Urea in Dermatology: A Review of its Emollient, Moisturizing, Keratolytic, Skin Barrier Enhancing and Antimicrobial Properties

Managing dry skin in patients with comorbidities or with advanced age: unmet needs and roles for products containing potential emollient-plus ingredients

In dry skin (DS), skin-barrier function is easily disturbed and moisturizing factors in the stratum corneum are reduced. Despite being a common condition, DS is often overlooked in patients with advanced age or comorbid diseases. In September 2022, specialists in dermatology and skin care met to discuss unmet needs and management of patients with DS with existing medical conditions or DS induced by ongoing pharmacological treatments. There was consensus about the need to improve the current understanding and management of DS in patients with comorbidities, including type 2 diabetes, chronic kidney disease, radiodermatitis, and photodamaged skin. Clinical guidance related to optimal treatment of DS in patients with advanced age or comorbid diseases is needed. Dexpanthenol-containing emollients have been shown to provide rapid relief from the symptoms and clinical signs of skin inflammation and are well-tolerated and effective in terms of moisturizing and soothing DS and maintaining skin-barrier function. Thus, dexpanthenol-containing emollients may play an important role in future management of DS. Further research is needed to elucidate the efficacy of dexpanthenol across the spectrum of DS, irrespective of comorbidity status or age.

Keratosis pilaris treatment paradigms: assessing effectiveness across modalities

This review aims to present a comprehensive synthesis of the existing treatment modalities for keratosis pilaris (KP) and evaluate their therapeutic efficacy. KP is a prevalent chronic dermatological condition typified by its unique 'chicken skin appearance', with the cheeks being the most commonly involved sites. Numerous therapeutic interventions have emerged, given its substantial prevalence and impact on skin aesthetics and psychological wellbeing. Nonetheless, a consistent therapeutic response has been challenging to achieve. This review endeavours to collate and critically appraise the current treatment landscape for KP. An exhaustive literature search was performed using databases such as Ovid, PubMed and Scopus. From an initial count of 459 articles identified after deduplication, 52 were selected for inclusion after a thorough full-text examination for articles with concrete outcome data highlighting the efficacies of different therapeutic modalities; articles that lacked data or were tangential to the core focus on KP treatment were excluded. The included articles were then catalogued based on the nature of treatment strategies and their respective outcomes. Among the various therapeutic interventions, laser and light modalities appear to be supported by the most substantial evidence base. Notably, the Nd:YAG (neodymium-doped yttrium-aluminium-garnet) laser, attributed to its longer wavelength, emerged as a preferred option. While other therapeutic avenues have also exhibited notable improvements in skin texture and discolouration relative to baseline, the inconsistency in outcome measures underscores the need for a standardized, KP-specific scoring system to foster a more coherent comparison across treatments. Based on the current evidence, Nd:YAG laser therapy demonstrates promising effectiveness with a relatively favourable side-effect profile. However, the landscape of KP treatment is multifaceted, and further studies are essential to solidify recommendations.

Microenvironmental host-microbe interactions in chronic inflammatory skin diseases

Several microbiome studies have recently demonstrated microbial dysbiosis in various chronic inflammatory skin diseases, and it is considered an important role in the pathogenesis. Although the role of skin dysbiosis in inflammatory skin diseases is debatable, the local microenvironment is considered essential concerning compositional changes and functional alterations of the skin microbiota. Indeed, various local nutrients (e.g., lipids), pH values, water, oxygen, and antimicrobial peptides may affect the level of skin dysbiosis in these skin diseases. In particular, in atopic dermatitis and hidradenitis suppurativa, significant changes in skin dysbiosis have been associated with local aberrant host immune changes. In this review, the potential pathogenic crosstalk between the host and the microbiota is reviewed in relation to the physical, chemical, and biological microenvironments of various chronic inflammatory skin diseases.

Ectoin attenuates cortisone-induced skin issues by suppression GR signaling and the UVB-induced overexpression of 11β-HSD1

BACKGROUND

Accelerated pace of modern work and lifestyles subject individuals to various external and psychological stressors, which, in turn, can trigger additional stress through visible signs of fatigue, hair loss, and obesity. As the primary stress hormone affecting skin health, cortisol connects to the glucocorticoid receptor (GR) to aggravate skin issues induced by stress. This activation depends on the expression of 11β-hydroxysteroid dehydrogenase 1 (11β-HSD1) in skin cells, which locally converts cortisone-produced by the central and peripheral hypothalamic-pituitary-adrenal axis-into its active form.

METHODS

Our study delves deeper into stress's adverse effects on the skin, including the disruption of keratinocyte structural proteins, the loss of basement membrane proteins, and the degradation of collagen.

RESULTS

Remarkably, we discovered that Ectoin, an amino acid derivative obtained from halophilic bacteria, is capable of mitigating the inhibitory impacts of cortisone on the expression of cutaneous functional proteins, including involucrin, loricrin, laminin-5, and claudin-1. Moreover, Ectoin reduces the suppressive effect of stress on collagen and hyaluronic acid synthesis by impeding GR signal transduction. Additionally, Ectoin counterbalances the UVB-induced overexpression of 11β-HSD1, thereby diminishing the concentration of endogenous glucocorticoids.

CONCLUSION

Our findings illuminate the significant potential of Ectoin as a preventative agent against stress-induced skin maladies.

