Treatment with a red-laser-based wound therapy device exerts positive effects in models of delayed keratinocyte and fibroblast wound healing.

BACKGROUND: Light therapy is widely used in medicine. Specifically, photobiomodulation has been shown to exert beneficial effects in wound healing disorders, which present a major challenge in health care. The study's aim was providing information on the effect of a novel, red-laser-based wound therapy device (WTD) on keratinocytes and fibroblasts during wound healing under optimal and non-optimal conditions. METHODS: The scratch wound assay was employed as a wound healing model for mechanical damage with readjustment of specific cell milieus, explicitly chronic TH1 inflammation and TH2-dominant conditions. Furthermore, gene expression analysis of pro-inflammatory cytokines (IL1A, IL6, CXCL8), growth factors (TGFB1, PDGFC), transcription factors (NFKB1, TP53) and heat shock proteins (HSP90AA1, HSPA1A, HSPD1) as well as desmogleins (DSG1, DSG3) in keratinocytes and collagen (COL1A1, COL3A1) in fibroblasts was performed after WTD treatment. RESULTS: It was shown that WTD treatment is biocompatible and supports scratch wound closure under non-optimal conditions. A distinct enhancement of desmoglein and collagen gene expression as well as induction of early growth factor gene expression was observed under chronic inflammatory conditions. Moreover, WTD increased HSPD1 transcript levels in keratinocytes and augmented collagen expression in fibroblasts during wound healing under TH2 conditions. WTD treatment also alleviated the inflammatory response in keratinocytes and induced early growth factor gene expression in fibroblasts under physiological conditions. CONCLUSION: Positive effects described for wound treatment with WTD could be replicated in vitro and seem to be to be conferred by a direct influence on cellular processes taking place in keratinocytes and fibroblasts during wound healing.

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.

Establishment and Characterization of Mild Atopic Dermatitis in the DNCB-Induced Mouse Model.

In dermatological research, 2,4-dinitrochlorbenzene (DNCB)-induced atopic dermatitis (AD) is a standard model as it displays many disease-associated characteristics of human AD. However, the reproducibility of the model is challenging due to the lack of information regarding the methodology and the description of the phenotype and endotype of the mimicked disease. In this study, a DNCB-induced mouse model was established with a detailed procedure description and classification of the AD human-like skin type. The disease was induced with 1% DNCB in the sensitization phase and repeated applications of 0.3% and 0.5% DNCB in the challenging phase which led to a mild phenotype of AD eczema. Pathophysiological changes of the dorsal skin were measured: thickening of the epidermis and dermis, altered skin barrier proteins, increased TH1 and TH2 cytokine expression, a shift in polyunsaturated fatty acids, increased pro-resolving and inflammatory mediator formation, and dysregulated inflammation-associated gene expression. A link to type I allergy reactions was evaluated by increased mast cell infiltration into the skin accompanied by elevated IgE and histamine levels in plasma. As expected for mild AD, no systemic inflammation was observed. In conclusion, this experimental setup demonstrates many features of a mild human-like extrinsic AD in murine skin.

Effects of Histamine and the α-Tocopherol Metabolite α-13'-COOH in an Atopic Dermatitis Full-Thickness Skin Model.

Atopic dermatitis is a T-cell mediated inflammatory skin disease with detected elevated levels of histamine in skin or plasma. In this study, the effects of histamine in a TH2 cytokine environment on human keratinocytes and three-dimensional skin models were investigated. These models were used to explore the anti-inflammatory properties of the α-tocopherol-derived long-chain metabolite α-13'-carboxychromanol (α-13'-COOH). Histamine and TH2 cytokine-induced proliferation of keratinocytes was studied using a scratch assay. The inflammatory marker interleukin-8 was significantly increased in healthy and TH2 cytokine-stimulated keratinocytes and skin models after histamine treatment. The incubation of full-thickness skin models with TH2 cytokines and histamine resulted in morphological changes in the epidermal layer, interpreted as hyperkeratosis. α-13'-COOH significantly decreased interleukin-8 in these disease-associated skin models. Histological staining of filaggrin showed skin-strengthening effects following α-13'-COOH treatment, without changes in mRNA expression. Cytokeratin 10 mRNA expression tended to be increased in response to α-13'-COOH. Anti-allergic properties of α-13'-COOH were studied by pre-incubation of human leukocytes with α-13'-COOH. This resulted in reduced sulfido-leukotriene synthesis. The hyperproliferation effect of histamine in atopic dermatitis skin models may be of further interest to the study of disease-associated morphological changes. Moreover, α-13'-COOH is a promising natural compound for the treatment of inflammatory skin diseases.

