Search Results (51)

Hyaluronic acid (HA) is a key extracellular matrix component of vertebrates, where it mediates cell adhesion, immune regulation, and tissue remodeling through its interaction with specific receptors. Although HA has been detected in a few invertebrate species, the lack of fundamental components of the molecular HA pathway poses relevant objections about its functional role in these species. Mining genomic and transcriptomic data, we considered the conservation of the gene locus encoding for the extracellular link protein (XLINK) in marine mussels as well as its expression patterns. Structural and phylogenetic analyses were undertaken to evaluate possible similarities with vertebrate orthologs and to infer the origin of this gene in invertebrates. Biochemical analysis was used to quantify HA in tissues of Mytilus galloprovincialis. As a result, we confirm that the mussel can produce HA (up to 1.02 ng/mg in mantle) and that its genome encodes two XLINK gene loci. These loci are conserved in Mytilidae species and show a complex evolutionary path. Mussel XLINK genes appeared to be expressed during developmental stages in three mussel species, ranking in the top 100 expressed genes in M. trossulus at 17 h post-fertilization. In conclusion, the presence of HA and an active gene with the potential to bind HA suggests that mussels have the potential to synthesize and use HA and are among the few invertebrates encoding this gene. Full article

Rosacea is a chronic inflammatory skin condition characterized by persistent erythema and telangiectasia, often accompanied by skin barrier disruption and abnormal angiogenesis. Currently, peptide-based therapies for rosacea are limited, and existing drugs still present certain limitations and side effects. Peptides have the advantage of being relatively safe and exhibiting high target specificity, which can reduce the risk of adverse effects. Considering these points, this study aimed to explore the adhesive peptide AdhPep3 (AYDPGYK) as a potential therapeutic candidate for rosacea. AdhPep3 was designed based on protein sequences with cell junction properties and has the potential to enhance skin barrier-related protein expression by improving cell–cell adhesion and increasing adhesion-related protein levels. In LL-37-stimulated HaCaT cells, AdhPep3 effectively alleviated skin inflammation and inhibited the Toll-like receptor–nuclear factor kappa B (TLR2–NFκB) signaling pathway. Additionally, in LL-37-stimulated human umbilical vein endothelial cells (HUVECs), it reduced cell migration and the expression of angiogenesis-related proteins. Since AdhPep3 demonstrated anti-inflammatory and anti-angiogenic effects at the in vitro level, it may serve as a potential therapeutic agent for rosacea. Moreover, by increasing the expression of skin barrier and tight junction-related proteins, AdhPep3 shows potential for development as a cosmetic ingredient to improve skin health. Full article

A transdermal drug delivery system based on hydrogel patches was explored, leveraging their sustained release properties and biocompatibility. Despite these advantages, conventional hydrogels often lack proper adhesion to the skin, limiting their practical application. To address this issue, we designed a skin-adhesive hydrogel using a polyacrylamide (PAM)/polydopamine (PDA) dual-network structure. The matrix combines the mechanical toughness of PAM with the strong adhesive properties of PDA, derived from mussel foot proteins, enabling firm tissue attachment and robust performance under physiological conditions. To demonstrate its applicability, the hydrogel was integrated with poly(lactic-co-glycolic acid) (PLGA) nanoparticles encapsulating the hydrophobic antioxidant vitamin E as a model compound. The resulting PAM/PDA@VitE hydrogel system exhibited improved swelling behavior, high water retention, and prolonged release of α-tocopherol. These results suggest that the PAM/PDA hydrogel platform is a versatile vehicle not only for vitamin E, but also for the transdermal delivery of various cosmetic and therapeutic agents. Full article

This review delves into environmentally conscious sustainable packaging materials, focusing on biodegradable polymers and innovative surface modification methodologies. Synthetic plastics have revolutionized various industries due to their physical attributes and affordability, particularly in packaging applications. Nonetheless, the substantial volume of plastic waste, especially from non-biodegradable sources, has provoked heightened environmental apprehensions. Notably, polymers derived from natural sources, such as cellulose, are classified as biopolymers and esteemed for their ecological benevolence. Among these, cellulose and its derivatives stand out as renewable and abundant substances, holding promise for sustainable packaging solutions. Nano-sized cellulose fibers’ incorporation into biodegradable films garners interest due to their remarkable surface area, robust mechanical strength, and other commendable properties. Surface modification techniques, such as a polydopamine (PDA) coating, have been explored to improve the dispersion, interfacial compatibility, and mechanical performance of cellulose nanocrystals (CNC) when incorporated into biodegradable polymer films. In this sense, PDA, derived from mussel proteins’ dopamine component, displays exceptional adhesion to diverse surfaces and has been extensively scrutinized for its distinctive attributes. Therefore, the core focus of this review was to approach ecologically friendly packaging materials, specifically investigating the synergy between CNC and PDA. The unparalleled adhesive characteristics of PDA serve as a catalyst for enhancing CNC, thereby elevating the performance of biodegradable polymers with potential implications across various domains. Full article

