Structure and function of the epidermis related to barrier properties

E-cadherin and aquaporin-3 are downregulated in wound edges of human chronic wounds

Chronic wounds are defined as wounds that fail to proceed through the normal phases of wound healing; a complex process involving different dynamic events including migration of keratinocytes in the epidermis. Chronic wounds are estimated to affect 1-2% of the human population worldwide and are a major socioeconomic burden. The prevalence of chronic wounds is expected to increase with the rising number of elderly and patients with diabetes and obesity, who are at high risk of developing chronic wounds. Since E-cadherin and the water channel aquaporin-3 are important for both skin function and cell migration, and aquaporin-3 is furthermore involved in wound healing of the skin demonstrated by impaired wound healing in aquaporin-3-null mice, we hypothesized that E-cadherin and aquaporin-3 expression may be dysregulated in chronic wounds. Therefore, we investigated the expression of E-cadherin and aquaporin-3 in biopsies from the edges of chronic wounds from human patients. This was accomplished by immunohistochemical stainings of E-cadherin and aquaporin-3 on serial sections followed by qualitative evaluation of staining patterns, which revealed low expression of both E-cadherin and aquaporin-3 at the wound edge. Future studies are needed to reveal if this downregulation is associated with the pathophysiology of chronic wounds.

The Burn Wound

Skin serves as a protective barrier against infection, prevents excessive fluid and electrolyte losses, performs crucial thermoregulation, and provides tactile feedback of surroundings. The skin also plays an essential role in human perception of body image, personal appearance, and self-confidence. With these many diverse functions, understanding normal anatomic composition of skin is pivotal to evaluating the extent of its disruption from burn injury. This article discusses the pathophysiology, initial evaluation, subsequent progression, and healing of burn wounds. By delineating the various microcellular and macrocellular alterations of burn injury, this review also augments providers' capacity to deliver patient-centered, evidence-based burn care.

In vivo detection of healthy skin: Comparison of multiphoton microscopy and reflectance confocal microscopy

BACKGROUND

Noninvasive skin examination evolved rapidly in recent years, with multiphoton microscopy (MPM) and reflectance confocal microscopy (RCM) being used to image in-vivo skin at high resolution. The aim of this study is to compare the imaging clarity between the two techniques and measure the thickness of the epidermis in different body sites. We also measured the degree of skin aging with noninvasive tools.

METHODS

Fifty-six volunteers were evaluated and measured at three different body sites, including the cheek, volar forearm, and back. We used RCM and MPM to evaluate the clarity of each skin layer, including stratum corneum, stratum granulosum, stratum spinosum, dermo-epidermal junction, and dermis. We measured epidermal thickness (ET) at the three body sites in individuals of different ages and genders. We assessed skin aging by the second harmonic to autofluorescence aging index of dermis (SAAID), and multiple linear regression was used to analyze the factors affecting SAAID.

RESULTS

MPM had advantages in observation of stratum granulosum, collagen fiber, and elastic fiber (p < 0.001), but RCM provided better observation in dermo-epidermal junction layer (p < 0.001). The epidermis was thicker in the cheek area than the volar forearm and back in both RCM and MPM detection, and the average ET measured by MPM was lower than RCM. ET varied among the three body sites with significant differences (p < 0.05). ET was significantly lower at almost all sites in individuals above 40y (p < 0.05). SAAID decreased with age, and more rapidly in women. Cheeks have lower SAAID scores than other body sites.

CONCLUSION

MPM and RCM provide noninvasive methods for imaging skin and each method has its own advantages. Epidermal thickness and SAAID correlated with age, gender, and different body sites. MPM could also assess the degree of skin aging, which could guide the clinical treatment of patients with diffferent ages and genders in the above body sites.

Comparative appraisal of in vitro biological profile and in vivo wound healing attributes of bergenin and Bergenia ciliata (Haw.) Sternb

ETHNOPHARMACOLOGICAL RELEVANCE

People of all ages experience injuries, whether mild or severe. The most available option to treat wounds as an alternative to allopathic care in both urban and rural populations is traditional medicine, which is mostly target inflammation. Bergenia ciliata (Haw.) Sternb rhizome and leaf powder are used in Ayurveda and local communities for various ailments including healing of wounds and burns. Owing to this property it is traditionally known as "Zakham-e-hayat" (wound healer).

AIM OF THE STUDY

In the present study, we compared biological activity and wound healing potential of B. ciliata rhizome (R) extract and bergenin, a glycoside isolated from B. ciliata.

MATERIALS AND METHODS

Reverse-phase high performance liquid chromatography (RP-HPLC) was performed to analyze polyphenols and bergenin in B. ciliata R extract. Samples were subjected to in vitro antioxidant assays including free radical scavenging, ferric chloride reducing power and total antioxidant capacity. Micro-broth dilution method, brine shrimp lethality assay and isolated RBC hemolysis assay were conducted to assess in vitro antibacterial and cytotoxic activities. Moreover, in vivo wound healing potential was determined by an excision wound model in mice.

RESULTS

RP-HPLC showed significant content of polyphenols and bergenin (6.05 ± 0.12 μg/mg) in B. ciliata R extract. Crude extract possesses higher overall antioxidant and antibacterial capacities than bergenin due to presence of multiple phytoconstituents in extract. Both samples showed low hemolytic activity indicating their safe profile. Furthermore, mice treated with B. ciliata R extract depicted substantial decrease in wound area (99.3%; p < 0.05) as compared to bergenin, which showed 88.8% of wound closure after 12 days of treatment. Additionally, both treatments reduced epithelization duration by 1.6- and 1.4-fold in B. ciliata R extract (12.0 ± 0.6 days) and bergenin (14.2 ± 0.8 days) treated mice, respectively. This was supported by histopathological examination that showed greater epithelization, fibroblast proliferation, collagen synthesis, and revascularization in mice treated with B. ciliata R.

CONCLUSION

Concisely, it is evident that B. ciliata R contains phytoconstituents in addition to bergenin, which potentiated wound healing activity of the extract. Hence, B. ciliata R is good source of compounds for treating wounds.

Macrophage Migration Inhibitory Factor in Psoroptes ovis: Molecular Characterization and Potential Role in Eosinophil Accumulation of Skin in Rabbit and Its Implication in the Host-Parasite Interaction

Psoroptes ovis, a common surface-living mite of domestic and wild animals worldwide, results in huge economic losses and serious welfare issues in the animal industry. P. ovis infestation rapidly causes massive eosinophil infiltration in skin lesions, and increasing research revealed that eosinophils might play an important role in the pathogenesis of P. ovis infestation. Intradermal injection of P. ovis antigen invoked massive eosinophil infiltration, suggesting that this mite should contain some relative molecules involved in eosinophil accumulation in the skin. However, these active molecules have not yet been identified. Herein, we identified macrophage migration inhibitor factor (MIF) in P. ovis (PsoMIF) using bioinformatics and molecular biology methods. Sequence analyses revealed that PsoMIF appeared with high similarity to the topology of monomer and trimer formation with host MIF (RMSD = 0.28 angstroms and 2.826 angstroms, respectively) but with differences in tautomerase and thiol-protein oxidoreductase active sites. Reverse transcription PCR analysis (qRT-PCR) results showed that PsoMIF was expressed throughout all the developmental stages of P. ovis, particularly with the highest expression in female mites. Immunolocalization revealed that MIF protein located in the ovary and oviduct of female mites and also localized throughout the stratum spinosum, stratum granulosum, and even basal layers of the epidermis in skin lesions caused by P. ovis. rPsoMIF significantly upregulated eosinophil-related gene expression both in vitro (PBMC: CCL5, CCL11; HaCaT: IL-3, IL-4, IL-5, CCL5, CCL11) and in vivo (rabbit: IL-5, CCL5, CCL11, P-selectin, ICAM-1). Moreover, rPsoMIF could induce cutaneous eosinophil accumulation in a rabbit model and increased the vascular permeability in a mouse model. Our findings indicated that PsoMIF served as one of the key molecules contributing to skin eosinophil accumulation in P. ovis infection of rabbits.

