Search Results (203)

Ants use their mandibles—effectively a two-finger gripper—for a wide range of grasping activities. Here, we investigate whether mimicking the internal hairs found on ant mandibles can improve performance of a two-finger parallel plate robot gripper. With bin-picking applications in mind, the gripper fingers are long and slim, with interchangeable soft gripping pads that can be hairy or hairless. A total of 2400 video-documented experiments have been conducted, comparing hairless to hairy pads with different hair patterns. Simply by adding hairs, the grasp success rate was increased by at least $29\%$, and the number of objects that remain securely gripped during manipulation more than doubled. This result not only advances the state of the art in grasping technology, but also provides novel insight into the mechanical role of mandible hairs in ant biology. Full article

Atopic dermatitis (AD) is a common chronic inflammatory skin disorder characterized by immune dysregulation and skin barrier impairment. This study evaluated the anti-inflammatory and immunomodulatory effects of Camellia japonica extract in a 2,4-dinitrochlorobenzene (DNCB)-induced AD mouse model using SKH-1 hairless mice. Topical application of Camellia japonica extract for four weeks significantly alleviated AD-like symptoms by reducing epidermal thickness, mast cell infiltration, and overall skin inflammation. Hematological analysis revealed a marked decrease in total white blood cell (WBC) and neutrophil counts. Furthermore, the Camellia japonica extract significantly decreased oxidative stress, as evidenced by reduced serum reactive oxygen species (ROS) and nitric oxide (NO) levels, while enhancing the activity of antioxidant enzymes such as catalase. Importantly, allergic response markers including serum immunoglobulin E (IgE), histamine, and thymic stromal lymphopoietin (TSLP), were also downregulated. At the molecular level, Camellia japonica extract suppressed the expression of key pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and T helper 2 (Th2)-type cytokines such as IL-4 and IL-5, while slightly upregulating the anti-inflammatory cytokine IL-10. Collectively, these findings suggest that Camellia japonica extract effectively modulates immune responses, suppresses allergic responses, attenuates oxidative stress, and promotes skin barrier recovery. Therefore, application of Camellia japonica extract holds the promising effect as a natural therapeutic agent for the prevention and treatment of AD-like skin conditions. Full article

The largest Eurasian rodent, the Eurasian beaver Castor fiber, is known for its amphibious lifestyle that allows it to adapt its environment to its needs. Due to its lifestyle and evolutionary history, the beaver is characterized by a distinct, unique parasitofauna. In this context, the occurrence of mites from the Demodecidae family in the Eurasian beaver was investigated. The topography of the Demodex castoris was analyzed: it was previously known from a single record from a single skin location of this host. The mite was found in large numbers in various locations in the hairy skin, including the head, trunk, and limbs. In addition, a new species associated with hairless skin, mainly around the mouth, was discovered and described: Demodex ovaportans sp. nov. The females of this species carry the egg on the dorsal side of the podosoma, which may be a form of care and a previously unknown reproductive strategy in Demodecidae. Our findings confirm that a host-specific demodecid mite species associated with the hairy skin of the entire body is a universal model in mammals. They also emphasize the uniqueness of the beaver parasitofauna, as evidenced by the host specificity and the different biology of the demodecids described in it. Full article

