Actinic keratosis, a frequent carcinoma in situ of non-melanoma skin cancer (NMSC), can transform into life-threatening cutaneous squamous cell carcinoma. Current treatment is limited due to low complete clearance rates and asks for novel therapeutic concepts; the novel purine nucleotide analogue OxBu may be an option. In order to enhance skin penetration, solid lipid nanoparticles (SLN, 136-156 nm) were produced with an OxBu entrapment efficiency of 96.5 ± 0.1%. For improved preclinical evaluation, we combined tissue engineering with clinically used keratin-18 quantification. Three doses of 10-3 mol/l OxBu, dissolved in phosphate-buffered saline as well as loaded to SLN, were effective on reconstructed NMSC. Tumour response and apoptosis induction were evaluated by an increase in caspase-cleaved fragment of keratin-18, caspase-7 activation as well as by reduced expression of matrix metallopeptidase-2 and Ki-67. OxBu efficacy was superior to equimolar 5-fluorouracil solution, and thus the drug should be subjected to the next step in preclinical evaluation.
Reconstructed human epidermis (RHE) is used in non-animal testing for hazard analysis and reconstructed human skin (RHS) gains growing interest in preclinical drug development. RHE and RHS have been characterised regarding their barrier function, but knowledge about biotransformation capacity in these constructs and in human skin remains rather poor. However, metabolising enzymes can be highly relevant for the efficacy of topical dermatics as well as genotoxicity and sensitisation. We have compared the esteratic cleavage of the prednisolone diester prednicarbate and the enzyme kinetic parameters (V-max and S-0.5) of the model substrate fluorescein diacetate (FDA) in commercially available RHS and RHE with excised human skin and monolayer cultures of normal and immortalised human keratinocytes and of fibroblasts. Formation of the main metabolite prednisolone and of fluorescein ranked as: RHS similar to RHE > excised human skin and keratinocytes > fibroblasts, respectively. Because of the aromatic probe, however, V-max of FDA cleavage did not show a linear relationship with prednicarbate metabolism. In conclusion, RHE and RHS may be useful to quantitatively address esterase activity of human skin in drug development and hazard analysis, although an increased activity compared to native human skin has to be taken into account. (C) 2012 Elsevier B.V. All rights reserved.
BACKGROUND:The clinical diagnosis of amelanotic melanoma is often challenging, because the classical clinical and dermoscopic features of pigmented melanoma are usually missing. The reflectance confocal microscopy (RCM) offers an additional possibility of an in vivo diagnosis of both pigmented and amelanotic melanoma lesions.OBJECTIVES:To test the value of RCM in vivo in the preoperative prediction of melanoma lesions lacking significant pigment and to compare the results with the evaluation by dermoscopy and histopathology.METHODS:We examined seven patients with the clinically uncertain differential diagnosis of partially or completely amelanotic melanoma by RCM and dermoscopy prior to surgical excision of the lesions according to the previously suggested dermoscopy algorithm and RCM score for melanoma. The following RCM features were evaluated: major criteria scored +2 (non-edged papillae, cytological atypia at the dermo-epidermal junction) and minor criteria +1 (roundish pagetoid cells, widespread pagetoid infiltration, nucleated cells within dermal papillae, cerebriform cell clusters). The dermoscopic evaluation included the following criteria: polymorphous vessels, dotted and linear irregular vessels, hairpin vessels, pink-erythematous colour, milky red areas, irregularly shaped depigmentation, blue-grey dots and subtle pigmentation.RESULTS:The preoperative in vivo RCM analysis revealed common features of melanoma also found in pigmented melanoma lesions. All lesions showed a score above three in the applied RCM algorithm which was proposed earlier as the threshold for malignancy. In dermoscopy, five of seven lesions showed characteristic vascular changes.CONCLUSION:In vivo RCM is a valuable tool in the preoperative diagnosis of partially and completely amelanotic tumours suspicious for melanoma in addition to dermoscopic evaluation.
