Intact Barrier Research Articles

Herbal nanocosmecuticals: A review on cosmeceutical innovation.

Cosmeceuticals are drugs, cosmetics, or a combination of both. Cosmeceuticals are personal care products that not only beautify but also need to have healing, therapeutic, and disease-fighting characteristics. For decades, phytocompounds have been employed in cosmeceuticals and have shown potential in applications such as moisturizing, sunscreen, antiaging, and hair-based therapy. The inability of phytocompounds to easily penetrate through the skin and their instability limit their usage in cosmetic products. This can be overcome by incorporating nanotechnology into cosmetic products for a more stable and long-lasting release. Nanotechnology's substantial impact on the cosmetics industry is due to the improved properties attained by particles at the nano scale, such as color, solubility, and transparency. Liposomes, solid lipid nanoparticles, niosomes, and many varieties of nanoparticulate systems are commonly used in cosmetics. Safety concerns for the usage of nanomaterials in cosmeceuticals have been raised lately, hence causing the restriction on the use of nanomaterials by cosmetic companies and enforcing laws demanding thorough safety testing prior to market entry. This review focuses on the types of nanomaterials used in phytocosmetics, along with the potential hazards they pose to human life and the environment, and what legislation has been enacted or can be enacted to address them. For relevant literature, a literature search was conducted using PubMed, ScienceDirect, and Google Scholar. Nanotechnology, cosmeceuticals, herbal cosmetics, and other related topics were researched and evaluated in articles published between 2016 and 2022. Herbal drugs provide a tremendous range of therapeutic benefits. And when nanoparticles were introduced to the personal care industry, the quality of the final product containing phyto-compounds continued to rise. Unfortunately, because these nano components can permeate intact skin barriers and create unwanted consequences, this revolution comes with a slew of health risks. The cosmeceutical industry's expansion and growth in the application of herbal compounds, as well as the entrance of nanotechnology into the cosmeceuticals business, entail the urgent need for scientific research into their efficacy, safety profile, and use.

<em>In Vivo</em> Vascular Permeability Detection in Mouse Submandibular Gland

Saliva plays an important role in oral and overall health. The intact endothelial barrier function of blood vessels enables saliva secretion, whereas the endothelial barrier dysfunction is related to many salivary gland secretory disorders. The present protocol describes an in vivo paracellular permeability detection method to evaluate the function of endothelial tight junctions (TJs) in mouse submandibular glands (SMG). First, fluorescence-labeled dextrans with different molecular weights (4 kDa, 40 kDa, or 70 kDa) were injected into the angular veins of mice. Afterward, the unilateral SMG was dissected and fixed in the customized holder under a two-photon laser-scanning microscope, and then images were captured for blood vessels, acini, and ducts. Utilizing this method, the real-time dynamic leakage of the different-sized tracers from blood vessels into the basal sides of the acini and even across the acinar epithelia into the ducts was monitored to evaluate the alteration of the endothelial barrier function under physiological or pathophysiological conditions.

LB962 Barrier integrity test for in vitro permeation testing of topical and transdermal products

In vitro skin permeation testing (IVPT) is often used to ensure sufficient efficacy of dermaceuticals. IVPT studies utilize viable tissue membrane to represent in vivo conditions. The intact barrier of such tissue membrane provides biological relevance, in vitro. Transepidermal water loss (TEWL) measures changes in water vapor density on the skin surface. The purpose of this study was to evaluate TEWL as an appropriate barrier integrity test, in vitro, and determine an acceptable range using a Delfin® Vapometer.

Facial skin ageing: Key concepts and overview of processes.

