Search Results (218)

Antimicrobial resistance (AMR) remains a serious public health concern, and methicillin-resistant Staphylococcus aureus (MRSA) continues to limit treatment options. This laboratory-based comparative study evaluated antibiotic resistance patterns and nanoparticle (NP) susceptibility among 110 S. aureus isolates recovered from human skin and soft tissue infections (n = 80) and camel milk (n = 30). Proteomic identification utilizing matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) was carried out for all isolates under study. Phenotypic differentiation between MRSA and methicillin-sensitive S. aureus (MSSA) was performed via the cefoxitin disk diffusion method, and antimicrobial susceptibility testing was carried out using the disk diffusion method as stated in international guidelines. Multidrug resistance (MDR) was defined by established criteria. The antibacterial activity of silver nanoparticles (AgNPs) and gold nanoparticles (AuNPs) was detected by broth microdilution to determine minimum inhibitory concentration values (MIC₅₀ and MIC₉₀). The ability to develop reduced susceptibility was evaluated through ten serial sub-inhibitory passages followed by stability testing without using nanoparticles. MRSA prevalence was 52.5% among human isolates and 70% among camel milk isolates. Overall, 56.4% of isolates met MDR criteria, with a significantly higher MDR rate among MRSA compared with MSSA. Both human and camel isolates showed similar resistance patterns. AgNPs exhibited strong antibacterial activity, with MIC₅₀ and MIC₉₀ values of 0.0078 mg/mL and 0.0156 mg/mL, respectively; nevertheless, AuNPs demonstrated higher MIC values. Response to NPs was similar between isolates, independent of methicillin resistance or MDR. Serial sub-inhibitory exposure resulted in increased MIC values in all tested isolates, and stable resistance persisted in 50% of cases. These results indicate ongoing MRSA circulation in human and animal settings and reinforce the need for careful and controlled use of NP-based antimicrobials. Full article

Surgical wound complications, particularly surgical site infection (SSI), remain common despite advances in perioperative care, and modern dressings—including emerging smart systems—are intended to optimize moisture balance, reduce bioburden, and support monitoring of healing. This narrative review, informed by PRISMA 2020, synthesized comparative clinical evidence on postoperative dressings across surgical specialties. PubMed and Embase were searched for peer-reviewed comparative human studies published in 2015–2025 involving adults undergoing surgery with primary closure or secondary intention healing. Outcomes included SSI, time to epithelialization/closure, scar outcomes, pain, peri-wound skin integrity, and dressing change frequency. Nine studies met the inclusion criteria across orthopedics, general and endocrine surgery, otolaryngology, maxillofacial surgery, and surgical oncology. In hip/knee arthroplasty, hydrofiber dressings were associated with lower SSI rates versus standard/absorbent dressings. A meta-analysis suggested that moist and silver-based dressings generally outperformed gauze, with ionic silver ranking highest for healing and metallic silver for SSI prevention, and hydrocolloids reduced dressing change frequency. Oxygen diffusion therapy improved scar outcomes after cervicotomy, and chitosan gel reduced synechiae after endoscopic sinus surgery. Evidence in oncologic surgery was inconclusive, and heterogeneity in interventions, endpoints, and follow-up limited pooling. Overall, advanced postoperative dressings may improve selected outcomes compared with traditional gauze, but effects appear procedure- and context-dependent; future studies should standardize outcomes, extend follow-up, and incorporate cost-effectiveness and patient-reported measures, alongside evaluation of sensor-enabled smart dressings. Full article