Epidermal Barrier Parameters in Psoriasis: Implications in Assessing Disease Severity

Psoriasis is characterized by an aberrant immune response due to myeloid dendritic cells and T helper cells intertwining with keratinocyte hyperproliferation. Skin integrity alterations may predispose patients to physiological imbalances, such as xerosis, reduced elasticity, and increased friability. This study aims to assess the epidermal barrier dysfunction in chronic plaque psoriasis and gain a comprehensive view of the dynamic changes in the epidermal barrier during various topical therapies. Adult patients with chronic plaque psoriasis were enrolled in this observational study. For each patient, skin barrier parameters, stratum corneum hydration (SCH), transepidermal water loss (TEWL), elasticity, erythema, and melanin levels were measured in lesional and non-lesional skin. Two extensions of the initial study design, with subsequent epidermal barrier determinations, were made as follows: one in which patients with moderate psoriasis were treated with clobetasol propionate 0.5% and the second one in which mild psoriasis was treated with either clobetasol propionate 0.5% or clobetasol propionate 0.5% with 10% urea. TEWL and erythema were found to be higher in the sites affected by psoriatic lesions than the unaffected sites, while SCH and elasticity were decreased. Severe psoriasis presented with higher TEWL (p = 0.032), erythema (p = 0.002), and lower SCH (p < 0.001) compared with the mild and moderate forms. SCH significantly improved during clobetasol propionate 0.5% treatment (p = 0.015). Clobetasol propionate 0.5% with 10% urea was found to be superior to clobetasol propionate 0.5% in improving TEWL and SCH in psoriasis.

Introducing the model of repeated exposure of skin to antiseptics: Randomised pilot trial

INTRODUCTION

Intensified hand hygiene measures were recommended for preventing the spread of SARS-CoV-2. However, these measures can lead to skin damage and the development of hand eczema, particularly among health professionals.

OBJECTIVES

This pilot study aimed to evaluate the effects of repeated antiseptic use on healthy skin under controlled conditions and to assess the emollient use.

METHODS

Twelve healthy volunteers (nine females, age = 22.3 ± 2.8 years (mean ± SD), Fitzpatrick phototypes II and III) with no skin diseases were recruited. Antiseptic was applied daily for 3 weeks on the volar sides of forearms. Emollient cream was also applied daily. Skin assessments were performed using non-invasive methods (transepidermal water loss-TEWL, skin hydration, erythema and melanin content).

RESULTS

Prolonged antiseptic use increased TEWL, decreased hydration and elevated erythema and melanin levels. Emollient cream significantly reduced TEWL and improved hydration on antiseptic-treated sites, and also enhanced hydration on intact skin.

CONCLUSIONS

Prolonged use of antiseptics can have adverse effects on the skin, including barrier disruption and inflammation. Emollient showed promise in improving skin hydration and reducing the damage caused by antiseptics. Further research with a larger sample is needed to confirm these findings and assess emollient efficacy during frequent antiseptic use.

Green Electrospun Poly(vinyl alcohol)/Gelatin-Based Nanofibrous Membrane by Incorporating 45S5 Bioglass Nanoparticles and Urea for Wound Dressing Applications: Characterization and In Vitro and In Vivo Evaluations

This study reports the fabrication and characterization of poly(vinyl alcohol) (PVA) and gelatin (Gel)-based nanofiber membranes cross-linked with citric acid (CA) by a green electrospinning method in which nano 45S5 bioglass (BG) and urea were incorporated. Various combinations of PVA, gelatin, and BG were prepared, and nanofiber membranes with average fiber diameters between 238 and 595 nm were fabricated. Morphological, chemical, and mechanical properties, porosity, swelling, water retention, and water vapor transmission rate of the fabricated membranes were evaluated. PVA:Gel (90:10), 15% CA, and 3% BG were determined as the optimum blend for nanofiber membrane fabrication via electrospinning. The membrane obtained using this blend was further functionalized with 10% w/w polymer urea coating by the electrospray method following the cross-linking. In vitro biocompatibility tests revealed that the fabricated membranes were all biocompatible except for the one that functionalized with urea. In vivo macroscopic and histopathological analysis results of PVA/Gel/BG and PVA/Gel/BG/Urea treated wounds indicated increased collagenization and vascularization and had an anti-inflammatory effect. Furthermore, careful examination of the in vivo macroscopic results of the PVA/Gel/BG/Urea membrane indicated its potential to decrease uneven scar formation. In conclusion, developed PVA/Gel/BG and PVA/Gel/BG/Urea electrospun membranes with multifunctional and biomimetic features may have the potential to be used as beneficial wound dressings.

Evaluation of molecular inhibitors of loop-mediated isothermal amplification (LAMP)

Loop-mediated isothermal amplification (LAMP) is a cost-effective and easy-to-perform assay that enables the direct detection of DNA. Its use in point-of-care diagnostic tests is growing, while it has the potential to be used in presumptive on-the-field forensic tests. Samples are often collected from complex matrices that contain high levels of contaminants. Herein, we evaluate the effect of seven common DNA amplification inhibitors on LAMP - bile salts, calcium chloride, hematin, humic acid, immunoglobulin G, tannic acid and urea. We study the effect of each inhibitor individually in real-time detection systems coupled with end-point measurements to delineate their inhibitory effects from the matrix in which they may be found. Our studies show LAMP inhibitors generally delay the onset of amplicon formation and quench fluorescence at similar or higher concentrations compared to PCR, but that end-point measurements of LAMP amplicons are unaffected. This is important as LAMP amplicons can be detected in non-fluorometric ways thus contributing to the assertions that LAMP is more robust to inhibitors than PCR.