IntroductionThe face is a cosmetically sensitive region where the process of ageing is most clearly manifested. With increased focus on anti‐ageing and longevity, more anti‐senescent treatments are being proposed despite limited evidence. This study outlines the pathways and mechanisms underpinning the biological process of ageing in the face.MethodsComprehensive searches of MEDLINE, EMBASE, Cochrane Library and CINAHL from inception to 2020. Inclusion criteria included all empirical human research studies specific to facial ageing features, written in the English language.ResultsA total of 65 papers met inclusion criteria for analysis. Pathways were subdivided into intrinsic and extrinsic senescence mechanisms. Intrinsic pathways included genetics, generation of reactive oxygen species and hormonal changes. Extrinsic pathways included photoageing and damage to skin layers. The combined intrinsic and extrinsic pathway alterations result in wrinkles, higher laxity, slackness and thinning of the skin. Skin functions such as barrier immune function, wound healing, thermoregulation and sensory function are also impaired.ConclusionThe ageing process is unique to the individual and depends on the interplay between an individual's genetics and external environmental factors. Through understanding the molecular and cellular mechanisms, an appreciation of the consequent structural and functional changes can be achieved. Based on this knowledge, further research can focus on how to slow or impede the ageing process and identify specific targets to develop and evolve new treatment strategies.

The mounted alloimmunity of the iris-ciliary body devotes a hotbed of immune cells for corneal transplantation rejection

Graft rejection is still the major obstacle causing corneal transplantation failure. However, the underlying pathogenesis remains largely unclear. The iris-ciliary body (I–C) is enriched with blood vessels and various immune cell populations, presumably predisposed to be involved in corneal transplantation rejection. After penetrating keratoplasty, compared to the normal (Nor) and syngeneic (Syn) groups, I–C tissues in the allogeneic (Allo) group displayed stronger alloimmune responses, with more infiltrations of CD45+ inflammatory cells and CD3+ lymphocytes, increased transcriptional levels of pro-inflammatory cytokines, and elevated NF-κB activity. This histopathology was similar to the pathological alterations of corneal allografts. Angiography analysis revealed the abnormal vasculature in the iris during allograft rejection, characterized by vasodilatation, increased vessel density, and vascular permeability. While, immunofluorescence staining showed the intact tight junction of the posterior iris epithelium. In vitro, human microvascular endothelial cells (HMECs) stimulated by tumor necrosis factor-α (TNF-α) showed an increased Evans blue (EB)-albumin leakage, with lower expression of zonula occludens-1 (ZO-1) and Occludin. The increased EB-albumin leakage, up-regulated NF-κB activity, and reduced expression of ZO-1 and Occludin could be partially reversed after cyclosporine A (CsA) administration. In contrast, the barrier function in primary mouse iris pigment epithelial cells (IPEs) after TNF-α treatment remained largely unchanged. These findings revealed the vigorous alloimmunity in I–C tissues, characterized with impaired vascularization but intact posterior epithelial barrier in the iris, which allowed proteins and immune cells to be exudated from the front surface of I–C tissues, and facilitated immune reaction in the anterior chamber, thereby contributing to aggravated corneal transplantation rejection.

Impact of in vitro digested zinc oxide nanoparticles on intestinal model systems

BackgroundZinc oxide nanoparticles (ZnO NP) offer beneficial properties for many applications, especially in the food sector. Consequently, as part of the human food chain, they are taken up orally. The toxicological evaluation of orally ingested ZnO NP is still controversial. In addition, their physicochemical properties can change during digestion, which leads to an altered biological behaviour. Therefore, the aim of our study was to investigate the fate of two different sized ZnO NP (< 50 nm and < 100 nm) during in vitro digestion and their effects on model systems of the intestinal barrier. Differentiated Caco-2 cells were used in mono- and coculture with mucus-producing HT29-MTX cells. The cellular uptake, the impact on the monolayer barrier integrity and cytotoxic effects were investigated after 24 h exposure to 123–614 µM ZnO NP.Results In vitro digested ZnO NP went through a morphological and chemical transformation with about 70% free zinc ions after the intestinal phase. The cellular zinc content increased dose-dependently up to threefold in the monoculture and fourfold in the coculture after treatment with digested ZnO NP. This led to reactive oxygen species but showed no impact on cellular organelles, the metabolic activity, and the mitochondrial membrane potential. Only very small amounts of zinc (< 0.7%) reached the basolateral area, which is due to the unmodified transepithelial electrical resistance, permeability, and cytoskeletal morphology.ConclusionsOur results reveal that digested and, therefore, modified ZnO NP interact with cells of an intact intestinal barrier. But this is not associated with serious cell damage.

