Skin Layer Research Articles

Toxicity and Dermatokinetic Analysis of Ibrutinib in Human Skin Models.

Background/Objectives: Ibrutinib (IBR) is a tyrosine kinase inhibitor under investigation in preclinical and clinical settings as an alternative treatment for melanoma. Nevertheless, the limited oral bioavailability of IBR and the need for high doses of the drug to kill melanoma cells are major drawbacks for this purpose. Considering that melanoma is restricted to the skin at early stages, the topical application of IBR might constitute an effective and safer administration route. In this study, we determined IBR's toxicity and dermatokinetics using human primary cells and human organotypic skin explant cultures (hOSECs). Methods: After demonstrating that human primary fibroblasts and keratinocytes present IBR target genes, the cytotoxicity of the drug was determined using the MTT and annexin V/PI staining assays. IBR toxicity in the skin was assessed using the TTC assay, and the irritation potential was established using histological assessment. Finally, IBR cutaneous permeation was assessed ex vivo to determine the drug dermatokinetics. Results: Our findings reveal that IBR exerts dose-dependent toxicity towards skin cells, presenting an IC50 in the same range as melanoma cells. The topical application of the drug successfully reduced irritation and toxicity in the skin, and the drug was shown to successfully permeate the stratum corneum and reach the viable skin layers in therapeutic concentrations. Conclusions: Overall, our data encourage the topical application of IBR to treat melanoma, paving the way for future studies in this theme.

Eucalyptus oil nanoemulsion for enhanced skin deposition of fluticasone propionate in psoriatic plaques: A combinatorial anti-inflammatory effect to suppress implicated cytokines.

Psoriasis is a chronic inflammatory skin disease that affects patients' quality of life. This study aimed to enhance the efficacy of topical application of fluticasone propionate (FP) using a eucalyptus oil-based nanoemulsion, an oil possessing anti-inflammatory activity and extracted from the leaves, fruits, and buds of Eucalyptus globulus or Eucalyptus maidenii, to improve the skin deposition of FP and aid its anti-inflammatory effect. Box-Behnken design was employed to optimize NE formulations, which were characterized for globule size, zeta potential, polydispersity index, rheological behavior, microscopic morphology, ex vivo skin permeation/deposition, and in vivo efficacy using imiquimod-induced psoriatic lesions. The optimized formulation depicted a droplet size of 188 ± 22.4 nm, a zeta potential of -17.63 ± 1.66 mV, and a viscosity of 204.9 mPa s. In addition to the increased FP retention in different skin layers caused by the NE and the reduced PASI score compared to the marketed cream, the levels of inflammatory cytokines IL-1α, IL-6, IL17a were markedly lowered, indicating the improved anti-psoriatic curable efficacy of the optimized formulation in comparison to the FP-marketed product.

Recent Innovations and Future Perspectives in Transferosomes for Transdermal Drug Delivery in Therapeutic and Pharmacological Applications.

There have been several non-invasive administrations that have emerged recently to replace conventional needle injections. With its minimal rejection rate, remarkable ease of administration, and remarkable patient comfort and perseverance, the transdermal drug delivery system (TDDS) is the most attractive of them all. The skincare industry, which includes cosmetics, may also find use for TDDS in addition to the pharmaceutical industry. As this strategy mainly entails local drug administration, it can prevent untargeted drug delivery to tissues not intended for the treatment and buildup of localized drug concentrations. Transdermal delivery is hampered by a number of physicochemical characteristics of the skin, which have led to a great deal of research into ways to get over these barriers. The majority of transdermal medicines that have proved effective do so by using smaller lipophilic compounds, which have a molecular weight of a few 100 Daltons. Transferosomes have proven to be an effective method for transdermal distribution of a range of therapies, including hydrophilic actives, bigger molecules, peptides, proteins, and nucleic acids, in order to get around the medications' size and lipophilicity limits. Because of their flexible form and increased surface hydrophilicity, transferosomes are essential for the delivery of medicines and other solutes through and into the skin by exploiting hydration gradients a source of energy. As a result, the medication is released into the skin layers under regulated conditions and has improved overall penetration. In this section we outline the development of transferosomes from liposomes and solid lipid nanoparticles, as well as their subsequent advancements as commercially available dosage forms, physical-chemical characteristics, and cutaneous kinetics.

