Skin Collagen Research Articles

Tanshinone IIA ameliorates the development of dermal fibrosis in systemic sclerosis.

We previously revealed the role of tanshinone IIA (TAN IIA) on endothelial cells and the impact of TAN IIA on the endothelial-to-mesenchymal transition in systemic sclerosis (SSc). In this study, we sought to further determine whether TAN IIA can directly act on the skin fibroblasts of scleroderma and look into its underlying anti-fibrotic mechanisms. Bleomycin was used to establish the SSc mouse model. After TAN IIA treatment, dermal thickness, type I collagen and hydroxyproline content were measured. Primary fibroblasts were acquired from SSc patients and cultured in vitro, and the effects of TAN IIA on proliferation, apoptosis and the cell cycle of fibroblasts were detected. In a bleomycin-induced SSc model, we discovered that TAN IIA significantly improved skin thickness and collagen deposition, demonstrating a potent anti-fibrotic action. TAN IIA inhibits the proliferation of skin fibroblasts derived from SSc patients by causing G2/M cell cycle arrest and promoting apoptosis. Additionally, TAN IIA downregulated extracellular matrix gene transcription and collagen protein expression in skin fibroblasts in a dose-gradient-dependent manner. Furthermore, we showed how TAN IIA can reduce the activation of the transforming growth factor-β (TGF-β)/Smad and mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) pathways, which are important factors in SSc. In summary, these data suggest that TAN IIA can reduce SSc-related skin fibrosis by modulating the TGF-β/Smad and MAPK/ERK signalling pathways. More importantly, our results imply that TAN IIA can directly act on the skin fibroblasts of SSc, therefore, inhibiting fibrosis.

The Effect of Giving Aloe Vera Gel on Collagen Growth in Wistar Rats (Rattus Norvegicus) with Exposure to Ultra Violet-B Light

Exposure to UV rays can cause photochemical damage to the DNA of cells in the body, triggering cancer formation, especially skin cancer in humans. The skin may lose elasticity. Research is needed to ensure that currently, we are still looking for plants or foods that contain collagen, which can prevent wrinkles. This research is an original experiment carried out in a laboratory. Two types of variables play a role in this research: independent variables and dependent variables. In this experiment, aloe vera gel was used as an independent variable as a substitute for UVB light exposure. Collagen development, measured in mouse skin, is the dependent variable here. This study found that the standard control group had no collagen growth and was stable. This was because the typical control treatment was not exposed to UVB rays; hence, collagen formation was stable. The group administered 15% aloe vera extract gel had a more substantial effect on rat skin tissue collagen development after UVB light exposure than the 5% and 10% groups. This is because a higher dose of aloe vera extract includes more chemical components that promote mouse skin collagen formation.

Collagen study advances for photoaging skin.

Collagen dominates the skin's extracellular matrix (ECM). Type I collagen comprises 80%-90% of the skin's collagen, followed by type III (8%-12%) and type V (5%). Reactive oxygen species, matrix metalloproteinases, and collagen degradation all increase during photoaging, which disrupts the ECM's dynamic balance and lowers the amount of total collagen in the body. In recent years, domestic and foreign researchers have conducted multidimensional and multifaceted studies on collagen and skin photoaging. Collagen and the peptides that are derivates of it are currently being used more and more in biomedicine and medical esthetics. Offering new suggestions for both the avoidance and remedy of photoaging. This article reviews collagen and its potential connection to skin photoaging, illustrates the effects of collagen and peptide supplementation derivatives on photoaged skin, and briefly describes other compounds that can also be used to fight photoaging by increasing collagen synthesis in the skin. Both internal and external aging are inevitable, and as the main component of extracellular matrix, collagen plays a variety of functions in maintaining skin structure and fighting skin aging, and its role in photoaging is undeniable. Ultraviolet radiation can induce increased fragmentation and degradation of cutaneous collagen, while conversely, supplementation with collagen can effectively counteract photodamage-induced skin impairment. Collagen and its derived peptides are indispensable in photoaging skin, holding promising prospects for applications in skin aging.