Barrier Perturbation in Porcine Peyer's Patches by Tumor Necrosis Factor is Associated With a Dysregulation of Claudins.

The proinflammatory cytokine tumor necrosis factor (TNF) has been described as one of the main mediators of intestinal inflammatory diseases, affecting the composition of tight junction (TJ) proteins and leading to a disruption of the epithelial barrier. An intact intestinal barrier is mandatory, because the follicle-associated epithelium of Peyer’s patches represents the first defense line of the intestinal immune system and ensures a controlled uptake of antigens from the gut lumen. In the current study, we have analyzed the detailed effects of TNF on the follicle-associated epithelium of porcine Peyer’s patches by applying the Ussing chamber technique. Epithelial tissue specimens of Peyer’s patches and the surrounding villus epithelium were mounted into conventional Ussing chambers and incubated with TNF for 10 h. The transepithelial resistance, representing epithelial barrier function of the tissue, was recorded. A reduction of transepithelial resistance was detected after 8 h in Peyer’s patch tissue specimens, whereas the villus epithelium was not significantly affected by TNF. Subsequent molecular analysis of TJ protein expression revealed a marked decrease of claudin-1 and -4, and an increase of claudin-2. In neighboring villus epithelium, no significant changes in the expression of TJ proteins could be shown. A strong increase of TNF receptor-2 (TNFR-2) could also be detected in Peyer’s patches, in agreement with the major role of this receptor in Peyer’s patches. Our findings were in accordance with changes detected by confocal laser scanning immunofluorescence microscopy. The regulation of TNF effects via myosin light chain kinase (MLCK) was analyzed in blocking experiments. Our detailed analysis is the first to show that TNF affects the barrier function of the follicle-associated epithelium of porcine Peyer’s patches but has no effects on the villus epithelium. These findings reveal not only the basic differences of epithelial barrier function between the two structures, but also the significance of Peyer’s patches as a primary mucosal immune defense.

Loss of γδ intraepithelial lymphocytes and reduced immunosurveillance of the epithelial barrier precedes the onset of Crohn’s disease‐like ileitis