Antiphotoaging and Skin-Protective Activities of Ardisia silvestris Ethanol Extract in Human Keratinocytes

Ardisia silvestris is a traditional medicinal herb used in Vietnam and several other countries. However, the skin-protective properties of A. silvestris ethanol extract (As-EE) have not been evaluated. Human keratinocytes form the outermost barrier of the skin and are the main target of ultraviolet (UV) radiation. UV exposure causes skin photoaging via the production of reactive oxygen species. Protection from photoaging is thus a key component of dermatological and cosmetic products. In this research, we found that As-EE can prevent UV-induced skin aging and cell death as well as enhance the barrier effect of the skin. First, the radical-scavenging ability of As-EE was checked using DPPH, ABTS, TPC, CUPRAC, and FRAP assays, and a 3-(4-5-dimethylthiazol-2-yl)-2-5-diphenyltetrazolium bromide assay was used to examine cytotoxicity. Reporter gene assays were used to determine the doses that affect skin-barrier-related genes. A luciferase assay was used to identify possible transcription factors. The anti-photoaging mechanism of As-EE was investigated by determining correlated signaling pathways using immunoblotting analyses. As-EE had no harmful effects on HaCaT cells, according to our findings, and As-EE revealed moderate radical-scavenging ability. With high-performance liquid chromatography (HPLC) analysis, rutin was found to be one of the major components. In addition, As-EE enhanced the expression levels of hyaluronic acid synthase-1 and occludin in HaCaT cells. Moreover, As-EE dose-dependently up-regulated the production of occludin and transglutaminase-1 after suppression caused by UVB blocking the activator protein-1 signaling pathway, in particular, the extracellular response kinase and c-Jun N-terminal kinase. Our findings suggest that As-EE may have anti-photoaging effects by regulating mitogen-activated protein kinase, which is good news for the cosmetics and dermatology sectors.

Skin drug delivery using lipid vesicles: A starting guideline for their development

Lipid vesicles can provide a cost-effective enhancement of skin drug absorption when vesicle production process is optimised. It is an important challenge to design the ideal vesicle, since their properties and features are related, as changes in one affect the others. Here, we review the main components, preparation and characterization methods commonly used, and the key properties that lead to highly efficient vesicles for transdermal drug delivery purposes. We stand by size, deformability degree and drug loading, as the most important vesicle features that determine the further transdermal drug absorption. The interest in this technology is increasing, as demonstrated by the exponential growth of publications on the topic. Although long-term preservation and scalability issues have limited the commercialization of lipid vesicle products, freeze-drying and modern escalation methods overcome these difficulties, thus predicting a higher use of these technologies in the market and clinical practice.

Reverse iontophoresis with the development of flexible electronics: A review

Skin-centric diagnosis techniques, such as epidermal physiological parameter monitoring, have developed rapidly in recent years. The analysis of interstitial fluid (ISF), a body liquid with abundant physiological information, is a promising method to obtain health status because ISF is easily assessed by implanted or percutaneous measurements. Reverse iontophoresis extracts ISF by applying an electric field onto the skin, and it is a promising method to noninvasively obtain ISF, which, in turn, enables noninvasive epidermal physiological parameter monitoring. However, the development of reverse iontophoresis was relatively slow around the 2010s due to the rigidity and low biocompatibility of the applied devices. With the rapid development of flexible electronic technology in recent years, new progress has been made in the field of reverse iontophoresis, especially in the field of blood glucose monitoring and drug monitoring. This review summarizes the recent advances and discusses the challenges and opportunities of reverse iontophoresis.

Applying sunscreen SPF 50 with high antioxidant capacity during fifteen days improves the dermis echogenicity and reduces the reddish skin undertone

BACKGROUND

Of the many effects induced by UV radiation on the skin, erythema is one of the most well-known features, which is a cutaneous inflammatory reaction correlated with acute photodamage. The utilization of sunscreen may reduce this process.

AIMS

To evaluate the utilization of a sunscreen SPF50 with high antioxidant capacity during 15 days by young men without photoprotection habits.

METHODS

For this, we evaluated erythema, skin hydration properties, and dermis echogenicity using skin imaging techniques. Forty male participants (aged between 18 and 28 years old), 36 without previous photoprotection habits, were recruited, and the erythema was evaluated using a visual score and skin colorimeter. Macroscopic images (VivaCam®) were also obtained. Dermis echogenicity was evaluated using high-frequency ultrasonography. All the participants received a sunscreen SPF 50 to use for 15 days.

RESULTS

The visual score presented a strong correlation (r = 0.8657) with the colorimeter results. Visually and using the biophysical methodologies was possible to observe the reduction of the visual erythema. The dermis echogenicity also improved, probably correlated with the acute inflammation reduction. No alterations were observed in the skin hydration and skin barrier parameters.

CONCLUSIONS

The utilization of complementary and correlated different skin biophysical and imaging techniques in this study allows a better comprehension regarding the skin early photoaging process due the direct sun exposure. The utilization with a SPF 50 sunscreen with high antioxidant potential allows for a reduction in the erythema after 15 days of usage, a quick result, however, did not improved the skin barrier or SC hydration.

Effects of probiotics supplementation on skin photoaging and skin barrier function: A systematic review and meta-analysis

BACKGROUND

Ultraviolet (UV) irradiation is one of the major causes of skin aging. To date, there remains limited evidence on using oral probiotics for skin anti-photoaging.

OBJECTIVES

This systematic review and meta-analysis aims to assess the effects of probiotics on skin photoaging.

METHODS

We searched the PubMed and Embase databases for studies published until August 31, 2021, and included randomized controlled trials, murine randomized controlled experiments, and in vitro studies. Skin barrier function was compared between UV irradiated probiotics and controls.

RESULTS

After given oral probiotics supplements, a significant reduction was shown in all types of measured MMPs in both murine and in vitro studies. Oral probiotics supplementation significantly reversed UV-induced increase of epidermal thickness (standardized mean differences [SMD] = -1.76; 95% confidence interval [CI] = -3.04 to -0.49; p = .007; I²  = 81%), UV-induced increase trans-epidermal water loss (SMD = -1.72; 95% CI = -2.76 to -0.67; p = .001; I²  = 57%), and UV-induced skin dehydration (SMD = 1.85; 95% CI = 1.16 to 2.55; p < .00001; I²  = 4%).

CONCLUSIONS

Probiotics are effective against skin photoaging in terms of MMP pathways and reversing skin barrier function from murine randomized data. Further randomized controlled trials on humans are required to warrant these results.

