Use of SkinFibrometer®to measure skin elasticity and its correlation with Cutometer®and DUB®Skinscanner

Skin viscoelasticity effects on the periodic mechanical stimuli propagation between skin layers

Our daily lives are constantly surrounded by dynamic stimuli, and our skin is deformed in a time-dependent manner. Although skin plays an important role in transmitting stimuli received at the surface to mechanoreceptors, few studies have investigated how differences in skin viscoelasticity affect the mechanical stimuli propagation in the skin. Therefore, using a finite element model, we evaluated the effects and trends of changes in the stiffness and viscoelasticity of the skin on the propagation of mechanical quantities between skin layers where mechanoreceptors are present when subjected to periodic stimuli. First, we constructed a new, sophisticated mathematical model of skin viscoelasticity based on the history-dependent deformation behavior of human skin obtained experimentally. We were able to construct a skin model that thoroughly reproduced the actual human skin deformation behavior at oscillations as fast as 10 Hz by setting viscoelastic parameters with a short time constant (0.001-0.006 s). Then, we calculated how skin material parameters affect the propagation of the mechanical quantities in the skin during the history-dependent skin deformation response to periodic stimuli. The finite element analysis showed that not only stiffness but also viscoelasticity markedly affected the mechanical stimuli propagation in the skin, and the effect differed depending on the layer. In particular, greater immediate responsiveness of the dermis contributed to greater propagation of the mechanical stimulus. Our results indicate that more attention needs to be given to the differences in the time-dependent intradermal mechanical stimuli propagation caused by individual's skin viscoelasticity.

Stratum corneum compliance enhances tactile sensitivity through increasing skin deformation: A study protocol for a randomized controlled trial

BACKGROUND

Tactile sensation plays a crucial role in object manipulation, communication, and even emotional well-being. It has been reported that the deformability of skin (also described as skin compliance) that shows a large mechanical response to stimuli is associated with high tactile sensitivity. However, although the compliance of the stratum corneum, the outermost layer of skin, can change daily due to skin care and environmental factors, few studies have quantified the effect of the stratum corneum on tactile sensation.

AIMS

We investigated the changes in tactile sensitivity resulting from skin hydration and identified corresponding alterations in the compliance of the stratum corneum.

METHODS

A randomized controlled trial was conducted. Participants were randomly assigned to an intervention group (n = 20) that had a moisturizing cream applied to their cheeks or a control group (n = 19) that had Milli-Q water applied to their cheeks. Tactile discrimination performance was assessed using psychophysical techniques before and after application. The water content, mechanical response characteristics, and penetration of PEG/PPG-17/4 dimethyl ether from the cream in the stratum corneum were evaluated to identify hydration effects. Skin deformations occurring during tactile sensation were measured concurrently using a suction device employed for tactile stimulation.

RESULTS

Tactile sensitivity was increased in participants who had cream applied to the skin surface, while no significant change was observed in participants who received Milli-Q water. The improved discrimination of tactile stimulus intensity was directly related to the magnitude of skin displacement. The higher water content of the stratum corneum due to cream application decreased the dynamic modulus of elasticity of the stratum corneum and increased the skin's extensibility in response to tactile stimuli.

CONCLUSIONS

Hydrating the stratum corneum significantly enhances tactile sensitivity and is accompanied by an increase in skin extensibility, a factor in tactile intensity perception. The compliance of the thin stratum corneum layer plays a crucial role in tactile experiences that involve skin stretching.

Tissue Dielectric Constant and Skin Stiffness Relationships in Lower Extremity Lymphedema

Background: Lower extremity lymphedema or edema (LELE) may progressively transition from a state of excess tissue fluid to increased fat accumulation and collagen deposition, with tissue fibrosis and hardening. Such changes may lead to altered tissue water holding and thereby impact tissue dielectric constant (TDC). This study seeks to evaluate the relationship between TDC and tissue indentation force (TIF) in patients with LELE and assess the utility of the leg/arm TDC ratio (LAR) as an indicator of LELE. Methods and Results: Thirty females (49-91 years) with previously diagnosed LELE were evaluated during a scheduled session. TDC and TIF were measured 8 cm proximal to the medial malleolus on the medial and lateral aspects of both legs and on one forearm 8 cm distal to the antecubital fossa. The TDC-TIC relationship and the LAR were subsequently determined. Main results showed an absence of a significant correlation between TDC and TIF on medial or lateral leg sites but a positive correlation on the normal forearm site. Further, LAR values exceeded the published proposed threshold of 1.35 for 29/30 patients when using medial-side TDC values and 28/30 patients when using lateral-side TDC values. Conclusions: Findings suggest that for patients with LELE, TDC values are significantly elevated on medial and lateral standardized sites. The LAR determined using either medial or lateral sites that are similar to each other and have values consistent with a lymphedema threshold of 1.35. In edematous legs of the type evaluated herein, there is no apparent relationship between TDC values and indentation force.

Use of a novel indentometer to evaluate skin stiffness in healthy and diseased human skin

BACKGROUND

Mechanical behavior of the skin can be evaluated by different non-invasive methods. In this study, we applied a new measurement device based on indentometry to determine the skin mechanical properties in healthy individuals and in patients with systemic sclerosis (SSc).

MATERIAL AND METHODS

Three studies were performed. Study 1 included 100 healthy individuals (46 male and 54 female) divided into four age groups with mean ages of 21.5, 28.9, 51.2, and 69.3 years, respectively. Test sites were located on the center of the forehead and the middle of both volar forearms. Study 2 included 16 healthy individuals (two males and 14 females). Test sites were on both volar forearms. Measurements were made before and after the application of Vaseline and emulsion with 12% urea. Study 3 included 20 patients (one male and 19 females) with SSc and 60 age-matched healthy individuals (23 males and 37 females). Test sites were on the center of the forehead and the middle of both volar forearms. Skin stiffness was measured with skin Indentometer IDM 800 (Courage + Khazaka, Cologne, Germany) equipped with two probes with pin diameters of 3 and 5 mm, respectively. The stiffer the skin, the less deep the displacement by the indenter. The smaller the diameter, the deeper the pin will go into the skin when using the same force. In addition, the Corneometer CM 820 (Courage + Khazaka) was used to determine epidermal water content in study 2.