Extraction-free analysis in cosmetics by digital image colorimetry, illustrated by the quantification of urea

An extraction-free methodology is proposed for quantifying urea in cosmetics, which relies on urea-mediated decrease of methyl red decoloration by sodium hypochlorite. The method is applied directly to the cosmetic formulation and the resulting color intensity is captured by a smartphone camera. We demonstrate a linear relationship between color intensity and urea concentration in O/W emulsions and a shampoo. This quantification methodology is fully validated by determining its technical characteristics in an O/W cosmetic emulsion: The standard curve is linear over 2.5-30.0 % w/w urea (R2 ≥ 0.985). The coefficient of variation (CV %) on all quality control levels is ≤ 12.54 % for intermediate precision, indicating acceptable precision. Bias is up to ±4.93 % in the emulsion, indicating acceptable accuracy and a countable matrix effect. The proposed analysis setup in combination with a standard addition methodology is applied to verify urea content in purpose-made emulsions: bias is ≤±10.9 %, even in the presence of interfering ammonia. We finally demonstrate that the camera-captured color intensity of an O/W emulsion is proportional to different colorant concentrations in the formulation. This opens the route for further applications of the proposed setup to other ingredients capable of generating a colored product upon suitable reaction inside the formulation matrix.

A Comprehensive Review on Potential Chemical and Herbal Permeation Enhancers Used in Transdermal Drug Delivery Systems

Using skin patches to deliver drugs is dependable and doesn't have the same issues as permeation enhancers, which help drugs get through the skin but struggle because of the skin's natural barrier. Strategies are required to increase topical bioavailability to enhance drug absorption. Natural compounds offer a promising solution by temporarily reducing skin barrier resistance and improving drug absorption. Natural substances allow a wider variety of medications to be distributed through the stratum corneum, offering a dependable approach to enhancing transdermal drug delivery. Natural substances have distinct advantages as permeability enhancers. They are pharmacologically effective and safe, inactive, non-allergenic, and non-irritating. These characteristics ensure their suitability for use without causing adverse effects. Natural compounds are readily available and well tolerated by the body. Studies investigating the structure-activity relationship of natural chemicals have demonstrated significant enhancer effects. By understanding the connection between chemical composition and enhancer activity, researchers can identify effective natural compounds for improving drug penetration. In conclusion, current research focuses on utilizing natural compounds as permeability enhancers in transdermal therapy systems. These substances offer safety, non-toxicity, pharmacological inactivity, and non-irritation. Through structure-activity relationship investigations, promising advancements have been made in enhancing drug delivery. Using natural compounds holds enormous potential for improving the penetration of trans-dermally delivered medications.

Assessing Excessive Keratinization in Acral Areas through Dermatoscopy with Cross-Polarization and Parallel-Polarization: A Dermatoscopic Keratinization Scale

Excessive epidermal hyperkeratosis in acral areas is a common occurrence in dermatology practice, with a notable prevalence of approximately 65% in the elderly, especially in plantar lesions. Hyperkeratosis, characterized by thickening of the stratum corneum, can have various causes, including chronic physical or chemical factors, genetic predispositions, immunological disorders, and pharmaceutical compounds. This condition can significantly impact mobility, increase the risk of falls, and reduce the overall quality of life, particularly in older individuals. Management often involves creams containing urea to soften hyperkeratotic areas. Currently, subjective visual evaluation is the gold standard for assessing hyperkeratosis severity, lacking precision and consistency. Therefore, our research group proposes a novel 6-point keratinization scale based on dermatoscopy with cross-polarization and parallel-polarization techniques. This scale provides a structured framework for objective assessment, aiding in treatment selection, duration determination, and monitoring disease progression. Its clinical utility extends to various dermatological conditions involving hyperkeratosis, making it a valuable tool in dermatology practice. This standardized approach enhances communication among healthcare professionals, ultimately improving patient care and research comparability in dermatology.

Implications of the Pore Size of Graphitic Carbon Nitride Monolayers on the Selectivity of Dual-Boron Atom Catalysts for the Reduction of N2 to Urea and Ammonia: A Computational Investigation

The formation of urea by electrocatalytic means remains a great challenge due to the lack of a suitable catalyst that is capable of not only activating inert N2 and CO2 molecules but also circumventing the complexity associated with subsequent reaction steps leading to urea formation. Herein, by means of comprehensive density functional theory simulations, we investigate the catalytic activity of highly stable transition-metal-free dual-boron atom-doped graphitic carbon-nitride monolayers with different pore sizes toward urea production under ambient conditions. As per the results, dual boron atoms impregnated in g-C2N and g-C6N6 monolayers with large pore diameters can successfully activate the N2 molecule and lead to the spontaneous formation of the *NCO*N intermediate, which is the most crucial step for urea formation via direct coupling of N2 and CO2. Interestingly, the B2@g-C2N and B2@g-C6N6 favor urea production with low limiting potentials of -1.11 and -1.18 V compared to very high limiting potentials of -1.71 and -1.88 V, respectively, for ammonia synthesis, leading to an almost 100% Faradaic efficiency for urea formation over ammonia. The dual-boron doping in g-C3N4 with a smaller pore size depicts comparatively weaker N2 adsorption than g-C2N and g-C6N6 counterparts. Further, B2@g-C3N4 prefers ammonia formation at a very low limiting potential of -0.40 V compared to a very high limiting potential of -2.11 V for urea formation. Thus, our findings clearly highlight the critical role played by the pore size of carbon-nitride monolayers in tuning the reactivity and catalytic activity of dual-boron atom catalysts toward urea formation in a selective manner, thereby providing valuable guidance in exploring other highly efficient urea catalysts.