Beauty from within: Improvement of skin health and appearance with Lycomato a tomato-derived oral supplement

BACKROUND

Healthy and a youthful appearance is a common desire of the aging population. "Beauty from within" involves using nutrition and nutraceuticals to support skin function for reducing and reversing signs of aging such as wrinkles, pigmentary changes, skin laxity, and dullness. Carotenoids possess strong antioxidant and anti-inflammatory activities and are effective in improving skin barrier and could thereby stimulate "beauty from within" by providing endogenous support to reduce the expressions of aging.

AIM

This study was designed to determine whether 3-month supplementation with Lycomato would improve skin condition.

METHOD

A panel of 50 female subjects used Lycomato capsules as nutritional supplements for 3 months. Skin status was observed via questionnaires for the assessment of skin condition and expert visual grading of facial markers such as wrinkles, tonality, roughness, laxity, and pore size. Skin barrier was assessed using transepidermal water loss (TEWL). Measurements were obtained before treatment and after 4 and 12 weeks of use.

RESULTS

Results indicated a statistically significant improvement (p < 0.05) in skin barrier as measured by TEWL after 12 weeks of consuming the supplement. There was also a significant improvement in skin tonality, lines and wrinkles, pore size, and skin firmness as observed by expert evaluation as well as subject self-assessment.

CONCLUSION

Based on the confines and conditions of this study, oral supplementation with Lycomato resulted in significant improvement in skin barrier. Visual appearance of lines and wrinkles, skin tonality, pores, smoothness, and firmness were considerably improved, and these improvements were found to be substantially discernible by the subjects.

Pannexin 3 channels regulate architecture, adhesion, barrier function and inflammation in the skin

The channel-forming glycoprotein Pannexin 3 (PANX3) functions in cutaneous wound healing and keratinocyte differentiation, but its role in skin homeostasis through aging is not yet understood. We found that PANX3 is absent in newborn skin but becomes upregulated with age. We characterized the skin of global Panx3 knockout mice (KO) and found that KO dorsal skin showed sex-differences at different ages, but generally had reduced dermal and hypodermal areas compared to aged-matched controls. Transcriptomic analysis of KO epidermis revealed reduced E-cadherin stabilization and Wnt signaling compared to WT, consistent with the inability of primary KO keratinocytes to adhere in culture, and diminished epidermal barrier function in KO mice. We also observed increased inflammatory signaling in KO epidermis and higher incidence of dermatitis in aged KO mice compared to wildtype controls. These findings suggest that during skin aging, PANX3 is critical in the maintenance of dorsal skin architecture, keratinocyte cell-cell and cell-matrix adhesion and inflammatory skin responses.

Fascia Layer-A Novel Target for the Application of Biomaterials in Skin Wound Healing

As the first barrier of the human body, the skin has been of great concern for its wound healing and regeneration. The healing of large, refractory wounds is difficult to be repaired by cell proliferation at the wound edges and usually requires manual intervention for treatment. Therefore, therapeutic tools such as stem cells, biomaterials, and cytokines have been applied to the treatment of skin wounds. Skin microenvironment modulation is a key technology to promote wound repair and skin regeneration. In recent years, a series of novel bioactive materials that modulate the microenvironment and cell behavior have been developed, showing the ability to efficiently facilitate wound repair and skin attachment regeneration. Meanwhile, our lab found that the fascial layer has an indispensable role in wound healing and repair, and this review summarizes the research progress of related bioactive materials and their role in wound healing.

The use of human-derived feeder layers for the cultivation of transplantable human epidermal cell sheet to repair second degree burn wounds

BACKGROUND AND OBJECTIVES

Human epidermal cell sheet (human-ECS) is a feasible treatment option for wound injury. Traditionally, researchers often use murine 3T3 fibroblast cells as feeder layer to support human epidermal cell sheet grafts, thus increase risk to deliver animal-borne infection. To overcome the potential risks involved with xenotransplantation, we develop human foreskin fibroblast cell as feeder layer culture system and investigate the effects of human-ECS on second-degree burn wound healing in mini-pig in order to develop more effective and safer therapies to enhance wound healing in human.

MATERIALS AND METHODS

Human epidermal keratinocytes and fibroblasts were isolated from foreskin tissue and were co-cultured to manufacture human-ECS. The cell morphology was monitored with phase-contrast microscopy, the stem cell markers were assessed by flow cytometry, and by colony-forming efficiency (CFE) assay. The structure of human-ECS was observed by hematoxylin and eosin staining. Expression of cytokines in human-ECS was confirmed by enzyme-linked immunosorbent assay. Second-degree burn wounds were created on the dorsal of miniature pig to evaluate the effect of oil gauze, oil gauze combined with commercial epidermal growth factor (EGF) cream, and oil gauze combined with human-ECS. Wound healing rate, histological examination, and Masson staining were measured to observe the wound repair efficacy. Real-time PCR and Western blot were utilized to detect the expression level of EGF and interleukin 6 (IL-6).

RESULTS

Stratified human-ECS with 6-7 layers of epidermal cells was successfully cultivated with human-derived feeder cells, in which epidermal cell highly expressed CD49f and CFE was 3% ± 0.45%. Application of human-ECS induced a higher wound healing rate than commerical EGF cream and oil gauze control. The expression of EGF in human-ECS group was higher than those in the other groups; however, the expression of IL-6 was significantly decreased at day 14 by human-ECS treatment group.

CONCLUSIONS

Human-derived feeder cells are suitable for cultivation of human-ECS, avoiding pathogen transmission. Human-ECS could enhance second-degree burn wound healing, and its promoting effect involved secreting a variety of cytokines to regulate tissue reparative process.

Introduction to the Development of Skin in Vertebrates

The integument of vertebrates is a complex and large organ positioned at the interface with the aquatic or terrestrial environment, and is derived from the embryonic ectoderm (epidermis) and mesoderm (dermis and hypodermis) [...].

Morus alba L. root decreases melanin synthesis via sphingosine-1-phosphate signaling in B16F10 cells

ETHNOPHARMACOLOGICAL RELEVANCE

Morus alba L. has long been used for beauty in many Asian countries and regions, including anti-aging and hyperpigmentation.

AIM OF THE STUDY

This study aimed at the inhibitory effect of Morus alba L. root on melanogenesis in B16F10 melanoma cells and the mechanism involved.

MATERIALS AND METHODS

This study evaluated the anti-melanogenic effect of Morus alba L. root extract (MAR) on B16F10 melanoma cells by assessing cell viability, melanin accumulation, cellular tyrosinase activity, intra/inter-cellular S1P levels, cellular S1P-related metabolic enzyme activity, and western blot analysis. In addition, the potential S1P lyase (S1PL) inhibitory constituents in MAR were identified by LC-MS/MS.

RESULTS

Without affecting the viability of B16F10 melanoma cells, MAR inhibited intracellular tyrosinase activity in a dose-dependent manner, thereby reducing the accumulation of melanin. MAR also downregulated the expression level of MITF via activating the ERK signaling pathway. Furthermore, MAR increased the intra/inter-cellular S1P by inhibiting S1PL. Several compounds with inhibitory S1PL activity have been identified in MAR, such as mulberroside A and oxyresveratrol.

CONCLUSIONS

The anti-melanogenic effects of MAR mainly involve promoting MITF degradation mediated via S1P-S1PR3-ERK signaling through increasing cellular S1P levels by inhibiting S1PL activity.