Background: Topical preparations are a common treatment for superficial acute wounds, which at the least do not interfere with healing and ideally result in enhanced wound healing irrespective of microbial colonization. Objective: To examine the effects of a topical antimicrobial gel and its vehicle on the wound healing of standardized, superficial abrasions. Methods: Thirty-three healthy volunteers were enrolled in a double-blinded, randomized, intraindividual comparison study. Three standardized, superficial abrasions were induced on their forearms. A tyrothricin 0.1% gel (Tyrosur® gel; Engelhard Arzneimittel GmbH & Co. KG, Niederdorfelden, Germany) and its vehicle were randomly applied to two of the test areas, and one lesion remained untreated. Results: A significant improvement of wound healing was seen with both tyrothricin 0.1% gel and its corresponding vehicle in the clinical assessment. The mean area under the curve (AUC) of wound healing scores was the same for both preparations and the mean reepithelization scores were comparable at all test points over the entire 12 days. A lower mean AUC representing less reepithelization was found for the untreated test fields. Conclusion: The use of tyrothricin 0.1% gel and its corresponding vehicle resulted in statistically significant improved wound healing with an earlier onset of healing in particular. Based on these results obtained using an abrasive wound model, it can be concluded that the addition of tyrothricin 0.1% to the gel vehicle did not interfere with the improved wound healing seen with the vehicle alone.
Antimikrobielle Peptide (AMPs) sind kleine, kationische, amphiphile Peptide mit breiter mikrobizider Aktivität sowohl gegen Bakterien als auch gegen Pilze. Bei Säugetieren bilden die AMPs die vorderste Verteidigungslinie des Wirts gegen Infektionen und sie spielen allgemein eine wichtige Rolle als Effektoren des angeborenen Immunsystems. Die Ära der AMPs wurde vor mehr als 60 Jahren eingeläutet, als mit den Polymyxinen und Tyrothricin die ersten kationischen zyklischen Peptidantibiotika Eingang in die klinische Anwendung fanden. Die guten klinischen Erfahrungen in der Behandlung von beispielsweise Schleimhautinfektionen und das spätere Verständnis des Wirkmechanismus haben dazu geführt, dass die AMPs heute zur Behandlung entzündlicher Hauterkrankungen und zur Verbesserung der Heilung infizierter Wunden in Betracht gezogen werden. Auf Grundlage der präklinischen Ergebnisse, darunter Pathobiochemie und molekulare Medizin, werden gezielte Therapiestrategien entwickelt, und ersten Ergebnissen zufolge beeinflussen AMPs die Prozesse in der erkrankten Haut. Wichtig ist, dass AMPs im Gegensatz zu anderen Antibiotika offenbar nicht die Entwicklung antibiotikaresistenter Mikroorganismen fördern. Daher sollten AMPs in klinischen Studien auf ihre Wirksamkeit und Verträglichkeit bei entzündlichen Hauterkrankungen und chronischen Wunden untersucht werden. Abgesehen von möglichen Anwendungsfeldern scheinen diese Peptide ein geeignetes Beispiel für das Paradigma der translationalen Medizin für Hautkrankheiten zu sein, das heute als «Straße mit Verkehr in beiden Richtungen» gesehen wird - aus dem Labor ans Krankenbett und umgekehrt vom Krankenbett ins Labor.