Snakehead Fish Extract in Increasing Skin Collagen & Fibroblasts

This study aim is to gain a deeper understanding of the mechanisms by which snakehead fish extract affects the skin, opening doors for the development of more effective and natural skincare products. The study employs a systematic literature review method using PRISMA strategy, identifying 156 relevant articles through platforms such as PubMed, Google Scholar, Scopus, SINTA, spanning from 2018 to 2023. Findings encompass increased VEGF production and NO levels with snakehead fish extract dosages, wounds healing potential of honey and snakehead fish skin combination in hydrogel formulations, increased fibroblast counts, reduced skin erythema, and decreased wound crust formation. Additionally, marine collagen exhibits promise in skin healing and bone repair. Collagen supplements, whether oral or topical, also prove beneficial in delaying skin aging. The study reveals crucial insights into the potential of snakehead fish extract in skincare and wound healing, supporting the development of more effective and natural skincare products.

Exploring marine collagen: Sustainable sourcing, extraction methods, and cosmetic applications

The predominant sources of collagen for cosmetic purposes were traditionally derived from bovine and porcine products, such as bones, tendons, and connective tissues. However, these sources are gradually declining in popularity due to their restricted availability, religious constraints, and disease-related concerns. Consequently, there is an urgent necessity to explore alternative sustainable collagen sources. Marine species offer a promising and sustainable supply for alternative collagen sources due to lower risk of disease transmission, freedom from religious restrictions, biocompatibility, lower molecular weight, lower production costs, and simpler absorption by the human body. This study objective highlights to explore potential collagen sources from marine resources (fishes, poriferans, mollusks, crustaceans, echinoderms, and coelenterates) for cosmetic applications. A variety of marine collagen sources with different extraction techniques will be compared. The study finds that fish by-products, particularly skins and bones, are becoming a very encouraging sustainable collagen source contrasted with other alternatives. They exhibit a significant collagen content, comprising up to 61.26 % of their dry weight under acid-soluble collagen (ASC) extraction method. Fish skin and bone-derived collagen is mostly composed of type I collagen and has been proven to possess notable capabilities as an antioxidant, antiaging, and skin-whitening agent. Therefore, the utilization of marine collagen as a key ingredient in cosmetics promotes responsible sourcing, encourages eco-friendly practices, and fosters a circular economy by making the most of underutilized marine materials.

An androgenetic alopecia remedy based on marine collagen peptide-incorporated dissolving microneedles

Given that current androgenetic alopecia (AGA) medications have adverse effects such as sexual dysfunction and drug dependence, researchers are actively exploring natural bioactive ingredients and innovative approaches (e.g., transdermal drug delivery systems) to effectively combat hair loss with minimal side effects. Herein, we develop a new transdermal drug delivery system incorporating globefish skin collagen peptides with dissolving microneedles (GSCPs-MNs) for hair regrowth. These microneedles generate skin micro-wounds upon application, which not only improves the efficiency of bioactive ingredients delivery, but also stimulates signals involved in hair follicle (HF) regeneration. Our in vivo study shows that minimally invasive implanted GSCPs-MNs are more effective than topical GSCPs in reducing inflammation and promoting collagen formation. Additionally, the upregulation of vascular markers including VEGF and CD31 alongside the downregulation of TNF-α, IL-1β, and malondialdehyde (MDA) index indicate that GSCPs-MNs can significantly alleviate inflammation and oxidation, as well as promoting vascularization and HF functionalization. Overall, our findings suggest that GSCPs-MNs can effectively promote hair regrowth in AGA mice, which offer excellent prospects for the development of new therapeutics and cosmetic supplements for hair loss, along with the combined drug delivery optimization, which could alleviate hair loss in patients with AGA.

Oral intake of collagen hydrolysate from mackerel scad (Decapterus macarellus) attenuates skin photoaging by suppressing the UVB-induced expression of MMP-1 and IL-6.