Inflammatory bowel disease, including Crohn’s disease (CD), affects over 3 million Americans. Recently, single cell sequencing of resected ileal tissue from CD patients revealed a loss of γδ intraepithelial lymphocytes (IELs). IELs expressing the γδ T cell receptor (γδ IEL) bridge innate and adaptive immunity and migrate dynamically within the intestinal epithelium as a means of immunosurveillance. However, the contribution of γδ IELs to the initiation of ileitis remains unknown. We and others have found that the onset of histopathology in TNFΔARE/+mice, which develop a chronic CD‐like ileitis, occurs at 8 weeks of age. We profiled the IEL populations of TNFΔARE/+mice prior to and during the initial stages of ileal inflammation (4, 6, 8 and 10 weeks). In agreement with CD patient data, we observed about a 2‐fold reduction in the γδ IEL population in ilea of 8‐week‐old TNFΔARE/+mice compared to TNF+/+ (WT) littermates (p=0.05). Seeding of γδ IELs within the epithelial compartment is regulated in part by expression of epithelial butyrophilin‐like genes Btnl1 and Btnl6. We find that the expression of both Btnl1 and Btnl6is reduced in 4‐ and 6‐week‐old TNFΔARE/+mice (p=0.05). Furthermore, the frequency of EdU+ γδ IELs is decreased in TNFΔARE/+mice compared to WT littermates at 6 weeks of age (p=0.05). γδ IEL motility and function contribute to maintenance of an intact epithelial barrier, as we have recently demonstrated that γδ IELs facilitate shedding of apoptotic epithelial cells. Cleaved caspase 3 staining in fixed ileal tissue revealed increased shedding of apoptotic enterocytes in 6‐week‐old TNFΔARE/+mice compared to WTlittermates (p=0.05). Since γδ IEL surveillance behavior is altered during the shedding of apoptotic enterocyte, we next assessed γδ IEL motility in 6‐week‐old WT and TNFΔARE/+ mice using intravital microscopy. γδ IEL migratory behavior is significantly impaired in TNFΔARE/+ mice, as reflected by reduced track speed (7.9 vs 2.8 μm/min, p=0.005) and increased arrest coefficient (p=0.001) relative to WT mice. To determine the contribution of γδ IELs in the development of CD‐like ileitis, we generated TNFΔARE/+ mice expressing diphtheria toxin (DT) receptor driven by a γδ T‐cell‐specific promoter (TNFΔARE/+ TcrdGDL). Our preliminary findings indicate that DT‐treated 3‐week‐old TNFΔARE/+ TcrdGDL mice exhibit reduced survival compared to TNFΔARE/+ littermates treated with vehicle control (Mantel‐Cox log‐rank test, p=0.155). In summary, we report that the onset of ileal inflammation coincides with the reduction of γδ IELs, which may be attributed to decreased epithelial Btnl expression and impaired γδ IEL proliferation. Reduced survival of TNFΔARE/+ mice following γδ T cell depletion suggests that γδ IEL‐mediated maintenance and surveillance of the barrier is critical to maintain mucosal tolerance prior to disease onset. These studies suggest that restoring γδ IEL number or migratory behavior may be effective therapeutic strategies to maintain remission in CD patients.

Reconstructing the epidermal proteolytic cascades in health and disease.

The epidermis is the outer stratified epithelium of the skin, forming the physical barrier that is indispensable for homeostasis. Epidermal proteolysis, mainly but not exclusively executed by kallikrein-related peptidases (KLKs), is tightly regulated to ensure maintenance of physiological skin renewal and an intact skin barrier. Perturbation of epidermal proteolytic networks is implicated in a wide array of rare and common skin pathologies of diverse genetic backgrounds. Recent studies of monogenic human skin diseases and newly developed animal models have revealed new mechanisms of regulation of proteolytic pathways in epidermal physiology and in disease states. These new data have challenged some accepted views, for example the role of matriptase in epidermal desquamation, which turned out to be restricted to mouse skin. The significance of PAR2 signaling in skin inflammation should also be reconsidered in the face of recent findings. Cumulatively, recent studies necessitate a sophisticated redefinition of the proteolytic and signaling pathways that operate in human skin. We elaborate how epidermal proteolysis is finely regulated at multiple levels, and in a spatial manner that has not been taken into consideration so far, in which specific proteases are confined to distinct epidermal sublayers. Of interest, transglutaminases have emerged as regulators of epidermal proteolysis and desquamation by spatially fixing endogenous protease inhibitors, constituting regulatory factors that were not recognized before. Furthermore, new evidence suggests a link between proteolysis and lipid metabolism. By synthesis of established notions and recent discoveries, we provide an up-to-date critical evaluation and synthesis of current knowledge and the extended complexity of proteolysis regulation and signaling pathways in skin. © 2022 The Pathological Society of Great Britain and Ireland.

Impact of Caveolin-Mediated Endocytosis on the Trafficking of HIV within the Colonic Barrier.

