Superficial Dermal Layer Research Articles

Rapidly molded sodium alginate/soy protein adhesive hydrogel with 808-nm laser inhibition of infected wounds

Infected wounds produce pus and heal slowly. To address this issue, we developed a rapid-setting SP/SA@BP-C hydrogel by combining sodium alginate (SA) and soy protein (SP) with black phosphorus (BP) grafted with clarithromycin (Cla) and incorporating Ca2+ for chelation. This hydrogel dressing exhibits excellent photothermal (PT) and photodynamic (PD) bacteriostatic effects without biotoxicity, making it suitable for treating infected wounds. Characterization confirmed its successful fabrication, and the bacteriostatic effect demonstrated over 99 % efficacy through the synergistic effects of PT, PD, and Cla. Cellular studies indicated nontoxicity and a promoting effect on cell proliferation (121.6 %). In the mouse-infected wound model, the hydrogel led to complete healing in 12 days, with good recovery of the skin's superficial dermal layer and appendages. Consequently, SP/SA@BP-C is a natural hydrogel dressing with promising properties.

A novel and biocompatible photopolymerizable resin based on cyclohexanedimethanol‐dimetacrylate designed to light‐print microneedles

AbstractMicroneedles offer a promising avenue for painless drug delivery through micro‐perforation, and additive manufacturing, particularly stereolithography, has proven effective for their fabrication. This study focuses on developing a novel biocompatible resin for 3D printing microneedles. Spectroscopic methods are employed to confirm the structures of all intended resin monomers, with a specific analysis of the crystallographic structure of cyclohexanedimethanol methacrylate (CDMM) using x‐ray diffraction. The results indicate that CDMM crystallizes in the monoclinic system, aligning with the P21/c space group. The fabricated conical microneedles, standing at approximately 655 μm in height, underwent thorough mechanical and thermal characterization. Depth analyses of micro‐perforations in Parafilm M and pig skin were performed using optical coherence tomography and histological sections, demonstrating successful penetration through the stratum corneum and epidermal layers into the superficial dermal layer (1.5–4 mm thickness) without affecting nerve endings. Cytocompatibility tests affirm the biocompatibility of the microneedles. This work highlights the potential of the newly developed biocompatible material for printable drug delivery systems, emphasizing microneedles and other implant forms.

Role of Dermabrasion Assisted Tangential Excision in Burns

Burn injury of second degree deep dermal and full thickness delays in healing and heals by scarring. Deep dermal burns need early treatment by tangential excision and skin grafting to promote healing. While wound irrigation, debridement, and local wound care may be sufficient for managing superficial burns (involving the epidermis and superficial dermal layer), deep burns (involving the deep dermal layer and other structures deeper to it) require tangential excision and skin grafting. If performed early it is associated with better outcomes in terms of reduced infection risk and hastened wound healing.

Revitalizing Hands: A Comprehensive Review of Anatomy and Treatment Options for Hand Rejuvenation.

Dorsal hand rejuvenation is gaining popularity as a solitary procedure and adjunct to face and neck rejuvenation treatments. As the hands age, the skin loses elasticity and becomes more translucent, the veins, joints, and tendons appear more prominent, and the bones become more noticeable. These changes are due to intrinsic and extrinsic factors. Current treatment methods include the injection of dermal fillers and autologous fat grafting. Anatomic studies to ensure the successful implementation of rejuvenation procedures identified three separate fascial layers in the dorsum, from superficial to deep. More recent re-evaluations revealed a less distinct, inseparable, sponge-like fascial layer. All authors agree that the superficial dermal layer is probably the optimal location for the injection of volumizing materials because it is free of anatomical structures. Many methods for harvesting, preparing, and injecting fat grafts to the dorsum of the hand have been described in the past three decades. Both filler and fat-graft procedures are performed on an ambulatory basis under local anesthesia. Good results with low postoperative and long-term complication rates and high patient satisfaction have been reported.

Hyaluronan Hydrogels for Injection in Superficial Dermal Layers: An In Vitro Characterization to Compare Performance and Unravel the Scientific Basis of Their Indication.

