Search Results (14)

Current diagnostic modalities for rheumatoid arthritis (RA), such as Magnetic Resonance Imaging (MRI) and ultrasound (US), excel at visualizing structural pathology but are either resource-intensive or often limited to morphological assessment. In this work, we present the design and technical validation of a low-cost continuous-wave near-infrared (NIR) dual-mode optical probe for functional monitoring of joint inflammation. Unlike superficial imaging, NIR light penetrates approximately 3–5 cm and is tissue and wavelength dependent, enabling trans-illumination of the synovial volume. The system combines reflectance and transmission geometries to resolve the ambiguity between disease presence and disease severity. To validate the diagnostic logic, we employed mcxyzn Monte Carlo (MC) simulations to model the optical signature of RA progression from early onset to EULAR-OMERACT grade 2 pannus hypertrophy on a simplified finger model, based on several tissue models in the literature and supported by physical measurements on a multilayer silicone phantom and in vivo signal verification on human volunteers. Our results demonstrate a distinct functional dichotomy: reflectance geometry serves as a binary discriminator of synovial turbidity onset, while transmission flux serves as a monotonic proxy for pannus volume, exhibiting a quantifiable signal decay consistent with the Beer–Lambert law. Signal verification on a subject with confirmed RA pathology demonstrated a significant increase in the effective attenuation coefficient (${\mu }_{eff} ~ 0.59$ mm⁻¹) compared to the healthy baseline (${\mu }_{eff} ~ 0.47$ mm⁻¹). Furthermore, simulation analysis revealed a critical “metric inversion” in darker skin phenotypes (Fitzpatrick V–VI), where the standard beam-broadening signature of inflammation is artificially suppressed by epidermal absorption. We conclude that while transmission flux remains a robust grading metric across diverse skin tones, morphological beam-shape metrics are not robust, particularly in high-absorption populations. By targeting the hemodynamic precursors of structural damage, this dual-mode probe design offers a potential pathway for longitudinal, quantitative monitoring of disease activity at the point of care, while the systematic use of the Monte Carlo framework provides insight into the measurement geometry most suitable for a given clinical endpoint, whether that be detecting the presence or severity of rheumatoid arthritis. Full article

This study aimed to evaluate the feasibility and safety of pulsed-current iontophoresis (IP) for the transdermal delivery of teriparatide, a therapeutic peptide for osteoporosis. Female rats were subjected to in vivo iontophoretic administration under constant or pulsed-current conditions. Serum teriparatide concentrations, skin irritation scores, and transepidermal water loss (TEWL) were assessed. After 2 h of IP, serum teriparatide concentrations reached 53.3 ± 4.0 pg/mL with pulsed current and 48.8 ± 12.6 pg/mL with constant current, confirming successful transdermal absorption of teriparatide (≈4 kDa) into systemic circulation. Skin irritation was significantly reduced under pulsed-current conditions, as indicated by lower erythema, edema, and TEWL values, despite identical total current exposure. These results suggest that intermittent current application during pulsed-current IP alleviates local electrical stress through partial depolarization and may provide a delivery efficiency comparable to that of constant direct current IP while improving tolerability. Overall, pulsed-current IP enables noninvasive and effective systemic delivery of peptide drugs with minimized skin irritation, representing a promising alternative to injection-based administration for macromolecular therapeutics. Full article

Hyaluronic acid (HA), which is present in various foods, has been the subject of various claims about its ability to relieve dry skin. In this study, the intestinal absorption of hyaluronic acid tetrasaccharide (HA4) and its ability to protect the skin from UV after oral administration were compared with those of high-molecular-weight HA. Intestinal absorption was evaluated by the Caco-2 cell monolayer mem-brane permeability assay. HA4 permeated the Caco-2 monolayer, reaching 2.67 µg/cm² after 120 min, whereas HA did not. HA or HA4 was orally administered to UVB-irradiated mice, and the effects were evaluated using transepidermal water loss (TEWL), water content of the stratum corneum (SC), and epidermal thickness. HA4 permeated the Caco-2 monolayer. On day 26, TEWL significantly increased by 17.5 ± 3.1 g/m²/h in the Control group but only 8.0 ± 1.7 g/m²/h in the HA4 group compared to the Normal group, but no significant difference was observed. Water content of SC decreased by 25.7 ± 1.5 arbitrary units (a.u.) in the Control group; the decrease was attenuated in the HA4 group (17.5 ± 0.7 a.u.) (p < 0.05 vs. Control). On day 28, epidermal thickness reached 69.5 ± 10.8 µm in the Control group and was significantly lower in the HA4 group (43.5 ± 5.1 µm) (p < 0.01 vs. Control). These findings indicate that orally administered HA4 is efficiently absorbed and significantly attenuates UVB-induced skin barrier impairment, suggesting its promise as a functional food ingredient for improving dry skin. Full article