Possibilities of Anxiolytic Therapy in the Elimination of Stress Skin Manifestations: A Case Report

The case of a 42-year-old female patient with pronounced itching and exanthema, mainly in the area of the trunk and lower limbs, is presented. Previously, the patient took antihistamines without effect, was treated for scabies, but the itching remained pronounced and led to rash and excoriations. From the anamnesis, it was found that the patient has a high level of stress. According to the Hospital Anxiety and Depression Scale, the anxiety of the patient reached 14 points, and depression 1 point. Functional (psychogenic) itching was suspected. Since the patient refused dermatologist consultation, therapy with the anxiolytic temgicoluril, topical antipruritic agents and nonpharmacological methods of treatment were recommended at the initial stage. The patient felt a significant relief of itching symptoms on the first day of anxiolytic usage, she withdrew topical antipruritic agents after 5 days of anxiolytic treatment, in 15 days she began to reduce the dose of temgicoluril, and at the end of the third week she stopped treatment with anxiolytic due to a significant positive effect. In three weeks, practically all elements of the rash, except for the largest wounds from scratching, disappeared. The peculiarity of the case is that functional itching was completely eliminated during anxiolytic therapy without other systemic medications, which emphasizes the importance of eliminating the component of stress and anxiety in the treatment of such patients.

Chronic Progressive Lymphedema in Belgian Draft Horses: Understanding and Managing a Challenging Disease

Chronic progressive lymphedema (CPL) in draft horses is characterized by increased dermal thickness and fibrosis, with the development of skinfolds and nodules, hyperkeratosis, and ulcerations on the distal limbs of affected horses. Secondary bacterial, fungal, or parasitic infections frequently complicate and aggravate the lesions, as well as the progression of this disease. CPL has a particularly high prevalence of up to 85.86% in the Belgian draft horse breed. Due to the disease's progressive and incurable nature, affected horses are often euthanized prematurely. The treatment options are solely symptomatic, aimed at improving the horse's quality of life. Despite the severity of this condition, many uncertainties about its etiology and pathogenesis still remain to date. The established scientific research on CPL is rather limited, although there is an urgent need for strategies to tackle this disease. This review summarizes the available knowledge, serving as a guideline for practitioners, and provides perspectives for future research programs.

Human glabrous skin contains crystallized urea dendriform structures in the stratum corneum which affect the hydration levels

Glabrous skin is hair-free skin with a high density of sweat glands, which is found on the palms, and soles of mammalians, covered with a thick stratum corneum. Dry hands are often an occupational problem which deserves attention from dermatologists. Urea is found in the skin as a component of the natural moisturizing factor and of sweat. We report the discovery of dendrimer structures of crystalized urea in the stratum corneum of palmar glabrous skin using laser scanning microscopy. The chemical and structural nature of the urea crystallites was investigated in vivo by non-invasive techniques. The relation of crystallization to skin hydration was explored. We analysed the index finger, small finger and tenar palmar area of 18 study participants using non-invasive optical methods, such as laser scanning microscopy, Raman microspectroscopy and two-photon tomography. Skin hydration was measured using corneometry. Crystalline urea structures were found in the stratum corneum of about two-thirds of the participants. Participants with a higher density of crystallized urea structures exhibited a lower skin hydration. The chemical nature and the crystalline structure of the urea were confirmed by Raman microspectroscopy and by second harmonic generated signals in two-photon tomography. The presence of urea dendrimer crystals in the glabrous skin seems to reduce the water binding capacity leading to dry hands. These findings highlight a new direction in understanding the mechanisms leading to dry hands and open opportunities for the development of better moisturizers and hand disinfection products and for diagnostic of dry skin.

Multifunctional and Tunable Coacervate Powders to Enable Rapid Hemostasis and Promote Infected Wound Healing

Hemostatic powders provide an important treatment approach for time-sensitive hemorrhage control. Conventional hemostatic powders are challenged by the lack of tissue adhesiveness, insufficient hemostatic efficacy, limited infection control, and so forth. This study develops a hemostatic powder from tricomponent GTP coacervates consisting of gelatin, tannic acid (TA), and poly(vinyl alcohol) (PVA). The physical cross-linking by TA results in facile preparation, good storage stability, ease of application to wounds, and removal, which provide good potential for clinical translation. When rehydrated, the coacervate powders rapidly form a cohesive layer with interconnected microporous structure, competent flexibility, switchable wet adhesiveness, and antibacterial properties, which facilitate the hemostatic efficacy for treating irregular, noncompressible, or bacteria-infected wounds. Compared to commercial hemostats, GTP treatment results in significantly accelerated hemostasis in a liver puncture model (∼19 s, >30% reduction in the hemostatic time) and in a tail amputation model (∼38 s, >60% reduction in the hemostatic time). In the GTP coacervates, gelatin functioned as the biodegradable scaffold, while PVA introduced the flexible segments to enable shape-adaptability and interfacial interactions. Furthermore, TA contributed to the physical cross-linking, adhesiveness, and antibacterial performance of the coacervates. The study explores the tunability of GTP coacervate powders to enhance their hemostatic and wound healing performances.