RESULTS

Indentometric (IDM) values of healthy subjects measured with both probes were lower on the forehead compared to volar forearms. There was no significant difference between both forearms. In all age groups, the IDM values on the male forearms were lower than on the female forearms whereas there was no significant difference on the forehead. In both sex and on all test locations a significant positive correlation between age and IDM values measured with both probes was observed. There was a significant positive correlation between IDM values measured with both probes. The application of moisturizers induced significant changes in epidermal water content whereas the IDM values remained unchanged. At both the forehead and volar forearms, the IDM values in patients with SSc were significantly lower compared to the healthy control skin.

CONCLUSION

The non-invasive indentometric method used can successfully distinguish the changes in normal skin mechanical properties related to age, sex, and anatomical location, as well as in patients with SSc. The method is not appropriate to study the changes related to epidermal hydration.

Intramuscular Polydeoxyribonucleotides in Fibrotic and Atrophic Localized Scleroderma: An Explorative Prospective Cohort Study

Effective options in the quiescent, scantily inflammatory phase of localized scleroderma (morphea) are lacking. A cohort study in patients with histologically confirmed fibroatrophic morphea explored the therapeutic value of the anti-dystrophic A2A adenosine agonist polydeoxyribonucleotide (PDRN, one daily 5.625 mg/3 mL ampoule for 90 days with a three-month follow-up). Primary efficacy endpoints: Localized Scleroderma Cutaneous Assessment Tool mLoSSI and mLoSDI subscores for disease activity and damage in eighteen areas; Physicians Global Assessment for Activity (PGA-A) and Damage (PGA-D) VAS scores; skin echography. Secondary efficacy endpoints: mLoSSI, mLoSDI, PGA-A, PGA-D, and morphea areas (photographs) over time; Dermatology Life Quality Index (DLQI); skin biopsy scores and induration over time. Twenty-five patients enrolled; 20 completed the follow-up period. Highly significant improvements at the end of the 3-month treatment period: mLoSSI-73.7%, mLoSDI-43.9%, PGA-A-60.4%, PGA-D-40.3%, with further improvements at follow-up visit for all disease activity and damage indexes. Overall, the outcomes suggest that a daily PDRN ampoule intramuscularly for 90 days reduces disease activity and damage rapidly and significantly in quiescent, modestly inflammatory morphea with few currently therapeutic options. The COVID-19 pandemic and lockdowns caused difficulties in enrollment, and some patients were lost to follow-up. Due to low final enrollment, the study outcomes may have only an exploratory value, yet they appear impressive. The anti-dystrophic potential of the PDRN A2A adenosine agonist deserves further in-depth exploration.

The dynamic behavior of skin in response to vibrating touch stimuli affects tactile perception

BACKGROUND

The tactile perceptions arising on the skin mediate representations of the body and perceptions of the external physical world. Thus, these tactile sensations greatly impact our lives. Although tactile perception is caused by skin deformation, few studies have investigated the contribution of skin physical properties to tactile perception because the skin deformation in response to mechanical stimuli is difficult to measure in real time. In this study, we investigated how the skin deforms in response to externally applied mechanical stimuli and the effect of skin deformation on tactile perception.

MATERIALS AND METHODS

Tactile perception was assessed using psychophysical methods. A suction device was used to measure skin deformation in response to mechanical stimuli while assessing tactile perception. The relationship between skin deformation and tactile perception was investigated.

RESULTS

Individuals show different skin deformation behavior in response to stimuli of the same intensity, and the amount of skin deformation affects the perceived pressure induced by suction stimulation. Furthermore, when the amount of skin deformation is small, tactile perception becomes more difficult, and the ease of tactile perception varies.

CONCLUSION

We argue that dynamic skin behavior is an important factor in tactile perception. Focusing on skin physical characteristics from a constructivist perspective of complex tactile perception may lead to improved tactile communication perception through the control of skin physical properties and realistic tactile presentation in remote environments.

The Effect of Sunscreens on the Skin Barrier

Transepidermal water-loss (TEWL), stratum-corneum hydration (SCH), erythema, elasticity, pH and melanin, are parameters of the epidermal barrier function and skin homeostasis that objectively indicate the integrity of the skin barrier. Sunscreens are necessary to protect people from skin cancer, but could modify the skin barrier function. Nevertheless, there are not many studies on their impact on skin homeostasis. The aim of this study is to evaluate the impact of sunscreens on the epidermal-barrier function and skin homeostasis of healthy individuals. A prospective observational study was designed. TEWL, SCH, erythema, elasticity, pH and melanin were measured on the cheek and volar region of the forearm, using non-invasive methods before and after applying sunscreen. Four different sunscreens were tested, one full-body sunscreen and three facial sunscreens. The study included 51 healthy volunteers, 72.5% (37/51) women, with a mean age of 41.63 years. After full-body sunscreen application, temperature increased by 0.68 °C (p < 0.001), pH by 0.16 units (p < 0.001), and elasticity by 0.22% (p = 0.039), while melanin decreased by 10.95 AU (p < 0.001), erythema by 28.79 AU (p < 0.001) and TEWL by 0.66 g·m−2·h−1 (p = 0.019). On the cheek, facial sunscreen 1 increased temperature by 0.51 °C, TEWL 0.7 g·m−2·h−1 (p < 0.05), pH by 0.12 units (p < 0.001) and elasticity by 0.059% (p < 0.001), but decreased erythema by 19.87 AU (p < 0.05) and SCH by 5.63 AU (p < 0.001). Facial sunscreen 2 increased temperature by 0.67 °C, TEWL by 1.93 g·m−2·h−1 (p < 0.001), pH by 0.42 units (p < 0.001) and elasticity by 0.12% (p < 0.01), but decreased melanin by 15.2 AU (p = 0.000), erythema by 38.61 AU (p < 0.05) and SCH by 10.80 AU (p < 0.01). Facial sunscreen 3 increased temperature by 1.15 °C, TEWL by 2.29 g·m−2·h−1 (p < 0.001), pH by 0.46 units (p < 0.001) and elasticity by 0.15% (p < 0.01), but decreased erythema by 35.7 (p < 0.05) and SCH by 10.80 AU (p < 0.01). In conclusion, sunscreen could slightly modify the skin-barrier function. All of them decreased erythema, likely in relation to anti-inflammatory power.

