Elastin Peptides Research Articles

Supplemented collagen peptide composition improves skin aging, elasticity, and tissue regeneration in zebrafish

A supplemented collagen peptide composition (SCPC) containing microbe-fermented collagen peptide, collagen tripeptide, elastin peptide, and sodium hyaluronate was investigated to determine its effects on skin aging, skin elasticity, and tissue regeneration in zebrafish. β-Galactosidase activity was inhibited, while telomerase activity was elevated, by exposure to 0.977 μL/mL of SCPC in an H2O2-induced aging zebrafish model, indicating that SCPC can delay cell senescence. Expression of the collagen I gene col1a1a was up-regulated by exposure to 62.5 μL/mL of SCPC, indicating that SCPC can improve skin elasticity. Regrowth of the injured caudal fin was enhanced by exposure to only 0.122 μL/mL of SCPC. These improvements to skin aging, elasticity, and tissue regeneration in zebrafish suggest that this SCPC has potential as a functional food with beneficial effects on skin health and aging resistance in humans.

Transdermal delivery of elastin peptide assisted by betaine-based deep eutectic solvent to ameliorate skin photoaging

The unique amino acid composition of elastin peptide (EP) makes it an excellent resource to obtain antioxidant peptides. It exhibits high elastase inhibitory activity with the potential to resist skin aging and is currently used in a many cosmetic products. However, the inherent low permeability of the skin limits its ability to penetrate the skin. To address this issue, a deep eutectic solvent (SAB) with excellent bioactivity was synthesized from betaine and succinic acid and used as a permeation enhancer to improve the absorption and utilization of EP in this paper. The results showed that low SAB concentrations significantly increased the transdermal delivery of EP. The 3D epidermal skin model (EpiKutis®) demonstrated that SAB/EP induced the synthesis of hyaluronic acid (HA) and filaggrin (FLG), accelerated skin barrier repair, and reduced water loss. Additionally, the zebrafish embryonic model showed that SAB/EP could reduce melanin secretion, decrease melanin deposition, and have an ameliorative effect on skin photoaging. Cellular experiments proved that SAB/EP can stimulate human skin fibroblasts to secrete procollagen I and elastin, improving skin elasticity and anti-wrinkle. The combination of EP and DES is a new attempt that is expected to be used as a safe and effective anti-wrinkle cosmetic material.

Altered Elastin Turnover, Immune Response, and Age-Related Retinal Thinning in a Transgenic Mouse Model With RPE-Specific HTRA1 Overexpression.

A single-nucleotide polymorphism in HTRA1 has been linked to age-related macular degeneration (AMD). Here we investigated the potential links between age-related retinal changes, elastin turnover, elastin autoantibody production, and complement C3 deposition in a mouse model with RPE-specific human HTRA1 overexpression. HTRA1 transgenic mice and age-matched CD1 wild-type mice were analyzed at 6 weeks and 4, 6, and 12 to 14months of age using in vivo retinal imaging by optical coherence tomography (OCT) and fundus photography, as well as molecular readouts, focusing on elastin and elastin-derived peptide quantification, antielastin autoantibody, and total Ig antibody measurements and immunohistochemistry to examine elastin, IgG, and C3 protein levels in retinal sections. OCT imaging indicated thinning of inner nuclear layer as an early phenotype in HTRA1 mice, followed by age and age/genotype-related thinning of the photoreceptor layer, RPE, and total retina. HTRA1 mice exhibited reduced elastin protein levels in the RPE/choroid and increased elastin breakdown products in the retina and serum. A corresponding age-dependent increase of serum antielastin IgG and IgM autoantibodies and total Ig antibody levels was observed. In the RPE/choroid, these changes were associated with an age-related increase of IgG and C3 deposition. Our results confirm that RPE-specific overexpression of human HTRA1 induces certain AMD-like phenotypes in mice. This includes altered elastin turnover, immune response, and complement deposition in the RPE/choroid in addition to age-related outer retinal and photoreceptor layer thinning. The identification of elastin-derived peptides and corresponding antielastin autoantibodies, together with increased C3 deposition in the RPE/choroid, provides a rationale for an overactive complement system in AMD irrespective of the underlying genetic risk.

