. Patients with chronic wounds present for more than three months, irrespective of previous treatments, were recruited into this study. Quantitative wound swabs were obtained before and after a 20-minute, wet-to-moist cleansing, using different wound irrigation solutions. Sterile 0.9% saline served as a control. RESULTS:: We recruited 308 patients, of which 260 patients with 299 chronic wounds were eligible for analysis. Staphylococcus aureus was the most common recovered (25.5%) microorganism, of which 8% were meticillin-resistant Staphylococcus aureus (MRSA) strains. Although 0.9% saline supported cleansing of the wound bed, it did not significantly reduce the bacterial burden. The highest reduction of bacterial burden was achieved with an aqueous solution containing betaine, zinc and polyhexamethylene biguanide (polihexanide; ln RF=3.72), followed by a 3% saline solution containing 0.2% sodium hypochlorite (ln RF=3.40). The most statistically significant reduction of bacterial burden, although not the highest, was achieved with povidone-iodine (ln RF=2.98; p=0.001) and an irrigation solution containing sea salt 1.2% and NaOCl 0.4% (ln RF=2.51; p=0.002). CONCLUSION:: If a reduction of bacterial burden is warranted, wound irrigation solutions containing a combination of hypochlorite/hypochlorous acid, or antiseptics such as polihexanide, octenidine or povidone-iodine, ought to be considered.

A purpose-designed monofilament-fibre pad for debridement of hard-to-reach wounds: experience in clinical practice.

OBJECTIVE: Effective and comfortable debridement is an important part of managing complex wounds. This user test evaluated a monofilament-fibre pad (with handle) (Debrisoft Lolly, Lohmann & Rauscher GmbH & Co. KG) in the debridement of various hard-to-reach wounds. METHOD: The multicentre, international user test was performed by experienced physicians and nurses in Germany and the UK, who used the monofilament-fibre pad in their clinical practice. After debridement, using the monofilament-fibre pad, the clinicians completed an evaluation questionnaire. The assessment comprised of performance, usability, tolerability, safety and suitability of the device for debridement, comparing it with standard methods used in the clinicians' centres. RESULTS: A total of 23 clinicians in 20 centres each treated between six and 10 patients with the monofilament-fibre pad (a total of 155 wounds of different aetiologies). Most participating patients had deep wounds (n=63 (41%)) or cavity (n=31 (20%)) wounds. When compared with the standard debridement method used at the centres, the tested device was scored as 'easier' or 'equally easy' to use in all cases. When comparing the standard debridement procedure with the monofilament-fibre pad, debridement duration was reported as equal to or shorter than the standard method in 90% of cases when using the monofilament-fibre pad. Debridement efficacy was scored by the clinician as 'better' or 'equal' for the monofilament-fibre pad in 67% of cases. Overall, patients reported that the study device was comfortable. CONCLUSION: The monofilament-fibre pad effectively, easily and safely removed slough and debris from wounds of various aetiologies and was effective in wounds of different shapes, such as in cavity wounds and those in hard-to-reach locations.

Handling properties of a superabsorbent dressing in the management of patients with moderate-to-very high exuding wounds.

OBJECTIVE: Exudate control is an important aspect of wound management in both acute and chronic wounds. Exudate can be an indicator of the wound bed condition, specifically inflammation and infection. This study aimed to evaluate the performance, in terms of usability, handling properties, exudate management, user satisfaction and patient comfort, in daily clinical practice, of a superabsorbent dressing, Vliwasorb Pro (Lohmann & Rauscher), suitable for the management of moderate-to-very high exudate levels. METHOD: The user test was conducted between September 2016 and July 2017, with clinicians from different specialisms in 55 centres across Germany. Both the dressing and user test were supplied by the sponsor. The superabsorbent dressing was used for at least three dressing changes, with frequency dependent on the patient and wound condition. RESULTS: A total of 55 clinicians recruited 171 patients with various wound types. The clinicians rated dressing application as 'easy' for 163 (95.3%) of the patients. The dressing was rated as easy to remove (168 (98.3%) and, according to clinicians, did not soil patients' clothing in 165 (97.1%) of cases. The dressing demonstrated a 'good absorbent capacity', as noted by clinicians in 167 (98.2%) of cases. Clinicians also commented that the dressing reduced foul odour, maceration and improved periwound skin condition. CONCLUSION: The evaluated dressing was easy to use, comfortable and reliable for patients with moderate-to-very high exuding wounds. In view of these results, superabsorbent dressings seem to be interesting for both clinicians and patients. Clinical studies are required to confirm these results.