Excessive skin exposure to UVB radiation can induce photoaging caused by an imbalance in oxidative stress and inflammatory responses, damaging the skin's structure and surface layer. A previous study revealed that collagen hydrolisate extracted from the skin of mackarel scads (Decapterus macarellus) had antiaging properties thatwere tested invitro, which serves as a foundation for asubsequent study of its use invivo. This study aimed at investigating the repair effect of the mackerel scad's skin collagen hydrolysate (MSS-CH) in photoaging conditions in amouse model. MSS-CH was given orally in mice model of skin photoaging under chronic exposure to UVB irradiation for12weeks. Morphological and histological changes on the skin were evaluated using SEM and HE staining, along withthe measurement of the expression of matrix metalloproteinases (MMP-1) and cytokine pro-inflammatory interleukin 6 (IL-6) using ELISA. MSS-CH inhibits the occurrence of epidermal thickening and damage to the dermal layer of the skin. As aresult, it restores the epidermis' barrier function and reduces surface damage caused by photoaging. The skin ofthe MSS-CH treated group exhibited improved physical appearance with reduced fine lines, wrinkles, and enhanced smoothness. Additionally, administering MSS-CH to the mice groups reduced the expression of MMP-1 and IL-6 in UVB-exposed skin. Altogether, this invivo study demonstrates thephotoaging-protective properties of CH-MSS, aligning with previous invitro data. Thus, MSS-CH emerges as a strong candidate for use as an ingredient in nutraceuticals and biocosmetics.

Antler stem cell-derived exosomes promote regenerative wound healing via fibroblast-to-myofibroblast transition inhibition

IntroductionThe typical outcome of mammalian wound healing is scarring, a fibrotic process mediated by myofibroblast aggregation. Perfect healing in a clinical setting is relatively unexplored. Surprisingly, our previous studies have shown that the large wound (10 cm diameter or more) of the pedicle of deer naturally achieves regenerative restoration, realized through a paracrine pathway from adjacent antler stem cells (AnSCs).MethodsAnSC-derived exosomes (AnSC-exos) were topically injected around the full-thickness wounds in a rat model. The effects on the rate of wound healing and the quality of healing were evaluated via morphological, histological, and molecular biological techniques on days 14 and 28 after surgery.ResultsThe results showed that AnSC-exos significantly accelerated the rate of wound healing and improved healing quality, including regeneration of cutaneous appendages (hair follicles and sebaceous glands) and the distribution pattern of collagen (basket-weave-like) in the healed skin. These effects of AnSC-exos were comparable to those of AnSCs but were significantly more potent than those of exosomes derived from bone marrow mesenchymal stem cells (bMSC-exos). Furthermore, AnSC-exos treatment effectively inhibited fibroblast-to-myofibroblast transition (FMT), as evidenced by the reduction of full-thickness skin injury-induced FMT in vivo and TGF-β1-induced FMT in vitro.ConclusionAnSC-exos could effectively promote regenerative cutaneous wound healing, highly likely through FMT inhibition. This suggests that AnSC-exos treatment could provide the potential for a novel approach to induce regenerative wound healing in the clinical setting.Graphical

Abstract 17425: Matricellular Protein CCN1 Modulates Post-Infarct Scar Integrity and Structure

Introduction: Collagen deposition is required for repair of the heart following myocardial infarction (MI). As collagen abundance increases, so does its alignment, potentially influencing scar integrity. Because cell-matrix interactions regulate fibroblast behavior and matrix dynamics, adhesive factors, like cellular communication network (CCN) proteins, may contribute to post-MI scar formation. CCN1's role in skin collagen modulation and its recent emergence as a heart failure biomarker indicate its potential contribution to post-MI matrix remodeling. Consequently, we focused on CCN1 as a potential regulator of collagen organization. Hypothesis: CCN1 guides collagen alignment to support scar integrity via enhancing fibroblast-matrix interactions. Methods & Results: Tamoxifen (TAM)-inducible Ccn1 fibroblast-specific KO ( Ccn1 -/- ) and control ( Ccn1 fl/fl ) mice (16-20 wk old) received TAM 3 wk prior to permanent coronary artery ligation. Cardiac function, heart mass, and scar structure were evaluated 1 wk post-MI using echocardiography, gravimetrics, and imaging techniques (picrosirius red, second harmonic generation, and transmission electron microscopy). Ccn1 -/- mice exhibited decreased survival (A) and an increased incidence of cardiac rupture compared to Ccn1 fl/fl (B-C). There were no differences in cardiac function or scar size among the groups. Macro- (E-F) and micro- (G) level structural analyses uncovered significant reductions in collagen organization in Ccn1 -/- mice. RNAi-mediated CCN1 depletion in fibroblasts resulted in reduced focal adhesion (FA) formation in culture (43.0 FA/cell ± 5.6 vs. 89.3 FA/cell ± 9.6; Mean ± SEM, p=0.0013, n=7), highlighting its role in facilitating fibroblast-ECM interactions. Conclusions: CCN1 is required for post-MI scar integrity. CCN1 may regulate fibroblast-ECM interactions to alter collagen organization.