Elastin-derived peptides favor type 2 innate lymphoid cells in chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a condition characterized by chronic airway inflammation and obstruction, primarily caused by tobacco smoking. Although the involvement of immune cells in COPD pathogenesis is well established, the contribution of innate lymphoid cells (ILCs) remains poorly understood. ILCs are a type of innate immune cells that participate in tissue remodeling processes, but their specific role in COPD has not been fully elucidated. During COPD, the breakdown of pulmonary elastin generates elastin peptides that elicit biological activities on immune cells. This study aimed to investigate the presence of ILC in patients with COPD and examine the impact of elastin peptides on their functionality. Our findings revealed an elevated proportion of ILC2 in the peripheral blood of patients with COPD, and a general activation of ILC as indicated by an increase in their cytokine secretion capacity. Notably, our study demonstrated that serum from patients with COPD promotes ILC2 phenotype, likely due to the elevated concentration of IL-5, a cytokine known to favor ILC2 activation. Furthermore, we uncovered that this increase in IL-5 secretion is partially attributed to its secretion by macrophages upon stimulation by elastin peptides, suggesting an indirect role of elastin peptides on ILC in COPD. These findings shed light on the involvement of ILC in COPD and provide insights into the potential interplay between elastin breakdown, immune cells, and disease progression. Further understanding of the mechanisms underlying ILC activation and their interaction with elastin peptides could contribute to the development of novel therapeutic strategies for COPD management.NEW & NOTEWORTHY Elastin-derived peptides, generated following alveolar degradation during emphysema in patients with COPD, are able to influence the response of type 2 innate lymphoid cells. We show that the orientation of innate lymphoid cells in patients with COPD is shifted toward a type 2 profile and that elastin peptides are indirectly participating in that shift through their influence of macrophages, which in turn impact innate lymphoid cells.

Anti-skin aging effects and bioavailability of collagen tripeptide and elastin peptide formulations in young and middle-aged women

BackgroundCollagen peptides (CP), including tripeptides and elastin peptides (EP), are known for their in vitro and in vivo anti-skin aging effects. Despite positive results in animal models, the combination effects of CP and EP and the bioavailability of CP in human studies, particularly in young and middle-aged women, remain underexplored. ObjectiveTo evaluate the effects of an orally administered collagen drink combining CP and EP on the skin health of young and middle-aged women. Materials and MethodsA single-center, randomized, double-blind, parallel-controlled trial was conducted, utilizing the WONDERLAB® fish collagen tripeptide beverage. Participants consumed the drink over an 8-week period. ResultsCompared to the placebo group, the collagen drink group showed significant improvements in skin hydration (39.19% increase), transepidermal water loss (33.45% decrease), skin elasticity (25.37% increase), dermal collagen content (21.64% increase), pore size (7.94% decrease), wrinkle length (18.09% decrease), skin smoothness (2.85% improvement), and skin roughness (15.32% decrease). Overall pore volume decreased by 60%, and visual assessments indicated a decrease in skin luminosity by 15.20% and smoothness index by 22.55%. Mass spectrometry demonstrated a significant increase in collagen efficacy components, including blood pH and GPH levels (P < 0.05). ConclusionThe study confirmed the combination nourishing and anti-skin aging effects of EP and CP on the skin of young and middle-aged women, demonstrating significant improvements in various skin parameters and good bioavailability of collagen peptides.

Exploring the Release of Elastin Peptides Generated from Enzymatic Hydrolysis of Bovine Elastin via Peptide Mapping.