Polarity in skin development and cancer

The epidermis is a stratified squamous epithelium that forms the outermost layer of the skin. Its primary function is to act as a barrier, keeping pathogens and toxins out and moisture in. This physiological role has necessitated major differences in the organization and polarity of the tissue as compared to simple epithelia. We discuss four aspects of polarity in the epidermis - the distinctive polarities of basal progenitor cells as well as differentiated granular cells, the polarity of adhesions and the cytoskeleton across the tissue as keratinocytes differentiate, and the planar cell polarity of the tissue. These distinctive polarities are essential for the morphogenesis and the function of the epidermis and have also been implicated in regulating tumor formation.

Extracellular matrix stiffness-The central cue for skin fibrosis

Skin fibrosis is a physiopathological process featuring the excessive deposition of extracellular matrix (ECM), which is the main architecture that provides structural support and constitutes the microenvironment for various cellular behaviors. Recently, increasing interest has been drawn to the relationship between the mechanical properties of the ECM and the initiation and modulation of skin fibrosis, with the engagement of a complex network of signaling pathways, the activation of mechanosensitive proteins, and changes in immunoregulation and metabolism. Simultaneous with the progression of skin fibrosis, the stiffness of ECM increases, which in turn perturbs mechanical and humoral homeostasis to drive cell fate toward an outcome that maintains and enhances the fibrosis process, thus forming a pro-fibrotic "positive feedback loop". In this review, we highlighted the central role of the ECM and its dynamic changes at both the molecular and cellular levels in skin fibrosis. We paid special attention to signaling pathways regulated by mechanical cues in ECM remodeling. We also systematically summarized antifibrotic interventions targeting the ECM, hopefully enlightening new strategies for fibrotic diseases.

Optical Epidermal Mimicry from Ultraviolet to Infrared Wavelengths

Optical tissue phantoms present substantial value for medical imaging and therapeutic applications. We have developed an epidermal tissue phantom to mimic the optical properties of human skin from the ultraviolet to the infrared region, exceeding the breadth of existing studies. An epoxy matrix is combined with melanin-mimicking polydopamine via a cost-effective fabrication strategy. Reflectance and transmittance measurements enable calculation of the wavelength-dependent complex refractive index and absorption coefficient. Results are compared with literature data to establish agreement with a real human epidermis. By analyzing emissive power at a typical skin temperature, the epidermal tissue phantom is shown to accurately mimic the radiative properties of human skin. This simple, multifunctional material represents a promising substitute for human tissue for a variety of medical and bioengineering applications.

Wound healing mechanism of antimicrobial peptide cathelicidin-DM

Background and Purpose: Chronic wound infections and the development of antibiotic resistance are serious clinical problems that affect millions of people worldwide. Cathelicidin-DM, an antimicrobial peptide from Duttaphrynus melanostictus, has powerful antimicrobial activity and wound healing efficacy. So, it could be a potential candidate to address this problem. In this paper, we investigate the wound healing mechanism of cathelicidin-DM to establish a basis for preclinical studies of the drug. Experimental Approach: The effects of cathelicidin-DM on cell proliferation and migration, cytokines, and mitogen-activated protein kinase (MAPK) signaling pathways were examined. Then mice whole skin wound model was constructed to evaluate the wound healing activity of cathelicidin-DM, and further histological changes in the wounds were assessed by hematoxylin-eosin staining (H&E) and immunohistochemical assays. Key Results: Cathelicidin-DM promotes the proliferation of HaCaT, HSF, and HUVEC cells in a concentration-dependent manner and the migration of HSF, HUVEC, and RAW.264.7 cells. Moreover,cathelicidin-DM can involve in wound healing through activation of the MAPK signaling pathway by upregulating phosphorylation of ERK, JNK, and P38. However, cathelicidin-DM didn't affect the secretion of IL-6 and TNF-α. At the animal level, cathelicidin-DM accelerated skin wound healing and early debridement in mice as well as promoted re-epithelialization and granulation tissue formation, α-SMA expression, and collagen I deposition in mice. Conclusion and Implications: Our data suggest that cathelicidin-DM can be engaged in the healing of infected and non-infected wounds through multiple pathways, providing a new strategy for the treatment of infected chronic wounds.

Clinical and metagenomic profiling of hormonal acne-prone skin in different populations

INTRODUCTION

Acne is one of the most common skin concerns of unknown etiology, often connected to the menstrual cycle in women, and possibly to the microbial profile and function.

OBJECTIVE

We aimed to investigate how hormonal fluctuation affects hormonal acne-prone skin in different populations in relation to skin clinical parameters and microbial profiles.

METHODS

We evaluated skin features by using biophysical and topographical tools. For microbial profiling, we sequenced facial skin microbiota and associated the findings with the skin clinical parameters during the different phases of the menstrual cycle.

RESULTS

We identified differences between and within hormonal phases in women of Chinese and Caucasian origin. Changes were discovered in transepidermal water loss (TEWL), sebum level, hydration level, and pore volume. The most abundant identifiable genera in both ethnicities were Cutibacterium, Staphylococcus, and Streptococcus, without any significant abundant differences within the menstrual cycle. Interestingly, 11 bacterial metabolic pathways were downregulated in Chinese compared to Caucasian skin during the follicular phase. The majority of these pathways were associated with skin redox balance, perhaps indicating a weaker oxidative stress response in Chinese versus Caucasian skin. Novosphingobium taxa were increased in the Chinese skin microbiome, which has been reported to protect skin from pollution-mediated oxidative stress.

CONCLUSION

Thus, this pilot study explored some of the clinical and metagenomic changes in acne-prone skin, and provide guidance to tailor-personalized skin care regimes during the menstrual cycle. Also, the skin redox status in acne-prone skin, provides more opportunity to tailor-personalized skin care regimes.

Cryptotanshinone protects skin cells from ultraviolet radiation-induced photoaging via its antioxidant effect and by reducing mitochondrial dysfunction and inhibiting apoptosis

The integrity of skin tissue structure and function plays an important role in maintaining skin rejuvenation. Ultraviolet (UV) radiation is the main environmental factor that causes skin aging through photodamage of the skin tissue. Cryptotanshinone (CTS), an active ingredient mianly derived from the Salvia plants of Lamiaceae, has many pharmacological effects, such as anti-inflammatory, antioxidant, and anti-tumor effects. In this study, we showed that CTS could ameliorate the photodamage induced by UV radiation in epidermal keratinocytes (HaCaT) and dermal fibroblasts (HFF-1) when applied to the cells before exposure to the radiation, effectively delaying the aging of the cells. CTS exerted its antiaging effect by reducing the level of reactive oxygen species (ROS) in the cells, attenuating DNA damage, activating the nuclear factor E2-related factor 2 (Nrf2) signaling pathway, and reduced mitochondrial dysfunction as well as inhibiting apoptosis. Further, CTS could promote mitochondrial biosynthesis in skin cells by activating the AMP-activated protein kinase (AMPK)/sirtuin-1 (SIRT1)/peroxisome proliferator-activated receptor-γ co-activator-1α (PGC-1α) signaling pathway. These findings demonstrated the protective effects of CTS against UV radiation-induced skin photoaging and provided a theoretical and experimental basis for the application of CTS as an anti-photodamage and anti-aging agent for the skin.