In Vitro and In Vivo Characteristics of Olive Oil as Excipient for Topical Administration

Oily excipients are vital components of dermatological products. In this study, the in vitro and in vivo characteristics of Wild Olive Oil (WOO) were compared with two other types of olive oils: Extra Virgin Olive Oil (EVOO) and Virgin Olive Oil (VOO). This work has also included Liquid Paraffin (LP) and Rosehip Oil (RO) as reference oils. Melatonin was used in the study as a model drug to demonstrate the antioxidant capacity of the oils. The melatonin carrier capacity and antioxidant performance was related to the degree of unsaturation of the oils and was highest for RO and WOO and lowest for LP. However, the most stable oil to oxidation was LP. The in vivo performance of the oils in the skin of eight healthy volunteers was investigated with a dermoanalyser. The highest increment of oil and hydration in the skin was obtained with RO. The lowest perception of oiliness was described for WOO, which produced the highest increase in elasticity of the skin area where it was applied. An in vitro-in vivo correlation was therefore performed through multivariable analysis (MVA).

Saccorhiza polyschides-A Source of Natural Active Ingredients for Greener Skincare Formulations

The growing knowledge about the harmful effects caused by some synthetic ingredients present in skincare products has led to an extensive search for natural bioactives. Thus, this study aimed to investigate the dermatological potential of five fractions (F1-F5), obtained by a sequential extraction procedure, from the brown seaweed Saccorhiza polyschides. The antioxidant (DPPH, FRAP, ORAC and TPC), anti-enzymatic (collagenase, elastase, hyaluronidase and tyrosinase), antimicrobial (Staphylococcus epidermidis, Cutibacterium acnes and Malassezia furfur), anti-inflammatory (nitric oxide, tumor necrosis factor-α, interleukin-6 and interleukin-10) and photoprotective (reactive oxygen species) properties of all fractions were evaluated. The ethyl acetate fraction (F3) displayed the highest antioxidant and photoprotective capacity, reducing ROS levels in UVA/B-exposed 3T3 fibroblasts, and the highest anti-enzymatic capacity against tyrosinase (IC50 value: 89.1 µg/mL). The solid water-insoluble fraction (F5) revealed the greatest antimicrobial activity against C. acnes growth (IC50 value: 12.4 µg/mL). Furthermore, all fractions demonstrated anti-inflammatory potential, reducing TNF-α and IL-6 levels in RAW 264.7 macrophages induced with lipopolysaccharides. Chemical analysis of the S. polyschides fractions by NMR revealed the presence of different classes of compounds, including lipids, polyphenols and sugars. The results highlight the potential of S. polyschides to be incorporated into new nature-based skincare products.

Leveraging the advancements in functional biomaterials and scaffold fabrication technologies for chronic wound healing applications

Exploring new avenues for clinical management of chronic wounds holds the key to eliminating socioeconomic burdens and health-related concerns associated with this silent killer. Engineered biomaterials offer great promise for repair and regeneration of chronic wounds because of their ability to deliver therapeutics, protect the wound environment, and support the skin matrices to facilitate tissue growth. This mini review presents recent advances in biomaterial functionalities for enhancing wound healing and demonstrates a move from sub-optimal methods to multi-functionalized treatment approaches. In this context, we discuss the recently reported biomaterial characteristics such as bioadhesiveness, antimicrobial properties, proangiogenic attributes, and anti-inflammatory properties that promote chronic wound healing. In addition, we highlight the necessary mechanical and mass transport properties of such biomaterials. Then, we discuss the characteristic properties of various biomaterial templates, including hydrogels, cryogels, nanomaterials, and biomolecule-functionalized materials. These biomaterials can be microfabricated into various structures, including smart patches, microneedles, electrospun scaffolds, and 3D-bioprinted structures, to advance the field of biomaterial scaffolds for effective wound healing. Finally, we provide an outlook on the future while emphasizing the need for their detailed functional behaviour and inflammatory response studies in a complex in vivo environment for superior clinical outcomes and reduced regulatory hurdles.

Buttocks' Skin Laxity Severity Scale

BACKGROUND

Clinical scales are useful to assess skin laxity in different areas of the body.

OBJECTIVE

To elaborate and validate a photonumeric scale to assess buttocks skin laxity.

MATERIALS AND METHODS

The Buttocks' Skin Laxity Severity Scale (SLSS) was developed based on a sample of 120 patients. The SLSS validity and reliability were assessed in 2 validation cycles, performed by 8 dermatologists assessing 50 clinical cases. Both criteria and construct validity were tested.

RESULTS

The Buttocks' SLSS is composed by 5 clinical aspects of skin laxity graded from absent (0) to severe (3): buttocks ptosis, skin scalloped appearance, infragluteal fold, localized fat on the lower third of the buttocks, and linear depressed lesions. Final skin laxity classification results from the sum of each item grade multiplied by its weight and varies from 0 to 24. Overall, Kendall, weighted kappa, and intraclass correlation coefficients indicated very good reliability and consistent interrater and intrarater agreement (p < .001). Cronbach alpha of 0.82 indicates high scale reliability. The scale validity was confirmed by criteria validity tests (rs: 0.72, p < .05).