To enhance the understanding of enzymatic hydrolysis and to accelerate the discovery of key bioactive peptides within enzymatic products, this research focused on elastin as the substrate and investigated the variations in peptide profiles and the production of key bioactive peptides (those exceeding 5% of the total) and their impacts on the biological activity of the hydrolysates. Through the application of advanced analytical techniques, such as stop-flow two-dimensional liquid chromatography and ultra-high-performance liquid chromatography-tandem mass spectrometry, the research tracks the release and profiles of peptides within elastin hydrolysates (EHs). Despite uniform peptide compositions, significant disparities in peptide concentrations were detected across the hydrolysates, hinting at varying levels of bioactive efficacy. A comprehensive identification process pinpointed 403 peptides within the EHs, with 18 peptides surpassing 5% in theoretical maximum content, signaling their crucial role in the hydrolysate's bioactivity. Of particular interest, certain peptides containing sequences of alanine, valine, and glycine were released in higher quantities, suggesting Alcalase® 2.4L's preference for these residues. The analysis not only confirms the peptides' dose-responsive elastase inhibitory potential but also underscores the nuanced interplay between peptide content, biological function, and their collective synergy. The study sets the stage for future research aimed at refining enzymatic treatments to fully exploit the bioactive properties of elastin.

Studies on blocking the JAK2/STAT3 signaling pathway with elastin peptides from skipjack tuna (Katsuwonus pelamis) bulbus cordis to alleviate osteoarthritis

Osteoarthritis (OA) is a chronic disease associated with bone and muscle degeneration that causes great disturbances to daily lives. Skipjack tuna elastin peptides (STEP) is a kind of small molecule mixed peptides extracted from skipjack tuna bulbus cordis that have multiple active functions, including anti-inflammatory activity. However, it is ambiguous whether STEP reduce OA inflammation. Zebrafish served as a model in the present research for verifying the anti-inflammatory efficacy of STEP. Then, the composition of STEP was figured out by LC-MS/MS analysis, and the potential anti-inflammatory peptides were screened by molecular docking and microscale thermophoresis (MST). Finally, in vitro experiments were conducted on the potential peptides. According to the in vivo findings, STEP protected the cartilage tissues of zebrafish and regulated the expression of inflammatory factors and the JAK2/STAT3 signaling pathway. The in vitro results showed that the potential peptides (LGVGSPPGK, GFDPSR and PGAPGGGFDI) positively regulated the inflammatory responses and the JAK2/STAT3 signaling pathway and were effective in inhibiting extracellular matrix (ECM) degeneration and chondrocyte apoptosis. As a consequence, STEP possess anti-inflammatory and chondroprotective effects and could be a functional product for the alleviation of OA.

RNA Sequencing and Related Differential Gene Expression Analysis in a Mouse Model of Emphysema Induced by Tobacco Smoke Combined with Elastin Peptides.

To establish a model of emphysema induced by tobacco smoke combined with elastin peptides (EP), explore the biochemical metabolic processes and signal transduction pathways related to emphysema occurrence and development at the transcriptional level, and identify new targets and signaling pathways for emphysema prevention and treatment. Mice were randomly divided into the air pseudoexposure group (NORMAL group) and the tobacco smoke + EP group (EP group). The differentially expressed genes (DEGs) in lung tissue between the two groups were identified by RNA-seq, and functional annotation and Gene Ontology (GO)/ Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed. The differential expression of the selected genes were verified using qRT‒PCR and immunohistochemistry (IHC). EP group mice showed emphysema-like changes. The expression levels of 1159 genes in the EP group differed significantly (529 up-regulated and 630 down-regulated) from those in the NORMAL group. GO enrichment analysis showed that the DEGs were significantly enriched in the terms immune system, adaptive immune response, and phosphorylation, while KEGG pathway enrichment analysis showed that the DEGs were enriched mainly in the pathways cytokine‒cytokine receptor interaction, T-cell receptor signaling pathway, MAPK signaling pathway, Rap1 signaling pathway, endocytosis, chemokine signaling pathway, Th17 cell differentiation, and Th1 and Th2 cell differentiation. The differential expression of the selected DEGs were verified by qRT‒PCR and IHC, and the expression trends of these genes were consistent with those identified by RNA-seq. Emphysema may be related to the inflammatory response, immune response, immune regulation, oxidative stress injury, and other biological processes. The Bmp4-Smad-Hoxa5/Acvr2a signaling pathway may be involved in COPD/ emphysema occurrence and development.