Nicotiana tabacum Leaf Waste: Morphological Characterization and Chemical-Functional Analysis of Extracts Obtained from Powder Leaves by Using Green Solvents

Tobacco cultivation and industrialization are characterized by the production of trillions of pre-harvest and post-harvest waste biomasses each year with the resulting negative effects on the environment. The leaves of blunt, pre-harvest waste, could be further used to obtain bioactive metabolites, i.e., polyphenols and alkaloids, for its potential cosmetic use. This study was conducted to obtain bio-compounds from pre-harvest tobacco leaf waste (var. Virginia) by applying conventional and green solvents (NaDES). Leaves and ground leaf waste were characterized based on their microscopic features. Conventional solvents, such as water, acetone, ethanol, and non-conventional solvents, such as Natural Deep Eutectic Solvents (NaDES), i.e., sucrose:lactic acid (LAS), frutose:glucose:sucrose (FGS), lactic acid:sucrose:water (SALA), choline chloride:urea (CU), and citric acid: propylene glycol (CAP) were used for bioactive extraction from tobacco waste powder. CU, FGS, and acetone/ethanol had similar behavior for the best extraction of alkaloids (6.37-11.23 mg ACE/g tobacco powder). LAS, FGS, SALA, and CU were more effective in phenolic compound extraction than conventional solvents (18.13-21.98 mg AGE/g tobacco powder). Because of this, LAS and SALA could be used to obtain phenolic-enriched extracts with lower alkaloid content rather than CU and FGS. Extracts of the powder obtained with conventional solvent or CU showed a high level of sugars (47 mg/g tobacco powder) The ABTS antioxidant capacity of tobacco leaf powder was higher in the extracts obtained with CU, FGS, and acetone (SC₅₀ 1.6-5 µg GAE/mL) while H₂O₂ scavenging activity was better in the extracts obtained with LAS, CAP and SALA (SC₅₀ 3.8-8.7 µg GAE/mL). Due to the biocompatibility of the NaDES with the components of tobacco leaf waste, the opportunity to apply these extracts directly in antioxidant formulations, such as cosmetics, phytotherapic, and other formulations of topic use seems promising. Furthermore, NaDES constituents, i.e., urea and organic acid can also have beneficial effects on the skin.

Efficacy and tolerability of a repairing moisturizing cream containing amino-inositole and urea 10% in adults with chronic eczematous dermatitis of the hands

BACKGROUND

Patients suffering from eczematous dermatitis always required moisturizing cream as a background therapy with the aim to reduce flares and minimize steroids use. The term emollients plus (EP) refers to a topical formulations with vehicle-type substances and additional active, non-medicated substances. We have conducted a study with a topical emollient containing urea 10% and amino-inositole on 20 patients affected from chronic eczematous dermatitis. Primary outcomes were to evaluate effectiveness, in term of Investigator Global Assessment (IGA), and tolerability of EP. Secondary aims included the comparison of NRS (numerical rating scale) itch and NRS-pain, DLQI (Dermatological Life Quality Index) between day one and day 28 and to evaluate the characteristics of EP.

METHODS

Subjects were instructed to apply the EP twice daily for 4 weeks on affected skin and use a soft soap while not to put any other topical or systemic product. Statistical analysis was conducted through the test t-Student by comparing IGA, itch-NRS, pain-NRS and DLQI at time 0 and day 28.

RESULTS

High statistically significant difference (P=0.0038) between IGA value at T0 and T4 has been demonstrated as for itch and pain (respectively P=0.0203 and P=0.0146). Almost all the patients (89.5%) have declared a good or better tolerability of EP. Two patients did not complete the study.

CONCLUSIONS

Patients with chronic eczema could often resolve the dermatitis with the correct choice of emollient without steroids use, especially if it is an EP.

Comprehensive Study of the Ammonium Sulfamate-Urea Binary System

The physicochemical properties of binary systems are of great importance for the application of the latter. We report on the investigation of an ammonium sulfamate-urea binary system with different component ratios using a combination of experimental (FTIR, XRD, TGA/DSC, and melting point) and theoretical (DFT, QTAIM, ELF, RDG, ADMP, etc.) techniques. It is shown that, at a temperature of 100 °C, the system under study remains thermally and chemically stable for up to 30 min. It was established using X-ray diffraction analysis that the heating time barely affects the X-ray characteristics of the system. Data on the aggregate states in specified temperature ranges were obtained with thermal analysis and determination of the melting point. The structures of the ammonium sulfamate-urea system with different component ratios were optimized within the density functional theory. The atom-centered density matrix propagation calculation of the ammonium sulfamate-urea system with different component ratios was performed at temperatures of 100, 300, and 500 K. Regardless of the component ratio, a regular increase in the potential energy variation (curve amplitude) with an increase in temperature from 100 to 500 K was found.

