Paul Christian Fuchs

The topical use of non-thermal dielectric barrier discharge (DBD): Nitric oxide related effects on human skin

Dielectric barrier discharge (DBD) devices generate air plasma above the skin containing active and reactive species including nitric oxide (NO). Since NO plays an essential role in skin physiology, a topical application of NO by plasma may be useful in the treatment of skin infections, impaired microcirculation and wound healing. Thus, after safety assessments of plasma treatment using human skin specimen and substitutes, NO-penetration through the epidermis, the loading of skin tissue with NO-derivates in vitro and the effects on human skin in vivo were determined. After the plasma treatment (0-60 min) of skin specimen or reconstructed epidermis no damaging effects were found (TUNEL/MTT). By Franz diffusion cell experiments plasma-induced NO penetration through epidermis and dermal enrichment with NO related species (nitrite 6-fold, nitrate 7-fold, nitrosothiols 30-fold) were observed. Furthermore, skin surface was acidified (~pH 2.7) by plasma treatment (90 s). Plasma application on the forearms of volunteers increased microcirculation fourfold in 1-2 mm and twofold in 6-8 mm depth in the treated skin areas. Regarding the NO-loading effects, skin acidification and increase in dermal microcirculation, plasma devices represent promising tools against chronic/infected wounds. However, efficacy of plasma treatment needs to be quantified in further studies and clinical trials.

Non-Thermal Dielectric Barrier Discharge (DBD) Effects on Proliferation and Differentiation of Human Fibroblasts Are Primary Mediated by Hydrogen Peroxide

The proliferation of fibroblasts and myofibroblast differentiation are crucial in wound healing and wound closure. Impaired wound healing is often correlated with chronic bacterial contamination of the wound area. A new promising approach to overcome wound contamination, particularly infection with antibiotic-resistant pathogens, is the topical treatment with non-thermal “cold” atmospheric plasma (CAP). Dielectric barrier discharge (DBD) devices generate CAP containing active and reactive species, which have antibacterial effects but also may affect treated tissue/cells. Moreover, DBD treatment acidifies wound fluids and leads to an accumulation of hydrogen peroxide (H2O2) and nitric oxide products, such as nitrite and nitrate, in the wound. Thus, in this paper, we addressed the question of whether DBD-induced chemical changes may interfere with wound healing-relevant cell parameters such as viability, proliferation and myofibroblast differentiation of primary human fibroblasts. DBD treatment of 250 μl buffered saline (PBS) led to a treatment time-dependent acidification (pH 6.7; 300 s) and coincidently accumulation of nitrite (~300 μM), nitrate (~1 mM) and H2O2 (~200 μM). Fibroblast viability was reduced by single DBD treatments (60–300 s; ~77–66%) or exposure to freshly DBD-treated PBS (60–300 s; ~75–55%), accompanied by prolonged proliferation inhibition of the remaining cells. In addition, the total number of myofibroblasts was reduced, whereas in contrast, the myofibroblast frequency was significantly increased 12 days after DBD treatment or exposure to DBD-treated PBS. Control experiments mimicking DBD treatment indicate that plasma-generated H2O2 was mainly responsible for the decreased proliferation and differentiation, but not for DBD-induced toxicity. In conclusion, apart from antibacterial effects, DBD/CAP may mediate biological processes, for example, wound healing by accumulation of H2O2. Therefore, a clinical DBD treatment must be well-balanced in order to avoid possible unwanted side effects such as a delayed healing process.

Our initial learning curve in the enzymatic debridement of severely burned hands—Management and pit falls of initial treatments and our development of a post debridement wound treatment algorithm

INTRODUCTION Excisional surgical debridement (SD) is still the gold standard in the treatment of deeply burned hands, though the intricate anatomy is easily damaged. Previous studies demonstrated that enzymatic debridement with the bromelain debriding agent NexoBrid® (EDNX) is more selective and thus can preserve viable tissue with excellent outcome results. So far no method paper has been published presenting different treatment algorithms in this new field. Therefore our aim was to close this gap by presenting our detailed learning curve in EDNX of deeply burned hands. METHODS We conducted a single-center prospective observational clinical trial treating 20 patients with deeply burned hands with EDNX. Different anaesthetic procedures, debridement and wound treatment algorithms were compared and main pitfalls described. RESULTS EDNX was efficient in 90% of the treatments though correct wound bed evaluation was challenging and found unusual compared to SD. Post EDNX surprisingly the majority of the burn surface area was found overestimated (18 wounds). Finally we simplified our process and reduced treatment costs by following a modified treatment algorithm and treating under plexus anaesthesia bedside through a single nurse and one burn surgeon solely. Suprathel® could be shown to be an appropriate dressing for wound treatment after EDNX. Complete healing (less 5% rest defect) was achieved at an average of day 28. CONCLUSION EDNX in deep burned hands is promising regarding handling and duration of the treatment, efficiency and selectivity of debridement, healing potential and early rehabilitation. Following our treatment algorithm EDNX can be performed easily and even without special knowledge in burn wound depth evaluation.