UVB skin pathology is initiated by reactive oxygen species (ROS), differentiating this condition from other inflammatory diseases involving first the immune cell activation by danger or pathogen molecular patterns followed by oxidative stress. Resolvin D2 (RvD2) has been found to reduce inflammation in preclinical models. However, whether or not RvD2 reduces skin pathology caused by UVB irradiation is not yet known. Therefore, the efficacy of RvD2 on skin pathology triggered by UVB irradiation in female hairless mice was assessed. RvD2 (0.3, 1 or 3 ng/mouse, i.p.) was found to protect the skin against UVB inflammation, as observed in the reduction in edema (46%), myeloperoxidase activity (77%), metalloproteinase-9 activity (39%), recruitment of neutrophils/macrophages (lysozyme⁺ cells, 76%) and mast cells (106%), epidermal thickening (93%), sunburn cell formation (68%), collagen fiber breakdown (55%), and production of cytokines such as TNF-α (100%). Considering the relevance of oxidative stress to UVB irradiation skin pathologies, an important observation was that the skin antioxidant capacity was recovered by RvD2 according to the results that show the ferric reducing antioxidant power (68%), cationic radical scavenges (93%), catalase activity (74%), and the levels of reduced glutathione (48%). Oxidative damage was also attenuated, as observed in the reduction in superoxide anion production (69%) and lipid hydroperoxides (71%). The RvD2 mechanism involved the inhibition of NF-κB activation, as observed in the diminished degradation of IκBα (48%) coupled with a reduction in its downstream targets that are involved in inflammation and oxidative stress, such as COX-2 (66%) and gp91^phox (77%) mRNA expression. In conclusion, RvD2 mitigates the inflammatory and oxidative pathologic skin aggression that is triggered by UVB. 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/Objectives: Actinic keratosis (AK) occurs on sun-damaged skin and is considered a precursor to squamous cell carcinoma (SCC). Photodynamic therapy (PDT), using 5-aminolevulinic acid (ALA) and red light, is a common treatment for AK. However, its clinical efficacy for invasive tumors such as SCC is limited by the poor penetration and distribution of the photosensitizer. Cold atmospheric plasma (CAP), a partially ionized gas, increases skin permeability and exhibits anti-cancer properties through the generation of reactive oxygen species (ROS). In a previous study, CAP showed promising synergistic effects when combined with ALA-PDT for the treatment of SCC cells in vitro. The present study investigated the effects of combining CAP with ALA-PDT on cutaneous AK and SCC induced by ultraviolet B (UV-B) irradiation in SKH1 hairless mice. Methods: We compared various application sequences (CAP-ALA–red light, ALA–red light–CAP, and ALA-CAP–red light) against conventional ALA-PDT using visual, histological, and molecular assessments of the affected skin. Results: The results demonstrated that combined treatments strongly inhibited the growth of UV-B-induced skin lesions. TUNEL staining revealed increased apoptosis following both single and combined therapies, while Ki-67 staining indicated reduced keratinocyte proliferation and diminished DNA damage in treated areas. mRNA expression analysis showed the upregulation of apoptosis-related genes (p16^INK4a, p21^CIP1) alongside enhanced anti-tumor immune responses (IL-6, IL-8) in the affected tissue samples. Notably, the combined treatment enhances the therapeutic effect, whereas the sequence of application does not seem to be relevant for therapeutic efficacy in vivo. Conclusions: Overall, these results suggest that CAP may enhance the anti-tumor effect of conventional ALA-PDT, supporting previous findings on SCC cells. Full article

Background/Objectives: Reverse iontophoresis (R-IP) is a technology that transdermally delivers components from inside the body to outside the body using electroosmotic flow (EOF) generated by applying a low electric current through the skin. It has attracted attention as a non-invasive sampling method for therapeutic drug monitoring (TDM). The purpose of this study was to determine whether urea and Tween 80 effectively enhance drug extraction from beneath the skin using R-IP. Methods: An in vitro drug extraction test using hairless mouse skin and R-IP was performed with a 3-chamber Franz cell and Ag|AgCl electrodes by applying a constant current (0.25 mA/cm²) for 6 h. Acetaminophen was chosen as the model drug, and its solution (30, 100, or 300 μg/mL) was placed in the subdermal compartment. The pH of both the electrode and subdermal compartment solutions was maintained at 7.4. Results: Acetaminophen was gradually extracted into the electrode compartment in a concentration-dependent manner and was more abundant in the cathode compartment than in the anode compartment. In addition, urea significantly promoted drug extraction, particularly on the cathode side, and a linear relationship was observed between the subdermal concentration and extracted amount. This effect is likely due to skin hydration caused by urea, which enhances EOF generation in the skin. Conversely, Tween 80 had no effect on drug extraction. Conclusions: R-IP combined with urea is expected to not only shorten the treatment time but also enable its application to drugs with low concentrations in blood. Full article

