General theory of skin reinforcement

Profhilo® Structura, Current Status and Future Perspectives: A Practical Review

Hyaluronic acid (HA)-based injectables continue to grow in popularity and are used worldwide to improve facial changes associated with aging. Profhilo® Structura (IBSA Farmaceutici Italia, Lodi, Italy) is a novel HA-based product that uses nano hybrid complex of hyaluronic acid (NAHYCO)® technology to create hybrid cooperative complexes consisting of high and low molecular weight HA. Profhilo® Structura's high concentration (45 mg of total HA) and rheological properties (ie, viscosity [resistance to flow] and elasticity [stickiness]) have been specially formulated to restore facial adipose tissue. Because of their early involvement in the facial aging process, the superficial medial and lateral-temporal cheek fat compartments are good candidates for treatment. However, recommendations and guidelines are necessary to ensure that treatment is safe and effective. Three experts were invited to IBSA Farmaceutici Italia Srl to discuss clinical rationale, optimal injection techniques, and clinical outcomes for treating the superficial medial and lateral-temporal cheek fat compartments with Profhilo® Structura. These techniques were developed using patients presenting with either initial hypotrophy of fat compartments within the preauricular area (ie, sinkers) or jowl sagging due to hypotrophy within the preauricular and zygomatic areas (ie, saggers). Targeting these areas using the optimal injection site can maximize product diffusion and minimize the risk for vascular compromise. Targeting these areas also leads to lateral tightening and lipolifting effects due to adipose tissue restoration. The experts agreed that Profhilo® Structura is currently the first and only HA-based injectable treatment that can integrate and restore the adipose tissue in these affected fat compartments.

The Pressurized Skin: A Review on the Pathological Effect of Mechanical Pressure on the Skin from the Cellular Perspective

Since human skin is the primary interface responding to external mechanical stimuli, extrinsic forces can disrupt its balanced microenvironment and lead to cutaneous lesions. We performed this review to delve into the pathological effects of mechanical pressure on skin from the cellular perspective. Fibroblasts of different subsets act as heterogeneous responders to mechanical load and express diverse functionalities. Keratinocytes relay mechanical signals through mechanosensitive receptors and the ensuing neurochemical cascades to work collaboratively with other cells and molecules in response to pressure. Mast cells release cytokines and neuropeptides, promoting inflammation and facilitating interaction with sensory neurons, while melanocytes can be regulated by pressure through cellular and molecular crosstalk. Adipocytes and stem cells sense pressure to fine-tune their regulations of mechanical homeostasis and cell differentiation. Applying mechanical pressure to the skin can induce various changes in its microenvironment that potentially lead to pathological alterations, such as ischemia, chronic inflammation, proliferation, regeneration, degeneration, necrosis, and impaired differentiation. The heterogeneity of each cellular lineage and subset from different individuals with various underlying skin conditions must be taken into consideration when discussing the pathological effects of pressure on the skin. Thus, elucidating the mechanotransduction and mechanoresponsive pathways from the cellular viewpoint is crucial in diagnosing and managing relevant dermatological disorders.

Theaflavin Chemistry and Its Health Benefits

Huge epidemiological and clinical studies have confirmed that black tea is a rich source of health-promoting ingredients, such as catechins and theaflavins (TFs). Furthermore, TF derivatives mainly include theaflavin (TF1), theaflavin-3-gallate (TF2A), theaflavin-3'-gallate (TF2B), and theaflavin-3,3'-digallate (TF3). All of these TFs exhibit extensive usages in pharmaceutics, foods, and traditional medication systems. Various indepth studies reported that how TFs modulates health effects in cellular and molecular mechanisms. The available literature regarding the pharmacological activities of TFs has revealed that TF3 has remarkable anti-inflammatory, antioxidant, anticancer, antiobesity, antiosteoporotic, and antimicrobial properties, thus posing significant effects on human health. The current manuscript summarizes both the chemistry and various pharmacological effects of TFs on human health, lifestyle or aging associated diseases, and populations of gut microbiota. Furthermore, the biological potential of TFs has also been focused to provide a deeper understanding of its mechanism of action.

Immunohistochemical evidence of striated muscle cells within midfacial superficial musculoaponeurotic system

INTRODUCTION

The superficial musculoaponeurotic system (SMAS) is a controversial functional fibro-adipose layer that connects the mimic muscles to the skin and is involved in a variety of facial mimic expressions. The presence of muscle fibers within SMAS fibrous septa is hypothetical. The present study analyzed SMAS fibrous septa composition for the existence of striated muscle cells.

METHODS

Histological serial sections of the sample borders (n=107) of 19 in sano-resected and diagnosed cutaneous tumors of the midfacial region were investigated. Immunohistochemical (actin and myosin) and hematoxylin and eosin staining were performed to detect striated muscle cells in SMAS fibrous septa.

RESULTS

A fibro-neuro-musculo-vascular functional unit within SMAS fibrous septa was demonstrated. SMAS striated muscle cells were morphologically independent from preparotideal and periorbital mimic muscles. Intraseptal blood vessels draining the superficial and deep SMAS vascular system were described.