Proton therapy offers superior dose localization, yet the biological effects of low-energy protons relevant to superficial tissues remain underexplored. We report the design and validation of a proton irradiation setup developed at the Tandem Accelerator of NCSR “Demokritos” for controlled radiobiological experiments. Monte Carlo simulations using Geant4 and Monte Carlo Damage Simulation (MCDS—Monte Carlo Damage Simulation) were used to determine proton energy spectra, linear energy transfer (LET), and predicted DNA damage yields. A single layer (15–20 μm in thickness) of human keratinocytes (HaCaT) was irradiated at doses from 0.65 to 3.65 Gy, and γ-H2AX foci were quantified as markers of tracks including one or more DNA double-strand breaks. The system achieved a uniform dose rate of 0.37 Gy/min, as calculated with Geant4, with a mean proton energy of 4.1 MeV (LET ≈ 8 keV/μm). A strong correlation (R² = 0.93) was observed between proton dose and γH2AX foci per nucleus (~10 foci/Gy), reflecting damage-inducing proton tracks rather than individual DNA double-strand breaks. At higher doses, an increased fraction of cells exhibited pan-nuclear γH2AX staining, characterized by a diffuse γH2AX signal throughout the nucleus and commonly associated with extensive or clustered DNA damage and global chromatin phosphorylation. These responses are consistent with the well-established dense ionization patterns produced by low-energy protons, as indicated by the LET spectrum and supported by MCDS-predicted clustered damage yields. While the γH2AX assay does not directly resolve simple versus complex DNA lesions, the agreement between Monte Carlo modeling and the observed cellular stress responses indicates that the irradiation platform reliably reproduces the expected biological signatures of low-energy proton exposure. Consequently, the developed system provides a robust experimental tool for systematic investigations of cellular radiosensitivity and radiotoxicity, with potential applications in skin dosimetry and radioprotection. Full article

Background/Objectives: Topical treatment of cutaneous tuberculosis (CTB) requires reliable models to evaluate dermal drug release and diffusion, particularly for fixed-dose combinations (FDCs) with contrasting physicochemical properties. Human skin remains the reference standard but poses ethical, logistical, and reproducibility challenges. This study investigated the suitability of Strat-M^® synthetic membranes as an alternative to human skin for assessing the simultaneous release and diffusion of clofazimine (CFZ) and pyrazinamide (PZA) from a topical FDC, and aimed to develop an optimized dermal emulsion using a Quality-by-Design (QbD)-informed formulation development tool. Methods: Self-emulsifying dermal emulsions containing CFZ and PZA were developed following QbD principles. Preformulation studies included drug solubility screening, oil phase selection, and pseudoternary phase diagram construction to identify stable emulsion regions. Formulations were characterized for droplet size, polydispersity index, zeta potential, viscosity, self-emulsification efficiency, and thermodynamic stability. Eight stable emulsions were identified, of which four were selected for in vitro drug release studies. The peppermint oil-based emulsion (PPO415) was further evaluated in comparative diffusion studies using Strat-M^® membranes and ex vivo human skin (Caucasian and African). Results: PPO415 demonstrated favorable physicochemical properties, including high CFZ solubility, uniform droplet distribution, and suitability for dermal application. Comparative diffusion studies showed that Strat-M^® underestimated the partitioning of lipophilic CFZ while overestimating the diffusion of hydrophilic PZA relative to human skin. These differences were attributed to compositional and structural disparities between synthetic membranes and biological skin. Conclusions: Strat-M^® membranes show potential as a reproducible and ethical in vitro screening tool during early-stage formulation development for topical FDCs. However, ex vivo human skin remains essential for accurately predicting dermal drug distribution and therapeutic performance. Full article

The global crisis concerning multidrug-resistant microorganisms necessitates the development of innovative antimicrobial strategies that avoid conventional antibiotics and overcome the toxicity and environmental persistence associated with traditional metal-based biocides. This work aims to develop safe and sustainable antibacterial filtration materials by integrating cationic hyperbranched polymer dendrimers (HBP) into electrospun nanofibers. Cationic HBPs were successfully embedded into recycled polyamide 6 nanofibers using industrial needleless electrospinning. Filtration efficiency, assessed against a 0.3 µm paraffin oil aerosol according to EN 149:2001, consistently exceeded 99.8%, meeting and surpassing the FFP3 classification threshold while maintaining low air resistance. The HBP-functionalized nanofibers exhibited pronounced contact-active antibacterial activity against Staphylococcus aureus and Escherichia coli. Quantitative plate count assays confirmed viability reductions of up to 74.1% after 2 h of co-incubation. Crucially, the absence of inhibition zones in agar diffusion tests confirmed that the active polymer was stably embedded within the nanofiber matrix and did not leach. Comprehensive toxicological tests, including cell line and 3D human skin and airway tissue models, confirmed the material’s safety for both dermal and respiratory contact. This study presents a scalable, metal-free, and environmentally responsible next-generation filtration system that combines high mechanical efficiency with active antimicrobial functionality. Full article