Moisturizers are key components of skincare products, and reliable test methods are essential for evaluating their barrier-repairing and hydrating efficacy. However, the viscous and waxy nature of many cosmetic moisturizers limits the applicability of conventional cell-based in vitro assays. In this study, we developed a novel in vitro dry skin model using epidermal sheets from minipig and human cadaver skin—models widely accepted in skin absorption research. To simulate dry skin conditions, various stimuli were applied, including the lipid-extracting solvent tert-butyl methyl ether (MTBE; 100%), 50/50 MTBE/Acetone solution (M/A), the irritant surfactant sodium dodecyl sulfate (SDS; 1%), ultraviolet B (UVB) irradiation (30 mJ/cm²), and tape stripping. Skin barrier disruption and stratum corneum damage were evaluated by assessing epidermal lipid integrity, histological alterations, transepidermal water loss (TEWL), and FITC-dextran permeation. All treatments induced significant dry skin conditions, as evidenced by disrupted lipid architecture, histological damage, and increased TEWL and FITC-dextran flux. Among them, M/A applied for 5 min produced the most consistent and reproducible changes across parameters. This protocol also yielded comparable results in human cadaver skin, supporting its applicability for evaluating the skin barrier-protective effects of cosmetic ingredients. Full article

Atopic dermatitis (AD) remains a therapeutic challenge due to the limitations of current treatments, creating demand for safer multi-target alternatives to corticosteroids. Our integrated study establishes Hibiscus syriacus L. (H. syriacus) as a mechanistically validated solution through computational and biological validation. The fraction’s two main compounds, linoleic acid and palmitic acid, exhibit favorable drug-like properties including high lipophilicity (LogP 5.2) and 87% oral absorption. Molecular docking collectively predicts comprehensive NF-κB pathway blockade. Experimental validation showed that the fraction (100 μg/mL) inhibited LPS-induced nitric oxide (NO) by 78% and TNF-α/IFN-γ-induced reactive oxygen species (ROS) by 40%, while significantly downregulating the chemokines TARC (73%) and MDC (71%). In DNCB-induced AD mice, the treatment (200 mg/kg/day) produced a 62% improvement in clinical severity scores, reduced serum IgE by 27%, decreased transepidermal water loss by 36%, and doubled skin hydration while normalizing pH levels from the alkaline to physiological range. While both treatments reduced DNCB-induced epidermal hyperplasia, H. syriacus (62.9% reduction) restored the normal thickness without pathological thinning, a critical advantage over corticosteroids that cause atrophy. This dual-action therapeutic achieves corticosteroid-level anti-inflammatory effects while restoring skin barrier integrity to normal levels and avoiding corticosteroid-associated atrophy, positioning it as a next-generation AD treatment. Full article

Ultraviolet B (UVB), a component of solar ultraviolet light, is a major contributor to skin photodamage. UVB exposure primarily affects the epidermis, which leads to wrinkle formation, loss of skin elasticity, oxidative stress, and inflammation. Prolonged or intense UVB exposure can increase the risk of skin cancer. Collagen peptides are known as functional foods that improve skin dryness and wound healing. In this study, we aimed to investigate the protective and ameliorative effects of a low-molecular-weight collagen peptide (LMWCP) with a high absorption rate and photodamage. In vitro analysis using human dermal fibroblasts (HDFs) demonstrated that LMWCP promoted skin protection by increasing procollagen type I production, enhancing cell proliferation and migration, and inhibiting MMP-1 activity. Furthermore, LMWCP intake was indicated by improved skin hydration, reduced trans-epidermal water loss (TEWL), and changes in the clinical parameters, including skin elasticity, erythema, and scaling scores in UVB-exposed hairless mice. In the UVB-damaged tissues, an increase in skin elasticity-related enzymes was observed along with a decrease in aging-related and pro-inflammatory gene expression. Histological analysis revealed an increase in collagen content and restoration of dermal thickness. These findings suggested that LMWCP has significant benefits in preventing and improving UVB-induced skin damage. Full article