CONCLUSION

Buttocks' SLSS is a reliable and valid scale to identify skin laxity severity and its different features, and it is an accurate tool for clinical research.

Biomarkers and Detection Platforms for Human Health and Performance Monitoring: A Review

Human health and performance monitoring (HHPM) is imperative to provide information necessary for protecting, sustaining, evaluating, and improving personnel in various occupational sectors, such as industry, academy, sports, recreation, and military. While various commercially wearable sensors are on the market with their capability of "quantitative assessments" on human health, physical, and psychological states, their sensing is mostly based on physical traits, and thus lacks precision in HHPM. Minimally or noninvasive biomarkers detectable from the human body, such as body fluid (e.g., sweat, tear, urine, and interstitial fluid), exhaled breath, and skin surface, can provide abundant additional information to the HHPM. Detecting these biomarkers with novel or existing sensor technologies is emerging as critical human monitoring research. This review provides a broad perspective on the state of the art biosensor technologies for HHPM, including the list of biomarkers and their physiochemical/physical characteristics, fundamental sensing principles, and high-performance sensing transducers. Further, this paper expands to the additional scope on the key technical challenges in applying the current HHPM system to the real field.

Epidermal Barrier Function and Skin Homeostasis in Atopic Dermatitis: The Impact of Age

Skin is damaged in atopic dermatitis (AD) patients. Age is also believed to have a negative effect on epidermal barrier function. The aim of this study was to investigate skin barrier function changes with age in AD patients. A cross-sectional study was conducted including 162 participants, 81 AD patients and 81 healthy volunteers. Skin barrier function parameters, such as transepidermal water loss (TEWL), erythema, temperature, stratum corneum hydration (SCH), pH, and elasticity, were evaluated. Healthy volunteers were evaluated on the volar forearm. AD patients were measured on two regions: on an eczematous lesion on the volar forearm and on a non-involved area 5 cm from the affected area. TEWL was lower on healthy skin than uninvolved AD skin (9.98 vs. 25.51 g·m⁻²·h⁻¹, p < 0.001) and AD eczematous lesions (9.98 vs. 28.38 g·m⁻²·h⁻¹, p < 0.001). SCH was lower on AD eczematous lesions than uninvolved AD skin (24.23 vs. 39.36 AU, p < 0.001) and healthy skin (24.23 vs. 44.36 AU, p < 0.001). Elasticity was lower on AD eczematous lesions than uninvolved AD skin (0.69 vs. 0.74, p = 0.038) and healthy skin (0.69 vs. 0.77, p = 0.014). A negative correlation was found between age and elasticity in all the population (r = −0.383, p < 0.001). This correlation was stronger in AD patients (r = −0.494, p < 0.001) than in controls (r = −0.266, p = 0.092). After conducting a linear regression model in AD patients adjusted by age, sex, and SCORing Atopic Dermatitis (SCORAD), it was found that elasticity was impaired by an increasing age (β = −0.004, p < 0.001) and a higher SCORAD (β = −0.003, p < 0.001). The skin barrier function is impaired by age and AD, reflected mainly in poor elasticity values in older AD patients.

Microalgal Peloids for Cosmetic and Wellness Uses

Peloids have been used for therapeutic purposes since time immemorial, mainly in the treatment of locomotor system pathologies and dermatology. Their effects are attributed to their components, i.e., to the properties and action of mineral waters, clays, and their biological fraction, which may be made up of microalgae, cyanobacteria, and other organisms present in water and clays. There are many studies on the therapeutic use of peloids made with microalgae/cyanobacteria, but very little research has been done on dermocosmetic applications. Such research demonstrates their potential as soothing, regenerating, antioxidant, anti-inflammatory, and antimicrobial agents. In this work, a method for the manufacture of a dermocosmetic peloid is presented based on the experience of the authors and existing publications, with indications for its characterization and study of its efficacy.

Skin biomechanical and viscoelastic properties measured with MyotonPRO in different areas of human body

BACKGROUND

There is still a lack of clinically practical device, which allows to perform rapid and accurate examination of the skin condition. For this reason, suitability of the MyotonPRO for the assessment of skin biomechanical and viscoelastic parameters was evaluated in this study. The aim of the study was to establish the reference values of five parameters measured by MyotonPRO various locations of human skin.

MATERIALS AND METHODS

Oscillation frequency, dynamic stiffness, logarithmic decrement, mechanical stress relaxation and creep were measured at three different skin locations (clavicula, volar forearm and shin), using L-shape short and medium arm probes in 32 young female volunteers. Mean values of obtained parameters recorded by both probes were compared among three skin locations while reliabilities of measurements were assessed. Additionally, relationships between all recorded parameters were examined RESULTS: There were no statistically significant differences between the mean values of five measured parameters obtained with both probes in all investigated areas. However, statistically significant differences of mean values of almost all parameters measured among three places examined were found. Despite considerable differences in mean values of obtained parameters, there were visible strong correlations between some studied parameters in all three investigated areas of skin.

CONCLUSION

It was demonstrated in all locations studied that the higher value of oscillation frequency corresponds to the higher value of dynamic stiffness, moreover such tissue recovers faster to its initial shape, and it was characterized by lower creep values. Such results indicate the existence of identical relationships between the same studied parameters in different areas of skin.

Elastic Fibres in the subcutaneous tissue: Is there a difference between superficial and muscular fascia? A cadaver study

BACKGROUND

In last years the role of fascia in proprioception and pain has been confirmed in numerous papers, but the real structure of fasciae is not still entirely known. To date, many studies have evaluated the elastic fibres in arteries, ligaments, lungs, epidermis and dermis, but only two studies exist about the elastic fibres in the fasciae, and they did not distinguish between superficial (in the subcutaneous tissue) and deep/muscular fasciae. The aim of the study was to assess the percentage of elastic fibres between superficial and deep fascia.