CONCLUSIONS

Striated muscle cells were demonstrated within SMAS fibrous septa. Nerve cells and vascular tissue together with the SMAS fibro-muscular meshwork demonstrated an autonomous operating functional unit that hypothetical modulated individual mimic expression contributing to the diversity of mimic expression. The SMAS develops with mimic muscle contractions as a synergetic effect during facial crease and fold formation processes.

A hyaluronic acid-based filler reduces lipolysis in human mature adipocytes and maintains adherence and lipid accumulation of long-term differentiated human preadipocytes

The beneficial role of subcutaneous adipose tissue in skin rejuvenation derived from its capacity to fill the under‐layer volumes but also from its ability to regulate the extracellular matrix production by dermis fibroblasts. Hyaluronic acid (HA), a major component of the extracellular matrix, is a commonly used injectable dermal filler showing excellent efficiencies to maintain tissue augmentation even after its biodegradation. To improve their stability, the HA molecules can also be “cross‐linked” to each other. The effects of cross‐linked HA‐based fillers on the dermal structure are well known. For safety reasons, most of the physicians prefer to use the blunt cannula for injections. However, evidences showed that the cannula could not be located in the dermis, but it passes through immediate hypodermis and the long‐lasting effect of cross‐linked HA‐based fillers may be related to its effects on adipose tissue. To test whether cross‐linked HA has a direct effect on human adipocytes, we treated isolated adipocytes and precursors cells from human skin donors with cross‐linked HA. Biochemical and cellular analysis demonstrated that treatment by cross‐linked HA showed beneficial effects on differentiated cell adherence and survival as well as reduced basal and induced lipolysis in fully mature adipocytes. Taken together, these data showed that cross‐linked HA promoted cell adherence and preserved the adipogenic capacity of preadipocytes during prolonged cell culture, bringing additional evidences of the beneficial role of cross‐linked HA‐based fillers in maintenance of the subcutaneous fat mass. This first study could defend a preventive approach to facial volume loss during natural aging.

Caveolin-1 in skin aging - From innocent bystander to major contributor

Caveolin-1 (Cav-1) appears to be both a pathophysiological contributor and a target in different inflammatory and hyperproliferative skin conditions as well as in skin aging. Skin fibroblasts demonstrate an up-regulation of Cav-1 expression both in chronological and UV-induced aging, and such an up-regulation was observed both in vitro and in vivo. Typical alterations in aging skin involve a reduction of the dermis thickness, a significant expansion of the dermal white adipose tissue as well as modifications of the content and distribution of hyaluronan, impairment of autophagic flux, a reduction of collagen expression and an increase in tissue inflammation. All of these phenomena can be connected with changes in Cav-1 expression in the aging skin. Modified expression of Cav-1 can also significantly influence the mechanical properties of individual skin layers, thus changing the total mechanical stability of the layered composite skin/WAT, leading to typical structural modifications of the skin surface in the aging skin. Selective reduction of Cav-1 expression has the potential to exert anti-aging effects on the skin.

Funktionelle Morphologie der Gesichtshaut

Die Gesichtshaut stellt eine Besonderheit dar, da sie neben den allgemeinen Funktionen der Haut auch der Informationsvermittlung durch die Mimik dient. Sie gliedert sich in 3 Schichten: Epidermis, Dermis und Subkutis. Letztere ist im Gesicht als superfizielles muskuloaponeurotisches System (SMAS) differenziert. Dieses SMAS verbindet die mimische Muskulatur mit der Haut und induziert als eigenständig agierende funktionelle Einheit die differenzierte Mimik. Die regionale unterschiedliche dreidimensionale Architektur des SMAS trägt zur spezifischen Morphogenese der Gesichts- und Halsfalten bei. Bei chirurgischen Eingriffen im Gesichtsbereich sind die Besonderheiten des SMAS in den verschiedenen Regionen des Gesichts zu beachten.

Theaflavin-Enriched Fraction Stimulates Adipogenesis in Human Subcutaneous Fat Cells

Skin provides the first defense line against the environment while preserving physiological homeostasis. Subcutaneous tissues including fat depots that are important for maintaining skin structure and alleviating senescence are altered during aging. This study investigated whether theaflavin (TF) in green tea (GT) has skin rejuvenation effects. Specifically, we examined whether high ratio of TF contents can induce the subcutaneous adipogenesis supporting skin structure by modulating lipid metabolism. The co-fermented GT (CoF-GT) fraction containing a high level of TF was obtained by co-fermentation with garland chrysanthemum (Chrysanthemum coronarium) and the conventionally fermented GT (F-GT) fraction was also obtained. The effects of the CoF- or F-GT fractions on adipogenesis were assessed using primary human subcutaneous fat cells (hSCF). Adipogenesis was evaluated based on lipid droplet (LD) formation, as visualized by Oil Red O staining; by analyzing of adipogenesis-related factors by real-time quantitative polyperase chain reaction (RT-qPCR); and by measuring the concentration of adiponectin released into the culture medium by enzyme-linked immunosorbent assay. TF-enriched CoF-GT fraction did not adversely affect hSCF cell viability but induced their adipogenic differentiation, as evidenced by LD formation, upregulation of adipogenesis-related genes, and adiponectin secretion. TF and TF-enriched CoF-GT fraction promoted differentiation of hSCFs and can therefore be used as an ingredient in rejuvenating agents.