Severe skin damage poses a significant clinical challenge, as limited availability of skin donors, postoperative skin defects, and scarring often impair skin function. Traditional two-dimensional (2D) nanofibers exhibit small pore sizes that hinder cellular infiltration, unable to simulate the three-dimensional (3D) structure of the skin. To address these issues, we developed 3D porous nanofiber scaffolds composed of polycaprolactone–polylactic acid–mussel adhesive protein (PLGA-PCL-MAP) using low-temperature electrospinning combined with nano-spray technology. Meanwhile, this 3D scaffold features high porosity, enhanced water absorption, and improved air permeability. The incorporation of mussel adhesive protein (MAP) further increased the scaffold’s adhesive properties and biocompatibility. In vitro experiments demonstrated that the 3D nanofiber scaffolds significantly promoted the adhesion, proliferation, and migration of epidermal keratinocytes (HaCaTs) and human fibroblasts (HFBs), while providing ample space for inward cellular growth. Successful co-culture of HaCaT and HFBs within the scaffold revealed key functional outcomes: HaCaTs expressed keratinocyte differentiation markers CK10 and CK14, while HFBs actively secreted extracellular matrix components critical for wound healing, including collagen I, collagen III, and fibronectin. This skin substitute with a composite structure of epidermis and dermis based on three-dimensional nanofiber scaffolds can be used as an ideal skin replacement and is expected to be applied in wound repair in the future. Full article

Although many tissue adhesives with good biocompatibility are currently available, their lack of wet adhesion capacity significantly hinders their clinical application. Therefore, further development and exploration of new medical adhesives are necessary. Inspired by the adhesion mechanism of marine mussels, through modifying gelatin protein with gallic acid (GA) for wet adhesion and cross-linking gelatin (Gel) molecular chains with tea polyphenols (TP), the adhesive TP-GA/Gel was developed. The adhesive exhibited an adhesion strength of up to 130.47 kPa to porcine skin tissues and maintained a high adhesion state in various aqueous environments, demonstrating excellent and reproducible adhesion. Additionally, TP-GA/Gel possessed outstanding antimicrobial, antioxidant, and biocompatibility properties. In an in vivo wound healing study with SD rats, the wound area treated with TP-GA/Gel adhesive decreased from 10.3 mm² to 0.9 mm² after 15 days, promoting effective and scarless wound healing. These results highlight the promising clinical potential of TP-GA/Gel as a medical adhesive. Full article

(1) Background: Atopic dermatitis (AD) is characterized as a chronic inflammatory skin disease with a significant incidence rate. The pathophysiological mechanisms underlying AD remain incompletely understood. However, extensive research demonstrates that a complex interplay among genetic, immune, and environmental factors contributes to the disruption of skin barrier function. Inflammation is identified as one of the pathological mechanisms in AD. Recombined mussel adhesive protein exhibits anti-inflammatory properties. However, recombinant mussel adhesive protein has been used less frequently for AD, so we explored the therapeutic effect of recombinant mussel adhesive protein for AD and the potential mechanism. (2) Methods: We established a mice model of AD in vivo and an LPS-induced inflammation model in HaCaT cells in vitro. Through assessment of skin lesion scores, itch frequency, transepidermal water loss, skin microcirculation, HE staining, Elisa assays for IL-6, IL-12, IL-13, IL-4, IL-5, IFN-γ, IgE, and TNF-α, immunohistochemical staining for filaggrin and CK14, Masson staining, and Western blot analysis of NF-κB p65, P-P65, Keap1, and Nrf2, the effects of recombined mussel adhesive protein on AD symptoms, pathology, inflammation, and its mechanisms are investigated. (3) Results: The recombined mussel adhesive protein significantly improved the compromised skin barrier, reduced scratching frequency in mice, decreased transepidermal water loss, and lowered the expression of inflammatory factors, thus ameliorating skin inflammation damage. Mechanistically, recombined mussel adhesive protein downregulated the expression of P-p65/p65 and Keap1 while upregulating the level of Nrf2. (4) Conclusions: Overall, our results demonstrate the effectiveness of recombined mussel adhesive protein in attenuating DNFB-induced AD by inhibiting NF-κB and activating the Keap1/Nrf2 signaling pathway. Thus, recombined mussel adhesive protein is a promising therapeutic candidate for the treatment of AD. Full article