A critical review on starch-based electrospun nanofibrous scaffolds for wound healing application

Starch-based nanofibrous scaffolds exhibit a potential wound healing processes as they are cost-effective, flexible, and biocompatible. Recently, natural polymers have received greater importance in regenerative medicine, mainly in the process of healing wounds and burns due to their unique properties which also include safety, biocompatibility, and biodegradability. In this respect, starch is considered to be one of the reliable natural polymers to promote the process of wound healing at a significantly faster rate. Starch and starch-based electrospun nanofibrous scaffolds have been used for the wound healing process which includes the process of adhesion, proliferation, differentiation, and regeneration of cells. It also possesses significant activity to encapsulate and deliver biomaterials at a specific site which persuades the wound healing process at an increased rate. As the aforementioned scaffolds mimic the native extracellular matrix more closely, may help in the acceleration of wound closure, which in turn may lead to the promotion of tissue reorganization and remodeling. In-depth knowledge in understanding the properties of nanofibrous scaffolds paves a way to unfold novel methods and therapies, also to overcome challenges associated with wound healing. This review is intended to provide comprehensive information and recent advances in starch-based electrospun nanofibrous scaffolds for wound healing.

Melanoma Management: From Epidemiology to Treatment and Latest Advances

Simple Summary

Melanoma is a major public health issue that claims the lives of thousands of people every year. Furthermore, the outlook for the coming years is not encouraging with increasing morbidity and mortality trends. This review aims to offer an updated overview of various aspects related to cutaneous melanoma, from epidemiology, etiology, clinical presentation, prevention, diagnosis and staging. Moreover, conventional treatments currently available as well as the latest advances in clinical trials regarding new drugs and/or combinations, including nanotechnology-based strategies are also reviewed.

Abstract

Melanoma is the deadliest skin cancer, whose morbidity and mortality indicators show an increasing trend worldwide. In addition to its great heterogeneity, melanoma has a high metastatic potential, resulting in very limited response to therapies currently available, which were restricted to surgery, radiotherapy and chemotherapy for many years. Advances in knowledge about the pathophysiological mechanisms of the disease have allowed the development of new therapeutic classes, such as immune checkpoint and small molecule kinase inhibitors. However, despite the incontestable progress in the quality of life and survival rates of the patients, effectiveness is still far from desired. Some adverse side effects and resistance mechanisms are the main barriers. Thus, the search for better options has resulted in many clinical trials that are now investigating new drugs and/or combinations. The low water solubility of drugs, low stability and rapid metabolism limit the clinical potential and therapeutic use of some compounds. Thus, the research of nanotechnology-based strategies is being explored as the basis for the broad application of different types of nanosystems in the treatment of melanoma. Future development focus on challenges understanding the mechanisms that make these nanosystems more effective.

Transdermal Drug Delivery: Determining Permeation Parameters Using Tape Stripping and Numerical Modeling

The function of transdermal drug delivery (TDD) systems is complex due to the multiple layers necessary for controlling the rate of drug release and the interaction with the patient’s skin. In this work, we study a particular aspect of a TDD system, that is, the parameters that describe the drug permeation through the skin layers. Studies of the diffusion of two compounds were carried out and supported by tape stripping and numerical modeling. The experimental studies are carried out for porcine skin in a Franz diffusion cell and tape stripping is used to quantify the concentration of drug in the stratum corneum. A multi-layered numerical model, based on Fickian diffusion, is used to determine the unknown parameters that define the skin’s permeability, such as the partition between layers and the mass transfer coefficients due to the surface barrier. A significant correlation was found between the numerical modeling and experimental results, indicating that the partition and mass transfer effects at the interlayer boundary are accurately represented in the numerical model. We find that numerical modeling is essential to fully describe the diffusion characteristics.

Epidermal Barrier Integrity is Associated with Both Skin Microbiome Diversity and Composition in Patients with Acne Vulgaris

Background

Although the changed lipid environment of the pilosebaceous unit and the growth of lipophilic Cutibacterium acnes (C. acnes) during puberty has long been considered as the trigger of acne vulgaris, the involvement of the interaction between the epidermal barrier integrity and the skin microbiome in this disease has not been fully elucidated.

Objective

The aim of this study was to analyze the differences in the epidermal barrier and skin microbiota in patients with acne vulgaris and their correlation.

Methods

The skin microbial samples and epidermal barrier data from 74 acne patients and 19 healthy subjects were collected in this cross-sectional study. The microbial diversity was analyzed based on a high-throughput sequencing approach that targets the V3-V4 region of the bacteria 16S ribosomal RNA genes.

Results

Compared with healthy controls, acne patients had significantly increased transepidermal water loss (TEWL), pH levels, sebum, porphyrins, and red areas, and reduced skin microbiome diversity according to the goods coverage diversity index (p = 0.021), Shannon diversity index (p = 0.037), and Simpson diversity index (p = 0.023). Moreover, the diversity gradually decreased with the increase in acne grading. Based on the principal coordinate analysis (PCoA) analysis plot, the skin microbiota of acne patients and healthy controls could be divided into two different sets, which could not be used to separate acne patients with different disease severity. Finally, this study found that both TEWL and sebum were negatively associated with the Shannon and Simpson diversity index. Meanwhile, the taxa Enhydrobacter and Stenotrophomonas were positively associated with TEWL, stratum corneum hydration, respectively.

Conclusion

This study demonstrated that acne vulgaris exists in patients with both damaged epithelial barriers and associated microbiota dysbiosis; the findings will help improve the understanding of the disease and may contribute to the development of better treatment options.

How to Treat Melanoma? The Current Status of Innovative Nanotechnological Strategies and the Role of Minimally Invasive Approaches like PTT and PDT

Melanoma is the most aggressive type of skin cancer, the incidence and mortality of which are increasing worldwide. Its extensive degree of heterogeneity has limited its response to existing therapies. For many years the therapeutic strategies were limited to surgery, radiotherapy, and chemotherapy. Fortunately, advances in knowledge have allowed the development of new therapeutic strategies. Despite the undoubted progress, alternative therapies are still under research. In this context, nanotechnology is also positioned as a strong and promising tool to develop nanosystems that act as drug carriers and/or light absorbents to potentially improve photothermal and photodynamic therapies outcomes. This review describes the latest advances in nanotechnology field in the treatment of melanoma from 2011 to 2022. The challenges in the translation of nanotechnology-based therapies to clinical applications are also discussed. To sum up, great progress has been made in the field of nanotechnology-based therapies, and our understanding in this field has greatly improved. Although few therapies based on nanoparticulate systems have advanced to clinical trials, it is expected that a large number will come into clinical use in the near future. With its high sensitivity, specificity, and multiplexed measurement capacity, it provides great opportunities to improve melanoma treatment, which will ultimately lead to enhanced patient survival rates.

Current knowledge of the implication of lipid mediators in psoriasis

The skin is an organ involved in several biological processes essential to the proper functioning of the organism. One of these essential biological functions of the skin is its barrier function, mediated notably by the lipids of the stratum corneum, and which prevents both penetration from external aggression, and transepidermal water loss. Bioactive lipid mediators derived from polyunsaturated fatty acids (PUFAs) constitute a complex bioactive lipid network greatly involved in skin homeostasis. Bioactive lipid mediators derived from n-3 and n-6 PUFAs have well-documented anti- and pro-inflammatory properties and are recognized as playing numerous and complex roles in the behavior of diverse skin diseases, including psoriasis. Psoriasis is an inflammatory autoimmune disease with many comorbidities and is associated with enhanced levels of pro-inflammatory lipid mediators. Studies have shown that a high intake of n-3 PUFAs can influence the development and progression of psoriasis, mainly by reducing the severity and frequency of psoriatic plaques. Herein, we provide an overview of the differential effects of n-3 and n-6 PUFA lipid mediators, including prostanoids, hydroxy-fatty acids, leukotrienes, specialized pro-resolving mediators, N-acylethanolamines, monoacylglycerols and endocannabinoids. This review summarizes current findings on lipid mediators playing a role in the skin and their potential as therapeutic targets for psoriatic patients.