Challenging level of rigid-body approach involving numerical elements (CHLORAINE) applied to repeated elastin peptides

Elastic proteins and derived biomaterials contain numerous tandemly repeated peptides along their sequences, ranging from a few copies to hundreds. These repetitions are responsible for their biochemical, biological and biomechanical properties. These sequences are considered to be intrinsically disordered, and the variations in their behavior are actually mainly due to their high flexibility and lack of stable secondary structures originating from their unique amino acid sequences. Consequently, the simulation of elastic proteins and large elastomeric biomaterials using classical molecular dynamics is an important challenge. Here, we propose a novel approach that allows the application of the DURABIN protocol to repeated elastin-like peptides (r-ELPs) in a simple way. Four large r-ELPs were studied to evaluate our method, which was developed for simulating extracellular matrix proteins at the mesoscopic scale. After structure clustering applied on molecular dynamic trajectories of constitutive peptides (5-mers and 6-mers), the main conformations were used as starting points to define the corresponding primitives, further used as rigid body fragments in our program. Contributions derived from electrostatic and molecular hydrophobicity potentials were tested to evaluate their influence on the interactions during simple mesoscopic simulations. The CHLORAINE approach, despite the thinner granularity due to the size of the patterns used, was included in the DURABIN protocol and emerges as a promising way to simulate elastic macromolecular systems.

Bacterial community mapping of the AIA mouse gastrointestinal tract under dietary intervention with skipjack tuna (Katsuwonus pelamis) elastin peptides

BackgroundOur previous study demonstrated that a dietary intervention with skipjack tuna (Katsuwonus pelamis) elastin peptides alleviated adjuvant-induced arthritis (AIA) and affected the gut microbiota of AIA mice. However, whether the faecal microbiota serves as a surrogate to reflect the dynamics of the gut microbiota has not been determined. MethodsUsing 16 S rRNA sequencing technology, the present study investigated the microbiota in three segments (stomach, colon and caecum) of mice to comprehensively define microbial dysregulation and regulation related to rheumatoid arthritis (RA). ResultsThe results showed that the composition and distribution of the microbiota in the stomach, colon and caecum were significantly different depending on their intrinsic environment and their functions, and the colon possessed the richest and most diverse microbiota structure. The gut microbiota of AIA mice showed ecological dysbiosis, and a dietary intervention with skipjack tuna elastin peptides improved this negative effect, particularly the changes in the gastric microbiota, which were most obvious at RA onset and remission. ImplicationThe results not only indicate the spatial heterogeneity of the gut microbiota in terms of composition and distribution, but also indicate the potential of the application of elastin peptides for the alleviation of RA.

Suitability of high-molecular-weight tissue-derived elastin polypeptides and their particles as cosmetic biomaterials.

We aimed to determine the coacervation properties of high-molecular-weight (HMW) tissue-derived elastin (TDE) and to examine the potential use of TDE particles as a cosmetic biomaterial. TDE solutions were filtered and divided into three fractions (1-3) according to the molecular weight of the elastin. The turbidity of fraction 2, which contained a large portion (58%) of HMW elastin polypeptides (>100 kDa), was measured under several pH values (3.0-11.0) and NaCl concentrations (0-1000 mM) to examine its coacervation ability. HMW TDE exhibited coacervation under the physiological conditions (temperature, pH, and NaCl concentration) of the skin surface. We performed inclusion and release experiments using three model chemicals with different molecular weights and measured the size and zeta potential of the fraction 3 particles to investigate the suitability of HMW elastin polypeptides. Fraction 3, which contained a larger portion (64%) of HMW elastin polypeptides, displayed a strong coacervation property at a phase transition temperature of 19.8 ± 0.1°C. The inclusion ratio of the model chemical Biebrich Scarlet (BS) with a molecular weight of <600 was approximately 92.1 ± 0.7%. The release profiles of BS from the particles linearly increased and reached a plateau after 15 days. Moreover, the average size of the particles with BS was 474.2 ± 24.6 nm. The low-molecular-weight (LMW) elastin peptides have moisturizing and whitening functions for the skin. We concluded that TDE, as a mixture of HMW polypeptides and LMW peptides, can potentially serve as a multifunctional and effective cosmetic biomaterial.