Antibacterial activity of polihexanide formulations in a co-culture of HaCaT keratinocytes and Staphylococcus aureus and at different pH levels.

Complex stalled wounds feature an alkaline milieu that favors tissue destruction and microbial growth. The presence of bacteria in turn perpetuates the inflammatory response. However, only limited knowledge exists of pH dependency on the antibacterial efficacy of polyhexamethylene biguanide (PHMB) or the influence of surfactants or delivery vehicle used in antiseptic formulations. So far, PHMB alone has been shown to protect the keratinocytes from bacterial damage in such a co-culture system as well as exhibiting increased antimicrobial activity at higher pH values. Here, the interaction of PHMB with the surfactants macrogolum and undecylenamidopropyl betaine that are most commonly used as additives in antiseptics and rinsing solutions such as Lavasept and Prontosan has been explored in addition to the PHMB-containing biocellulose dressing Suprasorb X + PHMB. Undecylenamidopropyl betaine was found to lower the antimicrobial activity of polihexanide in the co-culture system, while macrogolum and the biocellulose increased polihexanide efficiency to reduce Staphylococcus aureus especially in the presence of serum. The increasing antibacterial efficacy of PHMB with rising pH was not altered by undecylenamidopropyl betaine, macrogolum, or the biocellulose. The results suggest that application of PHMB with macrogolum or by delivery through a biocellulose dressing might be advantageous for management of wound infections.

Eradication of methicillin-resistant Staphylococcus aureus in pressure ulcers comparing a polyhexanide-containing cellulose dressing with polyhexanide swabs in a prospective randomized study.

OBJECTIVE: The study evaluated eradication of methicillin-resistant Staphylococcus aureus (MRSA) from pressure ulcers comparing swabs containing polyhexanide with a cellulose dressing + polyhexanide. After receiving approval from the ethics committee and informed consent, patients from the centers were recruited. DESIGN: Prospective randomized study. Thirty patients (n = 15/n = 15), not responding to wound disinfection after a washout period of 2 weeks, were included in the intention-to-treat analysis. SETTING: This study was performed on hospital patients. PATIENTS: Patients had pressure ulcers containing MRSA. INTERVENTIONS: For the control group, cleansing was performed with polyhexanide swabs (20 minutes), after which a foam dressing was applied. The study group received a polyhexanide-containing cellulose dressing. For bacterial analysis, semiquantitative swab cultures (Robert Koch Institute recommendations) were taken on days 0, 7, and 14 and during 3 consecutive days. RESULTS: The groups were comparable at baseline. At day 7, in the control group, 6 of 15 (40%) MRSA eradication. For the study group, there were 13 of 15 (86.67%) who showed MRSA eradication. At day 14, in the control group, there were 10 of 15 (66.67%) who had MRSA eradication, compared with the study group, where 15 of 15 (100%; P < .05) had the MRSA eradicated. CONCLUSIONS: Wound disinfection with polyhexanide was shown to be successful in both groups, showing superior results for the study group.

Basics in nutrition and wound healing.