Point mutations in the squalene epoxidase erg1 and sterol 14-α demethylase erg11 gene of T indotineae isolates indicate that the resistant mutant strains evolved independently.

BACKGROUND: The T indotineae population shows a high amount of terbinafine resistant isolates based on different point mutations of squalene epoxidase erg1 (ergosterol) gene. A significant proportion of these isolates also show azole resistance. OBJECTIVES: Elucidation of the molecular mechanism for azole resistance, especially the identification of mutations in the sterol 14-α demethylase Erg11 genes, which encode for enzymes interacting with azoles. METHODS: Sequencing of putative Erg11 genes and analysis of phenotypic resistance pattern using a microplate-laser-nephelometry-based growth assay. RESULTS: Four different types of Erg11B mutants were detected; two double mutants with Ala230Thr/Asp441Gly, respectively, Ala230/Tyr444His and single mutants with Gly443Glu, Tyr444Cys and Tyr444His. All isolates featured the wild type genotype of Erg11A. All strains demonstrated different combinations of Erg1 and Erg11 genotypes. CONCLUSION: Resistance against terbinafine and azoles developed several times independently within the T indotineae population. The challenge for fungal treatment is, therefore, that species identification is not enough for prediction of therapeutic efficacy of antifungals. In the future, it will also become important to analyse genes involved in resistance mechanisms.

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.

Effect of a DACC-coated dressing on keratinocytes and fibroblasts in wound healing using an in vitro scratch model.

Wound dressings that exert an antimicrobial effect in order to prevent and treat wound infections can be harmful to the wound healing process. Dressings with hydrophobic coatings, however, have been suggested to both reduce the microbial load and promote the healing process. Therefore, the potential effects of a dialkylcarbamoyl chloride (DACC)-coated dressing on fibroblasts and keratinocytes in wound healing were studied using mechanical scratch wounding of confluent cell layers as an in vitro model. Additionally, gene expression analysis by qRT-PCR was used to elucidate the longitudinal effects of the DACC-coated dressing on cell responses, specifically inflammation, growth factor induction and collagen synthesis. DACC promoted cell viability, did not stick to the cell layers, and supported normal wound healing progression in vitro. In contrast, cells became attached to the uncoated reference material, which inhibited scratch closure. Moreover, DACC slightly induced KGF, VEGF, and GM-CSF expression in HaCaT cells and NHDF. Physiological COL1A1 and COL3A1 gene expression by NHDF was observed under DACC treatment with no observable effect on S100A7 and RNASE7 levels in HaCaT cells. Overall, the DACC coating was found to be safe and may positively influence the wound healing outcome. Graphical abstract.

Antimicrobial effects of bacterial binding to a dialkylcarbamoyl chloride-coated wound dressing: an in vitro study.

OBJECTIVE: Wound dressings that inactivate or sequestrate microorganisms, such as those with a hydrophobic, bacteria-binding dialkylcarbamoyl chloride (DACC) surface, can reduce the risk of clinical infections. This 'passive' bioburden control, avoiding bacterial cell wall disruption with associated release of bacterial endotoxins aggravating inflammation, is advantageous in hard-to-heal wounds. Hence, the full scope of DACC dressings, including the potential impact of higher inoculum densities, increased protein load and different pH on antibacterial activity, needs to be evaluated. METHOD: The Japanese Industrial Standard (JIS) L 1902 challenge test was used to evaluate the antimicrobial activity of the DACC-coated dressing against several World Health Organization (WHO)-prioritised wound pathogens (e.g., meticillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, microorganisms with extended-spectrum beta-lactamases and Acinetobacter baumannii), the effect of repeated bacterial challenge in an adverse wound environment, and antimicrobial performance at wound-related pH. RESULTS: High antibacterial activity of the DACC-coated dressing against the WHO-prioritised bacteria strains by its irreversible binding and inhibition of growth of bound bacteria was confirmed using JIS L 1902. At increased inoculation densities, compared to standard conditions, the DACC-coated dressing still achieved strong-to-significant antibacterial effects. Augmenting the media protein content also affected antibacterial performance; a 0.5-1 log reduction in antibacterial activity was observed upon addition of 10% fetal calf serum. The pH did not influence antibacterial performance. The DACC-coated dressing also sustained antibacterial activity over subsequent reinfection steps. CONCLUSION: It can be assumed that the DACC-coated dressing exerts beneficial effects in controlling the wound bioburden, reducing the overall demand placed on antibiotics, without using antimicrobial substances.

How irritant are n-propanol and isopropanol? - A systematic review.