ABSTRACTIn the United States, most new cases of human immunodeficiency virus (HIV) belong to the at-risk group of gay and bisexual men. Developing therapies to reverse viral latency and prevent spread is paramount for the HIV cure agenda. In gay and bisexual men, a major, yet poorly characterized, route of HIV entry is via transport across the colonic epithelial barrier. While colonic tears and paracellular transport contribute to infection, we hypothesize that HIV entry through the colonic mucosa proceeds via a process known as transcytosis, involving (i) virion binding to the apical surface of the colonic epithelium, (ii) viral endocytosis, (iii) transport of virions across the cell, and (iv) HIV release from the basolateral membrane. Using Caco-2 colonic epithelial cells plated as a polarized monolayer in transwells, we characterized the mechanism of HIV transport. After exposing the monolayer to HIV apically, reverse transcription quantitative PCR (RT-qPCR) of the viral genome present in the basolateral chamber revealed that transport is dose dependent, cooperative, and inefficient, with released virus first detectable at 12 h. Inefficiency may be associated with >50% decline in detectable intracellular virus that correlates temporally with increased association of the virion with lysosomal-associated membrane protein 1 (LAMP-1+) endosomes. Microscopy revealed green fluorescent protein (GFP)-labeled HIV within the confines of the epithelial monolayer, with no virus detectable between cells, suggesting that viral transport is transcellular. Treatment of the monolayer with endocytosis inhibitors, cholesterol reducing agents, and small interfering RNA (siRNA) to caveolin showed that viral endocytosis is mediated by caveolin-coated endosomes contained in lipid rafts. These results indicate that HIV transport across the intestinal epithelial barrier via transcytosis is a viable mechanism for viral spread and a potential therapeutic target.IMPORTANCE Despite the success of combination antiretroviral therapy in suppressing HIV replication and the emergence and effectiveness of PrEP-based prevention strategies, in 2018, 37,968 people in the United States received a new HIV diagnosis, accompanied by 15,820 deaths. While the annual number of new diagnoses decreased 7% from 2014 to 2018, 14% of people with HIV did not know they were infected. Gay and bisexual men accounted for 69% of all HIV diagnoses and 83% of diagnoses among males. Due to the scope of the HIV epidemic, determining and understanding precise routes of infection and the mechanisms of viral spread are paramount to ending the epidemic. Since transcellular transport of HIV across an intact colonic epithelial barrier is poorly understood, our overall goal is to characterize the molecular events involved in HIV transcytosis across the intestinal epithelial cell.

Optimizing the protocol for retinal vascular permeability mapping from fluorescein videoangiography data.

An intact blood-retinal barrier is critical to maintaining the function of the retina. Many diseases of the eye have been directly associated with impairment in vascular permeability, and methods to measure vascular permeability could offer a window into early detection of disease; however, there exist no direct measures of vascular permeability that have be translated to the clinic. This work details a complete clinical workflow to quantify vascular permeability and volumetric blood flow from fluorescein videoangiography data, with validation through realistic simulations. For optimizing the protocol, this study carried on frame rate of fluorescein videoangiography to generate a high-resolution image while minimizing the error.

Expression characteristics of polymeric immunoglobulin receptor in Bactrian camel (Camelus bactrianus) lungs.

Polymeric immunoglobulin receptor (pIgR), the transmembrane transporter of polymeric immunoglobulin A and M, has multiple immune functions. To explore the characteristics of pIgR expression in Bactrian camel lungs, twelve healthy adult (2–7 years old) Bactrian camels were systematically studied. The results showed that pIgR was mainly expressed in the cytoplasm and membrane of ciliated cells, as well as in the cytoplasm and membrane of basal cells, serous cells of bronchial glands, club cells and alveolar type 2 cells in Bactrian camel lungs. Specially, as the bronchial branches extended, the pIgR expression level in ciliated cells significantly declined (p<0.05), and the corresponding bronchial luminal areas obviously decreased (p<0.05). However, pIgR was not expressed in goblet cells, endocrine cells, alveolar type 1 cells and mucous cells of bronchial glands. The results demonstrated that ciliated cells continuously distributed throughout the whole bronchial tree mucosa were the major expression sites of pIgR, and pIgR was also expressed in basal cells, serous cells of bronchial glands, club cells and alveolar type 2 cells, which would facilitate secretory immunoglobulin A (SIgA) transmembrane transport by pIgR and form an intact protective barrier. Moreover, the pIgR expression level in ciliated cells was positively correlated with the bronchial luminal areas; but negatively correlated with the cleanliness of airflow through the bronchial cross-sections, showing that the pIgR expression level in the bronchial epithelium was inhomogeneous. Our study provided a foundation for further exploring the regulatory functions of immunoglobulins (i.e., SIgA) after transport across the membrane by pIgR in Bactrian camel lungs.