Epigenetics insights from perceived facial aging

Facial aging is the most visible manifestation of aging. People desire to look younger than others of the same chronological age. Hence, perceived age is often used as a visible marker of aging, while biological age, often estimated by methylation markers, is used as an objective measure of age. Multiple epigenetics-based clocks have been developed for accurate estimation of general biological age and the age of specific organs, including the skin. However, it is not clear whether the epigenetic biomarkers (CpGs) used in these clocks are drivers of aging processes or consequences of aging. In this proof-of-concept study, we integrate data from GWAS on perceived facial aging and EWAS on CpGs measured in blood. By running EW Mendelian randomization, we identify hundreds of putative CpGs that are potentially causal to perceived facial aging with similar numbers of damaging markers that causally drive or accelerate facial aging and protective methylation markers that causally slow down or protect from aging. We further demonstrate that while candidate causal CpGs have little overlap with known epigenetics-based clocks, they affect genes or proteins with known functions in skin aging, such as skin pigmentation, elastin, and collagen levels. Overall, our results suggest that blood methylation markers reflect facial aging processes, and thus can be used to quantify skin aging and develop anti-aging solutions that target the root causes of aging.

Research Progress in Skin Aging, Metabolism, and Related Products.

In recent years, skin aging has received increasing attention. Many factors affect skin aging, and research has shown that metabolism plays a vital role in skin aging, but there needs to be a more systematic review. This article reviews the interaction between skin metabolism and aging from the perspectives of glucose, protein, and lipid metabolism and explores relevant strategies for skin metabolism regulation. We found that skin aging affects the metabolism of three major substances, which are glucose, protein, and lipids, and the metabolism of the three major substances in the skin also affects the process of skin aging. Some drugs or compounds can regulate the metabolic disorders mentioned above to exert anti-aging effects. Currently, there are a variety of products, but most of them focus on improving skin collagen levels. Skin aging is closely related to metabolism, and they interact with each other. Regulating specific metabolic disorders in the skin is an important anti-aging strategy. Research and development have focused on improving collagen levels, while the regulation of other skin glycosylation and lipid disorders including key membrane or cytoskeleton proteins is relatively rare. Further research and development are expected.

Collagen-EGCG Combination Synergistically Prevents UVB-Induced Skin Photoaging in Nude Mice.

Ultraviolet (UV)radiation is a major cause of skin photoaging through generating excessive oxidative stress and inflammation. One of the strategies is to use photo-chemoprotectors, such as natural products with antioxidant and anti-inflammatory properties, to protect the skin from photo damage. The present study investigates the photoprotective potentials of topical administration of unhydrolyzed collagen, epigallocatechin gallate (EGCG), and their combination against ultraviolet B (UVB)-induced photoaging in nude mice. It is found that both the solo and combined pretreatments could recover UVB-induced depletion of antioxidative enzymes, including superoxide dismutase and glutathione peroxidase (GSH-Px), as well as an increase of lipid peroxide malondialdehyde and inflammatory tumor necrosis factor-α. Meanwhile, the UVB-stimulated skin collagen degradation is attenuated significantly with drug treatments, which is evidenced by expression analysis of matrix metalloproteinase-1 and hydroxyproline. Additionally, the mouse skin histology shows that the drug-pretreated groups possess decreased epidermis thickness and normal collagen fiber structure of the dermis layer. These results demonstrate that both EGCG and collagen can protect the skin against UVB-induced skin photoaging. Synergistically, the combination of them shows the maximum prevention to skin damage, showing its potential in the application of anti-photoaging formulation products.