Urea and ocular surface: Synthesis, secretion and its role in tear film homeostasis

Urea has been detected in the tear film, aqueous humor, and vitreous of the eye. While most of the urea in the aqueous humor and vitreous is considered to be an ultrafiltrate from the blood vessels, the presence of urea transporters and urea-synthesizing enzymes in the lacrimal gland, meibomian glands, conjunctiva, and cornea suggests ureagenesis occurring at the ocular surface. This review summarizes the distribution and function of urea transporters, urea and its synthesizing enzymes at the ocular surface to analyze their role in the tear film homeostasis. Urea transporters (UT)-A- and UT-B-as well as the enzymes arginase I, II, and agmatinase are located at the ocular surface. Urea concentration on the ocular surface is influenced by blood urea concentration, the amount of urea released by the tear fluid, tear evaporation, and arginase concentration in the tears. There are conflicting reports on the relationship between tear and plasma urea levels though a linear correlation exists between their levels. Urea protects the ocular surface from osmotic stress and is thought to maintain a lipid-water interface in the lamellar phase of the tear film. The reduction of urea levels in the tears of patients with evaporative dry eye suggests its possible role in tear film stability. Other than mitigating osmotic stress, urea has hydrating properties as well. Animal studies have demonstrated the healing effects of urea on the corneal epithelium. Future studies examining the variations in urea content in tears from different ocular surfaces, at different times of day, and under different environmental conditions would further solidify the role of urea in tear film stability.

Efficacy of modified isolation in incontinence associated dermatitis

OBJECTIVE

To analyze the value of modified isolation in preventing the occurrence of incontinence associated dermatitis (IAD) in patients with incontinence, and to provide high value skin care intervention for the patients.

METHODS

Clinical data of 204 patients were collected for retrospective analysis. The patients were divided into a conventional group (conventional skin care protocol, n=102) and a modified group (modified isolation care protocol, n=102) according to the different treatment regimens. The differences in the incidence of IAD, time to IAD, required weekly care, cost of nursing supplies, perineal skin status and nursing satisfaction were compared between the two groups.

RESULTS

Compared with the conventional group, the modified group had a greatly lower incidence of IAD (42.16% vs. 2.94%), longer time to IAD occurrence (5.75±1.25 vs. 12.50±1.50), less required weekly care (43.05±8.41 vs. 13.54±2.57), lower cost of nursing supplies (330.16±98.44 vs. 115.53±32.58), and a better correlation between perineal skin status and nursing satisfaction (all P<0.05).

CONCLUSION

Modified isolation can greatly reduce the incidence of IAD in incontinent patients, improve their status of the perineal skin, increase patient satisfaction with care, and reduce the cost of required nursing supplies. So, modified isolation may serve as the preferred care protocol for incontinent patients.

Assessment of the efficacy, skin acceptability and cosmetic quality of an adjuvant cream based on 40% urea and amino-inositol in the treatment of mild psoriasis

BACKGROUND

Psoriasis is a chronic inflammatory disease with a multifactorial genesis. Structural changes are encountered in psoriasis and skin barrier function is impaired. Tight junctions (TJs) play a key role in skin barrier dysfunction. Loss of profilaggrin or filaggrin leads to changes in the stratum corneum and consequent loss of water and the development of xerosis.

METHODS

We carried out an observational study to evaluate the efficacy, skin acceptability and cosmetic qualities of a cream formulation, based on 40% urea and amino-inositol, in the treatment of mild psoriasis in the absence of other associated cosmetic/pharmacological treatments. All parameters were evaluated before (T0) and after 4 weeks (T4). Efficacy assessment was based on both clinical evaluation and photographic documentation.

RESULTS

The results showed significant clinical improvement (-64.18% PASI, -57.11% BSA, -61.84% Plaque Score, -41.86% PGA and -76.34% VAS -77.5 DLQI) in 4 weeks of treatment. No significant side effects were reported. Similarly, the degree of satisfaction with the product and adherence to its use were particularly satisfactory among patients.

CONCLUSIONS

The tested product was found to be a promising, effective adjuvant treatment in patients with mild psoriasis, and was also useful in reducing itchy symptoms, the impact on quality of life, as well as significantly reducing the clinical signs of psoriasis.

The Use of Urea Cream for Hand Eczema and Urea Foam for Seborrheic Dermatitis and Psoriasiform Dermatoses of the Scalp

PURPOSE

Urea as an ingredient in topical skin applications can aid skin integrity and hydration and have keratolytic, anti-fungal, anti-bacterial, and anti-pruritic effects. Skin conditions that urea-containing formulations have been utilized to treat include hand eczema/dermatitis, seborrheic dermatitis and psoriasiform dermatoses of the scalp. Two monocentric, simple blind, observational studies were carried out in healthy participants to examine the efficacy and safety of two urea-containing products in these skin conditions.

PATIENTS AND METHODS

Study 1 tested the actions of a commercially available 30% urea topical cream on hand eczema. The product was applied ≥2/day for 28 ±2 days. Transepidermal water loss, skin redness, skin hydration, and participant ratings of efficacy and qualities were assessed prior to first product application and on days 14 and 29. Study 2 tested the actions of a commercially available foaming product containing 10% urea on seborrheic dermatitis and scalp psoriasiform dermatoses. The product was applied ≥2/day for 28 ±2 days. Desquamation index and surface occupied by squames, analysis of extracted squames, microscopic assessment of scalp photos and participant ratings of product efficacy and qualities was carried out prior to first product application and on days 14 and 29.