A Review on Formulation of Body Lotion

The body is shielded by protective layers of skin. A plant-based herbal body lotion provides soothing hydration. Common ingredients often feature aloe vera, known for its healing properties, pain relief, and moisture retention. For centuries, it has been used to treat skin burns and wounds. Aloe vera, honey, glycerin, rose water, and triethanolamine were selected for the formulation of the herbal body lotion. Evaluation parameters were conducted to ensure that the formulation is safe for human use. The aloe vera body lotion was created using these ingredients, which include aloe vera known for its antimicrobial and hydrating properties, protecting the skin from microbial damage while providing moisture. In conclusion, this herbal body lotion is designed for topical application. Aloe vera enhances the lotion's synergistic and moisturizing effects on the skin. Herbal remedies are gaining worldwide popularity, and the combination of aloe vera, honey, coconut oil, Lavender oil, and glycerin in this formulation is an excellent approach. These formulations were assessed using various evaluation parameters, including homogeneity, appearance, after-feel, acid value, pH measurement, irritancy test, viscosity, accelerated stability testing, subjective properties, spreadability, type of emulsion test, sensitivity test, washability test, statistical analysis, in vitro permeation studies, thermal stability tests, total fatty matter determination, water content analysis, and patch tests. The aim of this review is to compile information on different herbal lotion formulations and their evaluations. Numerous researchers have studied herbal lotion formulations, and this knowledge can assist other researchers in developing novel herbal cosmetic formulations featuring new ingredients.

Development and evaluation of biocompatible coated microneedle array for controlled insulin delivery: Fabrication, characterization, in vitro, and in vivo investigations

Traditional insulin administration for people with diabetes often involves painful injections, leading to discomfort and challenges with patient compliance. A promising alternative to these conventional methods is transdermal insulin delivery using microneedle arrays, which offer a more comfortable way to deliver insulin through the skin. This study introduces an innovative approach using 3D-printed microneedle arrays coated with insulin via a dip-coating process. These microneedles present a compelling alternative to traditional injections, particularly due to their ability to gently pierce the stratum corneum, the outermost layer of skin, while minimizing discomfort. The microneedle arrays were fabricated using biocompatible resin polymers through 3D printing, creating solid conical needles with a length of 1200 µm, a base diameter of 200 µm, a tip diameter of 80 µm, and a needle spacing of 1.2 mm. The insulin coating was achieved by dip-coating the microneedles in a solution of insulin and polyvinyl alcohol (PVA), with careful optimization of the solution concentration, immersion time, and withdrawal speed to ensure a uniform and controlled coating thickness. Mechanical stability and skin penetration capabilities of the microneedles were assessed using skin models such as parafilm and porcine skin. The tests confirmed that the coated microneedles are robust enough to consistently penetrate the skin. In vivo studies with diabetic rats were conducted to evaluate skin irritation, penetration, and drug delivery efficiency. The insulin-coated microneedle arrays successfully penetrated the skin and delivered the drug with approximately 90 % efficiency. The study also showed that the microneedles provided consistent drug delivery, and the skin recovered without any signs of injury. Additionally, the hypoglycemic effect of the insulin-coated microneedles was comparable to that of traditional subcutaneous insulin injections. These findings underscore the potential of microneedle arrays as a painless and effective method for insulin delivery, maintaining stable glucose levels over an extended period. The demonstrated safety and efficacy of the coated microneedles open the door for clinical trials and potential use in diabetic patients, offering a promising advancement in diabetes management.

Comparative Study on Enhanced Skin Permeation Efficiency of Phenylephrine via Novel Lipid Vesicles: A Promising Approach in Preventing Chemotherapy-Induced Alopecia Management.