BACKGROUND: The use of alcoholic-based hand rubs (ABHRs) is an important tool for hand hygiene, especially in times of the COVID-19 pandemic. Possible irritant effects of ABHR may prevent their use by persons at risk of infection. METHODS: This systematic review is based on a PubMed search of articles published between January 2000 and September 2019 in English and German, and a manual search, related to the irritation potential of alcohol-based disinfectants restricted to n-propanol (1-propanol) and its structural isomer isopropanol (isopropyl alcohol, 2-propanol). RESULTS: The majority of the included studies show a low irritation potential of n-propanol alone. However, recent studies provide evidence for significant barrier damage effects of repeated exposure to 60% n-propanol in healthy, as well as atopic skin in vivo. The synergistic response of combined irritants, (ie, a combination of n-propanol or isopropanol with detergents such as sodium lauryl sulfate) is greater, compared with a quantitatively identical application of the same irritant alone. CONCLUSION: While recent studies indicate a higher risk of skin irritation for n-propanol and isopropanol than reported in the past, this risk still seems to be lower than that for frequent handwashing with detergents, as recommended by some to prevent COVID-19 infections.

Critical parameters in cultivation of experimental biofilms using the example of Pseudomonas fluorescens.

Formation and treatment of biofilms present a great challenge for health care and industry. About 80% of human infections are associated with biofilms including biomaterial centered infections, like infections of prosthetic heart valves, central venous catheters, or urinary catheters. Additionally, biofilms can cause food and drinking water contamination. Biofilm research focusses on application of experimental biofilm models to study initial adherence processes, to optimize physico-chemical properties of medical materials for reducing interactions between materials and bacteria, and to investigate biofilm treatment under controlled conditions. Exploring new antimicrobial strategies plays a key role in a variety of scientific disciplines, like medical material research, anti-infectious research, plant engineering, or wastewater treatment. Although a variety of biofilm models exist, there is a lack of standardization for experimental protocols, and designing experimental setups remains a challenge. In this study, a number of experimental parameters critical for material research have been tested that influence formation and stability of an experimental biofilm using the non-pathogenic model strain of Pseudomonas fluorescens. These parameters include experimental time frame, nutrient supply, inoculum concentration, static and dynamic cultivation conditions, material properties, and sample treatment during staining for visualization of the biofilm. It was shown, that all tested parameters critically influence the experimental biofilm formation process. The results obtained in this study shall support material researchers in designing experimental biofilm setups.

Superficial fungal infections in the department of dermatology, University Hospital Jena: A 7-year retrospective study on 4556 samples from 2007 to 2013.

BACKGROUND: Superficial fungal infections are often seen in day-to-day clinical practice, and their prevalence continues to rise worldwide. Over the years, a change in the pattern of dermatophytoses has been noted. OBJECTIVES: This study aimed to determine the epidemiologic profile of dermatophytes at the Department of Dermatology, University Hospital Jena, from 2007 to 2013. METHODS: The retrospective study was carried out with a total of 4556 samples collected from 3607 patients suspected of superficial fungal infections during the 7-year study period. RESULTS: Among the 3607 suspected patients, 1951 (54.09%) were men and 1656 (45.91%) were women. Of 4556 samples, 703 (15.43%) samples were positive for fungal culture, which included 585 (83.21%) dermatophytes and 118 (16.79%) non-dermatophytes. Trichophyton (T.) rubrum was the most common isolated pathogen in 73.33% of the dermatophyte cases. Among dermatophyte-infected patients, men were most likely to be affected (63.48%) as well as those of higher age (61 to 80). The most commonly affected areas were nails (33.16%) and feet (33%). T rubrum was recurrently isolated in several regions with exception of the scalp where M canis (58.33%) was the most frequently isolated pathogen. About 16.04% of cases had a history of treatment taken prior to sampling. The majority of the affected individuals did not have any prior animal contact (77.26%). T benhamiae was exclusively associated with contact to guinea pigs. CONCLUSION: Trichophyton rubrum was the most frequently isolated pathogen in several regions except the scalp. New dermatophyte species emerged with time especially T benhamiae.

Indian Trichophyton mentagrophytes squalene epoxidase erg1 double mutants show high proportion of combined fluconazole and terbinafine resistance.