Wound healing is a process that can be divided into three different phases (inflammatory, proliferative, and maturation). Each is characterized by certain events that require specific components. However, wound healing is not always a linear process; it can progress forward and backward through the phases depending on various intrinsic and extrinsic factors. If the wound-healing process is affected negatively, this can result in chronic wounds. Chronic wounds demand many resources in the clinical daily routine. Therefore, local wound management and good documentation of the wound is essential for non-delayed wound healing and prevention of the development of chronic wounds. During the wound-healing process much energy is needed. The energy for the building of new cells is usually released from body energy stores and protein reserves. This can be very challenging for undernourished and malnourished patients. Malnutrition is very common in geriatric patients and patients in catabolic phases of stress such as after injury or surgery. For that reason a close survey of the nutritional status of patients is necessary to start supplementation quickly, if applicable. Wound healing is indeed a very complex process that deserves special notice. There are some approaches to develop guidelines but thus far no golden standard has evolved. Because wounds, especially chronic wounds, cause also an increasing economic burden, the development of guidelines should be advanced.

In-vitro test for comparing the efficacy of wound rinsing solutions.

Wound coatings can severely delay chronic wound healing by inducing ischaemia and degradation of viable tissue and increasing susceptibility to infection. It is, therefore, essential to cleanse wounds gently and thoroughly to remove the detrimental coatings. In this study, an in-vitro model that mimics wound coatings (human plasma dried onto adhesive glass slides) was used to compare the efficacy of four sterile solutions used to cleanse wounds: saline and Ringer's (both salt solutions), a betaine surfactant-containing wound rinsing solution (Prontosan B. Braun) and an antiseptic solution (Octenisept Schülke & Mayr). Both salt solutions and the wound rinsing solution were found to remove protein from the test wound coatings, whereas the test coatings became fixed and insoluble when immersed in antiseptic solution.

Pedagogies of engagement in science: A comparison of PBL, POGIL, and PLTL*

Problem-based learning, process-oriented guided inquiry learning, and peer-led team learning are student-centered, active-learning pedagogies commonly used in science education. The characteristic features of each are compared and contrasted to enable new practitioners to decide which approach or combination of approaches will suit their particular situation.

Assessment of a wound cleansing solution in the treatment of problem wounds.

 Chronic wounds will heal in most cases if provided an optimal local wound environment and therapy that addresses underlying disease. The quality of topical wound management will influence the speed of the wound healing process. The value of cleansing chronic wounds is considered a basic principle in modern wound management. Several methods are available for wound cleansing and debridement. Currently, there has been focus on measures of wound cleansing whereby debris and exudate are gently and continuously removed to prepare the wound bed for wound closure. For this purpose, physiological solutions or specific disinfectants may be used. This retrospective analysis of existing data was performed looking at the clinical efficacy and cost-effectiveness of using a wound antiseptic to treat problem wounds. Wound cleansing upon dressing changes using a polyhexanide containing solution (Prontosan®, B Braun, Melsungen AG, Germany) in venous leg ulcers was compared to cleansing with either Ringer's solution or saline. The wounds of the patients treated with polyhexanide solution healed faster and in more cases (97% versus 89%). The Kaplan-Meier mean estimate (and associated standard error [SE]) demonstrated a statistically significant difference between treatment groups (P < 0.0001) in time to healing. The Kaplan-Meier mean time to healing for the study group (SG) was 3.31 months (SE = 0.17) compared to 4.42 months (SE = 0.19) for the control group ([CG], saline/Ringer's solution). .

An assessment of the wound healing properties of Algisite M dressings.

Haemostasis and fibrin formation contribute to the formation of a wound scab following skin damage. This process facilitates repair by providing a matrix within which cell migration and angiogenesis take place (van Hinsbergh, 2001; Phillips, 2000). Following injury, macrophages, which are normally present in tissue, increase in number, attracted by chemical messages released by the activation of the inflammatory process. They release the protein chemical messages, growth factors and growth stimulants needed to orchestrate the healing process (Leibovich and Ross, 1975). Macrophages have an essential role in the transition from wound inflammation to wound repair, the latter being characterised by the formation of granulation tissue (Clark, 1985).