Recent Advances in Nano-Formulations for Skin Wound Repair Applications

Skin injuries caused by accidents and acute or chronic diseases place a heavy burden on patients and health care systems. Current treatments mainly depend on preventing infection, debridement, and hemostasis and on supplementing growth factors, but patients will still have scar tissue proliferation or difficulty healing and other problems after treatment. Conventional treatment usually focuses on a single factor or process of wound repair and often ignores the influence of the wound pathological microenvironment on the final healing effect. Therefore, it is of substantial research value to develop multifunctional therapeutic methods that can actively regulate the wound microenvironment and reduce the oxidative stress level at the wound site to promote the repair of skin wounds. In recent years, various bioactive nanomaterials have shown great potential in tissue repair and regeneration due to their properties, including their unique surface interface effect, small size effect, enzyme activity and quantum effect. This review summarizes the mechanisms underlying skin wound repair and the defects in traditional treatment methods. We focus on analyzing the advantages of different types of nanomaterials and comment on their toxicity and side effects when used for skin wound repair.

Novel Pharmaceutical Strategies for Enhancing Skin Penetration of Biomacromolecules

Skin delivery of biomacromolecules holds great advantages in the systemic and local treatment of multiple diseases. However, the densely packed stratum corneum and the tight junctions between keratinocytes stand as formidable skin barriers against the penetration of most drug molecules. The large molecular weight, high hydrophilicity, and lability nature of biomacromolecules pose further challenges to their skin penetration. Recently, novel penetration enhancers, nano vesicles, and microneedles have emerged as efficient strategies to deliver biomacromolecules deep into the skin to exert their therapeutic action. This paper reviews the potential application and mechanisms of novel skin delivery strategies with emphasis on the pharmaceutical formulations.

Aquaporins Are One of the Critical Factors in the Disruption of the Skin Barrier in Inflammatory Skin Diseases

The skin is the largest organ of the human body, serving as an effective mechanical barrier between the internal milieu and the external environment. The skin is widely considered the first-line defence of the body, with an essential function in rejecting pathogens and preventing mechanical, chemical, and physical damages. Keratinocytes are the predominant cells of the outer skin layer, the epidermis, which acts as a mechanical and water-permeability barrier. The epidermis is a permanently renewed tissue where undifferentiated keratinocytes located at the basal layer proliferate and migrate to the overlying layers. During this migration process, keratinocytes undertake a differentiation program known as keratinization process. Dysregulation of this differentiation process can result in a series of skin disorders. In this context, aquaporins (AQPs), a family of membrane channel proteins allowing the movement of water and small neutral solutes, are emerging as important players in skin physiology and skin diseases. Here, we review the role of AQPs in skin keratinization, hydration, keratinocytes proliferation, water retention, barrier repair, wound healing, and immune response activation. We also discuss the dysregulated involvement of AQPs in some common inflammatory dermatological diseases characterised by skin barrier disruption.

Specific protection of sensitive skin against environmental stress by maintenance and improvement of barrier function

BACKGROUND

Sensitive skin is a common condition that can severely impact quality of life. Several mechanisms are thought to be involved, including those affecting the skin barrier function, hydration and skin innervation.

OBJECTIVES

To investigate the benefit of cream and balm formulations dedicated to sensitive skin and containing Aquaphilus dolomiae extract-G3 (ADE-G3) on skin barrier functions (lipid composition, pH, TEWL), as well as protective responses to dry and pollution stresses.

METHODS

In vitro sensitized (using histamine) reconstructed human epidermis (RHE) were subjected to dehydration and pollution stress in the absence and presence of the formulations. Endpoint measurements included transepithelial electric resistance (TEER), stratum corneum protein expression and lipid contents. Clinical measurements included transepithelial water loss (TEWL), skin pH and the lipid index.

RESULTS

When applied in cream and balm formulations, ADE-G3, increased the TEER in sensitized RHEs. In non-sensitized dehydrated RHEs, both formulations increased recovery of skin barrier integrity after dehydration, evident as a return of the ratios of filaggrin/profilaggrin and caspase-14/procaspase-14 to values measured in control non-stressed RHEs, as well as reducing the 'natural moisturizing factor' to control levels. In clinical studies performed on dry human skin, the formulations helped to maintain and improve the skin barrier function. This was evident as an intense and sustained moisturization (total lipids and lipid esters were increased), an increase in pH and a decrease in the TEWL by both formulations. When exposed to pollution stress by treating the models with benzo[a]pyrene and airborne particulate matter (PM10), application of both formulations prior to exposure attenuated the induction of CYP1A1, CYP1B1 and UGT1A7 expression, indicating a protective effect.

CONCLUSIONS

ADE-G3 cream and balm formulations increased the hydration of the skin but also protected and improved the skin barrier integrity of sensitive skin exposed to dry and cold and airborne pollutant-induced stress environments.

Olfactomedin 4 regulates migration and proliferation of immortalized non-transformed keratinocytes through modulation of the cell cycle machinery and actin cytoskeleton remodelling

Olfactomedin 4 (OLFM4), a multifunctional matricellular protein, is involved in regulation of angiogenesis, innate immunity, inflammation, tumorigenesis and metastasis formation via modulation of important cellular processes like adhesion, proliferation, differentiation as well as apoptosis. In our previous work we demonstrated the upregulation of OLFM4 during liver regeneration and cutaneous wound healing. Here we studied the outcomes of OLFM4 downregulation in human immortalized keratinocytes - the HaCaT cells. The suppression of OLFM4 inhibited migration but enhanced the proliferation of these cells. By using proteomic, and phosphoproteomic analysis, we found that OLFM4 downregulation induced changes in the levels of 184 proteins and 348 phosphosites. An integrated pathway analysis suggested that the increased phosphorylation of CDK7 at Ser164 and Thr170 may serve as the key event in the activation of CDK2 and consequent activation of cell cycle progression. Furthermore, the decrease in GIT1 and WAVE2 protein levels were connected to the disorganization of the actin cytoskeleton, reduction of lamellipodia formation at the leading edge of HaCaT cells, and decrease in their migration capacity.

Human Tissue Kallikreins-Related Peptidases Are Targets for the Treatment of Skin Desquamation Diseases

Human tissue Kallikrein-related peptidases (hKLKs) are serine proteases distributed in several tissues that are involved in several biological processes. In skin, many are responsible for skin desquamation in the Stratum Corneum (SC) of the epidermis, specially hKLK5, hKLK7, hKLK6, hKLK8, and hKLK14. In SC, hKLKs cleave proteins of corneodesmosomes, an important structure responsible to maintain corneocytes attached. As part of skin desquamation, hKLKs are also involved in skin diseases with abnormal desquamation and inflammation, such as Atopic Dermatitis (AD), psoriasis, and the rare disease Netherton Syndrome (NS). Many studies point to hKLK overexpression or overactive in skin diseases, and they are also part of the natural skin inflammation process, through the PAR2 cleavage pathway. Therefore, the control of hKLK activity may offer successful treatments for skin diseases, improving the quality of life in patients. Diseases like AD, Psoriasis, and NS have an impact on social life, causing pain, itchy and mental disorders. In this review, we address the molecular mechanisms of skin desquamation, emphasizing the roles of human tissue Kallikrein-related peptidases, and the promising therapies targeting the inhibition of hKLKs.