Background: Scald burns pose significant morbidity, and effective topical treatments remain a clinical priority. Burn injuries pose a significant clinical challenge due to the prolonged inflammation and high infection risk. Traditional treatments focus on moisture retention and infection prevention, but biocompatible formulations such as hydrogels and oleogels offer advantages. Hydrogels hydrate, cool, and promote epidermal regeneration, while oleogels form a lipid barrier that enhances the absorption of lipophilic bioactive compounds. There is an increasing demand for novel topical alternatives that can effectively improve wound healing by modulating the inflammatory cascade, accelerating epithelial and dermal regeneration, and restoring barrier function. Objective: This study aimed to determine the most effective plant-based topical formulations for enhancing second-degree scald burn wound healing. Methods: Utilizing a standardized rat model, we compared 21 distinct topical formulations, consisting of oleogel and hydrogel bases enriched with extracts from Boswellia serrata (frankincense), Ocimum basilicum (basil), Sambucus nigra flower (elderflower), and Galium verum (lady’s bedstraw). Second-degree burns were uniformly induced in 24 Wistar rats using boiling water (100 °C for 8 s) using the RAPID-3D device, a validated 3D-printed tool that ensures reproducible burns through controlled exposure to boiling water. Post-burn, rats were divided into three equal subgroups, and topical formulations were applied daily. Wound healing efficacy was evaluated through wound surface area measurements, transepidermal water loss (TEWL), skin hydration, sebum production, pigmentation, inflammation (erythema), skin perfusion, and histological parameters at multiple timepoints (days 1, 4, 9, 14, and 21 post-burn induction). Results: Statistical analyses indicated significant advantages of oleogel-based formulations over hydrogel-based formulations. Specifically, formulations containing Boswellia serrata and Ocimum basilicum extracts significantly reduced wound size and inflammation, improved skin hydration, and decreased melanin production by days 9 and 21 (p < 0.05). Conclusions: These findings underscore the potential clinical value of oleogel-based topical preparations containing specific plant extracts for improving scald burn wound healing outcomes, warranting further clinical evaluation. Full article

Dermal drug delivery presents a significant challenge for poorly soluble active compounds like curcumin, which often struggle to penetrate the skin barrier effectively. In this study, the dermal penetration efficacy of curcumin nanocrystals and bulk suspensions when applied to skin using microneedles of varying lengths—0.25 mm, 0.5 mm, and 1.0 mm—was investigated in an ex vivo porcine ear model. The findings revealed that all formulations, in conjunction with microneedle application, facilitated transepidermal penetration; however, the combination of microneedles and curcumin nanocrystals demonstrated the highest efficacy. Notably, the 1.0 mm microneedle length provided optimal penetration, significantly enhancing curcumin delivery compared with bulk suspensions alone. Additionally, even the use of 0.25 mm microneedles resulted in a high level of efficiency, indicating that shorter microneedles can still effectively facilitate drug delivery. Overall, this study underscores the potential of microneedle technology in improving the transepidermal absorption of poorly soluble actives like curcumin, suggesting that the integration of nanocrystals with microneedles could enhance the therapeutic effects of topical curcumin applications. Full article

Chitosan (CS) has a natural origin and is a biodegradable and biocompatible polymer with many skin-beneficial properties successfully used in the cosmetics and pharmaceutical industry. CS derivatives, especially those synthesized via a Schiff base reaction, are very important due to their unique antimicrobial activity. This study demonstrates research results on the use of hydrogel microspheres made of [chitosan-graft-poly(ε-caprolactone)]-blend-(ĸ-carrageenan)], [chitosan-2-pyridinecarboxaldehyde-graft-poly(ε-caprolactone)]-blend-(ĸ-carrageenan), and chitosan-sodium-4-formylbenzene-1,3-disulfonate-graft-poly(ε-caprolactone)]-blend-(ĸ-carrageenan) as innovative vitamin carriers for cosmetic formulation. A permeation study of retinol (vitamin A), L-ascorbic acid (vitamin C), and α-tocopherol (vitamin E) from the cream through a human skin model by the Franz Cell measurement system was presented. The quantitative analysis of the release of the vitamins added to the cream base, through the membrane, imitating human skin, showed a promising profile of its release/penetration, which is promising for the development of a cream with anti-aging properties. Additionally, the antibacterial activity of the polymers from which the microspheres are made allows for the elimination of preservatives and parabens as cosmetic formulation ingredients. Full article

Atopic dermatitis (AD) is a common dermatological disease affecting both children and adults. No drug-free emulgel has been developed and studied in vitro and in vivo for the treatment of AD. The aim of this study was to develop and assess the efficacy of a topical emulgel containing hyaluronic acid, glycerol, Calendula officinalis, Aloe vera, polyphenols and EGF for the concomitant treatment in patients with AD aged over 14. Objective skin barrier function parameters were included, such as transepidermal water loss (TEWL), skin temperature, pH, stratum corneum hydration, skin elasticity and erythema. The subjective opinion of the patients was determined including acceptability, absorption, comfort of use and tolerability, as well as the degree of improvement in patients’ quality of life. We observed an improvement in the subjective parameters studied and statistically significant differences in the objective parameters. Specifically, we found an improvement in TEWL (p = 0.006), erythema (p = 0.008) and hydration (p < 0.001), parameters indicating an improvement in the epidermal barrier. One hundred per cent of patients were satisfied with the product. Therefore, these results suggest that the product may contribute to the treatment of AD. Full article