Intraalveolar TNF-α in combined burn and inhalation injury compared with intraalveolar interleukin-6.

The objective of this study was to evaluate the role of intraalveolar tumor necrosis factor-&agr; (TNF-&agr;) and interleukin-6 (IL-6) in a combination of skin burn and smoke inhalation injuries because this combined trauma is associated with an increased morbidity and mortality compared with either of these traumas alone. We used a standardized small animal model (rats n = 84) to investigate the early intraalveolar excretion of TNF-&agr; during the first one, three, and six hours after a singular skin burn injury, singular smoke inhalation injury, and a combination involving both the traumas. The data were compared with the data from control rats that only received preparation and mechanical ventilation. The TNF-&agr; serum levels and intraalveolar IL-6 concentrations were also measured. One hour after trauma, there was a significant difference in the TNF-&agr; concentration between the controls and both the singular traumas (control vs burn P < .0444 and control vs smoke P < .005) and between the inhalation injury and the combined trauma (smoke vs burn + smoke P < .0084). After three and six hours, no significant differences among the groups were observed. Compared with the controls, both the singular skin burn and smoke inhalation injuries led to increased intraalveolar TNF-&agr; excretion, whereas the combined trauma showed the least intraalveolar TNF-&agr; levels at three and six hours post-trauma. These findings differed from the serum TNF-&agr; levels. Compared with the IL-6 levels, we observed a negative correlation within the intraalveolar cytokine concentrations after one hour (r = −.809), three hours (r = −.627), and six hours (r = −.746). This study confirms the importance of the intraalveolar cytokine reaction in the early posttraumatic stage after a combined burn and inhalation injury. The differences between the combined and singular traumas indicate that TNF-&agr; plays a role in the immunologic hyporesponsiveness of the lung and therefore in the systemic pathophysiological pathway, that often leads to patient mortality. In addition, an inverse correlation between TNF-&agr; and IL-6, both classical markers of inflammation, in the intraalveolar space was observed.

Blue light inhibits transforming growth factor‐β1‐induced myofibroblast differentiation of human dermal fibroblasts

Transforming growth factor‐β1 (TGF‐β1) is the major promoter of phenotypic shift between fibroblasts and myofibroblasts accompanied by the expression and incorporation of α‐smooth muscle actin (α‐SMA). This differentiation is crucial during normal wound healing and wound closure; however, myofibroblasts are considered as the main effecter cell type in fibrosis, for example in scleroderma and hypertrophic scarring. As blue light has exerted antiprolific and toxic effects in several cell types, we investigated whether blue light irradiations with a light‐emitting diode array (420 nm) were able to affect proliferation and differentiation of human dermal fibroblasts (HDF). We found that repeated irradiation with non‐toxic doses significantly inhibits TGF‐β1‐induced differentiation of HDF into myofibroblasts shown by α‐SMA immunocytochemistry and Western blotting. Additionally, used doses reduced proliferation and myofibroblast contractibility measured by resazurin and collagen gel contraction assays. It could be demonstrated that blue light mediates cell toxicity by oxidative stress due to the generation of singlet oxygen. We postulate that irradiations at non‐toxic doses induce low‐level oxidative stress and energy‐consuming cellular responses, which both may effect proliferation stop and interfere with myofibroblast differentiation. Thus, targeting differentiation, proliferation and activity of myofibroblasts by blue light may represent a useful strategy to prevent or reduce pathological fibrotic conditions.

Etiology, incidence and gender-specific patterns of severe burns in a German Burn Center - Insights of 25 years

INTRODUCTION Burns often require special treatment in specialized burn centers. One of the specialized German burn centers is located in Cologne-Merheim. Only little is known about the etiology of burns in Germany, their monthly distribution and changes over the past 25 years. METHODS We therefore retrospectively analyzed the etiology for all patients treated at the burn intensive care unit (BICU) of Cologne in the last 25 years and categorized them into groups. Thereafter all groups were analyzed according to distribution of age, gender and occurrence. RESULTS In this way we were able to show that the number of severe burns did not decrease over the time under evaluation and that it did not show seasonal variation. Injured females were older than males but fewer in number. The highest numbers of burns were related to fire, followed by electricity, hot liquids, chemicals and heat contact. Work-related burns occurred mostly with males. However, most of the burns were not work-related for either gender. CONCLUSION The number of burns in Germany and in the world is still high, and prevention strategies do not always have the desired effect. This study aims to fill the gap in published burn knowledge in Germany by way of describing the gender differences and etiology characteristics. It can therefore help to identify risks and expand effective burn prevention strategies.