Background/Objectives: Burn injuries present significant treatment challenges due to the intricate nature of the healing process. Bombyx mori L. (silkworm) derivatives, containing healing-promoting proteins such as sericin and fibroin, as well as the anti-inflammatory enzyme serrapeptase, have shown promise as potential healing agents. This study aimed to identify the optimal dosage of silkworm body and gland extracts for burn healing, compare the selected dose’s effectiveness with that of silkworm cocoons, and assess the combined healing effects of a cocoon dressing and a silkworm body extract gel. Methods: An experimental model was employed using hairless SKH-hr2 female mice subjected to standardized second-degree burns. The mice received treatments with various formulations of silkworm body and gland extracts, silkworm cocoons, and a combined application of a cocoon dressing and silkworm body extract gel. Results: The most effective treatments were the cocoon dressing and the combination of cocoon dressing with 60% body extract gel. By Day 20, complete healing (100%) was observed in the 20% and 60% body and gland extract groups, while the cocoon and 60% gland extract groups exhibited 60% healing, significantly higher than the control group (0% healing). Wound contraction analysis showed the greatest reduction in surface area from Day 3 to Day 17 in the cocoon and 60% body extract groups (p < 0.05). Histopathological assessments revealed that the combination group exhibited the least tissue damage (score: 7), compared to the control (score: 10–13). Conclusions: The study highlights the poorly examined therapeutic potential of silkworm body and gland extracts, demonstrating their efficacy in accelerating burn healing. The effects observed by the silkworm cocoon and body extract suggests a novel and promising approach for burn wound management, warranting further clinical exploration. Full article

Background: Skin photoaging caused by ultraviolet B (UV-B) irradiation leads to the formation of wrinkles. A method to lessen wrinkles is the application of Polydioxanone (PDO) lifting threads. HanDam (Twist) is a PDO lifting thread with a unique morphological twisted shape. Objective: The aim of this study was to evaluate the wrinkle improvement ability of HanDam (Twist) on UV-B irradiation-induced skin photoaging in a hairless mouse model. Methods: Wrinkles were induced by UV-B irradiation to the backs of female hairless mice for six weeks. After induction, the wrinkles were treated with threads, and the mice were monitored for six weeks post-treatment. Results: Our results showed that treatment with HanDam (Twist) effectively ameliorated UV-B irradiation-induced wrinkle depth and significantly increased collagen density by 13% compared to HanDam (non-Twist) in the histological analysis. In measuring protein expression related to collagen production, HanDam (Twist) significantly increased transforming growth factor beta (TGF-β) and collagen type 1 (COL1) by 46% and 67% compared to HanDam (non-Twist). Matrix metalloproteinase-1 (MMP-1) protein expression showed similar density and no significance compared to HanDam (non-Twist). Conclusions: These findings suggest that HanDam (Twist) improves the effectiveness of lifting threads for skin care compared to that of existing products. Full article

Background/Objectives: Gingivitis and dental caries are oral diseases resulting from bacterial accumulation in dental plaque, leading to inflammation, tissue destruction and the demineralization of tooth structures. Dioscorea communis, due to its anti-inflammatory and antimicrobial properties, could be a new treatment candidate. Methods: This study evaluated the preventive and therapeutic effect of a D. communis berry juice paste, formulated at 3% and 7% concentrations, on gingivitis and dental caries, in 55 male SKH-hr2 hairless mice. Gingivitis and dental caries were induced by ligation of the upper left incisor and the paste was applied topically three times daily, five days a week. Treatment efficacy was assessed through clinical examinations, photo-documentation, histopathological analysis and FT-IR spectroscopy. Results/Conclusions: Preventive administration of D. communis 7% significantly delayed disease onset, while therapeutic effects on established conditions were limited. Both concentrations were non-toxic to gingival tissues and dental structures. Full article

Staphylococci are common pathogens in dogs, causing a variety of dermatological problems. This study aimed to characterize the prevalence, antibiotic resistance, and biofilm-forming potential of Staphylococcus species isolated from the skin of shelter dogs. Overall, 108 samples were collected from the hairless skin areas of dogs in a shelter over one year. Isolates were cultured using standard microbiological methods and identified through biochemical testing, MALDI-TOF MS, and multiplex PCR. A total of 67 Staphylococcus isolates were identified, with S. pseudintermedius being the most prevalent. Antibiotic susceptibility was assessed using disk diffusion and MIC methods, revealing high resistance to ampicillin, erythromycin, and tetracycline. Notably, 12 multidrug-resistant SIG (S. intermedius group; S. pseudintermedius) and 4 CoNS strains (coagulase-negative staphylococci; S. equorum) were identified. Biofilm production was evaluated using a crystal violet assay, showing variable biofilm-forming capabilities among isolates and PCR, to confirm genes associated with biofilm formation. These findings highlight the presence of multidrug-resistant Staphylococcus species in shelter dogs, emphasizing the need for careful monitoring and antibiotic stewardship to manage potential risks to both animal and human health. Full article