Effects of Zinc Oxide Nanoparticles on Model Systems of the Intestinal Barrier.

Zinc oxide nanoparticles (ZnO NP) are often used in the food sector, among others, because of their advantageous properties. As part of the human food chain, they are inevitably taken up orally. The debate on the toxicity of orally ingested ZnO NP continues due to incomplete data. Therefore, the aim of our study was to examine the effects of two differently sized ZnO NP (<50 nm and <100 nm primary particle size; 123–614 µmol/L) on two model systems of the intestinal barrier. Differentiated Caco-2 enterocytes were grown on Transwell inserts in monoculture and also in coculture with the mucus-producing goblet cell line HT29-MTX. Although no comprehensive mucus layer was detectable in the coculture, cellular zinc uptake was clearly lower after a 24-h treatment with ZnO NP than in monocultured cells. ZnO NP showed no influence on the permeability, metabolic activity, cytoskeleton and cell nuclei. The transepithelial electrical resistance was significantly increased in the coculture model after treatment with ≥307 µmol/L ZnO NP. Only small zinc amounts (0.07–0.65 µg/mL) reached the basolateral area. Our results reveal that the cells of an intact intestinal barrier interact with ZnO NP but do not suffer serious damage.

Immunomodulatory effects of mixed Lactobacillus plantarum on lipopolysaccharide-induced intestinal injury in mice.

The intestine is the largest digestive and immune organ in the human body, with an intact intestinal mucosal barrier. Lactobacillus plantarum is an important strain of probiotics in the intestine for boosting intestinal immunity to defend against intestinal injury. In the lipopolysaccharide-induced intestinal injury model, mixed L. plantarum (L. plantarum KLDS 1.0318, L. plantarum KLDS 1.0344, and L. plantarum KLDS 1.0386) was suggested to boost intestinal immunity. In detail, compared with LPS-induced mice, mice in the mixed L. plantarum group showed significantly reduced intestine (jejunum, ileum, and colon) tissue injury, pro-inflammatory cytokine (TNF-α, IL-6 and IL-12) levels, myeloperoxidase activities, and serum D-lactate (P < 0.05) content. Moreover, the mixed L. plantarum significantly increased the number of immunocytes (CD4+ T cells, IgA plasma cells) and the expression of tight junction proteins (Claudin1 and Occludin). The results also showed that the mixed L. plantarum significantly down-regulated (P < 0.05) the intestinal protein expression of TLR4, p-IκB, and NF-κB p65. The mixed L. plantarum group increased the relative abundance of the genera, including Lactobacillus, Lachnoclostridium, and Desulfovibrio, which are related to improving the levels of SCFAs (acetic acid, butyric acid) and total bile acid (P < 0.05). Overall, these results indicated that the mixed L. plantarum had great functionality in reducing LPS-induced intestinal injury.

Microneedle Transdermal Drug Delivery Systems for Allergen-Specific Immunotherapy, Skin Disease Treatment, and Vaccine Development.

Transdermal drug delivery systems (TDDSs) overcome the hurdle of an intact skin barrier by penetrating the skin to allow molecules through. These systems reduce side effects associated with conventional hypodermic needles. Here, we introduce novel microneedle (MN) TDDSs that enhance drug delivery by creating micron-sized pores across the skin. Many MN TDDSs designed to deliver a diverse array of therapeutics, including allergen-specific immunotherapy, skin disease treatments, and vaccines, are under pre-clinical and clinical trials. Although epicutaneous approaches are emerging as new options for treating food allergy in many clinical trials, MN TDDSs could provide a more efficient and convenient route to deliver macromolecules. Furthermore, MN TDDSs may allow for safe vaccine delivery without permanent scars. MN TDDSs are a major emerging strategy for delivering novel vaccines and treatments for diseases, including skin diseases, allergic diseases, and so on.