Enzymatic Versus Traditional Surgical Debridement of Severely Burned Hands: A Comparison of Selectivity, Efficacy, Healing Time, and Three-Month Scar Quality

Severe burns of the hands are extremely challenging, given their anatomic complexity and vulnerability. Although excisional debridement with autografting remains the standard of care (SOC), previous studies have shown that use of enzymatic debridement with bromelain (NexoBrid, EDNX) enables rapid, selective enzymatic debridement, preserving viable tissue. To date, only two studies accruing data on EDNX in this setting have been published. The current study was conducted to compare EDNX with traditional surgical debridement (TSD) of deep dermal and full-thickness hand burns. This single-center, controlled clinical trial included 40 patients, aged 18 to 76 years, with deep dermal burns of the hand. The first 20 patients were debrided surgically, and the other 20 patients were using EDNX for debridement. Therapeutic selectivity, time to complete debridement and healing, complications, and 3-month functional/esthetic outcomes were compared by group. EDNX (vs TSD) significantly reduced time to complete debridement after admission (0.95 day vs 7.750 days; P < .001) and treatments needed for complete debridement (1.05 vs 1.45; P < .001), improving burn depth evaluation (initially overestimated in 55% of EDNX-treated patients). The number of wounds requiring autografting was certainly reduced (15% vs 95%; P = .034), as was time to complete healing after first debridement (23.30 vs 32.00 days; P < .001), and early scar quality after 3 months was nearly equivalent, with only heightened local redness in the EDNX group (P < .001). Compared with TSD, EDNX was superior in burn depth evaluation, tissue preservation, completeness of debridement, and wound closure. Scar quality after 3 months did not differ substantially.

Macrophage Migration Inhibitory Factor - A Favorable Marker in Inflammatory Diseases?

BACKGROUND Macrophage migration inhibitory factor (MIF) was firstly described in the 1960s as a pleiotropic cytokine affecting a variety of immune cells. Different physiological functions mainly involving inflammatory reactions such as chemokine-like function and regulating systemic stress responses have been reported. OBJECTIVE In several clinical studies the use of MIF as a biomarker has been investigated promising support for diseases with an inflammatory aspect such as sepsis, systemic infections and autoimmune diseases. This article in detail reviews clinical data and evaluates the function as biomarker focusing on inflammatory and autoimmune diseases. CONCLUSION Recent studies suggest MIF to be a marker for different inflammatory diseases and might serve as therapeutic target in the future.

Presurgical mapping of basal cell carcinoma or squamous cell carcinoma by confocal laser endomicroscopy compared to traditional micrographic surgery: a single-centre prospective feasibility study

BackgroundAt present, no ideal diagnostic tools exist in the market to excise cancer tissue with the required safety margins and to achieve optimal aesthetic results using tissue-conserving techniques.ObjectivesIn this prospective study, confocal laser endomicroscopy (CLE) and the traditional gold standard of magnifying glasses (MG) were compared regarding the boundaries of in vivo basal cell carcinoma and squamous cell carcinoma.Materials & methodsTumour diameters defined by both methods were measured and compared with those determined by histopathological examination. Nineteen patients were included in the study.ResultsThe CLE technique was found to be superior to excisional margins based on MG only. Re-excision was required in 68% of the cases following excision based on MG evaluation, but only in 27% of the cases for whom excision margins were based on CLE.ConclusionOur results are promising regarding the distinction between tumour and healthy surrounding tissue, and indicate that presurgical mapping of basal cell carcinoma and squamous cell carcinoma is possible. The tool itself should be developed further with special attention to early detection of skin cancer.

Vitamin D deficiency may stimulate fibroblasts in Dupuytren’s disease via mitochondrial increased reactive oxygen species through upregulating transforming growth factor-β1

Dupuytrens disease, a benign fibroproliferative disorder of the palmar fascia, represents an ideal model to study tissue fibrosis. Transforming growth factor-β1 (TGF-β1) and its downstream Smad signaling system is well established as a keyplayer during fibrogenesis. Vitamin D has been extensively studied as an anti-fibrotic agent in malignant chronic diseases. A number of studies have shown that myofibroblasts are main target cells of 1,25(OH)2D3 inhibitory action. The myofibroblast in the palmar aponeurosis of patients in different stages of Dupuytrens disease was found by electron microscopy to contain a large number of mitochondria. Mitochondria play a critical role in cell metabolism being the major source of reactive oxygen species (ROS) in cells. TGF-β1 has been shown to increase mitochondrial ROS production in different cell types, which mediate fibrosis related gene expression and myofibroblast differentiation. TGF-β1 increases mitochondrial ROS production in patients with Dupuytrens contracture potentially in consequence of Vitamin D deficiency, leading to myofibroblast differentiation. Thus, targeting this basic pathomechanism seems suitable to establish new treatment strategies.