MATERIALS AND METHODS

Three full thickness specimens (proximal, middle and distal respectively) were taken from each of four regions of the thigh of three non-embalmed cadavers: the anterior (Ant), the lateral (Lat), the posterior (Post) and the medial (Med) aspect. Thus, a total of 12 specimens were collected from each analysed thigh and histological Weigert Van Gieson stains was performed. Three sections per specimen were considered for the morphometric analysis.

RESULTS

In all the specimens the superficial and deep fasciae were clearly recognizable. The difference in percentage of elastic fibres between superficial and deep fasciae in same region for all four was highly significant (p < 0.001). They are abundant in the superficial fascia than deep fascia.

CONCLUSIONS

In the light of these findings is evident that the superficial (in the subcutaneous tissue) and deep fasciae have different elasticity. This difference may improve grading of fascial dysfunction in dermatological diseases as burns, scars and lymphedema to better plan treatments.

Study of Skin Barrier Function in Psoriasis: The Impact of Emollients

Psoriasis is a chronic multi-systemic inflammatory disease that affects the epidermal barrier. Emollients can be used as a coadjutant therapy for psoriasis management, but little is known about how the epidermal barrier function in psoriatic patients is modified by moisturizers. The objective of this study is to evaluate the effect of Vaseline jelly and a water-based formula on epidermal barrier function in psoriatic patients. Thirty-one patients with plaque-type psoriasis and thirty-one gender and age-matched healthy controls were enrolled in the study. Temperature, transepidermal water loss (TEWL), stratum corneum hydration (SCH), pH, elasticity and the erythema index were measured using non-invasive tools before and after applying Vaseline jelly and a water-based formula. TEWL was higher in psoriatic plaques than uninvolved psoriatic skin (13.23 vs. 8.54 g·m^-2·h^-1; p < 0.001). SCH was lower in psoriatic plaques than uninvolved psoriatic skin and healthy skin (13.44 vs. 30.55 vs. 30.90 arbitrary units (AU), p < 0.001). In psoriatic plaques, TEWL decreased by 5.59 g·m^-2·h^-1 (p = 0.001) after applying Vaseline Jelly, while it increased by 3.60 g·m^-2·h^-1 (p = 0.006) after applying the water-based formula. SCH increased by 9.44 AU after applying the water-based formula (p = 0.003). The use of emollients may improve epidermal barrier function in psoriatic patients. TEWL is decreased by using Vaseline, and SCH is increased by using the water-based formula.

Light emitting diode-red light for reduction of post-surgical scarring: Results from a dose-ranging, split-face, randomized controlled trial

Scarring has significant esthetic and functional consequences for patients. A need exists for anti-scarring therapeutics. Light emitting diode-red light (LED-RL) has been shown to modulate skin fibrosis. The aim of this study is to evaluate the safety and efficacy of LED-RL to reduce post-operative scarring. Cutaneous Understanding of Red-light Efficacy on Scarring was a randomized, mock-controlled, single-blind, dose-ranging, split-face phase II clinical trial. Starting 1 week post-surgery, patients received LED-RL irradiation and temperature-controlled mock therapy to incision sites at fluences of 160, 320 or 480 J/cm² , triweekly for 3 weeks. Efficacy was assessed at 1, 3 and 6-12 months. The primary endpoint was difference in scar pliability between LED-RL-treated and control sites. Secondary outcomes included Patient and Observer Scar Assessment Scale, collagen and water concentration, and adverse events. There were no significant differences in scar pliability between treated and control scars. At certain fluences, treated scars showed greater improvements in observer rating and scar pliability, reflected by greater reductions in induration, from baseline to 6 months compared to control scars. Treatment-site adverse events included blistering (n = 2) and swelling (n = 1), which were mild and resolved without sequelae. LED-RL phototherapy is safe in the early postoperative period and may reduce scarring.

Evaluating a Topical Adjunctive Post Submental ATX-101 (Deoxycholic Acid) Injections for Improved Recovery: A Single-Center, Double-Blind, Randomized Controlled Pilot Study

Background

Optimizing postprocedural recovery and outcomes for patients is the aim for all physicians. TransFORM Body Treatment with TriHex Technology (TFB) is a topical product that aids in the elimination of fat particles created during procedures and the reduction of associated inflammation, thus speeding up postprocedure recovery time.

Objectives

Evaluation of postprocedural symptoms, signs, and healing following submental deoxycholic acid (DCA) injections in combination with TFB.

Methods

Participants received 2 treatments of submental DCA injections. Posttreatment 1, every participant received TFB to apply twice daily to the submental area. Follow-up visits included weeks 1, 2, and 4. After week 4, participants discontinued TFB for 30 days before the second treatment. At the second treatment visit, participants were randomized to receive either TFB or a bland moisturizer to apply twice daily with the same follow-up visits as posttreatment 1. Induration measurements, submental fullness grading, and standardized photography were captured at every visit. At all follow-up visits and before treatment 2, investigator assessments and participant assessments were completed.

Results

Posttreatment 2, investigator assessments of edema and induration decreased in participants using TFB at weeks 1 and 2 compared with the bland moisturizer. Induration measurements objectively showed a statistically significant reduction at week 2 (posttreatment 2) in participants using TFB compared with the bland moisturizer. Furthermore, participants reported less tenderness and soreness in the TFB group over the bland moisturizer.

Conclusions

Investigator assessments, participant query, and objective induration analyses have demonstrated that the use of TFB post DCA injections may reduce induration, edema, and discomfort associated with this procedure.