Airway inflammation due to SARS-CoV-2

Although there has been a large number of studies focusing on the role of airways in coronavirus disease 2019 (COVID-19), the relationship still remains unclear. With the disruption of the defense mechanism of the airways, including the intact mucus barrier, ciliary activity, and normal cough reflex, sticky and difficult-to-remove sputum becomes the main problem and the cough becomes the main symptom. Although interferons are considered the main elements of the defense against the virus, the pathogenesis of COVID-19 is complex and cannot be elucidated with only elevated interferon levels; there is more. The progression of the disease is mainly determined by the type and the levels of interferons and the affected part of the respiratory system. The airways have an important role in the pathogenesis of COVID-19, as the microorganism uses the airways as a gateway to the body, being the first element of defense against the virus, the importance of its relationship with the immune system, and its importance in the treatment.

Management of Unusual Pattern of Internal Inflammatory Tooth Resorption and Periapical Cystic Lesion - A Unique Case Report

Dental trauma is a challenge for dental integrity and can lead to various consequences, among which internal inflammatory root resorption can also be the fate of anterior teeth as they are commonly involved in traumatic events. The internal inflammatory root resorption occurs as a result of damage to the predentin due to trauma, plus root canal system becoming infected with bacteria. Trauma generates chronic inflammation, which leads to periapical inflammation and necrosis of epithelial cells, resulting in the formation of a cyst. The aim of the treatment approaches should be to assure complete biological healing and functional integration. This case report presents the unique characterization of traumatic consequences, including large periapical lesion and unique pattern of internal tooth resorption with intact apical barrier which was diagnosed by cone-beam computed tomography imaging and well managed by surgical intervention using mineral trioxide aggregate – both as a retrograde filling and tooth reinforcement material and sticky bone (platelet-rich fibrin + Bio-Oss) as a regenerative approach. The follow-up showed good results both clinically and radiographically. Thus, it can be concluded that endodontic reinforcement of thin roots due to internal resorption with intact apical barrier and surgical microendodontic procedure with regeneration is a potential therapeutic option in cases of traumatic injuries.

Tracking macrophages in diabetic neuropathy with two-color nanoemulsions for near-infrared fluorescent imaging and microscopy

BackgroundThe incidence of diabetes and diabetic peripheral neuropathy continues to rise, and studies have shown that macrophages play an important role in their pathogenesis. To date, macrophage tracking has largely been achieved using genetically-encoded fluorescent proteins. Here we present a novel two-color fluorescently labeled perfluorocarbon nanoemulsion (PFC-NE) designed to monitor phagocytic macrophages in diabetic neuropathy in vitro and in vivo using non-invasive near-infrared fluorescent (NIRF) imaging and fluorescence microscopy.MethodsPresented PFC-NEs were formulated with perfluorocarbon oil surrounded by hydrocarbon shell carrying two fluorescent dyes and stabilized with non-ionic surfactants. In vitro assessment of nanoemulsions was performed by measuring fluorescent signal stability, colloidal stability, and macrophage uptake and subsequent viability. The two-color PFC-NE was administered to Leprdb/db and wild-type mice by tail vein injection, and in vivo tracking of the nanoemulsion was performed using both NIRF imaging and confocal microscopy to assess its biodistribution within phagocytic macrophages along the peripheral sensory apparatus of the hindlimb.ResultsIn vitro experiments show two-color PFC-NE demonstrated high fluorescent and colloidal stability, and that it was readily incorporated into RAW 264.7 macrophages. In vivo tracking revealed distribution of the two-color nanoemulsion to macrophages within most tissues of Leprdb/db and wild-type mice which persisted for several weeks, however it did not cross the blood brain barrier. Reduced fluorescence was seen in sciatic nerves of both Leprdb/db and wild-type mice, implying that the nanoemulsion may also have difficulty crossing an intact blood nerve barrier. Additionally, distribution of the nanoemulsion in Leprdb/db mice was reduced in several tissues as compared to wild-type mice. This reduction in biodistribution appears to be caused by the increased number of adipose tissue macrophages in Leprdb/db mice.ConclusionsThe nanoemulsion in this study has the ability to identify phagocytic macrophages in the Leprdb/db model using both NIRF imaging and fluorescence microscopy. Presented nanoemulsions have the potential for carrying lipophilic drugs and/or fluorescent dyes, and target inflammatory macrophages in diabetes. Therefore, we foresee these agents becoming a useful tool in both imaging inflammation and providing potential treatment in diabetic peripheral neuropathy.