Background Terbinafine nail solution (TNS) was developed for the treatment of onychomycosis. Objective To assess the efficacy of TNS vs. vehicle and amorolfine 5% nail lacquer. Methods Subjects with mild-to-moderate toe onychomycosis (25% to 75% nail-involvement, matrix uninvolved) were randomized to receive either TNS or vehicle in two double-blind studies, and to TNS or amorolfine in an active-controlled, open-label study. Primary endpoint was complete cure (no residual clinical involvement and negative mycology) at week 52. Secondary endpoints were mycological cure (negative mycology defined as negative KOH microscopy and negative culture) and clinical effectiveness (10% residual-involvement and negative mycology) at week 52. Results Complete cure was not different between TNS vs. vehicle and amorolfine. Mycological cure was higher with TNS vs. vehicle, as was clinical effectiveness with TNS vs. vehicle, and TNS and amorolfine were not different for secondary efficacy endpoints. Patients achieving mycological cure had a better clinical outcome, and efficacy was improved in subjects with milder disease. Post hoc analysis suggests that nail thickness is an important prognostic factor. Moreover, mycological cure may require 6months of treatment regimen while complete cure and clinical effectiveness may be achievable only after 10months. A simulation study suggests that longer treatment duration would have resulted in higher complete cure with TNS vs. vehicle. Study treatments were well-tolerated. Conclusion Primary efficacy objectives were not met in the studies reported herein. Possible reasons for failure to achieve significant outcomes include insufficient length of treatment; stringency of primary endpoint and severity of nail involvement of study population.
Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has an important role not only in glycolysis but also in nonmetabolic processes, including transcription activation and apoptosis. We report the isolation of a human GAPDH (hGAPDH) (2-32) fragment peptide from human placental tissue exhibiting antimicrobial activity. The peptide was internalized by cells of the pathogenic yeast Candida albicans and initiated a rapid apoptotic mechanism, leading to killing of the fungus. Killing was dose-dependent, with 10 mu g ml (3.1 mu m) and 100 mu g ml hGAPDH (2-32) depolarizing 45% and 90% of the fungal cells in a population, respectively. Experimental C. albicans infection induced epithelial hGAPDH (2-32) expression. Addition of the peptide significantly reduced the tissue damage as compared with untreated experimental infection. Secreted aspartic proteinase (Sap) activity of C. albicans was inhibited by the fragment at higher concentrations, with a median effective dose of 160 mg l(-1) (50 mu M) for Sap1p and 200 mg l(-1) (63 mu m) for Sap2p, whereas Sap3 was not inhibited at all. Interestingly, hGAPDH (2-32) induced significant epithelial IL-8 and GM-CSF secretion and stimulated Toll-like receptor 4 expression at low concentrations independently of the presence of C. albicans, without any toxic mucosa! effects. In the future, the combination of different antifungal strategies, e.g., a conventional fungicidal with immunomodulatory effects and the inhibition of fungal virulence factors, might be a promising treatment option. Journal of Investigative Dermatology (2013) 133, 144-153; doi:10.1038/jid.2012.254; published online 26 July 2012
Antimicrobial peptides (AMPs) are small, cationic, amphiphilic peptides with broad-spectrum microbicidal activity against both bacteria and fungi. In mammals, AMPs form the first line of host defense against infections and generally play an important role as effector agents of the innate immune system. The AMP era was born more than 6 decades ago when the first cationic cyclic peptide antibiotics, namely polymyxins and tyrothricin, found their way into clinical use. Due to the good clinical experience in the treatment of, for example, infections of mucus membranes as well as the subsequent understanding of mode of action, AMPs are now considered for treatment of inflammatory skin diseases and for improving healing of infected wounds. Based on the preclinical findings, including pathobiochemistry and molecular medicine, targeted therapy strategies are developed and first results indicate that AMPs influence processes of diseased skin. Importantly, in contrast to other antibiotics, AMPs do not seem to propagate the development of antibiotic-resistant micro-organisms. Therefore, AMPs should be tested in clinical trials for their efficacy and tolerability in inflammatory skin diseases and chronic wounds. Apart from possible fields of application, these peptides appear suited as an example of the paradigm of translational medicine for skin diseases which is today seen as a ‘two-way road’ – from bench to bedside and backwards from bedside to bench.