Level of Evidence: 2

Evaluation of the changes in sebum, moisturization and elasticity in acne vulgaris patients receiving systemic isotretinoin treatment

AIM

The aim of this study was to determine the change in facial skin sebum, hydration and elasticity of acne vulgaris patients after being treated with systemic isotretinoin.

METHOD

Patients who were diagnosed with acne vulgaris and who received systemic isotretinoin treatment for 6 months in Cerrahpaşa Medical Faculty Department of Dermatology between June 2012 and May 2017 were included in this study. The sebum, hydration and elasticity of the skin were measured non-invasively with a device called "Soft Plus Skin Analyses System" before treatment and 6 months after treatment. The relationship between the pre-treatment and post-treatment values were evaluated statistically. 35 adult patients (20 female, 15 male) who were diagnosed with acne vulgaris and who received systemic isotretinoin treatment for 6 months.

RESULTS

The pre-treatment sebum value for both sexes ranged between 5 and 100 and the mean value was calculated as 75.8 ± 28.0. The post-treatment sebum values ranged between 1 and 98 and the mean value was calculated as 48.4 ± 31.8. The difference between the pre-treatment and post-treatment values was statistically significant, p < 0.001. The decline in sebum value after treatment was 36%. The pre-treatment hydration values ranged between 9 and 77.5 and the mean was 34.6 ± 14.6. The post treatment hydration values ranged between 4.8 and 100 and the mean was calculated as 62.4 ± 28.6. The difference between the pre-treatment and post-treatment hydration values were statistically significant, p < 0.001. The post-treatment increase in hydration was 79%. The pre-treatment skin elasticity ranged between 28 and 50; the mean was 40.4 ± 5.5. The post-treatment elasticity values ranged between 20 and 50; and the mean was 37.5 ± 8.2. However, the difference was not statistically significant (p = 0.1).

CONCLUSION

With this study, it was concluded that, systemic isotretion leads to a 36% decline in skin sebum values and a 79% increase in the skin hydration. However, the change in skin elasticity was not statistically significant. Furthermore, the changes in sebum and skin hydration did not lead to a change in skin elasticity.

Identification of skin aging biomarkers correlated with the biomechanical properties

BACKGROUND

Skin aging can be described as a combination of intrinsic and extrinsic aging. Various parameters for evaluating skin characteristics have been proposed. However, an accurate biomarker for skin aging and the relationship between biomarkers and biomechanical parameters of the skin is yet to be explored.

MATERIALS AND METHODS

This study included 20 subjects by age. Skin aging was measured using non-invasive devices. Skin tissues were acquired through punch biopsy for immunohistochemistry and qRT-PCR of skin aging biomarkers, and analyzed correlation both, validated their use.

RESULTS

Biomechanical properties of skin aging decreased with age. Among the biomarkers previously reported, we found that the expression of Moesin, TXNDC5, RhoGDI, and RSU1 decreased, while that of Vimentin and FABP5 increased with age. Pearson correlation showed that the expression levels of TXNDC5, RhoGDI, RSU1, and Vimentin were significantly correlated with the results of non-invasive measurements. In addition, the expression of TXNDC5, RhoGDI, and RSU1 increased, while that of Vimentin decreased, in skin explants upon treatment with one of the anti-aging compounds, retinoic acid.

CONCLUSION

From this study, we identified practical molecular biomarkers of skin aging, TXNDC5, RhoGDI, RSU1, and Vimentin, which correlated with the skin biomechanical properties of skin aging.

Epidermal barrier changes in patients with psoriasis: The role of phototherapy

BACKGROUND

Some skin diseases may modify epidermal barrier function. Psoriasis is a chronic multi-systemic inflammatory disease that affects the epidermal barrier. Phototherapy is an option for treating psoriasis, but little is known about how epidermal barrier function is modified by phototherapy in psoriatic patients.

OBJECTIVES

(a) To compare skin homeostasis between involved and uninvolved skin in psoriatic patients with healthy controls (b) To evaluate changes in the epidermal barrier function in psoriatic patients treated with phototherapy.

METHODS

Sixty patients with plaque-type psoriasis and sixty gender and age-matched healthy controls were enrolled. Temperature, transepidermal water loss (TEWL), stratum corneum hydration (SCH), pH, elasticity, erythema and melanin index were measured using non-invasive tools in the healthy control and involved and uninvolved psoriatic skin before and after phototherapy.

RESULTS

Healthy controls had lower TEWL and erythema index and higher SCH than psoriatic patients, both at uninvolved psoriatic skin and psoriasis plaques. TEWL was higher at psoriasis plaques than at uninvolved skin (19.20 vs 11.57 g/h/m² ; P < .001). Following phototherapy, a decreasing trend was observed for TEWL, of 1.03 (SD 0.75) and 0.97 (SD 0.81) g/h/m² for uninvolved and involved skin respectively. SCH was significantly lower at psoriatic plaques than at uninvolved skin (7.32 vs 36.62Arbitrary Units [AU]; P < .001). SCH increased by 1.15AU (SD 0.26) on psoriatic plaques after the phototherapy session (P < .001).

CONCLUSION

Psoriatic plaques showed epidermal barrier dysfunction compared to uninvolved skin and healthy controls. Phototherapy may improve epidermal barrier function in psoriatic patients. SCH increased after a phototherapy session on the psoriatic plaques.

The relationship between habitual physical activity and skin mechanical properties

BACKGROUND

Physical activity (PA) is important for body health. A few reports suggested that PA also influenced skin structure and components. Little data are available on the influence of PA on skin mechanical properties (SMP). Here, we investigated the relationship between PA and SMP.

METHODS

Twenty-five healthy Japanese female subjects (31.0 ± 3.3 years) were enrolled in the study. To monitor the 24-hr pulse rate, a wrist watch-type pulse monitor was used. PA intensity was divided into five PA intensity zones (max, anaerobic, aerobic, fat combustion, and warm-up) by the pulse monitor. The average values of the time spent on each intensity for 70 days were calculated. To measure SMP, a Cutometer was used at the end of the monitoring. R0 indicated the height of the maximal skin deformation, and R6 was the ratio between viscoelastic and elastic deformation.