Caveolin-1 as a pathophysiological factor and target in psoriasis

Low expression of caveolin-1 (Cav-1) is typical in psoriatic lesions and overexpression of Cav-1 leads to a reduction of inflammation and suppression of epidermal hyperproliferation, thus ameliorating these two well-known hallmarks of psoriasis. At the same time, the interfacial layers of the white adipose tissue (WAT) adjacent to psoriatic lesions demonstrate much higher stiffness, which also points to a modification of Cav-1 expression in this tissue. These processes are connected with each other and regulated via exosomal exchange. Here we discuss the role of Cav-1 expression in inflammatory and hyperproliferative processes and analyze the ways to provide spatially different modulation of Cav-1 expression in the skin and WAT. Such modulation can be induced by different pharmacological and physical factors. These include application of mechanical stress and supra-physiological temperatures. Cav-1 should therefore be considered as an important target in treatment of psoriasis.

Aesthetic dermatology: What's new, what's true?

Aesthetic dermatology (AD) is a rapidly growing subspecialty of dermatology. The acceptance of AD in scientific community and the society is associated with its competence, efficiency, and seriousness. This review highlights some recent developments toward new tools, techniques, and understanding in the field of AD. Analyzing the specific needs of patients and assessing the effect by objective measurements is important for further progress. For long time ignored, white adipose tissue has gained increasing interest in biology and rejuvenation. Characterization of dermal and subcutaneous white adipose tissue has made progress. The interaction of hyaluronic acid and calcium hydroxyl apatite (CaHA) fillers with adipocytes could be responsible for clinical efficacy. New developments of oral collagen treatment and highly diluted CaHA to contour the body outside the face will be discussed. Submental contouring using purified desoxycholic acid is another new development.

Adipose tissue, fillers, and skin tightening

The role of adipose tissue has long been underestimated in esthetic dermatology. With the development of liposculpture and lipolysis, subcutaneous adipose tissue has gained an increasing interest. Harvested tissue has been used for lipofilling. In recent years, a better understanding of adipocyte physiology and its role in aging opened a new road for targeted treatments. Subcutaneous adipose tissue is no longer an innocent bystander in the combat of aging and the correction in esthetics. Adipose tissue is of importance for metabolic function and thermoregulation. Adipose tissue is involved in inflammation. Adipose tissue is heterogeneous in sense of function, color and size of adipocytes. The tissue is an important source of somatic stem cells.

Skin aging as a mechanical phenomenon: The main weak links

From a mechanical point of view, human skin appears as a layered composite containing the stiff thin cover layer presented by the stratum corneum, below which are the more compliant layers of viable epidermis and dermis and further below the much more compliant adjacent layer of subcutaneous white adipose tissue (sWAT). Upon exposure to a strain, such a multi-layer system demonstrates structural instabilities in its stiffer layers, which in its simplest form is the wrinkling. These instabilities appear hierarchically when the mechanical strain in the skin exceeds some critical values. Their appearance is mainly dependent on the mismatch in mechanical properties between adjacent skin layers or between the skin and sWAT, on the adhesive strength and thickness ratios between the layers, on their bending and tensile stiffness as well as on the value of the stress existing in single layers. Gradual reduction of elastic fibers in aging significantly reduces the skin's ability to bend, prompting an up to 4-fold reduction of its stability against wrinkling, thereby explaining the role of these fibers in skin aging. While chronological and extrinsic aging differently modify these parameters, they lead to the same end result, reducing the critical strain required for the onset of instabilities. Comparing of mechanical properties of the skin presented as a bi-, tri- or tetra-layer structure demonstrates the particular importance of the papillary dermis in skin aging and provides the arguments to consider the undulations on the dermal-epidermal and dermal-sWAT interfaces as the result of mechanical bifurcation, leading to structural instabilities inside of the skin. According to this model, anti-aging strategies should focus not as much on the reinforcement of the dermis, but rather aim to treat the elastic mismatch between different adjacent layers in the skin and sWAT as well as the adhesion between these layers.

Role of adipose tissue in facial aging

Age-dependent modification of the facial subcutaneous white adipose tissue (sWAT) connected with reduction of its volume, modification of collagen content and adhesion between dermal and adipose layers can significantly influence mechanical stability of the skin and cause the development of aging symptoms such as wrinkles. Typical aging appearance in facial skin is at least partly connected with special phenotypical features of facial preadipocytes and mature adipocytes. In this paper, we have discussed the possible roles of local inflammation, compartmental structure of facial sWAT and trans-differentiation processes such as beiging of white adipocytes and adipocyte-myofibroblast transition in facial skin aging.