A comprehensive two-dimensional liquid chromatography platform (LC × LC) was developed and validated for dermal permeability studies. In this implementation, the two separation dimensions were applied to mimic the layered structure of human skin: a ceramide-like stationary phase in the first dimension (¹D) to simulate the lipid-rich epidermis, and an immobilized artificial membrane (IAM) phase in the second (²D) to emulate the dermis. Experimental conditions were optimised to reflect the microenvironment of the in vivo skin. For validation purposes, 43 pharmaceutical and cosmetic compounds whose transdermal permeability coefficients (log K_p) were known from the scientific literature were selected as model solutes. A good degree of separation was achieved across the whole dataset, and affinity profiles correlated with transdermal passage properties, suggesting that retention within specific chromatographic ranges may be predictive of skin permeation. To complement this approach, mass diffusion measurements were also conducted using Permeapad^® 96-well plates and LC was performed on a narrow bore column in MS-friendly conditions. These log K_p values were compared against both in vivo and chromatographic retention data. The combined use of these techniques offers a strategic framework for profiling new chemical entities for their dermal absorption in a manner that is both ethically compliant and eco-sustainable. Full article

In this review we present a comprehensive overview of the published literature related to the use of Hybrid Cooperative Complexes (HCCs) of low- and high-molecular-weight hyaluronic acid in aesthetic medicine. HCCs have been developed to overcome the shortcomings of traditional hyaluronic based dermal fillers. Specifically, HCCs deliver both high- and low-molecular-weight hyaluronic acid (HA), maximizing their complementary effects. They are biocompatible and formulated without the addition of foreign agents. Cooperative hydrogen bonds extend their durability and make them more resistant to hyaluronidase compared to high-molecular-weight HA. The rheological properties of HCC formulations allow for easy exertion through the needle and diffusion in the tissue compared to high-molecular-weight HA alone. In vitro studies have shown that HCCs improve vitality of fibroblasts, keratinocytes and adipocytes, and stimulate production of collagen and elastin. Studies on scratched co-cultures of immortalized human keratinocytes and human dermal fibroblasts demonstrated that HCCs accelerate wound closure. Furthermore, HCCs delayed senescence of mesenchymal stromal cells to a greater extent than high-molecular-weight HA or low-molecular-weight HA alone. Clinical studies show a reduction in wrinkle severity, improvement in skin roughness profile and reduction of skin laxity with pronounced improvement in superficial skin hydration lasting up to 6 months. The formulation intended for restoration of fat compartments demonstrated reduction in cheek volume loss and improvement in skin thickness. Subjects report moderate-to-high satisfaction and are likely to recommend the treatment. Limitations of the published studies are also addressed, as well as reported adverse events and published safety data. Full article

This study is devoted to investigating the effect of aerosols on solar UV radiation. In the ultraviolet range, scattering processes are dominant and lead to a substantial contribution of diffuse UV radiation to the global UV irradiance. The paper introduces a method for estimating solar UV Index. The proposed method is first compared with other UV Index estimation methods and is subsequently applied to examine the influence of aerosols and ozone on solar UV radiation and on its diffuse component. Human skin exposure to diffuse solar UV radiation can be potentially harmful to health. Full article

Dermal drug delivery is a promising alternate route of drug administration, offering localized therapeutic effects, reduced systemic effects, and improved patient compliance. However, the skin’s intricate configuration, especially the stratum corneum (SC), presents formidable barriers, restricting drug permeation. This review summarizes biological, synthetic, and methodological models employed to study dermal absorption and permeability. Ex vivo human skin is a reference point, but limited availability and ethical constraints necessitate reliance on animal models, including porcine, rodent, rabbit, monkey, and even snake skin, each with unique advantages and drawbacks. Synthetic substitutes, e.g., reconstructed human epidermis and Strat-M^® membranes, provide reproducibility and economic practicality, though none fully mimic the barrier functions of human skin. Innovative analytical methods, including diffusion cells, skin-PAMPA, tape stripping, and advanced imaging techniques, enable quantitative, semi-quantitative, and qualitative insights into drug transport. Collectively, these tools support formulation optimization and aid regulatory bioequivalence assessments. However, challenges remain in correlating in vitro, ex vivo, and in vivo outcomes and in replicating the skin’s dynamic physiology. This review highlights current opportunities and limitations, emphasizing the need for more physiologically relevant models to advance safe, effective, and innovative dermal drug delivery systems. Full article