RESULTS

R0 was positively correlated with the time spent in four of the five PA intensity zones (max, anaerobic, aerobic, and fat combustion), whereas R6 was negatively correlated with the time spent in these four PA intensity zones. The time of warm-up did not correlate with SMP.

CONCLUSION

These results suggest that habitual moderate-to-vigorous PA influences SMP.

Comparison of different MyotonPRO probes for skin stiffness evaluation in young women

BACKGROUND

Stiffness of skin is widely used parameter in many research areas, for example cosmetic industry, dermatology or rheumatology for assessing of skin condition as well as changes occurring in skin. In this pioneering study, we conducted measurements of skin stiffness using MyotonPRO -novel tool, which was mainly used to evaluate biomechanical properties of muscles, ligaments and tendons. We expected that MyotonPRO , which shows great reproducibility in previous studies, will also be able to measure skin stiffness.

MATERIALS AND METHODS

Four replaceable probes designed by MyotonPRO (L-shape short and medium arm, standard cylindrical flat-end probe and the same standard probe with disc attachment ) were tested for measurement of skin stiffness in young women (30 healthy females) at three different locations (clavicula, volar forearm and shin).

RESULTS

There was no significant difference between stiffness values obtained with L-shape short and L-shape medium arm probes in all investigated areas. Stiffness values recorded by regular probe and regular probe with disc attachment differ significantly from those collected with L-shape probes. There was also significant difference between values of stiffness obtained by standard with disc attachment and standard probes.

CONCLUSION

Both L-shape probes show a great reliability for skin stiffness assessment. Therefore, MyotonPRO can be considered a reliable device for assessing skin stiffness.

Treating Hypertrophic Burn Scar With 2940-nm Er:YAG Laser Fractional Ablation Improves Scar Characteristics as Measured by Noninvasive Technology

Their group previously demonstrated high-patient satisfaction for the treatment of hypertrophic burn scar (HBS) with the erbium: yttrium aluminum garnet (Er:YAG) laser, but this and other literature supporting the practice suffer from a common weakness of a reliance on subjective assessments by patients or providers. Herein, they sought to prospectively study the effects of Er:YAG fractional ablation on HBS using noninvasive, objective technologies to measure outcomes. Patients with HBS had identical regions of scar designated for treatment by the Er:YAG laser (TREAT) or to be left untreated (CONTROL). They prospectively collected scar measurements of TREAT and CONTROL regions preoperatively, 3 weeks, and 3 months after Er:YAG treatment. Scar measurements included viscoelastometry, transepidermal water loss, optical coherent tomography, and high-frequency ultrasound. Outcomes were measured for the aggregate difference between the TREAT group vs the CONTROL group, as well as within each group in isolation. Seventeen patients were seen preoperatively, followed by n = 15 at 3 weeks and n = 11 at 3 months. A mixed-model repeated measures analysis showed no significant effect of fractional ablation when comparing the overall TREAT group measurements with those of the CONTROL group. However, when considered as within-group measurements, TREAT scars showed significant improvement in viscoelastic deformity (P = .03), elastic deformity (P = .004), skin roughness (P = .05), and wrinkle depth (P = .04) after fractional ablation, whereas CONTROL scars showed no such within-group changes. HBS treated by the Er:YAG laser showed objective improvements, whereas no such changes were seen within the untreated scars over the same time frame.

EEMCO Guidance for the in vivo Assessment of Biomechanical Properties of the Human Skin and Its Annexes: Revisiting Instrumentation and Test Modes

Biomechanics of the skin is an important subject in skin research. It has been studied for many decades involving various technologies and methods to characterize and quantify mechanical properties of the skin under different in vivo conditions. The present EEMCO paper reviews the current rel-evant information, providing practical orientation to researchers dedicated to in vivo assessment of biomechanics of skin and its annexes. We discuss the available non-invasive instruments, including their principles and variables. A correspondence between the descriptors nomenclature proposed by Agache and the designation for the suction-based standard instruments is proposed. The addressed properties include skin softness/stiffness, firmness, elasticity, elastic and viscoelastic properties, extensibility, resilience, anisotropy, acoustical shock wave hardness, friction (in relation to topographic properties), thickness, fiber/stress mechanics (bending, cyclic, tensile, fatigue, or torsion), and hardness. We provide the relation of these properties to biomechanical descriptors and in some cases to SI units. Practical guidance for the proper use of these instruments, limitations, and possible interpretations are provided, while discussing the meaning of descriptive or "phenomenological" variables. For studies intended to quantify the effect of an intervention with regard to mechanical properties, we recommend a minimum of 30-40 participants, based on normal distribution of the data sets. Some important limitations are recognized, including the lack of standardization of procedures and calibration of instruments, which compromises the relevance and real nature of the descriptors/parameters obtained with these devices. The present work highlights an approach to a better practice and a science-supported biomechanical assessment of human skin, hair, and nails.

Evaluation of anisotropic properties of striae distensae with regard to skin surface texture and viscoelasticity

BACKGROUND

Striae distensae (SD) are skin lesions of parallel streaks, which mostly occur during rapid tissue expansion. Considering the etiological mechanism of SD, including dermal network ruptures and alignment to mechanical stretch, structural directionality or anisotropy could be expected. Non-invasive objective methods for measuring the anisotropy of SD have not been suggested yet. Therefore, we evaluated the anisotropic properties of SD with regard to skin surface texture and viscoelasticity, to verify them as new objective evaluation parameters of SD.

METHODS

Thirty-two healthy subjects with SD on their body participated. Anisotropy of skin surface texture and biomechanical properties of SD-involved skin and adjacent normal skin was assessed and compared.