In vivo evaluation of topical ascorbic acid application on skin aging by 50MHz ultrasound

Ascorbic acid (AA) is a powerful antioxidant capable of acting significantly both in the prevention and treatment of the skin aging process. One way to assess the in vivo efficacy of anti-aging treatments is by using the high-frequency ultrasound (HFUS) skin image analysis technique, a non-invasive approach that allows for a new level of evaluating the effectiveness of dermatological and cosmetic products. The aim of the present study was to assess the performance of a topical emulsion of liquid crystalline structures containing AA using the 50 MHz HFUS skin image analysis method. Twenty-five healthy female participants between 35 and 60 years old were included, all of whom randomly applied a placebo formulation and an AA-containing formulation to each forearm, once a day, for 30 days. HFUS measurements were performed before using the products (T0), two hours later (T2h), and after 30 days of use (T30d). The analyzed parameters included total skin, dermal, and epidermal echogenicity; variation and mean thickness of total skin, the epidermis and dermis; and surface roughness. Statistical analyses were performed using the Friedman test, followed by Dunn's test for comparisons of multiple means (α=0.05). A significant increase in total skin and dermal echogenicity was observed after topical AA application. Our findings suggest that collagen synthesis significantly increased after topical therapy with AA, which was responsible for the increment in dermal echogenicity. This study showed, through the HFUS technique, that the topical use of AA promoted dermal redensification after 30 days of application.

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.

1-Iodohexadecane Alleviates 2,4-Dinitrochlorobenzene-Induced Atopic Dermatitis in Mice: Possible Involvements of the Skin Barrier and Mast Cell SNARE Proteins

Atopic dermatitis (AD) is a chronic inflammatory dermal disease with symptoms that include inflammation, itching, and dry skin. 1-Iodohexadecane is known as a component of Chrysanthemum boreale essential oil that has an inhibitory effect on AD-like lesions. However, its effects on AD-related pathological events have not been investigated. Here, we explored the effects of 1-iodohexadecane on AD lesion-related in vitro and in vivo responses and the mechanism involved using human keratinocytes (HaCaT cells), mast cells (RBL-2H3 cells), and a 2,4-dinitrochlorobenzene (DNCB)-induced mouse model (male BALB/c) of AD. Protein analyses were performed by immunoblotting or immunohistochemistry. In RBL-2H3 cells, 1-iodohexadecane inhibited immunoglobulin E-induced releases of histamine and β-hexosaminidase and the expression of VAMP8 protein (vesicle-associated membrane proteins 8; a soluble N-ethylmaleimide-sensitive factor attachment protein receptor [SNARE] protein). In HaCaT cells, 1-iodohexadecane enhanced filaggrin and loricrin expressions; in DNCB-treated mice, it improved AD-like skin lesions, reduced epidermal thickness, mast cell infiltration, and increased filaggrin and loricrin expressions (skin barrier proteins). In addition, 1-iodohexadecane reduced the β-hexosaminidase level in the serum of DNCB-applied mice. These results suggest that 1-iodohexadecane may ameliorate AD lesion severity by disrupting SNARE protein-linked degranulation and/or by enhancing the expressions of skin barrier-related proteins, and that 1-iodohexadecane has therapeutic potential for the treatment of AD.

Repeated restraint stress modifies fatty acid and amino acid metabolism in the mouse skin

In modern society, stress caused by relationships and emotions is one of the greatest social problems. Similar to humans, domestic and captive animals live under various stresses. Several stresses have been associated with skin disorders, such as atopic dermatitis, but there is a lack of reliable and objective indicators for the characterization of this association. This study aimed to define the changes in fatty acid composition and amino acid concentration in the skin following repeated restraint stress in ICR mice. Mice subjected to 30 min of daily restraint stress for 8 days showed changes in the composition of saturated fatty acids, such as an increase in palmitic acid content, which are the substrates of Δ-9 desaturase. Conversely, unsaturated fatty acids decreased with stress treatment, which appeared to be a result of these fatty acids being the substrate of Δ-6 desaturase. Changes in fatty acid composition after stress treatment may be one of the factors that cause skin inflammation. The water-retention capacity may have been lowered by stress treatment because histidine and leucine, which are natural moisturizing factors, were significantly decreased. The collagen content in the skin gradually decreased after repeated stress treatment. Our results indicate that repeated restraint stress may impact skin health through changes in both the fatty acid composition and amino acid concentration in mice.

Recent Advances in Drug Design and Delivery Across Biological Barriers using Computational Models

Abstract:

The systemic delivery of pharmacological substances generally exhibits several significant limitations associated with the bio-distribution of active drugs in the body. As per consequence, human body’s defense mechanisms become impediments to drug delivery. Various technologies to overcome these limitations have been evolved including computational approaches and advanced drug delivery. As the body of human has evolved to defend itself from hostile biological as well as chemical invaders, along with that these biological barriers such as ocular barriers, blood-brain barriers, intestinal and skin barriers also limit the passage of drugs across desired sites. Therefore, efficient delivery remains an utmost challenge for researchers and scientists. The present review focuses on the techniques to deliver the drugs with efficient therapeutic efficacy at the targeted sites. This review article considered the insights into main biological barriers along with the application of computational or numerical methods dealing with different barriers by determining the drug flow, temperature and various other parameters. It also summarizes the advanced implantable drug delivery system to circumvent the inherent resistance showed by these biological barriers and in turn to improve the drug delivery.

Synergistic Antimicrobial Effect of Lactiplantibacillus plantarum and Lawsonia inermis Against Staphylococcus aureus

Purpose

The developed resistance of pathogenic microorganisms towards the currently used antimicrobial agents requires the fast search for newer potent antimicrobials. One of the most important ways to combat the previously mentioned disaster is the use of natural alternatives like medicinal plants. Our study aimed to estimate the anti-inflammatory property, and antibacterial effects of probiotics Lactiplantibacillus plantarum and ethanol extracts of Lawsonia inermis leaves against Staphylococcus aureus when they were used separately or collectively as synergism.

Material and Methods

Experimentally induced infected wound model in mice was created and divided into 10 groups then treated for two days by L. plantarum and L. inermis individually or in combination, followed by biochemical assays. The antibacterial, anti-inflammatory, and wound healing activity were evaluated through histopathological sections taken before and after treatment.

Results

Our results revealed that L. plantarum and L. inermis mixture could inhibit growth of S. aureus and decrease the minimal inhibitory concentration (MIC) of L. plantarum to 2 mg/mL. The mixture decreased level of both interleukin 6 (IL-6) and interferon-alpha (TNF-α) to a level near the normal uninfected group. Histopathological study showed that animals treated with both L. plantarum and L. inermis had achieved almost 90% healing.

Conclusion

These results suggest that L. plantarum and L. inermis mixture has synergistic effect on healing of infected wound.