Blocking CD40 Alleviates Th1 and Th17 Cell Responses in Elastin Peptide-Induced Murine Emphysema.

To investigate the role of the CD40-CD40 ligand (CD40L) pathway in the regulation of Th1, Th17, and regulatory T (Treg)-cell responses in an elastin peptide (EP)-induced autoimmune emphysema mouse model. BALB/c mice were transnasally treated with EP on day 0, injected intravenously with anti-CD40 antibody via the tail vein on day 33, and sacrificed on day 40. The severity of emphysema was evaluated by determining the mean linear intercept (MLI) and destructive index (DI) from lung sections. The proportions of myeloid dendritic cells (mDCs) and Th1, Th17, and Treg cells in the blood, spleen, and lungs were determined via flow cytometry. The levels of the cytokines interleukin (IL)-6, IL-17, interferon (IFN)-γ, and transforming growth factor (TGF)-β were detected via enzyme-linked immunosorbent assay. Ifnγ, IL17a, Rorγt and Foxp3 transcription levels were detected via polymerase chain reaction. CD40+ mDCs accumulated in the lungs of EP-stimulated mice. Blocking the CD40-CD40L pathway with an anti-CD40 antibody alleviated Th1 and Th17 responses; increased the proportion of Treg cells; decreased MLI and DI; reduced the levels of cytokines IL-6, IL-17, and IFN-γ as well as the transcription levels of Ifnγ, IL17a, and Rorγt; and upregulated the expression of TGF-β and Foxp3. The CD40-CD40L pathway could play a critical role in Th1, Th17 and Treg cell dysregulation in EP-mediated emphysema and could be a potential therapeutic target.

Bacterial Community Mapping of the AIA Mouse Gastrointestinal Tract Under Dietary Intervention with Tuna Elastin Peptide

Bacterial Community Mapping of the AIA Mouse Gastrointestinal Tract Under Dietary Intervention with Tuna Elastin Peptide

Improving the productivity of malic acid by alleviating oxidative stress during Aspergillus niger fermentation

BackgroundAs an attractive platform chemical, malic acid has been commonly used in the food, feed and pharmaceutical field. Microbial fermentation of biobased sources to produce malic acid has attracted great attention because it is sustainable and environment-friendly. However, most studies mainly focus on improving yield and ignore shortening fermentation time. A long fermentation period means high cost, and hinders the industrial applications of microbial fermentation. Stresses, especially oxidative stress generated during fermentation, inhibit microbial growth and production, and prolong fermentation period. Previous studies have shown that polypeptides could effectively relieve stresses, but the underlying mechanisms were poorly understood.ResultsIn this study, polypeptides (especially elastin peptide) addition improves the productivity of malic acid in A. niger, resulting in shortening of fermentation time from 120 to 108 h. Transcriptome and biochemical analyses demonstrated that both antioxidant enzyme-mediated oxidative stress defense system, such as superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and nonenzymatic antioxidant system, such as glutathione, were enhanced in the presence of elastin peptide, suggesting elastin peptide relieving oxidative stresses is involved in many pathways. In order to further investigate the relationship between oxidative stress defense and malic acid productivity, we overexpressed three enzymes (Sod1, CAT, Tps1) related to oxidation resistance in A. niger, respectively, and these resulting strains display varying degree of improvement in malic acid productivity. Especially, the strain overexpressing the Sod1 gene achieved a malate titer of 91.85 ± 2.58 g/L in 96 h, corresponding to a productivity of 0.96 g/L/h, which performs better than elastin peptide addition.ConclusionsOur investigation provides an excellent reference for alleviating the stress of the fungal fermentation process and improving fermentation efficiency.