RESULTS

Analysis of skin surface texture, based on the ×60 magnified images, revealed that SD have more disordered patterns compared to the regular honeycomb patterns seen in the normal surrounding skin. SD have bigger sizes of each blob than normal skin. The overall anisotropy of skin texture was significantly higher in SD. Skin biomechanical parameters, measured using Cutiscan^® , indicated the less deformable, less recovered, and less viscoelastic properties of SD. When comparing viscoelastic properties over 360°, SD were more anisotropic than the adjacent normal skin as well.

CONCLUSION

We observed that SD were significantly more anisotropic than adjacent normal skin with regard to skin surface texture and viscoelasticity. Therefore, anisotropy could be an objective evaluation parameter to represent the distinctive features of SD. It can be applied for evaluation of the SD severity and clinical efficacy of various treatments.

A transparent, glue-free, skin-attachable graphene pressure sensor with micropillars for skin-elasticity measurement

Strong peeling resistance and water-drainable properties on rough and wet skin surfaces are highly desirable for realizing wearable and skin-attachable electronic sensors. Here, we propose a transparent, sensitive, glue-free pressure sensor for skin electronics. To achieve a thin, light-weight, transparent, and stretchable sensor patch, we laminated a single-layer graphene film as a sensing element on a thin polymeric supporter of polydimethylsiloxane. By assembling the graphene layer with densely populated micropillars, the pressure sensor achieved 10 times the sensitivity of a similar sensor without micropillars in the low-pressure range (<6 kPa). We then employed hexagonal patterns inspired by the toe pads of a tree frog, giving the assembled patch sensor with strong peeling resistance under both dry and wet conditions on surfaces such as silicon (15.5 J cm^-2 for dry and 11.6 J cm^-2 for wet conditions) and pig skin (2.0 J cm^-2 for dry and 1.4 J cm^-2 for wet conditions) without contamination after detachment. Our layered sensor patch also demonstrated successful measurement of water-dependent skin elasticity with transparent, conformal, and residual-free attachment, suggesting a variety of cosmetic and medical applications.

A dose-ranging, parallel group, split-face, single-blind phase II study of light emitting diode-red light (LED-RL) for skin scarring prevention: study protocol for a randomized controlled trial

BACKGROUND

Skin fibrosis is a significant global health problem that affects over 100 million people annually and has a profoundly negative impact on quality of life. Characterized by excessive fibroblast proliferation and collagen deposition, skin fibrosis underlies a wide spectrum of dermatologic conditions ranging from pathologic scars secondary to injury (e.g., burns, surgery, trauma) to immune-mediated diseases. Effective anti-scarring therapeutics remain an unmet need, underscoring the importance of developing novel approaches to treat and prevent skin fibrosis. Our in vitro data show that light emitting diode-red light (LED-RL) can modulate key cellular and molecular processes involved in skin fibrosis. In two phase I clinical trials (STARS 1 and STARS 2), we demonstrated the safety and tolerability of LED-RL at fluences of 160 J/cm² up to 480 J/cm² on normal human skin.

METHODS/DESIGN

CURES (Cutaneous Understanding of Red-light Efficacy on Scarring) is a dose-ranging, randomized, parallel group, split-face, single-blind, mock-controlled phase II study to evaluate the efficacy of LED-RL to limit post-surgical skin fibrosis in subjects undergoing elective mini-facelift surgery. Thirty subjects will be randomly allocated to three treatment groups to receive LED-RL phototherapy or temperature-matched mock irradiation (control) to either periauricular incision site at fluences of 160 J/cm², 320 J/cm², or 480 J/cm². Starting one week post-surgery (postoperative days 4-8), treatments will be administered three times weekly for three consecutive weeks, followed by efficacy assessments at 30 days, 3 months, and 6 months. The primary endpoint is the difference in scar pliability between LED-RL-treated and control sites as determined by skin elasticity and induration measurements. Secondary outcomes include clinical and photographic evaluations of scars, 3D skin imaging analysis, histological and molecular analyses, and adverse events.

DISCUSSION

LED-RL is a therapeutic modality of increasing importance in dermatology, and has the potential to limit skin fibrosis clinically by decreasing dermal fibroblast activity and collagen production. The administration of LED-RL phototherapy in the early postoperative period may optimize wound healing and prevent excessive scarring. The results from this study may change the current treatment paradigm for fibrotic skin diseases and help to pioneer LED-RL as a safe, non-invasive, cost-effective, portable, at-home therapy for scars.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03795116 . Registered on 20 December 2018.

Truncated Hollow Cone Probe for Assessing Transepidermal Water Loss and Skin Hardness

This study proposes a skin analysis device using a truncate hollow cone (THC) probe for measuring both transepidermal water loss (TEWL) and skin hardness. Because skin health is closely related to the epidermal barrier function and skin mechanical property, it is important to measure their biophysical indicators at the same time, to understand skin conditions and diagnose skin disorders such as atopic dermatitis and systemic sclerosis. Previous skin analyzers, however, required different probes with different protocols for each biophysical indicators, which makes the measurement inconvenient and increases the measurement uncertainty. The present device consists of a THC probe equipped with humidity and force sensors, and an actuator that simultaneously measure both TEWL and skin hardness which indicate the integrity of the epidermal barrier function and the skin mechanical property, respectively. Using artificial reference skins, the prototype device showed the TEWL with a sensitivity and linearity of 0.011 (%/s)/(g/m²/h) and 99.5%, and the hardness with 0.075 N/(Shore 00) and 97.6%, respectively, which are within the appropriate range for the properties of human skin. The on-body measurement of five subjects showed that the proposed device could measure both the TEWL and skin hardness without any crosstalk from each other. The proposed device has great potential for in-depth analysis of the health status of the skin which could indicate various skin diseases.