Acral peeling in Nagashima type palmo-plantar keratosis patients reveals the role of serine protease inhibitor B 7 in keratinocyte adhesion

Acral peeling skin syndrome (APSS) is a heterogenous group of genodermatoses, manifested by peeling of palmo-plantar skin and occasionally associated with erythema and epidermal thickening. A subset of APSS is caused by mutations in protease inhibitor encoding genes, resulting in unopposed protease activity and desmosomal degradation and/or mis-localization, leading to enhanced epidermal desquamation. We investigated two Arab-Muslim siblings with mild keratoderma and prominent APSS since infancy. Genetic analysis disclosed a homozygous mutation in SERPINB7, c.796C > T, which is the founder mutation in Nagashima type palmo-plantar keratosis (NPPK). Although not previously formally reported, APSS was found in other patients with NPPK. We hypothesized that loss of SERPINB7 function might contribute to the peeling phenotype through impairment of keratinocyte adhesion, similar to other protease inhibitor mutations that cause APSS. Mis-localization of desmosomal components was observed in a patient plantar biopsy compared with a biopsy from an age- and gender-matched healthy control. Silencing of SERPINB7 in normal human epidermal keratinocytes led to increased cell sheet fragmentation upon mechanical stress. Immunostaining showed reduced expression of desmoglein 1 and desmocollin 1. This study shows that in addition to stratum corneum perturbation, loss of SERPINB7 disrupts desmosomal components, which could lead to desquamation, manifested by skin peeling.

Molecular mechanisms underlying the promotion of wound repair by coenzyme Q10: PI3K/Akt signal activation via alterations to cell membrane domains

Coenzyme Q10 (CoQ10) promotes wound healing in vitro and in vivo. However, the molecular mechanisms underlying the promoting effects of CoQ10 on wound repair remain unknown. In the present study, we investigated the molecular mechanisms through which CoQ10 induces wound repair using a cellular wound-healing model. CoQ10 promoted wound closure in a dose-dependent manner and wound-mediated cell polarization after wounding in HaCaT cells. A comparison with other CoQ homologs, benzoquinone derivatives, and polyisoprenyl compounds suggested that the whole structure of CoQ10 is required for potent wound repair. The phosphorylation of Akt after wounding and the plasma membrane translocation of Akt were elevated in CoQ10-treated cells. The promoting effect of CoQ10 on wound repair was abrogated by co-treatment with a phosphatidylinositol 3-kinase (PI3K) inhibitor. Immuno­histochemical and biochemical analyses showed that CoQ10 increased the localization of caveolin-1 (Cav-1) to the apical membrane domains of the cells and the Cav-1 content in the membrane-rich fractions. Depletion of Cav-1 suppressed CoQ10-mediated wound repair and PI3K/Akt signaling activation in HaCaT cells. These results indicated that CoQ10 increases the translocation of Cav-1 to the plasma membranes, activating the downstream PI3K/Akt signaling pathway, and resulting in wound closure in HaCaT cells.

The influence of benzoyl peroxide on skin microbiota and the epidermal barrier for acne vulgaris

The disordered skin microbiome has been reported to contribute to the pathogenesis of acne vulgaris, for which benzoyl peroxide (BPO) has long been recommended as the first-line therapy. However, there are no data regarding the effect of BPO treatment on skin microbiota and the epidermal barrier in young adults with acne vulgaris. Thirty-three patients with acne vulgaris and 19 healthy controls were enrolled in the study. All patients received topical treatment with BPO 5% gel for 12 weeks. The epidermal barrier was analyzed at baseline and after treatment. Microbial diversity was analyzed using a high-throughput sequencing approach targeting the V3-V4 region of 16S rRNA genes. After receiving treatment with BPO, patients had significant improvement in their Global Acne Grading System (GAGS) score, porphyrin, and red areas (p < 0.05), and the presence of sebum, stratum corneum hydration (SCH), and transepidermal water loss (TEWL) increased (p < 0.05). When compared with baseline, microbial diversity was significantly reduced after treatment, as calculated by the goods coverage (p = 0.0017), Shannon (p = 0.0094), and Simpson (p = 0.0017) diversity indices. The prevalence of the genus Cutibacterium (before treatment: 5.64 [3.50, 7.78] vs. after treatment: 2.43 [1.81, 3.05], p = 0.011) was significantly reduced after treatment while Staphylococcus (before treatment: 43.80 [36.62, 50.98] vs. after treatment: 53.38 [44.88, 61.87], p = 0.075) tended to increase. The abundance of Staphylococcus was negatively associated with SCH (p = 0.008, r = -0.286). Despite its contribution to an improved GAGS score, BPO treatment for acne vulgaris may reduce microbial diversity and damage the epidermal barrier. This article is protected by copyright. All rights reserved.

Ultraviolet B Irradiation Alters the Level and miR Contents of Exosomes Released by Keratinocytes in Diabetic Condition

Ultraviolet B (UVB) stimulates the generation of extracellular vesicles, which elicit systemic effects. Here, we studied whether UVB affects the release and microRNA (miR) content of keratinocyte exosomes (EXs) in diabetic conditions. In vitro, we examined the UVB effects on affecting EX release from keratinocyte HaCaT cells (HaCaT‐EX) pretreated with high glucose. HaCaT‐EX functions were evaluated on Schwann cells (SCs). In vivo, UVB‐induced miR change in skin EXs of diabetic db/db mice was analyzed. The miRs of interest were validated in HaCaT‐EXs. We found that: (1) UVB promoted HaCaT‐EX generation in dose‐ and time‐dependent manners; 100 and 1800 J m⁻² of UVB had the most prominent effect and were selected as effective low‐ and high‐fluence UVB in vitro. (2) A total of 13 miRs were differentially expressed >3‐fold in skin EXs in UVB‐treated db/db mice; miR‐126 was the most up‐regulated by low‐fluence UVB. (3) Functional studies revealed that the SC viability was improved by low‐fluence UVB HaCaT‐EXs, while worsened by high‐fluence UVB HaCaT‐EXs. (4) MiR‐126 inhibitor attenuated the effects induced by low‐fluence UVB HaCaT‐EXs. Our data have demonstrated that low‐ and high‐fluence UVBs promote HaCaT‐EX generation but differentially affect exosomal miR levels and functions under diabetic conditions.

Topical Application of Galgeunhwanggeumhwangryeon-Tang Recovers Skin-Lipid Barrier and Ameliorates Inflammation via Filaggrin-Thymic Stromal Lymphopoietin-Interleukin 4 Pathway

Background and objectives: The purpose of this study was to confirm the effect of Galgeunhwanggeumhwangryeon-tang (GGRT) on the skin barrier integrity and inflammation in an atopic dermatitis-like animal model. Materials and Methods: The model was established using lipid barrier elimination (LBE) in BALB/c mice. Ceramide 3B, a control drug, and GGRT were applied to the skin of LBE mice. Gross observation and histological examination were combined with measurement of skin score, trans-epidermal water loss, and pH. The expression of filaggrin, kallikrein-related peptidase 7 (KLK7), protease-activated receptor-2 (PAR-2), thymic stromal lymphopoietin (TSLP), and interleukin 4 (IL-4) was examined. Results: The effect of GGRT on atopic dermatitis was estimated in silico using two individual gene sets of human atopic dermatitis. In animal experiments, GGRT treatment reduced atopic dermatitis-like symptoms, as confirmed via gross and histological observations, skin score, pH change, and trans-epidermal water loss. The expression level of filaggrin increased in the skin of GGRT-treated mice compared to that in the LBE group. The expression levels of KLK7, PAR2, TSLP, and IL-4 were decreased in GGRT-treated mice skin compared to those in LBE mice. Conclusions: We demonstrated that GGRT restored the skin barrier and reduced inflammatory reactions in a murine model of atopic dermatitis.