Recently, various biocompatible and biodegradable materials have garnered significant attention as cosmetic fillers for skin rejuvenation. Among these, poly ε-caprolactone (PCL), poly L-lactic acid (PLLA), poly D,L-lactic acid (PDLLA), and polydioxanone (PDO) microspheres have been developed and commercialized as a dermal filler. However, its irregularly hydrophobic microspheres pose hydration challenges, often causing syringe needle blockages and side effects such as delayed onset nodules and papules after the procedure. In this study, we synthesized a polyethylene glycol-poly D,L-lactic acid (mPEG-PDLLA) copolymer to address the limitations of conventional polymer fillers. Comprehensive characterization of the copolymer was performed using nuclear magnetic resonance spectroscopy, Fourier transform infrared spectroscopy, and differential scanning calorimetry. The mPEG-PDLLA copolymers demonstrated a unimodal size distribution of approximately 121 ± 20 nm in an aqueous solution. The in vitro cytotoxicity and collagen genesis of mPEG-PDLLA copolymers were evaluated using human dermal fibroblast cells. In this study, angiogenesis was observed over time in hairless mice injected with mPEG-PDLLA copolymers, confirming its potential role in enhancing collagen synthesis. To assess the inflammatory response, the expression levels of the genes MMP1 and IL-1β were analyzed. Additionally, gene expression levels such as transforming growth factor-β and collagen types I and III were compared with Rejuran^® in animal studies. The newly developed collagen-stimulating PEGylated PDLLA may be a safe and effective option for skin rejuvenation. Full article

Background/Objectives: Research on pleasant tactile perception has primarily focused on C-tactile fibers found in hairy skin, with the forearm and face as common study sites. Recent findings of these fibers in hairless skin, such as the palms, have sparked interest in tactile stimulation on the hands. While studies have examined comfort and brain activity in passive touch, active touch remains underexplored. This study aimed to investigate differences in pleasant sensation and brain activity during active touch with stress balls of varying hardness. Methods: Forty healthy women participated. Using functional magnetic resonance imaging (fMRI), brain activity was measured as participants alternated between gripping stress balls of soft, medium, and hard hardness and resting without a ball. Participants rated hardness and comfort on a 9-point scale. Results: Soft stress balls were perceived as soft and comfortable, activating the thalamus and left insular cortex while reducing activity in the right insular cortex. Medium stress balls elicited similar perceptions and thalamic activation but with reduced right insular cortex activity. Hard stress balls caused discomfort, activating the insular cortex, thalamus, and amygdala while reducing anterior cingulate cortex activity. Conclusions: Soft stress balls may reduce aversive stimuli through perceived comfort, while hard stress balls may induce discomfort and are unlikely to alleviate stress. Full article

Background/Objectives: The skin, being the body’s outermost organ, plays a vital role in protecting against various external stimuli. Ultraviolet generates reactive oxygen species (ROS), promoting the secretion of matrix metalloproteinases (MMPs) and inducing collagen degradation. Many studies have been conducted to identify natural substances that can prevent or delay the harmful effects of UV. Methods: A wound healing assay, DCF-DA reactive oxygen species (ROS) assay, and JC-1 assay were performed to assess the effects of bio-converted eggplant peels (BEPs) on human dermal fibroblasts (HDFs). Western blot analysis was also conducted to understand the underlying mechanisms for their effects. Finally, hematoxylin–eosin staining and immunohistochemistry were also performed in animal studies. Results: Our study evaluated the antioxidant efficacy of BEPs fermented with Lactobacillus plantarum in hydrogen peroxide (H₂O₂)-HDFs and UVB-induced skin damage in hairless mice. We demonstrated that BEPs exhibited enhanced antioxidant properties compared to non-fermented eggplant peels (EPs). BEPs facilitated wound healing in H₂O₂-damaged HDFs, reduced ROS levels, and restored mitochondrial membrane potential. BEPs suppressed the phosphorylation of ERK, p38, and JNK as their underlying mechanism. We further demonstrated that dietary supplementation of BEPs also downregulated matrix metalloproteinase 1 (MMP1) expression and upregulated collagen I (COL1) in UVB-damaged hairless mice, indicating that BEPs were more effective compared to EPs. Conclusions: Our studies suggest that BEPs fermented with Lactobacillus plantarum hold significant potential as a protective agent for mitigating UVB-induced damage and promoting skin health. Full article