Background: Skinboosters represent the latest category of hyaluronan (HA) hydrogels released for aesthetic purposes. Different from originally developed gels, they are intended for more superficial injections, claiming a skin rejuvenation effect through hydration and possibly prompting biochemical effects in place of the conventional volumetric action. Here, three commercial skinboosters were characterized to unravel the scientific basis for such indication and to compare their performances. Methods: Gels were evaluated for water-soluble/insoluble-HA composition, rheology, hydration, cohesivity, stability and effect, in vitro, on human dermal fibroblasts towards the production of extracellular matrix components. Results: Marked differences in the insoluble-hydrogel amount and in the hydrodynamic parameters for water-soluble-HA chains were evidenced among the gels. Hydration, rigidity and cohesivity also varied over a wide range. Sensitivity to hyaluronidases and Reactive Oxygen Species was demonstrated allowing a stability ranking. Slight differences were found in gels’ ability to prompt elastin expression and in ColIV/ColI ratio. Conclusions. A wide panel of biophysical and biochemical parameters for skinboosters was provided, supporting clinicians in the conscious tuning of their use. Data revealed great variability in gels’ behavior notwithstanding the same clinical indication and unexpected similarities to the volumetric formulations. Data may be useful to improve customization of gel design toward specific uses.

A Comparative Study of Pigmented and Non-pigmented Basal Cell Carcinoma in Reflectance Confocal Microscopy.

Basal cell carcinoma (BCC) is a common skin cancer, especially in the elderly population. The probability of BCC development increases past the age of 55. Dermoscopy and reflectance confocal microscopy (RCM) are two modern tools useful in the diagnosis of BCC. This is a retrospective study conducted on a group of 21 patients with a confirmed diagnosis of BCC. All patients were examined by dermoscopy and RCM. Dermoscopic images were taken using a videodermoscope. RCM was performed in three layers: epidermal, dermoepidermal junction (DEJ), and superficial dermal layer. In each layer, a few RCM criteria of basal cell carcinoma diagnosis were taken into consideration. Dermoscopy of pigmented BCCs revealed blue globules of pigment (p<0.05), gray and blue ovoid nests, which were absent in the entire non-pigmented carcinomas group. In RCM, the epidermis showed no differences between pigmented and non-pigmented carcinomas, however, significant differences were observed at the DEJ. In pigmented BCCs, cordlike structures and plump atypical cells were observed (p<0.05), while in non-pigmented carcinomas, dark silhouettes were present (p<0.05). To our knowledge, that is the first study comparing features between pigmented and non-pigmented BCC by RCM. Pigmented and non-pigmented BCCs presented different features in both dermoscopy and RCM. Furthermore, RCM revealed more discriminating features at the DEJ than dermoscopy, thus can be more efficient in the differential diagnosis of difficult BCC.

Isolation of Papillary and Reticular Fibroblasts from Human Skin by Fluorescence-activated Cell Sorting.

Fibroblasts are a highly heterogeneous cell population implicated in the pathogenesis of many human diseases. In human skin dermis, fibroblasts have traditionally been attributed to the superficial papillary or lower reticular dermis according to their histological localization. In mouse dermis, papillary and reticular fibroblasts originate from two different lineages with diverging functions regarding physiological and pathological processes and a distinct cell surface marker expression profile by which they can be distinguished. Importantly, evidence from explant cultures from superficial and lower dermal layers suggest that at least two functionally distinct dermal fibroblasts lineages exist in human skin dermis as well. However, unlike for mouse skin, cell surface markers enabling the discrimination of different fibroblast subsets have not yet been established for human skin. We developed a novel protocol for the isolation of human papillary and reticular fibroblast populations via fluorescence-activated cell sorting (FACS) using the two cell surface markers Fibroblast Activation Protein (FAP) and Thymocyte antigen 1 (Thy1)/CD90. This method enables the isolation of pure fibroblast subsets without in vitro manipulation, which was shown to affect gene expression, thus permitting accurate functional analysis of human dermal fibroblast subsets in regard to tissue homeostasis or disease pathology.