Human C-peptide is a ligand of the elastin-receptor-complex and therewith central to human vascular remodelling and disease in metabolic syndrome

This hypothesis ties together various causal risk factors from our “Western-lifestyle” (elevated blood-glucose, smoking, processed red-meat-products, obesity, and inflammation) in a unifying perspective on the cause of human vascular disease in metabolic syndrome.When, in response to enhanced blood-glucose levels, insulin is excreted, it is always excreted together with C-peptide. I identified an elastin-receptor-complex (ERC) binding amino-acid motif xGxxPG in C-peptide and pose that C-peptide’s earlier unknown receptor is this ERC. This receptor is involved in vascular remodelling, commonly activated by vascular-lesion-derived elastin-peptides with said motif xGxxPG. Systemic elastin-peptides may arise from smoking or from consuming elastin-rich processed red-meat-products, therewith interfering with vascular remodelling. Both excess elastin-peptides as well as excess C-peptide associate with core-manifestations of metabolic syndrome: insulin resistance, angiogenesis, and vascular remodelling. C-peptide fragments as well as elastin peptide-fragments with motif xGxxPG are angiogenic and blocked by antagonists of ERC. Many other bioactive peptides with an xGxxPG motif exist, a third example discussed here is galectin-3, elevated in obesity and inflammation, and again associated with insulin resistance, angiogenesis, and vascular remodelling in metabolic syndrome.On the one side of this hypothesis, a lack of ERC-mediated vascular remodelling through a lack of C-peptide is central to microvascular disease in T1D. On the other side, excess ERC-activity through excess activation (by systemic C-peptide, elastin-peptide, galectin-3, or others), is centrally involved in metabolic syndrome and T2D, inducing insulin resistance with excess and maladaptive macrovascular remodelling. Systemic C-peptide is increased in a “Western-diet” lifestyle, systemic elastin peptides are increased after smoking and possibly after elastin-consumption, and systemic galectin-3 increases in chronic inflammation and obesity. As all these risk-factors associate with life-style mediated metabolic syndrome, this hypothesis poses one up-stream cause: excess activation of ERC stands central in causing metabolic syndrome.

"The Synergistic Effects of Fish Collagen Peptide, Bonito Elastin Peptide, Fish Maw Powder and Rose Water on The Improvement of Skin Conditions: A Mechanistic Study"

The consumption of beauty from within has been growing rapidly in recent years due to the increase number of female individuals who care about facial appearance. The formulation originally designed by Bio-E composed of fish collagen peptide, bonito elastin peptide, fish maw powder and rose water was demonstrated to stimulate the fibroblast to produce type I collagen. Compared to individual ingredients alone, the scientific Bio-E’s formulation of the four ingredients at specific ratio had synergistic benefits on improvement of skin conditions potentially due to the multi-target effects including skin fibroblast regeneration, bone recovery, hydration and free radicals’ eradication. Beyond traditional care of skin rejuvenation, rejuvenating changes in the facial skeleton was also highly appreciated against facial ageing. All ingredients were produced from high value-added natural resources by environmental, sustainable and patented processes. Apart from functionality, scientific literature demonstrated the Bio-E’s formulation consisting of the four ingredients had no adverse events during oral supplementation. Overall, the synergistic effects of the f Bio-E’s formulation on rejuvenating the structures of both bone and skin should provide a valuable and novel insight for facial anti-ageing.

Elastin-Hyaluronan Bioconjugate as Bioactive Component in Electrospun Scaffolds.

Hyaluronic acid or hyaluronan (HA) and elastin-inspired peptides (EL) have been widely recognized as bioinspired materials useful in biomedical applications. The aim of the present work is the production of electrospun scaffolds as wound dressing materials which would benefit from synergic action of the bioactivity of elastin peptides and the regenerative properties of hyaluronic acid. Taking advantage of thiol-ene chemistry, a bioactive elastin peptide was successfully conjugated to methacrylated hyaluronic acid (MAHA) and electrospun together with poly-D,L-lactide (PDLLA). To the best of our knowledge, limited reports on peptide-conjugated hyaluronic acid were described in literature, and none of these was employed for the production of electrospun scaffolds. The conformational studies carried out by Circular Dichroism (CD) on the bioconjugated compound confirmed the preservation of secondary structure of the peptide after conjugation while Scanning Electron Microscopy (SEM) revealed the supramolecular structure of the electrospun scaffolds. Overall, the study demonstrates that the bioconjugation of hyaluronic acid with the elastin peptide improved the electrospinning processability with improved characteristics in terms of morphology of the final scaffolds.