RESULTS

In Study 1 (n = 20 females), results showed a significant (p < 0.05) decrease in transepidermal water loss, with an increase in hydration level of the upper skin layers, and a decrease in skin redness. In Study 2 (n = 13 females, 7 males), product use led to significant (p < 0.05) decreases in desquamation measures and dryness. In both studies, the majority of participants "agreed" or "slightly agreed" that the product had good efficacy and was easy to apply. No adverse reactions were reported.

CONCLUSION

These findings point to the utility of urea in topically applied vehicles for hand eczema, seborrheic dermatitis, and psoriasiform dermatoses.

Biocompatible Self-Assembled Hydrogen-Bonded Gels Based on Natural Deep Eutectic Solvents and Hydroxypropyl Cellulose with Strong Antimicrobial Activity

Natural deep eutectic solvents (NADES)-hydroxypropyl cellulose (HPC) self-assembled gels with potential for pharmaceutical applications are prepared. FT-IR, 1HNMR, DSC, TGA and rheology measurements revealed that hydrogen bond acceptor−hydrogen bond donor interactions, concentration of NADES and the water content influence significantly the physico-chemical characteristics of the studied gel systems. HPC-NADES gel compositions have thermal stabilities lower than HPC and higher than NADES components. Thermal transitions reveal multiple glass transitions characteristic of phase separated systems. Flow curves evidence shear thinning (pseudoplastic) behavior. The flow curve shear stress vs. shear rate were assessed by applying Bingham, Herschel−Bulkley, Vocadlo and Casson rheological models. The proposed correlations are in good agreement with experimental data. The studied gels evidence thermothickening behavior due to characteristic LCST (lower critical solution temperature) behavior of HPC in aqueous systems and a good biocompatibility with normal cells (human gingival fibroblasts). The order of antibacterial and antifungal activities (S.aureus, E.coli, P. aeruginosa and C. albicans) is as follows: citric acid >lactic acid > urea > glycerol, revealing the higher antibacterial and antifungal activities of acids.

The use of urea for skin barrier correction

The review summarizes information about the main causes and pathogenesis of xerosis cutis as one of the conditions indicating a violation of the epidermal barrier. Xerosis cutis is a clinical sign of a decrease in the amount and/or quality of lipids and/or hydrophilic substances in the stratum corneum of the epidermis. The modern approach to the treatment of dermatoses accompanied by violations of the epidermal barrier includes basic moisturizers. Urea not only moisturizes the skin. It is involved in the regulation of barrier function and antimicrobial protection. It is a low-molecular regulator of protein synthesis in keratinocytes, such as filaggrin, loricrin, involucrin and transglutaminase 1, cathelicidin, beta-defensin-2, water and urea carrier proteins into the cell, as well as proteins that promote the synthesis of intercellular matrix lipids. The main dermatotropic pharmacological effects of urea (hydration of the epidermis, strengthening of the barrier function of the skin, keratolytic effect, increased penetration of drugs into the skin) have been used in dermatological practice for many years. External agents with urea are used to treat skin diseases accompanied by dryness and excessive keratinization, to correct the deformation of nail plates of various genesis, to facilitate the local penetration of medicines. The use of topical UrocrEM5, UrocrEM10, Uroderm ointments containing 5%, 10% and 30% urea, respectively, is effective and safe.

Exploring strain diversity of dominant human skin bacterial species using single-cell genome sequencing

To understand the role of the skin commensal bacterial community in skin health and the spread of pathogens, it is crucial to identify genetic differences in the bacterial strains corresponding to human individuals. A culture-independent genomics approach is an effective tool for obtaining massive high-quality bacterial genomes. Here we present a single-cell genome sequencing to obtain comprehensive whole-genome sequences of uncultured skin bacteria from skin swabs. We recovered 281 high-quality (HQ) and 244 medium-quality single-amplified genomes (SAGs) of multiple skin bacterial species from eight individuals, including cohabiting group. Single-cell sequencing outperformed in the genome recovery from the same skin swabs, showing 10-fold non-redundant strain genomes compared to the shotgun metagenomic sequencing and binning approach. We then focused on the abundant skin bacteria and identified intra-species diversity, especially in 47 Moraxella osloensis derived HQ SAGs, characterizing the strain-level heterogeneity at mobile genetic element profiles, including plasmids and prophages. Even between the cohabiting individual hosts, they have unique skin bacterial strains in the same species, which shows microdiversity in each host. Genetic and functional differences between skin bacterial strains are predictive of in vivo competition to adapt bacterial genome to utilize the sparse nutrients available on the skin or produce molecules that inhibit the colonization of other microbes or alter their behavior. Thus, single-cell sequencing provides a large number of genomes of higher resolution and quality than conventional metagenomic analysis and helps explore the skin commensal bacteria at the strain level, linking taxonomic and functional information.