Simvastatin Attenuates Areca Nut Extract-Induced Subdermal Fibrosis in Mice by Targeting TGF-β Signaling Pathways.

Oral submucous fibrosis (OSMF) is a chronic inflammatory disease and a potentially malignant oral disorder, characterized by fibrosis of the oral mucosa. TGF-β signaling pathways have been implicated in the development of OSMF, with areca nut extract (ANE) contributing to the disease progression. Simvastatin, a statin drug, has demonstrated anti-fibrotic properties in various fibrotic conditions. However, its therapeutic potential in treating OSMF remains unclear. In this study, 8-week-old male BALB/c mice were randomly divided into three groups based on different time points. Each mouse was then treated with four different drug formulations. Post-treatment, specimens were collected for histopathological examination and staining to assess skin thickness, fibrosis, and collagen deposition. ANE treatment alone significantly increased skin thickness and collagen deposition compared to the control group after the 4-week time point. The combined administration of ANE and simvastatin, resulted in a notable reduction in skin thickness and collagen deposition. Western blot analysis revealed that simvastatin effectively suppressed the expression of fibrosis-related proteins, including CTGF, and α-SMA, in ANE-induced subdermal fibrosis. These results suggest that simvastatin has potential therapeutic effects on ANE-induced subdermal fibrosis, providing a foundation for future studies and possible clinical applications.

Physicochemical properties and cell proliferation and adhesive bioactivity of collagen-hyaluronate composite gradient membrane.

Membrane materials were widely used in guided tissue regeneration (GTR) to prevent fibroblast invasion and form a confined area for preferentially growing of osteoblast. A novel collagen-hyaluronate composite gradient membrane was prepared by Tilapia (Oreochromis mossambicus) skin collagen and sodium hyaluronate for potential GTR applications and their bioactivities were investigated by cellular viability. SEM results indicated the membrane showed a dense outer and a porous inner surface for effectively guiding the growth of bone tissue. Physicochemical and biosafety experiments showed the tensile strength of membrane was 466.57 ± 44.31KPa and contact angle was 74.11°, and the membrane showed perfect biocompatibility and cytocompatibility as well, which met the requirements of GTR material. Cell morphology revealed that the membrane could facilitate the adherence and proliferation of fibroblast and osteoblast. The results of qRT-PCR and ELISA demonstrated that the membrane could effectively activate TGF-β/Smad pathway in fibroblast, and promote the expressions of TGF-β1, FN1 and VEGF. Remarkably, RUNX2 was stimulated in BMP2 pathway by the membrane to regulate osteoblast differentiation. In summary, the collagen-hyaluronate composite gradient membrane not only fulfills the prerequisites for use as a GTR material but also demonstrates substantial potential for practical applications in the field.

Physicochemical and functional characteristics of glycated collagen protein from giant salamander skin induced by ultrasound Maillard reaction

Chinese giant salamander skin collagen (CGSSC) was successfully conjugated with glucose (Glu)/xylose (Xy) by ultrasound Maillard reaction (MR) in nature deep eutectic solvents (NADES). The effects of ultrasound and reducing sugar types on the degree graft (DG) of MR products (MRPs), as well as the influence of DG on the structure and functional properties of MRPs were investigated. The results indicated that the ultrasound assisted could markedly enhance the MR of CGSSC, and low molecular weight reducing sugars were more reactive in MR. The ultrasound MR significantly changed the microstructure, secondary and tertiary structures of CGSSC. Moreover, the free sulfhydryl content of MRPs were increased, thus enhancing the surface hydrophobicity, emulsifying properties and antioxidant activity, which were positively correlated with DG. These findings provided theoretical insights into the effects of ultrasound assisted and different sugar types on the functional properties of collagen induced by MR.