Lineage Identity and Location within the Dermis Determine the Function of Papillary and Reticular Fibroblasts in Human Skin

Human skin dermis is composed of the superficial papillary dermis and the reticular dermis in the lower layers, which can easily be distinguished histologically. Invitro analyses of fibroblasts from explant cultures from superficial and lower dermal layers suggest that human skin comprises at least two fibroblast lineages with distinct morphology, expression profiles, and functions. However, while for mouse skin cell surface markers have been identified, allowing the isolation of pure populations of one lineage or the other via FACS, this has not been achieved for human skin fibroblasts. We have now discovered two cell surface markers that discriminate between papillary and reticular fibroblasts. While FAP+CD90- cells display increased proliferative potential, express PDPN and NTN1, and cannot be differentiated into adipocytes, FAP-CD90+ fibroblasts express high levels of ACTA2, MGP, PPARγ, and CD36 and readily undergo adipogenic differentiation, a hallmark of reticular fibroblasts. Flow cytometric analysis of fibroblasts isolated from superficial and lower layers of human dermis showed that FAP+CD90- cells are enriched in the papillary dermis. Altogether, functional analysis and expression profiling confirms that FAP+CD90- cells represent papillary fibroblasts, whereas FAP-CD90+ fibroblasts derive from the reticular lineage. Although papillary and reticular fibroblasts are enriched in the upper or lower dermis, respectively, they are not spatially restricted, and the microenvironment seems to affect their function.

Skin Impact of Alcohol-Based Hand Rubs vs Handwashing.

Skin Impact of Alcohol-Based Hand Rubs vs Handwashing.

Optical coherence tomography angiography offers comprehensive evaluation of skin optical clearing in vivo by quantifying optical properties and blood flow imaging simultaneously.

Tissue optical clearing (TOC) is helpful for reducing scattering and enhancing the penetration depth of light, and shows promising potential in optimizing optical imaging performances. A mixture of fructose with PEG-400 and thiazone (FPT) is used as an optical clearing agent in mouse dorsal skin and evaluated with OCT angiography (Angio-OCT) by quantifying optical properties and blood flow imaging simultaneously. It is observed that FPT leads to an improved imaging performance for the deeper tissues. The imaging performance improvement is most likely caused by the FPT-induced dehydration of skin, and the reduction of scattering coefficient (more than ∼ 40.5%) and refractive-index mismatching (more than ∼ 25.3%) in the superficial (epidermal, dermal, and hypodermal) layers. A high correlation (up to ∼ 90%) between the relative changes in refractive-index mismatching and Angio-OCT signal strength is measured. The optical clearing rate is ∼ 5.83 × 10(-5) cm/s. In addition, Angio-OCT demonstrates enhanced performance in imaging cutaneous hemodynamics with satisfactory spatiotemporal resolution and contrast when combined with TOC, which exhibits a powerful practical application in studying microcirculation.

Lymphoepithelioma-like Carcinoma of the Skin in the Cheek with a Malignant Metastatic Cervical Lymph Node.

Lymphoepithelioma-like Carcinoma of the Skin in the Cheek with a Malignant Metastatic Cervical Lymph Node.

A Pentagram Suture Technique for Closing Tumor Resection Sites in the Face.

Background:Resection of facial skin tumors aims to remove the tumors completely and make the surgical scar unnoticeable as much as possible. By improving the purse string suture method, we developed a new pentagram suture technique that enables simple and safe suturing of small to large defects with early satisfactory esthetic outcomes. The surgical outcomes of a case series were examined in this report.Methods:As in drawing a unicursal star, 5 suture sites were marked at specific intervals around the defect area. A needle with 5-0 polydioxanone suture was passed from the subcutaneous tissue to the superficial dermal layer at one site and then from the superficial dermal layer to the subcutaneous layer at the next site, and the process was repeated until the pentagram was complete. When apposition was not tight enough, a couple of external stitches were added using 6-0 nylon suture.Results:In 13 patients (16 benign or malignant tumors; mean age, 51.1 years) with a mean tumor size of 10.1 ± 5.2 mm and postoperative skin defect diameter of 12.1 ± 8.2 mm, closure did not result in high tension on the suture, and there was reduced mechanical stress at the wound margin. Surgical outcomes were good esthetically at 6 months after surgery without keloid formation or scar contracture. None of the patients had postoperative pain, infection, or tumor recurrence.Conclusions:This simple alternative method for the closure of facial skin defects after skin tumor excision could be performed easily and provided satisfactory surgical outcomes.