Pilot Study on the Forehead Skin Microbiome and Short Chain Fatty Acids Depending on the SC Functional Index in Korean Cohorts.

Dry skin is one of the indicators of a compromised skin barrier. An intact skin barrier is not only important to reserve the hydration within the epidermal tissue but also to protect our skin from environmental stressors and inhibit pathogen invasion; damage to the skin barrier may lead to inflammatory skin diseases. Some microbial metabolites such as short chain fatty acids may inhibit or destroy harmful bacteria and regulate the host immune system. The impact of the skin microbiome and short chain fatty acids on skin barrier function was studied in two groups of 75 participants each. The cohort was equally divided in dry and moist skin types, based on stratum corneum (SC) functionality index (SCFI), reflecting the ratio of transepidermal water loss (TEWL). A dry group represents a low SCFI and a moist group a high SCFI. Compared with the dry skin group, propionate and Cutibacterium levels (previously known as Propionibacterium acnes) were significantly higher (p < 0.001) in the moist group. Levels of Cutibacterium were negatively correlated with those of Staphylococcus (p < 0.0001) in both dry and moist groups. The moist group also had a significantly higher propionate concentration (p < 0.001). This study showed that the microbial community and short chain fatty acid concentration may be considered as significant determinants of the SCFI of the skin.

Longitudinal atopic dermatitis endotypes: An atopic march paradigm that includes Black children

The atopic march has been studied mostly in White populations, biasing our current paradigms. We sought to define the atopic march in Black and White children and explore mechanisms for racial differences. Utilizing the Mechanisms of Progression of Atopic Dermatitis to Asthma in Children (MPAACH) cohort (n= 601), we assessed longitudinal sensitization, food allergy (FA), allergic rhinitis, risk of asthma development (through the Pediatric Asthma Risk Score), Scoring for Atopic Dermatitis (SCORAD), transepidermal water loss, skin filaggrin (FLG) expression, exposures, and genetic heritability to define AD progression endotypes in Black and White children. White MPAACH children were more likely to be sensitized to aero and food allergens (P= .0001) and over 3 times more likely to develop FA and/or allergic rhinitis (AR) without asthma risk (P< .0001). In contrast, Black children were over 6 times more likely to proceed to high asthma risk without FA, sensitization, or AR (P< .0001). White children had higher lesional and nonlesional transepidermal water loss (both P< .001) as well as decreased nonlesional keratinocyte FLG expression (P= .02). Black children had increased genetic heritability for asthma risk and higher rates of exposures to secondhand smoke and traffic-related air pollution. Black and White children with AD have distinct allergic trajectories defined by different longitudinal endotypes. Black children exhibit higher asthma risk despite a more intact skin barrier and less sensitization, FA, and AR. White children have less asthma risk, despite a more dysfunctional skin barrier, and more FA, AR, and sensitization. The observed racial differences are likely due in part to increased genetic heritability for asthma risk and harmful environmental exposures in Black children. Collectively, our findings provide a new paradigm for an atopic march that is inclusive of Black children.