BACKGROUND: The Indian ITS genotype VIII Trichophyton mentagrophytes population shows a high amount of different erg1 (ergosterol) mutants encoding for squalene epoxidase, which catalyses the first step of ergosterol biosynthesis. OBJECTIVES: Illumination of the implication of point mutations at position Ala448Thr in single and double erg1 T mentagrophytes mutants because mutants of this type were abundantly found within the Indian fungal population. METHODS: Growth in fluconazole or terbinafine containing medium was analysed using a microplate-laser-nephelometry (MLN)-based growth assay. RESULTS: Ala 448 Thr erg1 single mutants were terbinafine sensitive, but about 50% of isolates showed an increased fluconazole resistance, whereas 95% of the double mutants (Phe 397 Leu, Ala 448Thr) demonstrated combined terbinafine and increased fluconazole resistance. CONCLUSION: The new Indian T mentagrophytes populations show several point mutations in erg1. Point mutations at position 397 were previously described and cause terbinafine resistance. A large part of the double mutants exhibit resistance to terbinafine and fluconazole, demonstrating a selective advantage of the combination of both mutations.

Alarming India-wide phenomenon of antifungal resistance in dermatophytes: A multicentre study.

BACKGROUND: An alarming increase in recalcitrant dermatophytosis has been witnessed in India over the past decade. Drug resistance may play a major role in this scenario. OBJECTIVES: The aim of the present study was to determine the prevalence of in vitro resistance to terbinafine, itraconazole and voriconazole in dermatophytes, and to identify underlying mutations in the fungal squalene epoxidase (SQLE) gene. PATIENTS/METHODS: We analysed skin samples from 402 patients originating from eight locations in India. Fungi were identified by microbiological and molecular methods, tested for antifungal susceptibility (terbinafine, itraconazole, voriconazole), and investigated for missense mutations in SQLE. RESULTS: Trichophyton (T.) mentagrophytes internal transcribed spacer (ITS) Type VIII was found in 314 (78%) samples. Eighteen (5%) samples harboured species identified up to the T interdigitale/mentagrophytes complex, and T rubrum was detected in 19 (5%) samples. 71% of isolates were resistant to terbinafine. The amino acid substitution Phe397Leu in the squalene epoxidase of resistant T mentagrophytes was highly prevalent (91%). Two novel substitutions in resistant Trichophyton strains, Ser395Pro and Ser443Pro, were discovered. The substitution Ala448Thr was found in terbinafine-sensitive and terbinafine-resistant isolates but was associated with increased MICs of itraconazole and voriconazole. CONCLUSIONS: The high frequencies of terbinafine resistance in dermatophytes are worrisome and demand monitoring and further research. Squalene epoxidase substitutions between Leu393 and Ser443 could serve as markers of resistance in the future.

[Occupational Trichophyton verrucosum infection in a cattle farmer]. / Berufliche Infektion mit Trichophyton verrucosum bei einem Rinderzüchter.

Ringworm in cattle may cause an occupational skin disease in humans. Trichophyton verrucosum lead to a highly inflammatory fungal skin infection that is often misdiagnosed as bacterial disease and consequently mistreated with antibiotics. To establish the correct diagnosis, it is necessary to collect skin scales; in addition, a skin biopsy can be helpful. Deep dermatophyte infections by Trichophyton verrucosum can be treated effectively with oral terbinafine. In addition, it is necessary to pay careful attention to use suitable hygiene measures in the stables to protect against reinfection.

Pilot study on the influence of cold atmospheric plasma on bacterial contamination and healing tendency of chronic wounds.

BACKGROUND: Cold atmospheric plasma (CAP) has been used successfully for wound treatment, with thrice weekly treatment intervals. In this study, we wished to investigate whether comparably beneficial results can be achieved even with once weekly CAP treatment. PATIENTS AND METHODS: In this randomized clinical pilot study (RCT) patients with therapy-refractory chronic wounds were examined over a maximum of twelve weeks. Groups 1 and 2 were treated with CAP once and twice a week, respectively. Patients in Group 3 received placebo therapy once a week. RESULTS: Wound area decreased significantly by 63.0 % in Group 1 (n = 14, P = 0.005) and by 46.8 % in Group 2 (n = 13, P = 0.007). In Group 3 (n = 10) the wounds grew on average 17.5 % larger. A significant reduction in pain was measured in both CAP-treated groups (Group 1: P = 0.042; Group 2: P = 0.027). Only in Group 2 was there a significant improvement in wound-specific quality of life (P = 0.005). After the 12-week CAP treatment, the reduction in bacterial load compared to the day of study inclusion averaged 50.4 % for Group 1 and 35.0 % for Group 2. CONCLUSIONS: Our RCT shows that treatment with CAP improves various aspects of wound healing in patients with therapy-refractory chronic wounds. The results obtained for once weekly treatment with CAP were not inferior to those obtained when CAP treatment was three times a week. Treatment once a week is also easier and more economical to implement in clinical routine.

The current Indian epidemic of superficial dermatophytosis due to Trichophyton mentagrophytes-A molecular study.