Deep dermal fibroblast profibrotic characteristics are enhanced by bone marrow–derived mesenchymal stem cells

Hypertrophic scars are a significant fibroproliferative disorder complicating deep injuries to the skin. We hypothesize that activated deep dermal fibroblasts are subject to regulation by bone marrow-derived mesenchymal stem cells (BM-MSCs), which leads to the development of excessive fibrosis following deep dermal injury. We found that the expression of fibrotic factors was higher in deep burn wounds compared with superficial burn wounds collected from burn patients with varying depth of skin injury. We characterized deep and superficial dermal fibroblasts, which were cultured from the deep and superficial dermal layers of normal uninjured skin obtained from abdominoplasty patients, and examined the paracrine effects of BM-MSCs on the fibrotic activities of the cells. In vitro, deep dermal fibroblasts were found higher in the messenger RNA (mRNA) levels of type 1 collagen, alpha smooth muscle actin, transforming growth factor beta, stromal cell-derived factor 1, and tissue inhibitor of metalloproteinase 1, an inhibitor of collagenase (matrix metalloproteinase 1). As well, deep dermal fibroblasts had low matrix metalloproteinase 1 mRNA, produced more collagen, and contracted collagen lattices significantly greater than superficial fibroblasts. By co-culturing layered fibroblasts with BM-MSCs in a transwell insert system, BM-MSCs enhanced the fibrotic behavior of deep dermal fibroblasts, which suggests a possible involvement of BM-MSCs in the pathogenesis of hypertrophic scarring.

Features of wound healing shown by fibroblasts obtained from the superficial and deep dermis

Dermal fibroblasts (DF) obtained from the superficial dermal layer and those from the deep dermal layer have different cellular functions. These differences are often associated with excessive scarring; they also influence early wound healing. We therefore investigated the differences between superficial and deep dermal fibroblasts with special emphasis on their contractile properties, and ability to produce connective tissue. We investigated their proliferation kinetics, ability to contract collagen lattices, and chronological mRNA expression of eight genes associated with wound healing. To estimate the changes in the differences between them during the early phase of wound healing, we investigated mRNA expression in bFGF supplemented medium because bFGF is a representative cytokine that is familiar to clinicians. Superficial DF proliferate faster than deep DF in culture, whereas deep DF are better at contracting collagen lattices than superficial ones. In realtime analysis of polymerase chain reaction, the expression of type I and III collagen, fibronectin, TGF β1 and β3, and connective tissue growth factor were higher in deep DF than in superficial DF, while the expression of TGF β2 was higher in superficial DF. After bFGF supplementation, the relative dominance of mRNA expression between superficial and deep DF remained constant except for the expression of collagenase. According to our analysis, deep DF are superior to superficial DF at promoting wound healing (particularly contraction and production of connective tissue). The intradermal distribution of DF is appropriate for efficient wound healing.

Akt/Protein Kinase B Is Required for Lymphatic Network Formation, Remodeling, and Valve Development