Chemotherapy-induced alopecia (CIA) significantly impacts patients' emotional and psychological well-being and treatment regimen. Phenylephrine, a topical vasoconstrictor, can potentially reduce hair loss by limiting chemotherapy drug delivery to hair follicles. However, effective delivery of Phenylephrine through the skin remains challenging. This study investigates lipid vesicles as delivery vehicles to enhance Phenylephrine's skin permeation and sustained release due to their biocompatibility and encapsulation capabilities. This study aimed to formulate and compare different lipid vesicles of Phenylephrine HCl for enhanced permeation through the skin for deep dermal delivery with sustained release of the drug so as to achieve local vasoconstriction. Phenylephrine-loaded ethosomes, invasomes, and transfersomes were prepared and characterized for particle size (PS), polydispersity index (PDI), and entrapment efficiency (EE %). These lipid vesicles were incorporated into hydrogels to facilitate sustained drug release to deep dermal layers where they could target local vasculature and cause vasoconstriction. The prepared vesicular gels were evaluated for various permeation parameters. The entrapment efficiencies of the developed vesicles ranged from 49.51 ± 3.25% to 69.09 ± 2.32%, with vesicle sizes ranging from 162.5 ± 5.21 nm to 321.32 ± 3.75 nm. Statistical analysis revealed significantly higher flux values (Jss, μg/cm2 h) of 0.6251, 0.6314, and 0.4075 for invasomal gel, ethosomal gel, and transfersomal gel, respectively, compared to plain gel (0.1254) (p < 0.005). The enhancement factors were 4.9848, 5.0350, and 3.2496 for invasomal gel, ethosomal gel, and transfersomal gel, respectively, indicating superior permeation abilities of ethosomal and invasomal formulations. The results demonstrate that ethosomal and invasomal formulations were efficient in delivering the drug to deep dermal layers of skin in a sustained manner. These findings suggest that these Lipidic vesicles would be able to target the local vasoconstrictor to vasculature, causing reduced hair loss by limiting chemotherapy drug delivery to hair follicles and managing chemotherapy-induced alopecia.

Tethered gold-liposome nanoparticles for iontophoresis-enhanced topical delivery for anti-inflammation

Topical delivery is a widely utilized drug administration route globally due to its convenience, non-invasiveness, and minimal drug metabolism. However, the skin barrier, particularly the stratum corneum (SC), poses a challenge by hindering drug absorption and permeation. To address this issue, green-synthesized gold nanoparticles (AuG) were loaded into liposomes to increase electron density and facilitate cathodal iontophoresis for topical drug delivery enhancement. Ginger rhizome extract served as a model hydrophobic compound encapsulated within the gold-liposomes to evaluate its anti-inflammatory effect. Our study demonstrated that the ginger-gold loaded liposomes (AuGL) enhanced cellular uptake of the hydrophobic payload and improved drug penetration through skin layers compared to conventional liposomes following iontophoresis. We investigated different ratios of gold nanoparticles to liposomes and characterized the nanoparticles using DLS, TEM, and FT-IR. Additionally, AuGL significantly inhibited nitric oxide release and TNF-α in RAW 264.7 cells. Furthermore, we formulated AuGL-loaded topical emulgel, which exhibited good stability under accelerated conditions. Our findings suggest that the AuGL combined with iontophoresis offers superior benefits for topical drug delivery, potentially enabling the treatment of skin inflammations and inflammation-related skin cancers.

Adaptation of skin structures to environmental variations in anurans from southern and southwestern China.

Variations in skin structures can possibly reflect local adaptation to distinct environmental factors. As the primary interface with the surrounding environment, amphibian skin undergoes phenotypic innovations that play a key role in protection, water absorption, and respiration. However, the effects of environmental factors on skin structures have been examined in only a limited number of species. Here, we conducted a comparative analysis of the skin structures of 102 Chinese anuran species across varying geographical distributions and habitat types. Our results revealed that the total volume of granular glands and capillary density in the dorsal skin significantly increased with increasing latitude. We also found that the thickness of calcified layers in both dorsal and ventral skin was positively correlated with annual temperature and negatively correlated with humidity. Additionally, terrestrial species exhibited the largest dorsal granular gland, whereas arboreal species had the smallest one. Likewise, the largest dorsal mucous gland was observed in aquatic species, while the smallest was found in terrestrial species. These results highlighted the importance of understanding the relationship between skin phenotypes and environmental variables and thus providing conservation strategies based on the evolutionary adaptations in anurans. Our study can contribute to the broader knowledge of evolutionary biology in anurans by demonstrating how specific skin traits are linked to survival and fitness across various ecological contexts.