Urea-Based Patches with Controlled Release for Potential Atopic Dermatitis Treatment

Skin diseases such as atopic dermatitis (AD) are widespread and affect people all over the world. Current treatments for dry and itchy skin are mostly focused on pharmaceutical solutions, while supportive therapies such as ointments bring immediate relief. Electrospun membranes are commonly used as a drug delivery system, as they have a high surface to volume area, resulting in high loading capacity. Within this study we present the manufacturing strategies of skin patches using polymer membranes with active substances for treating various skin problems. Here, we manufactured the skin patches using electrospun poly(vinyl butyral-co-vinyl alcohol-co-vinyl acetate) (PVB) fibers blended and electrosprayed with urea. The highest cumulative release of urea was obtained from the PVB patches manufactured via blend electrospinning with 5% of the urea incorporated in the fiber. The maximum concentration of released urea was acquired after 30 min, which was followed up by 6 h of constant release level. The simultaneous electrospinning and electrospraying limited the urea deposition and resulted in the lowest urea incorporation followed by the low release level. The urea-based patches, manufactured via blend electrospinning, exhibited a great potential as overnight treatment for various skin problems and their development can bring new trends to the textile-based therapies for AD.

Topical calcipotriol combined with urea 20% versus intralesional injection of triamcinolone acetonide, 5-fluorouracil, and methotrexate in the treatment of nail psoriasis: A comparative study

BACKGROUND

There is no consistently effective treatment for psoriatic nails. Topical and intralesional modalities have been recently investigated and showed promising efficacy and safety.

OBJECTIVE

To compare the efficacy and safety of intralesional injection of 5-fluorouracil (5-FU), methotrexate (MTX), triamcinolone acetonide (TA) versus topical calcipotriol plus urea 20% in the treatment of nail psoriasis.

METHODS

This study included 60 patients with nail psoriasis who were randomly assigned to 4 groups, each containing 15 patients. The first 3 groups received intralesional injection of 0.1 ml of 5-FU (group A), MTX (group B), and TA (group C) into the nail matrix and bed monthly for 3 months. Group D received a topical combination of calcipotriol/urea 20% twice daily for 3 months. Therapeutic response was assessed every month for 3 months using the target nail psoriasis severity index (NAPSI).

RESULTS

The mean percentage of improvement was significantly higher in topical calcipotriol/urea combination (57.1 ± 26.4) than intralesional TA (44.2 ± 32.7), intralesional MTX (37.7 ± 14.2), and intralesional 5-FU (29.6 ± 14). Adverse effects were mild and insignificant in the studied groups.

CONCLUSION

Topical calcipotriol/urea combination seems to be more effective and safe than intralesional injections of 5-FU, MTX and TA. This article is protected by copyright. All rights reserved.

Skin Barrier Enhancing Alternative Preservation Strategy of O/W Emulsions by Water Activity Reduction with Natural Multifunctional Ingredients

Water activity (aw) as an important parameter for self-preservation can help to control microbial growth in cosmetic formulations. However, high amounts of water-binding substances are required to lower the aw enough to affect microbial growth. Since consequences for the skin barrier have been poorly studied so far, we investigated the effect of aw-lowering agents on both the antimicrobial properties of o/w emulsions and skin physiological parameters. A combination of selected natural humectants (Sodium lactate, Propanediol, Erythritol, Betaine and Sodium PCA) with a total concentration of 28 wt% in an o/w emulsion was able to reduce its aw from 0.980 ± 0.003 to 0.865 ± 0.005. The challenge test results of the aw-lowered emulsion showed a convincing microbial count reduction in potentially pathogenic microorganisms. The addition of as little as 0.5% of the antimicrobial multifunctionals Glyceryl Caprylate and Magnolia Officinalis Bark Extract further enhanced the antimicrobial effect, resulting in adequate antimicrobial protection. Moreover, twice-daily application of the aw-lowered emulsion for a period of four weeks led to a skin barrier-enhancing effect: TEWL significantly decreased, and SC hydration significantly increased. Thus, we present an opportunity to replace conventional preservatives with a natural alternative preservation strategy that has been shown to offer benefits for the skin.

Three-Dimensional Skin Tissue Printing with Human Skin Cell Lines and Mouse Skin-Derived Epidermal and Dermal Cells

Since the skin covers most surfaces of the body, it is susceptible to damage, which can be fatal depending on the degree of injury to the skin because it defends against external attack and protects internal structures. Various types of artificial skin are being studied for transplantation to repair damaged skin, and recently, the production of replaceable skin using three-dimensional (3D) bioprinting technology has also been investigated. In this study, skin tissue was produced using a 3D bioprinter with human skin cell lines and cells extracted from mouse skin, and the printing conditions were optimized. Gelatin was used as a bioink, and fibrinogen and alginate were used for tissue hardening after printing. Printed skin tissue maintained a survival rate of 90% or more when cultured for 14 days. Culture conditions were established using 8 mM calcium chloride treatment and the skin tissue was exposed to air to optimize epidermal cell differentiation. The skin tissue was cultured for 14 days after differentiation induction by this optimized culture method, and immunofluorescent staining was performed using epidermal cell differentiation markers to investigate whether the epidermal cells had differentiated. After differentiation, loricrin, which is normally found in terminally differentiated epidermal cells, was observed in the cells at the tip of the epidermal layer, and cytokeratin 14 was expressed in the lower cells of the epidermis layer. Collectively, this study may provide optimized conditions for bioprinting and keratinization for three-dimensional skin production.