Nanoemulsions represent a remarkable class of colloidal systems that play a pivotal role in the encapsulation, protection, and targeted delivery of active ingredients to the skin. One of the primary objectives in skincare science is to maximize the interaction between the active ingredients and the skin. This can be achieved through various mechanisms, two of which are occlusion and extended contact of the formulation with the skin. Cosmetic masks can be used to improve the skin’s hydration by creating a barrier that minimizes transepidermal water loss while acting as a repository of the active ingredient, increasing the skin’s absorption of the formulation’s active ingredients. In order to diminish the environmental impact, natural-polymeric-material masks are being used, as an alternative to synthetic materials, for its biocompatibility and biodegradability. In this work pectin and tapioca starch were used to develop a polymeric mask to deliver a rice bran oil nanoemulsion and study some characteristics of the final product. The results show that the association of pectin and tapioca starch can be used to produce a film that can be molded and shows occlusive effects, besides being flexible and compatible with the skin. Full article

Imiquimod (IMQ) is a potent immune response modifier with antiviral and antitumor properties. IMQ’s low aqueous solubility and unsatisfactory cutaneous permeability limit its formulation into effective dosage forms. This work aimed to develop IMQ-loaded microemulsions (MEs) based on phospholipids and oleic acid to improve IMQ penetration into the epidermis. A pseudo-ternary phase diagram was constructed, and the microstructure of the formulations was examined by measuring the conductivity values. Selected MEs were characterized and studied for their ability to deliver IMQ into and through ex vivo human skin. ME₁ with 1% IMQ (bicontinuous ME with Bingham rheology) delivered similar IMQ quantities to the human epidermis ex vivo as the commercial product while having a 5-fold lower IMQ dose. IMQ was not detected in the acceptor phase after the permeation experiment, suggesting a lower systemic absorption risk than the established product. Infrared spectroscopy of the stratum corneum revealed less ordered and less tightly packed lipids after ME₁ application. The ME₁-induced barrier disruption recovered within less than 5 h after the formulation removal, as detected by transepidermal water loss measurements. In conclusion, our findings demonstrate that phospholipid and oleic acid-based MEs could become a promising alternative for topical IMQ administration. Full article

Arnica tincture is a traditional herbal medicine used to treat blunt injuries, e.g., bruises and squeezes. In addition, a potential new use in the treatment of cutaneous leishmaniasis is currently under investigation. Therefore, detailed information about the dermal absorption of the tincture and especially its bioactive constituents, sesquiterpene lactones (STLs) of the helenalin- and 11α,13-dihydrohelenalin type, is mandatory. Consequently, this article reports on dermal absorption studies of Arnica tincture using diffusion cells and porcine skin as well as two human skin samples with different permeability. The amounts of STLs on the skin surfaces, in skin extracts and in the receptor fluids were quantified by ultra-high-performance liquid chromatography with high-resolution mass spectrometry (UHPLC-HRMS). It was found that Arnica STLs permeated into the receptor fluid already 4 h after the application, but the amount was rather low. Within 48 h, a maximum of 8.4%, 14.6% and 36.4% of STLs permeated through porcine skin, human skin A (trans-epidermal water loss (TEWL) = 11.518 g·m⁻²·h⁻¹) and the more permeable human skin B (TEWL = 17.271 g·m⁻²·h⁻¹), respectively. The majority of STLs was absorbed (penetrated into the skin; 97.6%, 97.8% and 99.3%) after 48 h but a huge portion could not be extracted from skin and is expected to be irreversibly bound to skin proteins. To better visualize the analytes in different skin layers, a fluorescence-labeled STL, helenalin 3,4-dimethoxycinnamate, was synthesized. Fluorescence microscopic images depict an accumulation of the fluorescent derivative in the epidermis. For the treatment of local, cutaneous complaints, an enrichment of the bioactive substances in the skin may be considered beneficial. Full article

The absorption modulating activity of two alkylglycerol derivatives (batyl and chimyl alcohol) on skin barrier properties was evaluated. Biophysical tests such as transepidermal water loss (TEWL) and attenuated total reflectance–Fourier transform infrared (ATR-FTIR) spectroscopy, as well as in vitro skin permeation studies, were performed in order to determine the effect of these compounds as chemical absorption modulators. Four drugs were used as models: three NSAIDS (diclofenac, naproxen, and piroxicam) and glycyrrhizic acid. The results showed that treatment of the skin with alkylglycerols caused (i) a reduction on the amount of drug permeated; (ii) a reduction in TEWL; and (iii) changes in the ATR-FTIR peaks of stratum corneum lipids, indicative of a more ordered structure. All of these findings confirm that alkyl glycerols have an absorption retarding effect on the drugs tested. Such effects are expected to give rise to important applications in the pharmaceutical and cosmetic sectors, in cases where it is desirable for the drug to remain in the superficial layers of the skin to achieve a local effect. Full article