Mometasone furoate, a potent glucocorticoid (class III) with a favorable benefit/risk ratio, has emerged as a standard medication for the treatment of inflammatory skin disorders. The purpose of the investigation presented here was to determine the noninferiority of a topical mometasone formulation, a light cream (O/W 60/40 emulsion) with mometasone furoate 0.1% (water content of 33%) versus marketed comparators. Using the vasoconstrictor assay, a strong blanching effect of the new cream (called Mometasone cream) comparable to that of a mometasone comparator, a fatty cream with mometasone furoate 0.1%, could be demonstrated. Thus, the topical bioavailability of the active ingredient mometasone furoate (0.1%) was regarded to be similar for Mometasone cream and the mometasone comparator. Using the psoriasis plaque test, a strong antipsoriatic effect comparable to that of the mometasone comparator was found for Mometasone cream after 12 days of occlusive treatment. A nearly identical reduction in the mean infiltrate thickness and similar mean AUC values were noted with both formulations confirmed by clinical assessment data. The noninferiority of Mometasone cream to its active comparator with respect to the AUC of change to baseline in infiltrate thickness was demonstrated. Both medications were well tolerated. Overall, Mometasone cream and the mometasone comparator showed similar efficacy and tolerability. Mometasone cream, in addition to its high potency and good tolerability, provides the properties of a light cream, which might make this new medication particularly suitable for application on acutely inflamed and sensitive skin.
The purpose of this open study was to evaluate the rate and extent of the penetration of sertaconazole nitrate (CAS 99592-32-2, Zalain (R)) penetration into the stratum corneum/lucidum of the human skin. Selected areas of 9 cm(2) each of the back skin of 12 healthy volunteers were exposed over 8 different time intervals (between 0 and 48 h) to 100 mg of a 2 % cream preparation of the compound or to placebo. Using a HPLC-assay the relative amounts of the applied dose of sertaconazole nitrate were determined in the residual cream of the skin surface as well as in 3 layers of the epidermis obtained by the stripping technique.Sertaconazole nitrate was shown to penetrate into the stratum corneum shortly after application, disappearing from the application areas with a mean apparent half-life of approximately 60 h. Immediately after topical application the residual amount of the applied mean dose of 2103 +/- 146.3 mu g on the skin's surface was 88.9 +/- 2.3%, decreasing steadily to 52.4 +/- 8.5 % after 48 h. A relevant amount of the applied dose (5.3 +/- 3.0 %) was recovered from the stratum corneum already 30 min after application, and 3 h after administration a plateau was reached (6.9 +/- 3.2) which could be maintained until 48 It. A gradient from the site of application to the epidermis was apparent since the amounts recovered in the upper strip fraction were markedly higher than in the lower strip fraction. The estimated average level of sertaconazole nitrate for a volume of 1 mL of stratum corneum after application of 100 mg cream was 1409 mu g immediately after application and reached a plateau at 3 h with 9029 mu g. Although not directly measured, the results also gave information about the mean amount of sertaconazole nitrate that penetrated through the stratum corneum and deeper layers allowing an estimate of the total mean amount of compound penetrating into the skin. The relative portion of this amount steadily increased from 1.1 % of the applied dose at 0 It to 24.1 % at 12 h, 34.2 % at 24 h and finally to 37.6 % of dose after 48 h of exposure.In view of the high target organ levels of the compound maintained over days, its rapid appearance in the stratum corneum after application and the earlier finding that Sertaconazole nitrate is not distributed into blood in substantial quantities the pharmacokinetic properties of this antifungal preparation therapy can be regarded as favourable.