Wound healing activity of Ipomoea staphylina leaves extract in Wistar rats

Wound repair is the practice of repairing the skin and other soft tissues after an injury. An inflammatory response is activated after an injury, and cells below the dermis (deepest skin layer) begin to produce more collagen (connective tissue). A scientific assessment was made for the wound-healing potential of Ipomoea staphylina leaves extract, using ethanol. The crude extract was made into a 2.5% and 5% (w/w) ointment and tested for wound healing activity in Wistar rats using excision and incision wound models. In the excision wound model, the period of epithelialization was reduced and an increase in wound contraction rate was observed in the extract treated groups (III and IV). On the tenth day, tissue from the excision wound area was taken and processed for the assessment of pro-inflammatory cytokines (TNF-α), and it was found that there was a notable decrease in the TNF-α concentration in the extract-treated animals. In an incision wound model, the breaking strength was significantly increased in animals treated with 2.5% and 5% (w/w) ointment of I. staphylina leaves extract. The extract significantly promoted fibroblast migration in an in vitro experiment (scratch assay), which may have been caused by the presence of flavonoids.

Simvastatin and adenosine-co-loaded nanostructured lipid carriers for wound healing: Development, characterization and cell-based investigation

Chronic wounds represent a significant global health burden, characterized by delayed skin healing and associated comorbidities. The present study aimed to develop nanostructured lipid carriers (NLCs) as a topical delivery system for the co-administration of simvastatin and adenosine to address chronic wound management. The rationale behind the co-delivery approach was to mitigate the cytotoxicity associated with high-dose simvastatin, while preserving its therapeutic benefits through a potential synergistic or additive effect. A significant challenge in the development of these NLCs was the encapsulation of the highly hydrophilic adenosine within the hydrophobic lipid matrix. The NLCs were prepared using a hot homogenization-sonication method with a double emulsion technique and optimized through a series of formulation trials, employing various surfactants, solid and liquid lipids, to achieve efficient drug encapsulation, particularly for the hydrophilic adenosine. Optimized formulations F5- and F10-S/A 0.6 %/2 % (containing 0.6 % simvastatin and 2 % adenosine), exhibited promising physicochemical properties. The main difference was the liquid lipid used: F5 contained Miglyol 810 N, while F10 contained Capmul MCM C-8. Both formulations displayed a mean particle size below 230 nm, a polydispersity index (PDI) of approximately 0.2, and a zeta potential around –22 mV. While simvastatin association efficiency (AE) was nearly 100 %, adenosine AE was higher for F10 (24 %), compared to F5 (13.5 %). F5 demonstrated superior stability compared to F10, maintaining consistent particle size and PDI over a 60-day period. Formulation F5 also demonstrated superior cell-based in vitro performance compared to F10, with higher cell viability (MTT assay), greater cell proliferation induction (SRB assay), and enhanced cell proliferation and migration in the wound-scratch assay. While F10 displayed higher adenosine AE, F5 excelled in terms of stability and biological activity. The slight increase in intracellular reactive oxygen species levels observed with F5 may contribute to its enhanced proliferative effects. In-depth characterization revealed that F5 comprised spherical nanoparticles, and thermal analysis indicated no significant changes in the nanocarrier structure upon drug encapsulation. Additionally, ex vivo permeability study demonstrated superior skin retention of both simvastatin and adenosine for F5 compared to an emulsion control. Overall, the F5 nanocarrier demonstrated suitable physicochemical properties, cellular biocompatibility, induction of cell proliferation and migration events, and drug retention capacity in the skin layers, indicating its potential as a promising topical treatment for difficult-to-heal wounds.

Evaluating facial dermis aging in healthy Caucasian females with LC-OCT and deep learning

Recent advancements in high-resolution imaging have significantly improved our understanding of microstructural changes in the skin and their relationship to the aging process. Line Field Confocal Optical Coherence Tomography (LC-OCT) provides detailed 3D insights into various skin layers, including the papillary dermis and its fibrous network. In this study, a deep learning model utilizing a 3D ResNet-18 network was trained to predict chronological age from LC-OCT images of 100 healthy Caucasian female volunteers, aged 20 to 70 years. The AI-based protocol focused on regions of interest delineated between the segmented dermal-epidermal junction and the superficial dermis, exploiting complex patterns within the collagen network for age prediction. The model achieved a mean absolute error of 4.2 years and exhibited a Pearson correlation coefficient of 0.937 with actual ages. Furthermore, there was a notable correlation (r = 0.87) between quantified clinical scoring, encompassing parameters such as firmness, elasticity, density, and wrinkle appearance, and the ages predicted by deep learning model. This strong correlation underscores how integrating emerging imaging technologies with deep learning can accelerate aging research and deepen our understanding of how alterations in skin microstructure are related to visible signs of aging.