Elastin Peptides with Ferrous Ferric Chloride Activate Human Melanocytes and Elastin Fibers

Background: Elastin peptides stimulate the development of mouse melanocytes in neural crest culture. Ferrous ferric chloride (FFC) promotes mammalian melanocyte growth in culture. However, it is unclear whether elastin peptides in the presence of FFC can stimulate human melanocyte growth in situ. Objectives: This study aimed to investigate the mechanism of human melanocyte growth for skin and stem cell science since melanocytes control human skin color. Methods: In this clinical trial study, a lotion containing elastin peptides and/or FFC was applied to the normal skin of 6 volunteers twice a day for 1 to 3 months. Punch biopsies were taken from treated skin and surveyed by histochemical methods using the dopa reaction (detect melanocytes) and dopa-premelanin reaction (detect melanocytes and melanoblasts). Elastin fibers were detected by Victoria blue staining. Results: Only the combined treatment of elastin peptides and FFC increased melanocyte populations in addition to dopa reactivity, melanogenesis, dendritogenesis, and epidermal melanin pigmentation. Mitotic divisions of melanocytes were also observed. However, the melanoblast population failed to increase, and no mitotic melanoblasts were observed. In the dermis, elastin fibers became thicker and denser after the treatment. The data of statistical analyses were performed by tabulation, mean, and SD on Microsoft Excel for Macintosh OS Catalina 10 system. Conclusions: Our present study suggests that elastin peptides with FFC can promote melanocyte growth, melanin synthesis, skin pigmentation, and elastin fiber formation. Our study can be expected to contribute to advancing skin and stem cell science.

Resource Utilization of Bovine Neck Ligament: Enzymatic Preparation of Elastin Peptide and Its Antioxidant Activity.

Elastin is considered an excellent resource for obtaining antioxidant peptides due to unique amino acid composition. However, it is hardly soluble in water or in dilute acid or alkali; most of the elastases have low yields for preparing elastin peptides, making it difficult to meet industrial applications. To address above problems, enzymes capable of hydrolyzing elastin into soluble peptides were preferred from typical commercial protease preparations. The optimal enzymatic hydrolysis process conditions for elastin peptides were obtained by response surface optimization design. The molecular weight, amino acid composition, and antioxidant activity of the enzymatic hydrolysis products were determined. The results show that the alkaline protease NUE has a strong hydrolysis effect. The optimized enzymatic hydrolysis conditions are as follows: substrate concentration is 5%, enzyme concentration is 650 U/mL, pH is 10.0, temperature is 60°C, time is 6h. The degree of hydrolysis of elastic protein peptides obtained through this method is 14.42%. The distribution of molecular weight is 200-6500Da, more than 85% of the component molecular amount is greater than 800Da; the amino acid content related to antioxidant activity has reached 68mg/100mg, so it has extremely high free radical clearance. Compared with acid and alkali methods, the anti-oxidation capacity of enzyme-based peptide is better, the reaction conditions are milder, the yield is higher, and by-products and pollutants are fewer. It provides an effective way to industrialized production of elastin peptides with high antioxidant activity and a basis for its widespread application in the food and pharmaceutical industries.

Engineering Natural and Recombinant Silks for Sustainable Biodevices.

Silk fibroin (SF) is a structural protein derived from natural silkworm silks. Materials fabricated based on SF usually inherit extraordinary physical and biological properties, including high mechanical strength, toughness, optical transparency, tailorable biodegradability, and biocompatibility. Therefore, SF has attracted interest in the development of sustainable biodevices, especially for emergent bio-electronic technologies. To expand the function of current silk devices, the SF characteristic sequence has been used to synthesize recombinant silk proteins that benefit from SF and other functional peptides, such as stimuli-responsive elastin peptides. In addition to genetic engineering methods, innovated chemistry modification approaches and improved material processing techniques have also been developed for fabricating advanced silk materials with tailored chemical features and nanostructures. Herein, this review summarizes various methods to synthesize functional silk-based materials from different perspectives. This review also highlights the recent advances in the applications of natural and recombinant silks in tissue regeneration, soft robotics, and biosensors, using B. mori SF and silk-elastin-like proteins (SELPs) as examples.