Short-time thermal exchange (0–20 s) between human skin and textile surfaces determines initial warm–cool sensations, which influences comfort perception. Classical Fourier models predicting a √t cannot fully describe this early transient phase, particularly for porous or heterogeneous materials such as fabrics. This study investigates the early and short-time temperature response of a fingertip to contact with eight woven and knitted fabrics of different compositions, densities, thermal resistances, and thicknesses, measured under controlled laboratory conditions using a fine-gauge thermocouple at the skin–fabric interface. Experimental temperature–time data, when converted to the Laplace domain, exhibited slopes corresponding to time-domain exponents of t^⅙, t^¼, and occasionally t^⅒, all lower than the classical diffusion exponent of ½.The dual-phase lag (DPL) model was applied to interpret these deviations through two lag times—τq (heat flux) and τT (temperature gradient)—and their ratio Z = τT/τq, which controls the slope of the Laplace-domain response. DPL curves reproduced the observed exponents without additional empirical parameters. The results show that short-time heat transfer depends strongly on textile structure: higher thickness leads to slower transient responses (“warmer” feel), whereas denser fabrics promote faster equilibration (“cooler” feel). This dual-phase interpretation bridges physical heat transfer with tactile thermal perception, providing a predictive framework for the design of textiles with thermal properties. Full article

We investigate crosstalk effects in a dual-modality tactile–proximity sensing system based on Time-of-Flight (ToF) technology integrated within a flat poly(methyl methacrylate) (PMMA) light guide. Building on the OptoSkin framework, we employ two commercially available TMF8828 multi-zone ToF sensors, one configured for tactile detection via frustrated total internal reflection (FTIR) and the other for external proximity measurements through the same transparent substrate. Controlled experiments were conducted using a 2 cm² silicone pad for tactile interaction and an A4-sized diffuse white target for proximity detection. Additional measurements with a movable PMMA sheet were performed to quantify signal attenuation, peak broadening, and confidence degradation under transparent-substrate conditions. The results demonstrate that the TMF8828 can simultaneously resolve both contact-induced scattering and distant reflections, but that localized interference zones occur when sensor fields of view overlap within the substrate. Histogram analysis reveals the underlying multi-path contributions, providing diagnostic insight not available from black-box ToF devices. These findings highlight both the opportunities and limitations of integrating multiple ToF sensors into transparent waveguides and inform design strategies for scalable robotic skins, wearable interfaces, and multi-modal human–machine interaction systems. Full article

With the development of deep learning technology, virtual try-on technology has developed important application value in the fields of e-commerce, fashion, and entertainment. The recently proposed Leffa technology has addressed the texture distortion problem of diffusion-based models, but there are limitations in that the bottom detection inaccuracy and the existing clothing silhouette persist in the synthesis results. To solve this problem, this study proposes CaP-VTON (Clothing-Agnostic Pre-Inpainting Virtual Try-On). CaP-VTON integrates DressCode-based multi-category masking and Stable Diffusion-based skin inflation preprocessing; in particular, a generated skin module was introduced to solve skin restoration problems that occur when long-sleeved images are converted to short-sleeved or sleeveless ones, introducing a preprocessing structure that improves the naturalness and consistency of full-body clothing synthesis and allowing the implementation of high-quality restoration considering human posture and color. As a result, CaP-VTON achieved 92.5%, which is 15.4% better than Leffa, in short-sleeved synthesis accuracy and consistently reproduced the style and shape of the reference clothing in visual evaluation. These structures maintain model-agnostic properties and are applicable to various diffusion-based virtual inspection systems; they can also contribute to applications that require high-precision virtual wearing, such as e-commerce, custom styling, and avatar creation. Full article

Background/Objectives: Transdermal formulations are widely utilized in the pharmaceutical and cosmetic fields because they enable non-invasive administration and sustained local drug delivery. Conventional ex vivo skin permeation experiments using Franz diffusion cells have limitations in capturing the spatial and temporal dynamics of skin penetration. This study aimed to develop a confocal laser scanning microscopy (CLSM)-based approach to visualize and semi-quantitatively assess the penetration behavior of fluorescent dyes with differing lipophilicities. Methods: Four fluorescent dyes with different Log P values—Rhodamine B (Rho-B), Rhodamine 123 (Rho-123), Fluorescein Sodium (Flu-Na), and Nile Red (NR)—were formulated into lotion-based vehicles and applied to excised human abdominal skin. CLSM imaging was performed from 10 min to 240 min post-application. Fluorescence intensities were extracted from depth-resolved regions (R1–R4, 30-μm intervals) to examine penetration kinetics and distribution. Results: CLSM imaging demonstrated that Rho-B penetrated through stratum corneum and entered deep into the skin via the hair follicles. Rho-123 and Flu-Na exhibited intercellular and follicular penetration; however, Flu-Na showed only a slight increase in intensity over time; NR showed negligible penetration into the deeper layers. The results of our analysis indicated that moderately lipophilic substances such as Rho-B and Rho-123 diffused deeply into the skin via both transdermal and follicular routes, whereas highly hydrophobic or lipophilic substances remained in the superficial layers. Conclusions: The CLSM-based approach enabled spatially and temporally resolved, semi-quantitative evaluation of transdermal penetration in a single, non-destructive experiment. Although restricted to fluorescent probes, this approach provides a practical early-stage screening tool for comparing route-specific and time-dependent penetration behaviors of compounds with different lipophilicities. Full article