A double-crosslinked nanocellulose-reinforced dexamethasone-loaded collagen hydrogel for corneal application and sustained anti-inflammatory activity

In cases of blinding disease or trauma, hydrogels have been proposed as scaffolds for corneal regeneration and vehicles for ocular drug delivery. Restoration of corneal transparency, augmenting a thin cornea and postoperative drug delivery are particularly challenging in resource-limited regions where drug availability and patient compliance may be suboptimal. Here, we report a bioengineered hydrogel based on porcine skin collagen as an alternative to human donor corneal tissue for applications where long-term stability of the hydrogel is required. The hydrogel is reinforced with cellulose nanofibers extracted from the Ciona intestinalis sea invertebrate followed by double chemical and photochemical crosslinking. The hydrogel is additionally loaded with dexamethasone to provide sustained anti-inflammatory activity. The reinforced double-crosslinked hydrogel after drug loading maintained high optical transparency with significantly improved mechanical characteristics compared to non-reinforced hydrogels, while supporting a gradual sustained drug release for 60 days in vitro. Dexamethasone, after exposure to crosslinking and sterilization procedures used in hydrogel production, inhibited tube formation and cell migration of TNFα-stimulated vascular endothelial cells. The drug-loaded hydrogels suppressed key pro-inflammatory cytokines CCL2 and CXCL5 in TNFα-stimulated human corneal epithelial cells. Eight weeks after intra-stromal implantation in the cornea of 12 New-Zealand white rabbits subjected to an inflammatory suture stimulus, the dexamethasone-releasing hydrogels suppressed TNFα, MMP-9, and leukocyte and fibroblast cell invasion, resulting in reduced corneal haze, sustained corneal thickness and stromal morphology, and reduced overall vessel invasion. This collagen-nanocellulose double-crosslinked hydrogel can be implanted to treat corneal stromal disease while suppressing inflammation and maintaining transparency after corneal transplantation. Statement of significanceTo treat blinding diseases, hydrogel scaffolds have been proposed to facilitate corneal restoration and ocular drug delivery. Here, we improve on a clinically tested collagen-based scaffold to improve mechanical robustness and enzymatic resistance by incorporating sustainably sourced nanocellulose and dual chemical-photochemical crosslinking to reinforce the scaffold, while simultaneously achieving sustained release of an incorporated anti-inflammatory drug, dexamethasone. Evaluated in the context of a corneal disease model with inflammation, the drug-releasing nanocellulose-reinforced collagen scaffold maintained the cornea's transparency and resisted degradation while suppressing inflammation postoperatively. This biomaterial could therefore potentially be applied in a wider range of sight-threatening diseases, overcoming suboptimal administration of postoperative medications to maintain hydrogel integrity and good vision.

Non-invasive assessment of hair regeneration in androgenetic alopecia mice in vivo using two-photon and second harmonic generation imaging.

The identification of crucial targets for hair regrowth in androgenetic alopecia (AGA) involves determining important characteristics and different stages during the process of hair follicle regeneration. Traditional methods for assessing key features and different stages of hair follicle primarily involve taking skin tissue samples and determining them through various staining or other methods. However, non-invasive assessment methods have been long sought. Therefore, in this study, endogenous fluorescence signals from skin keratin and second harmonic signals from skin collagen fibers were utilized as probes, two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) imaging techniques were employed to non-invasively assess hair shafts and collagen fibers in AGA mice in vivo. The TPEF imaging technique revealed that the alternation of new and old hair shafts and the different stages of the growth period in AGA mice were delayed. In addition, SHG imaging found testosterone reduced hair follicle area and miniaturized hair follicles. The non-invasive TPEF and SHG imaging techniques provided important methodologies for determining significant characteristics and different stages of the growth cycle in AGA mice, which will facilitate future non-invasive assessments on human scalps in vivo and reduce the use of animal testing.

Assessment of the change in the conformation and content of collagen of the goat skin due to different unhairing process