Advancements in skin grafting: Development and application of a novel two-blade dermatome for concurrent split-thickness and dermal graft harvesting

This investigation delineates the evolution and prospective utilisation of an innovative two-blade dermatome, designed for the concurrent harvesting of a conventional split-thickness skin graft (STSG) and an additional dermal graft within the same surgical harvest. Historically, the extraction of dermal grafts has encountered substantial technical impediments, contributing to its limited acceptance and utilisation in clinical practice. The prototype dermatome, introduced in this technical note, offers a solution that could facilitate the more extensive adoption of dermal grafting techniques.The dermal segment of an STSG, obtained as a second graft, confers four notable advancements: First, employing solely the dermal component for grafting and repositioning the uppermost skin flap to the donor site, markedly diminishes donor site morbidity. Second, owing to its elasticity, the dermal graft reduces the need for meshing, thereby enhancing cosmetic outcomes. Third, utilising both the uppermost skin layer and a deeper dermal layer for the recipient site can reduce donor site areas. Fourth, the dermal segment of the graft can serve as a dermal matrix in reconstructive procedures, potentially reducing the need for an allogenic dermal matrix and obviating the subsequent STSG; the dermal graft may heal independently, eliminating the need for an additional conventional STSG.The findings of this study, predicated on the application of a first-generation two-blade dermatome on four cadavers, demonstrate the feasibility of extracting at least two distinct grafts with pre-determined thicknesses in a single, technically less challenging, surgical harvest procedure.In conclusion, this proof-of-concept research elucidates the feasibility of a two-blade dermatome, capable of simultaneously yielding at least one conventional STSG and one dermal graft, thereby simplifying skin graft harvesting. Although these preliminary investigations were conducted on human cadavers, the results hold promise for the development of two-blade dermatomes and represent a significant advancement in skin graft harvesting. Further research is imperative to refine the prototype and to broaden our comprehension of the potential applications of dermal grafting in various clinical scenarios.

Scanning Transmission Soft X-Ray Microscopy Probes Topical Drug Delivery of Rapamycin Facilitated by Microneedles.

Scanning Transmission X-ray microscopy (STXM) is a sensitive and selective probe for the penetration of rapamycin which is topically applied to human skin ex vivo and is facilitated by skin treatment with microneedles puncturing the skin. Inner-shell excitation serves as a selective probe for detecting rapamycin by changes in optical density as well as linear combination modeling using reference spectra of the most abundant species. The results indicate that mechanical damage induced by microneedles allows this drug to accumulate in the stratum corneum without reaching the viable skin layers. This is unlike intact skin which shows no drug penetration at all and underscores the mechanical impact of microneedle skin treatment. These results are compared to drug penetration profiles of other drugs highlighting the importance of skin barriers. High spatial resolution studies also indicate that the lipophilic drug rapamycin is observed in corneocytes. Attempts in data evaluation are reported to probe rapamycin also in the lipid layers between the corneocytes, which was not accomplished before. These results are compared to recent results on rapamycin uptake in skin where barrier impairment was induced by pre-treatment with the enzyme trypsin and drug formulations leading to occlusion.

Transdermal Drug Delivery Systems: Different Generations and Dermatokinetic Assessment of Drug Concentration in Skin.

Transdermal drug delivery systems (TDDS) are a highly appealing and innovative method of administering drugs through the skin, as it enables the drugs to achieve systemic effects. A TDDS offers patient convenience, avoids first-pass hepatic metabolism, enables local targeting, and reduces the toxic effect of drug. This review details several generations of TDDS and the advancements made in their development to address the constraints associated with skin delivery systems. Transdermal delivery methods of the first generation have been consistently growing in their clinical application for administering small, lipophilic, low-dose drugs. Second-generation TDDS, utilizing chemical enhancers and iontophoresis, have led to the development of clinical products. Third-generation delivery systems employ microneedles, thermal ablation, and electroporation to specifically target the stratum corneum, which is the skin's barrier layer. Dermatokinetics is the study of the movement of drugs and formulations applied to the skin over a period of time. It provides important information regarding the rate and extent to which drugs penetrate skin layers. Several dermatokinetic techniques, including tape stripping, microdialysis, and laser scanning microscopy, have been used to study the intricate barrier properties and clearance mechanisms of the skin. This understanding is essential for developing and improving effective TDDS.