Skin aging is influenced by both internal and external factors, resulting in wrinkles, decreased elasticity and irregular pigmentation. Hyaluronic acid (HA), a key component of the extracellular matrix, is essential for skin hydration and structural support. Peptides, short amino acid chains, have gained attention in cosmetics due to their multifunctional biological activities. This study explored the moisturizing and metal-chelating properties of Chrono Control Penta (S-Cannabis Sativa-pentapeptide-1), a novel plant-derived peptide whose sequence is WVSPL. In vitro, it chelated iron ions up to 17.86 ± 2.50% and copper ions up to 47.08 ± 1.49% at 10 mM and 3 mM, respectively. Western blot and Enzyme-Linked Immunosorbent Assay (ELISA) analysis showed that, under H₂O₂-induced stress, Chrono Control Penta increased hyaluronan synthase 2 (HAS2) production by 81.72% in BJ-5ta fibroblasts and enhanced HA secretion by 20.11% compared to simulated aging conditions alone, respectively. Furthermore, experiments carried out with the Franz diffusion cell and human full thickness skin demonstrated the peptide’s ability to penetrate the skin layers and even diffuse laterally with a quantified peptide skin biodistribution accounting for 0.095/0.06 nM/mg in 6 h. Advanced AI-based modeling (AlphaFold2, RosettaFold) and docking analysis revealed stable peptide-peptide transporter 2 (PEPT2) interactions, supporting carrier-mediated skin permeation and linking computational predictions with experimental diffusion data. Hence, this study extends previous evidence on the cosmetic efficacy of Chrono Control Penta by (i) adding mechanistic insights into metal chelation and HAS2/HA modulation, (ii) rigorously quantifying local skin penetration and lateral diffusion with HPLC-MS/MS, and (iii) providing a plausible mechanistic link between skin biodistribution and PEPT2-mediated transport based on deep learning structural models. Full article

Acne is a common skin condition that causes pimples, redness and inflammation. Benzoyl peroxide (BENZ), salicylic acid (SAL), curcumin (CUR), rosmarinic acid (ROS) and resveratrol (RESV) exhibit antimicrobial, anti-inflammatory and antioxidant properties and are recommended for its treatment. These five active pharmaceutical ingredients (APIs) were incorporated into a green clay, honey and gelatin face mask and determined by an HPLC-DAD (diode array) method. For the chromatographic separation of the analytes, a gradient mobile phase with two solvents mixtures: A, comprising H₂O with 0.1% TFA-ACN with 0.1% TFA, 85:15 v/v, and B, comprising 100% ACN with 0.1% TFA, and a C18 column (250 × 4.6 mm, 5 μm), at 40 °C (diluent: MeOH-ACN 0.1% TFA 2:1 v/v), were selected. The method was validated according to the ICH guidelines for pharmaceutical products (R² > 0.999, %RSD < 1.2, % Recovery > 98.2, LOD_μg/mL: ROS = 0.267, RES = 0.047, SAL = 0.636, CUR = 0.296 and BENZ = 0.083). For the processing of mask samples and the quantitative extraction of the analytes, the “D-optima mixture” experimental design methodology was applied (% Recovery 95.4–102.1%, %RSD < 2.4). Finally, the permeability rate (Papp) of the mask ingredients through the skin was studied using Franz vertical diffusion cells, in a cellulose membrane (in vitro), in rat tissue and in human skin (ex vivo). To ensure the reliability of the results, APIs’ stability rate under the given experimental conditions was studied. In addition, a second method for sample processing in Franz cells was developed and validated (% Recovery > 90.6–106.9, %RSD < 5.2). Based on the results obtained, both the effectiveness of the new face mask formulation and the suitability of the membranes were evaluated. Full article