Background: Due to its strong water binding potential, hyaluronic acid (HA) is a well-known active ingredient for cosmetic applications. However, based on its varying molecular size, skin penetration of HA may be limited. Recent studies have demonstrated that low-molecular-weight HA (LMW HA) may show a certain proinflammatory activity. We thus aimed to characterize an LMW-sized HA molecule that combines strong anti-aging abilities with efficient skin penetration but lacks potential proinflammatory effects. Methods: Total RNA and total protein were isolated from reconstituted human epidermis following incubation with HAs of various molecular weights (20, 50, 130, 300, 800 and 1,500 kDa). Tumor necrosis factor-α expression was determined using quantitative PCR. Genomic and proteomic expression of various junctional proteins was determined using Affymetrix and common Western blotting techniques. Results: LMWHA of approximately 50 kDa did not significantly alter tumor necrosis factor-α expression compared to 20-kDa HA, but revealed significantly higher skin penetration rates than larger sized HA associated with increased expression of genes and proteins known to be involved in tight junction formation and keratinocyte cohesion. Conclusion: LMW HA of approximately 50 kDa shows better penetration abilities than larger-sized HA. In addition, LMW HA influences the expression of various genes including those contributing to keratinocyte differentiation and formation of intercellular tight junction complexes without showing proinflammatory activity. These observations contribute to current knowledge on the effects of LMW HA on keratinocyte biology and cutaneous physiology.
Rosacea is like no other disease a problem for patients regarding the use of skin care and cleaning products. The subjective assessment of the severity of the illness is an important factor regarding the development of depression in these patients. Inadequate skin care and cleaning products can lead to irritation and stinging of the skin. Dermatologists should address questions regarding skin care, cleaning and sun screens. Because of the higher irritability of the skin of rosacea patients, all possibly irritating cleaning products or procedures should be avoided. The water temperature is also important; it should be lukewarm to avoid the provocation of a vascular reaction. Soaps should be avoided, because they are alkaline and thus lead to a higher pH of the skin. A higher pH of the skin can lead to irritation. Appropriate make-up causes no aggravation of the skin and increases patient's satisfaction with their skin and thus leads to a higher compliance with pharmacological therapy. Laser or intense pulsed light treatment can improve telangiectasia or erythema. Operative treatment of rhinophyma is effective and well-established.
SynopsisThe aim of this study was to evaluate different urea‐containing cosmetic preparations designed for foot care regarding skin occlusion. The primary aim was therefore to screen the short‐term transepidermal water loss (TEWL) as a parameter for skin barrier function and skin occlusion and to characterize the relative role of the vehicle, i.e. cream or foam in the context of cosmetics containing urea in the 2–10% range addressing the cosmetic products urea 2% cream (GEHWOL FUSSKRAFT blau), petrolatum containing cream (GEHWOL med Schrundensalbe), urea 10% cream (GEHWOL med Lipidro‐Crème), urea 10% foam (Allpresan Fuss Schaum) and vaseline (positive control) compared with an untreated area on the volar forearms of volunteers. Moreover, the short time (24 h) kinetics regarding the moisturizing effect of cream and foam formulations in diabetic patients were compared. The efficacy of a cream on reduction of skin thickness of hyperkeratotic skin in the heel region before and after a period of product application was also evaluated. In some of the trials, healthy individuals and in others, diabetic patients (type I and II) were enrolled. TEWL was determined before product application, as well as at given points of time thereafter. In this study, no excessive occlusion effects comparable with a blockage of the skin’s natural water evaporation could be observed for any of the test products. To the extent to be expected, this was found neither for the cream products nor for the foam product. Slightly lowered TEWL values after application of the 10% urea cream can be interpreted as a beneficial effect in terms of an improved barrier function. Regarding skin moisture, the urea‐containing cream formulation appeared equal or slightly superior to the foam formulation. The thickness of the horny layer was found reduced after application of 10 % urea‐containing cream. At present it looks as if cream vehicles would still be vehicles of choice in general, when it comes to the formulation of skin care preparations for not only dry skin but also in the context of pedal skin care.