Recently, more attention has paid to the reduction of environmental pollution due to leather processing, the beamhouse step especially unhairing part has been named as the one which contribute high pollutants in the total industrial waste. Therefore, different types of unhairing have been studied intending to reduce waste produced by unhairing step, however, no more findings on the influence of those alternatives to the collagen of the skin which determine the features of the leather. This study explores the impacts of those unhairing alternatives to the collagen of the skin. The shrinkage temperature values were lower as compared to that of raw skin sample, where oxidative unhaired skin, shows high difference (50.50C) from raw skin sample which was 64.90C. There were no significant differences in the hydroxyproline concentration between unhairing, this was due to triple helix structure of the collagen which make it more stable and not easily destroyed by unhairing chemicals. FT-IR results shows the differences in intensity (percentage) for side chain of collagen, where raw sample was 99.67%, oxidative was 90.83% while for conventional, hair saves and painting were 97.38%, 97.93% and 96.02% respectively. The stretching of N-H bond and bending for C-N bond for amide II, displays vibrations with wavenumber of 1519.20cm-1 for oxidative unhaired wet blue, as compared to other unhaired wet blue and raw skin sample which reads at 1539.20cm-1. The small differences in strength of the leather produced were associated with the change in the side chain intensity and conformation of collagen. The strength properties of the leather do not depend only on the concentration of the collagen but also on the proper packing of the collagen structures. The disturbance occurs to the hierarchical network of the collagen was reflected in the physical properties of the leather.

High-Intensity Focused Ultrasound Increases Collagen and Elastin Fiber Synthesis by Modulating Caveolin-1 in Aging Skin.

Caveolin-1 (Cav-1) induces cellular senescence by reducing extracellular signal-regulated kinase (ERK)1/2 phosphorylation and activating p53 via inhibition of mouse double minute 2 homolog (MDM2) and sirtuin 1 (Sirt1), promoting cell cycle arrest and decreasing fibroblast proliferation and collagen synthesis. High-intensity focused ultrasound (HIFU) treatment increases collagen synthesis, rejuvenating skin. Using H2O2-induced senescent fibroblasts and the skin of 12-month-old mice, we tested the hypothesis that HIFU increases collagen production through Cav-1 modulation. HIFU was administered at 0.3, 0.5, or 0.7 J in the LINEAR and DOT modes. In both models, HIFU administration decreased Cav-1 levels, increased ERK1/2 phosphorylation, and decreased the binding of Cav-1 with both MDM2 and Sirt1. HIFU administration decreased p53 activation (acetylated p53) and p21 levels and increased cyclin D1, cyclin-dependent kinase 2, and proliferating cell nuclear antigen levels in both models. HIFU treatment increased collagen and elastin expression, collagen fiber accumulation, and elastin fiber density in aging skin, with 0.5 J in LINEAR mode resulting in the most prominent effects. HIFU treatment increased collagen synthesis to levels similar to those in Cav-1-silenced senescent fibroblasts. Our results suggest that HIFU administration increases dermal collagen and elastin fibers in aging skin via Cav-1 modulation and reduced p53 activity.

Preparation of Nanoemulsions with Low-Molecular-Weight Collagen Peptides from Sturgeon Fish Skin and Evaluation of Anti-Diabetic and Wound-Healing Effects in Mice.

This study aims to isolate collagen peptides from waste sturgeon fish skin, and prepare nanoemulsions for studying their anti-diabetic and wound-healing effects in mice. Collagen peptides were extracted and purified by acetic acid with sonication, followed by two-stage hydrolysis with 0.1% pepsin and 5% flavourzyme, and ultrafiltration with 500 Da molecular weight (MW) cut-off dialysis membrane. Animal experiments were performed with collagen peptides obtained by pepsin hydrolysis (37 kDa) and pepsin plus flavourzyme hydrolysis (728 Da) as well as their nanoemulsions prepared at two different doses (100 and 300 mg/kg/day). The mean particle size of low-MW and low-dose nanoemulsion, low-MW and high-dose nanoemulsion, high-MW and low-dose nanoemulsion and high-MW and high-dose nanoemulsion was, respectively, 16.9, 15.3, 28.1 and 24.2 nm, the polydispersity index was 0.198, 0.215, 0.231 and 0.222 and zeta potential was -61.2, -63.0, -41.4 and -42.7 mV. These nanoemulsions were highly stable over a 90-day storage period (4 °C and 25 °C) and heating at 40-100 °C (0.5-2 h). Experiments in mice revealed that the low-MW and high-dose nanoemulsion was the most effective in decreasing fasting blood glucose (46.75%) and increasing wound-healing area (95.53%). Collectively, the sturgeon fish skin collagen peptide-based nanoemulsion is promising for development into a health food or wound-healing drug.