The disease burden of chronic-relapsing and therapy-refractory superficial dermatophytosis dramatically increased in India within the past 5-6 years. In order to evaluate the prevalence of this trend, 201 skin scrapings were collected from patients from all parts of India and were tested for dermatophytes using both fungal culture and a PCR-ELISA directly performed with native skin scrapings. Fungal culture material was identified by genomic Sanger sequencing of the internal transcribed spacer (ITS) region and the translation elongation factor (TEF)-1α gene. In total, 149 (74.13%) out of the 201 samples showed a dermatophyte-positive culture result. Out of this, 138 (92.62%) samples were identified as Trichophyton (T.) mentagrophytes and 11 (7.38%) as Trichophyton rubrum. The PCR-ELISA revealed similar results: 162 out of 201 (80.56%) samples were dermatophyte-positive showing 151 (93.21%) T mentagrophytes- and 11 (6.79%) T rubrum-positive samples. In this study, we show for the first time a dramatic Indian-wide switch from T rubrum to T mentagrophytes. Additionally, sequencing revealed a solely occurring T mentagrophytes "Indian ITS genotype" that might be disseminated Indian-wide due to the widespread abuse of topical clobetasol and other steroid molecules mixed with antifungal and antibacterial agents.

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.

The application of UV resonance Raman spectroscopy for the differentiation of clinically relevant Candida species.

Candida-related infections have become a major problem in hospitals. The species identification of yeast is the prerequisite for the initiation of adequate antifungal therapy. In the present study, the connection between inherent UV resonance Raman (RR) spectral profiles of Candida species and taxonomic differences was investigated for the first time. UV RR in combination with statistical modeling was applied to extract taxonomic information from the spectral fingerprints for subsequent differentiation. The identification accuracies of independent batch cultures were determined by applying a leave-one-batch-out cross validation. The quality of differentiation can be divided into three levels. Within a defined taxonomic group comprising the species C. glabrata, C. guilliermondii, and C. haemulonii, the identification accuracy was low. On the next level, the identification results of C. albicans and C. tropicalis were characterized by high sensitivities of 98 and 95% but simultaneously challenged by false-positive predictions due to the misallocation of C. spherica (as C. albicans) and C. viswanathii (as C. tropicalis). The highest level of identification accuracies was reached for the species C. dubliniensis, C. krusei, C. africana, C. novergica, and C. parapsilosis. Reliable identification results were observed with accuracies ranging from 93 up to 100%. The species allocation based on the UV RR spectral profiles could be reproduced by the identification of independent batch cultures. We conclude that the introduced spectroscopic approach is capable of transforming the high-dimensional UV RR data of Candida species into clinically useful decision parameters. Graphical abstract.

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.

Does noncontact low-frequency ultrasound therapy contribute to wound healing at the molecular level?

Noncontact low-frequency ultrasound (NLFU) is used to treat various types of chronic wounds including venous, diabetic, and pressure ulcers. The objective for this substudy of the IN BALANCE RCT VLU trial was to characterize and compare the NLFU treatment group and patients receiving standard of care (SOC) with respect to the effect of the assigned study treatment on content/quantity of inflammatory cytokines and fibrinogen as well as bacteria. Higher mean wound area reduction was observed in the NLFU treatment group (67.0%) compared to the SOC group (41.6%, p < 0.05). Hypertension, diabetes type II, coronary artery disease, and anemia were identified as the most common comorbidities of the Chronic venous leg ulcer (CVLU) patients included in the study. Pseudomonas, Corynebacterium, and unclassified Enterobacteriaceae were dominant in the highest number of samples. Anaerococcus, Peptoniphilus, and Finegoldia, had the highest median proportion in the samples overall. Peptoniphilus abundance decreased more in the NLFU treatment group relative to SOC; similar trends were observed for Anaerococcus and Finegoldia. Progression of mediators like TNF-alpha, IL-1beta, IL-6, IL-8, and IL-10 as well as PF4, TGF-beta, and fibrinogen was monitored and trends for several of the mediators were identified. Fibrinogen amounts were significantly reduced over time in the NLFU treatment group (p < 0.05). IL-8 levels declined in wound fluid from NLFU responders as well as SOC responders. Bacterial load (total bacterial abundance) determined local parameters of ulcer inflammation. If a bioburden of ≥ 10E5 was found compared to < 10E5 , levels of IL-1beta, IL-8, and TNF-alpha were significantly higher. In conclusion, NLFU treatment is an effective adjuvant tool for CVLU therapy. This study demonstrates that it improves wound healing by equally inhibiting abundant levels of pro-inflammatory cytokines as well as by reducing the overall bacterial burden.