Microbial imbalance in Darier disease: Dominance of various staphylococcal species and absence of Cutibacteria

Darier disease (DD) is a rare autosomal dominant genodermatosis characterized by erythematous papules and plaques mainly involving sebaceous areas, such as the face, chest and back. Skin microbiome plays an essential role in maintaining skin homeostasis. A disturbed skin microbiome may contribute to the exacerbation of DD. We investigated the bacterial composition of two predilectional sites in DD patients and healthy individuals. We also measured the microbiome composition of deeper skin layers, where diversity was significantly reduced compared to the superficial layer of the skin from the same area. The microbiome of DD patients at lesional sites differed from that of non-lesional skin areas; moreover, non-lesional sites were different from those of the controls. Lesional areas were dominated by Staphylococcus species, such as S. aureus, S. epidermidis, S. hominis, S. sciuri, and S. equorum. However, levels of Cutibacterium acnes (formerly Propionibacterium acnes) and C. acnes subspecies defendens were significantly lower in lesional sites than in non-lesional sites. A significant decrease was measured in the levels of these two bacteria between non-lesional and control samples. Our findings may indicate that alterations in the skin microbiome could contribute to the inflammation of skin lesions in DD.

Invasomes: An Artificial Vesicle Nanocarrier to Enhance Transdermal Drug Delivery

Abstract: The greatest and most noticeable organ in the body is the skin. The stratum corneum, or top layer of skin, acts as a vital barrier to prevent skin penetration for many drugs. To over-come this barrier, numerous nanocarrier frameworks have been developed, which are important for the functioning of active agents. Vascular systems known as invasomes contain low levels of ethanol as well as terpenes or terpene combinations, which have a higher skin penetration rate and function as potential carriers. Improved drug delivery via the skin using a carrier that can pene-trate these barriers presents a wide range of difficulties and possibilities for further study and the creation of new and better treatment options. The main objective of an invasome-based delivery system is to significantly improve patient compliance and therapeutic value, in addition to bol-stering the safety and efficacy of the drug. This article gives a summary of the synthesis process, invasome characterizations, penetration mechanisms, and applications. This review paper also in-cludes phospholipids and their classification. Phospholipids are present in the cell membrane and provide ceramide, a bioactive molecule that moisturizes skin and protects against environmental damage in transdermal drug delivery systems. Pharmaceutical studies demonstrate that many drug molecules have less solubility, stability, bioavailability, and penetrating power. Invasomes repre-sent a novel dosage form with promising properties for enhancing transdermal drug delivery.

Impacts of Photooxidation on Commercially Available Homo and Copolymers of Polypropylene on Their Microstructure and Mechanics: A Cross‐Sectional Analysis

ABSTRACTPolyolefin degradation is widely studied to assess the lifetime of packaging materials. In this work, a combination of bulk (DSC, GPC, 13C‐NMR, XRD), surface (FTIR) and cross‐sectional characterization (Raman spectroscopy and nanoindentation) was used to examine changes in the mechanical properties and microstructure of two different commercially‐available polyolefins, with similar crystallinities, produced by injection molding—a polypropylene homopolymer (PPH) and a polypropylene random copolymer (PPRC)—aged under accelerated UV‐A conditions. The aim was to characterize the variations in the crystallinity and microstructure across the cross‐section of these materials. Our results suggest that the presence of ethylene comonomer units in PPRC results, on average, in smaller crystal dimensions, leads to improved packing, and a more homogeneous microstructure and hardness across the cross‐section of the sample. The ethylene monomers stabilize PPRC from oxidation during the first 14 days of accelerated aging, but eventually the rate of degradation matches the PPH at 28 days of aging, probably because of the higher surface area to volume ratio of the smaller crystals. The work emphasizes the importance of incorporating ethylene comonomers into polyolefins to limit variation of the microstructure across the core to the skin layer, for improved future design of packaging that degrades fully.