Die Rosazea stellt wie kaum eine andere Erkrankung ein Problem für die betroffenen Patienten bezüglich der Auswahl ihrer Hautreinigungs- und Hautpflegeprodukte dar. Außerdem ist die subjektive Einschätzung des Schweregrads ihrer Erkrankung entscheidend für die psychische Belastung durch die Rosazea. Ungeeignete Pflege und Hautreinigung kann zu Irritationen und Missempfindungen der Haut führen. Die betreuenden Dermatologen sind hier als Ansprechpartner bezüglich Beratung zu geeigneten Hautpflege-, Hautreinigungs- und UV-Schutzprodukten besonders gefragt. Aus der erhöhten Empfindlichkeit der Haut bei Rosazeapatienten ergibt sich, dass auf jegliche aggressive Substanzen oder Reinigungsprozeduren zu verzichten ist. Insofern ist auch schon die Wassertemperatur entscheidend, die lauwarm sein sollte, um eine Gefäßreaktion zu vermeiden. Auf Seifen ist zu verzichten, da diese alkalisch sind und den pH der Haut erhöhen. Eine pH-Anhebung kann zu Irritationen der Haut führen. Geeignete abdeckende Kosmetik führt zu keiner Verschlechterung des Hautbefundes und erhöht die Zufriedenheit der Patientinnen und Patienten mit ihrem Hautbild und erhält damit die Compliance der Patienten bei Durchführung der medikamentösen Therapie. Eine Besserung der Teleangiektasien und Rötung bei Rosazea lässt sich durch geeignete Laser- oder Blitzlampentherapie erreichen. Eine operative Sanierung von Phymen ist möglich und wird beim Rhinophym regelmäßig eingesetzt.
Loss-of-function mutations in the filaggrin gene (FLG) are a strong predisposing factor for atopic dermatitis, although their relevance to the disease pathomechanism needs further elucidation. The generation of an in vitro model of atopic skin would not only permit further evaluation of the underlying pathogenetic mechanisms and the testing of new treatment options, but would also allow toxicological studies to be performed in a simple, rapid and inexpensive manner. In this study, we have knocked down FLG expression in human keratinocytes and created three-dimensional skin models, which we used to investigate the impact of FLG on epidermal maturation and on skin absorption and its response to irritation. Histopathological evaluation of the skin models showed impaired epidermal differentiation in the FLG knock-down model. In addition, skin irritation induced by an application of sodium dodecyl sulphate resulted in significantly higher lactate dehydrogenase leakage, and interleukin (IL)-6 and IL-8 levels, than in the control model. To assess the effect of filaggrin deficiency on skin absorption of topically applied agents, we quantified the percutaneous absorption of lipophilic and hydrophilic model drugs, finding clinical relevance only for lipophilic drugs. This study clearly demonstrates that important clinical characteristics of atopic skin can be mimicked by using in vitro skin models. The FLG knock-down construct is the first step toward an in vitro model that allows clinical and toxicological studies of atopic-like skin.
Fluticasone propionate (FP), a medium potent glucocorticoid (class III) of carbothioate nature with a favourable benefit/risk ratio, has emerged as a standard medication for the topical treatment of inflammatory skin disorders, in particular atopic dermatitis (AD). FP is available as a 0.05% cream and a 0.005% ointment formulation. The glucocorticoid is characterized by high lipophilicity, high affinity binding to the glucocorticoid receptor and a rapid hepatic biotransformation. Though skin blanching following topical application of FP surpasses that given with glucocorticoids of medium strength, clinical trials show a low potential of FP for local and systemic adverse effects. Even in paediatric patients with AD as well as in difficult-to-treat areas like face, eyelids and intertriginous areas, FP proved to be both effective and safe. Thus, the therapeutic effects of FP clearly outweigh the unwanted effects. Correspondingly, a therapeutic index of 2.0 can be attributed to this glucocorticoid. In this respect, topical FP does not differ from other topical glucocorticoids with increased benefit-to-risk ratio, e.g. prednicarbate, methylprednisolone aceponate and mometasone furoate. However, randomized controlled trials do not only support conventional intervention but also innovative maintenance treatment.