Akt-mediated signaling plays an important role in blood vascular development. In this study, we investigated the role of Akt in lymphatic growth using Akt-deficient mice. First, we found that lymphangiogenesis occurred in Akt1(-/-), Akt2(-/-), and Akt3(-/-) mice. However, both the diameter and endothelial cell number of lymphatic capillaries were significantly less in Akt1(-/-) mice than in wild-type control mice, whereas there was only a slight change in Akt2(-/-) and Akt3(-/-) mice. Second, valves present in the small collecting lymphatics in the superficial dermal layer of the ear skin were rarely observed in Akt1(-/-) mice, although these valves could be detected in the large collecting lymphatics in the deep layer of the skin tissues. A fluorescence microlymphangiography assay showed that the skin lymphatic network in Akt1(-/-) mice was functional but abnormal as shown by fluorescein isothiocyanate-dextran draining. There was an uncharacteristic enlargement of collecting lymphatic vessels, and further analysis showed that smooth muscle cell coverage of collecting lymphatic vessels became much more sparse in Akt1-deficient mice than in wild-type control animals. Finally, we showed that lymphatic vessels were detected in compound Akt-null mice and that lymphangiogenesis could be induced by vascular endothelial growth factor-C delivered via adenoviral vectors in adult mice lacking Akt1. These results indicate that despite the compensatory roles of other Akt isoforms, Akt1 is more critically required during lymphatic development.

Clinical study on the effects of a cosmetic product on dermal extracellular matrix components using a high-resolution multiphoton tomograph

The aim of this study was to demonstrate the effects of selected plant extracts in a cosmetic cream on the dermal network components after a 3-month treatment using an in vivo multiphoton tomographic device. Twenty-four Caucasian women aged between 45 and 65 applied randomly a cosmetic emulsion B containing active ingredients (soy and jasmine) twice a day on one arm and its vehicle A (without active ingredients) on the other arm during 3 months. Measurements were performed on the internal side of the forearm before starting the treatment (T0), after 4 week (T4) and 12 weeks (T12) treatment. Measurements consisted of a multi-layers acquisitions using a multiphoton tomograph with subcellular resolution. Optical sections (about 6 microm thick) were recorded from 0 to about 200 microm using two different wavelengths: 760 and 820 nm. To compare the series of images and obtain an objective quantification of the signal of second harmonic generation (SHG) and autofluorescence, the method used consisted of taking the integrated brightness of an image (same rectangular area for all images) as a measure of the signal. Following this step, a ratio between brightness of images from the area treated with cream A or B and brightness of untreated area was calculated and used as an assessment of treatment efficacy. The parameter used for statistical analysis (variance analysis) is the difference before and after 12 weeks of treatment by either cream A or B of the signal ratios calculated in the upper dermis (118-130 microm) and those from a deeper region of the upper dermis (165-178 microm). Signals (autofluorescence+SHG) of extracellular matrix do not change significantly with time (weeks 0, 4 and 12) when cream A (vehicle with no active ingredient) is applied. Treatment with cream B results in an enhancement in the signal level of extracellular matrix at week 12. The comparison of signals, in both areas (118-130 microm and 160-178 microm), show an higher increase in the deeper region than in the more superficial one for product B while we do not notice any change with product A. The multiphoton tomograph provided excellent high-resolution images, which describe clearly the different skin layers, single cells and extracellular matrix components in all the 24 volunteers. Statistic analyses reveal a real effect for product B with selected plant extracts, known to increase collagen synthesis. Changes observed are characteristics of modifications in dermal collagen and elastin content. To our knowledge, it is the first time that it was possible to demonstrate in vivo the effect of a cosmetic product on the superficial dermal layer, in a non-invasive and non-destructive process, i.e. without cutting the skin.

Phaeohyphomycosis of the face caused by Exophiala oligosperma

A 57-year-old previously healthy woman who works in the fish-processing industry presented with a 1-year history of a slightly pruritic, hyperkeratotic, brownish, erythematous lesion of the left cheek measuring 5 × 5 mm in diameter. Histopathology revealed granuloma formation in the superficial dermal layer by multinucleated giant cells that contained pale-brown septate hyphae. Periodic acid-Schiff stain showed many hyphae and catenate spores within the multinucleated giant cells. Tissue specimens and skin scrapings were obtained and incubated on mycosel agar, yielding black, velvety colonies that were morphologically identified as belonging to Exophiala species. Sequence analysis of the internal transcribed spacer region of the ribosomal RNA gene showed 99-100% homology to Exophiala oligosperma sequences. This report describes a rare case of phaeohyphomycosis of the face caused by E. oligosperma.