Acoustic radiation characteristics of shark skin inspired surface modified plates

This paper aims to evaluate the acoustic radiation characteristics of thin plates featuring a layer of small-scale biomimetic shark skin type additive surface treatment. The shark skin dermal denticles are modelled as point masses arranged in a bi-directional pattern on both the upper and lower surfaces of the plate. The governing equations are obtained through a variational approach, incorporating the Dirac Delta function in the derivation of the proposed semi-analytical model for the shark skin layer. A semi-analytical method based on the Rayleigh–Ritz formulation is utilized to analyze the vibrations of these plates with surface modification. The sound radiation characteristics are then derived from the solution of the Rayleigh integral. A comprehensive investigation is performed on the influence of surface modification on different vibro-acoustic characteristics, using a continuous structural mode and power transfer matrix-based approach. Notable observations include a reduction in peak vibro-acoustic responses with dense denticle arrangements, especially at resonance, demonstrating a direct relationship with mass ratios, i.e., the ratio of denticle mass to plate mass. The study further reveals a shift of vibro-acoustic responses towards low frequencies with an increase in mass ratios. A thorough comparative study indicates that while additive surface modifications inspired by shark skin may weaken sound radiation characteristics at resonance frequencies, a reverse effect can be observed at intermittent operational frequencies.

The Beauty Revolution of Nanotechnology: Unveiling the Impact of Cosmetic Nano Wonders.

The infusion of nanotechnology into cosmetic formulations marks a transformative shift in beauty science. Although Raymond Reed originally used the word "cosmeceutical," Dr. Albert Kligman popularised the idea in the late 1970s. Cosmetic Nano Wonders are redefining skincare by leveraging nanomaterials to enhance the stability, delivery, and efficacy of active ingredients. The paradigm shift holds promise for overcoming longstanding challenges in traditional cosmetic formulations. This article aims to explore and showcase the revolutionary impact of nanotechnology on the cosmetic industry. Focusing on key nanocarriers, such as liposomes and nanoparticles, our objective is to illuminate how nanotechnology elevates the performance of beauty products, providing advanced solutions for skincare concerns. This revolution promotes sustainability through green synthesis techniques and enables more accurate and effective therapies for a variety of skin issues, including acne and ageing that raises the bar for safety and innovation in the cosmetics business by enhancing product performance and environmental impact. Conducting a thorough literature review, we analyze recent scientific studies and industry reports to unveil the mechanisms and applications of nanotechnology in cosmetics. Special attention is given to the role of nanocarriers in stability enhancement, targeted delivery, and controlled release, unraveling the methods that drive the transformative potential of Cosmetic Nano Wonders. The database sources are Scopus, PubMed, Google Scholar, and Google Patents. The examination of recent research underscores the tangible benefits of nanotechnology in cosmetics. Cosmetic Nano Wonders demonstrate superior stability, enhanced penetration into skin layers, and controlled release mechanisms, showcasing their potential to revolutionize beauty science and address longstanding challenges in skincare. Cosmetic Nano Wonders represent a groundbreaking shift in beauty science, offering unprecedented possibilities for formulators and consumers. As nanotechnology continues to reshape cosmetic formulations, the future holds the promise of safer, more effective, and personalized skincare solutions, ushering in a new era in beauty science.

Experimental validation of effective glass transition temperature‐based model for predicting skin thickness in solid‐state microcellular foams

AbstractThe solid‐state foaming process produces microcellular foams with an outer layer of solid skin that encapsulates the cellular core. In this article, we implement a 1D model to predict the thickness of the solid skin based on the effective Tg of the polymer‐gas system for a given foaming temperature. The model is based on the understanding that bubbles nucleate when the foaming temperature exceeds the effective Tg during the foaming process. The model was validated with experimental results on the PC‐CO2 system, which showed that skin thickness decreases with increased foaming temperature. We also developed a linear correlation to accurately predict effective Tg at different CO2 concentrations. The article also explores the model sensitivity to the key input parameters related to gas diffusion.Highlights Linear correlation to accurately predict effective Tg profiles in PC‐CO2 system. Increasing foaming temperature decreases skin thickness. Model is sensitive to the input parameters related to gas diffusion.