316 POSTER Oncogenic H-Ras V12 promotes anchorage-independent cytokinesis

Akt-mediated signaling plays an important role in blood vascular development. In this study, we investigated the role of Akt in lymphatic growth using Akt-deficient mice. First, we found that lymphangiogenesis occurred in Akt1−/−, Akt2−/−, and Akt3−/− mice. However, both the diameter and endothelial cell number of lymphatic capillaries were significantly less in Akt1−/− mice than in wild-type control mice, whereas there was only a slight change in Akt2−/− and Akt3−/− mice. Second, valves present in the small collecting lymphatics in the superficial dermal layer of the ear skin were rarely observed in Akt1−/− mice, although these valves could be detected in the large collecting lymphatics in the deep layer of the skin tissues. A fluorescence microlymphangiography assay showed that the skin lymphatic network in Akt1−/− mice was functional but abnormal as shown by fluorescein isothiocyanate-dextran draining. There was an uncharacteristic enlargement of collecting lymphatic vessels, and further analysis showed that smooth muscle cell coverage of collecting lymphatic vessels became much more sparse in Akt1-deficient mice than in wild-type control animals. Finally, we showed that lymphatic vessels were detected in compound Akt-null mice and that lymphangiogenesis could be induced by vascular endothelial growth factor-C delivered via adenoviral vectors in adult mice lacking Akt1. These results indicate that despite the compensatory roles of other Akt isoforms, Akt1 is more critically required during lymphatic development.

Leiomiosarcoma de pene: presentación de un caso y revisión de la literatura

Primary penile leiomyosarcoma is a rare entity. Since 1930 only 30 cases have been reported in the bibliography. We wanted to add a new case to the international literature, in addition to a review of all available publications on the topic from 1957. A 54-year-old patient presented with a lobulated 8x4x3 cm lesion in the balanopreputial groove over two years; he was treated initially with partial penectomy and subsequently with total penectomy We analyze the evolution, progression and adjuvant treatments of this rare pathology. We report one case with its clinical presentation, diagnostic tests performed for staging, treatment and follow-up. The first case of penile leiomyosarcoma was described by Levi in 1930. In 1957 Ashley and Edwards reported the first case in the British literature and in 1963 Pack reported the first in the American literature. MacKenzie et al. were the first to recognize two types of leiomyosarcoma: superficial and deep. The first develop from smooth muscle cells from the superficial dermal layers of the glans penis or distal third of the penis, they are generally asymptomatic and less malignant, rarely invading deeper structures and without involvement of the urethra on physical exam. The best prognostic predictors are type of tumor at presentation (superficial vs. deep) and treatment choice, being total penectomy more effective for failures of local resections than for primary treatment of deep tumors.

Collagen morphology in human skin and scar tissue: no adaptations in response to mechanical loading at joints

Dermal collagen displays a random-like structure that has a major role in strength and function of the human integument. It is hypothesised that collagen bundles align in a parallel fashion in the direction of mechanical tension during scarring, which may explain the problematic scar formation that occurs specifically at joints. Scar tissue and normal skin were biopsied from joints and control areas and evaluated by the Fourier analysis. Collagen orientation was represented by an index ranging from 0 (perfectly random) to 1 (perfectly parallel). Collagen bundle packing signifies the average distance between the centres of collagen bundles. No differences were shown in collagen morphology of scar tissue and normal skin between joints and control areas. Normal skin had a significantly lower collagen orientation index than scar tissue (0.26 versus 0.44, P<0.001). The bundle packing of scar tissue differed significantly from normal skin (18.1 μm versus 23.7 μm, P<0.001). Collagen appeared less parallel orientated in deep dermis compared to superficial dermis especially for normal skin (0.27 versus 0.33, P=0.06). Normal skin had a less parallel organisation in sections that were cut parallel compared to those that were cut perpendicular to the epidermis (0.24 versus 0.30, P=0.02). Collagen orientation of scar tissue is more parallel compared to normal skin. Morphology differs with respect to superficial and deep dermal layers and parallel and perpendicular planes, but appears not to respond to mechanical tension.