Water molecules pose a significant obstacle to conventional adhesive materials. Nevertheless, some marine organisms can secrete bioadhesives with remarkable adhesion properties. For instance, mussels resist sea waves using byssal threads, sandcastle worms secrete sandcastle glue to construct shelters, and barnacles adhere to various surfaces using their barnacle cement. This work initially elucidates the process of underwater adhesion and the microstructure of bioadhesives in these three exemplary marine organisms. The formation of bioadhesive microstructures is intimately related to the aquatic environment. Subsequently, the adhesion mechanisms employed by mussel byssal threads, sandcastle glue, and barnacle cement are demonstrated at the molecular level. The comprehension of adhesion mechanisms has promoted various biomimetic adhesive systems: DOPA-based biomimetic adhesives inspired by the chemical composition of mussel byssal proteins; polyelectrolyte hydrogels enlightened by sandcastle glue and phase transitions; and novel biomimetic adhesives derived from the multiple interactions and nanofiber-like structures within barnacle cement. Underwater biomimetic adhesion continues to encounter multifaceted challenges despite notable advancements. Hence, this work examines the current challenges confronting underwater biomimetic adhesion in the last part, which provides novel perspectives and directions for future research. Full article

Many anti-microbial peptides (AMPs) and pro-apoptotic peptides are considered as novel anti-microbial agents, distinguished by their different characteristics. Nevertheless, AMPs exhibit certain limitations, including poor stability and potential toxicity, which hinder their suitability for applications in pharmaceutics and medical devices. In this study, we used recombinant mussel adhesive protein (MAP) as a robust scaffold to overcome these limitations associated with AMPs. Mussel adhesive protein fused with functional peptides (MAP-FPs) was used to evaluate anti-microbial activities, minimal inhibitory concentration (MIC), and time-kill kinetics (TKK) assays against six of bacteria strains. MAP and MAP-FPs were proved to have an anti-microbial effect with MIC of 4 or 8 µM against only Gram-negative bacteria strains. All tested MAP-FPs killed four different Gram-negative bacteria strains within 180 min. Especially, MAP-FP-2 and -5 killed three Gram-negative bacteria strain, including E. coli, S. typhimurium, and K. pneumoniae, within 10 min. A cytotoxicity study using Vero and HEK293T cells indicated the safety of MAP and MAP-FP-2 and -3. Thermal stability of MAP-FP-2 was also validated by HPLC analysis at an accelerated condition for 4 weeks. This study identified that MAP-FPs have novel anti-microbial activity, inhibiting the growth and rapidly killing Gram-negative bacteria strains with high thermal stability and safety. Full article

With the increasing demand for recycling composite materials and re-use of fibers and matrices as new resources in the context of a circular economy, composite materials often pose problems as they form complex aggregates. The user properties of high strength and long lifetime require strong interfaces between a matrix and reinforcing fibers, while recycling would benefit from easy separation of the two phases. Therefore, the design of an interface with reversible bonding upon thermal or chemical activation may offer a good balance. In addition, the request for bio-based composites incorporating cellulose fibers should be combined with bio-inspired interface modification avoiding traditional chemical surface modification. An impressive example of reversible bonding in nature is observed in mussels and is regulated by the so-called mussel foot proteins. The latter includes dopamine as a main component that presents reversible bonding upon a change in pH. In the present work, cellulose fibers were modified with a dopamine (DA) or polydopamine (PDA) coating that was polymerized when in contact with the cellulose surface, thus providing good chemical compatibility and interaction with cellulose hydroxyl groups. The adhesive properties of the modified cellulose fibers were investigated via local adhesive measurements using atomic force microscopy and varied between strong adhesion (low pH) and weak adhesion (high pH). In parallel, the macroscale mechanical strength of the epoxy composites with modified fibers improved, while the interface adhesion of the modified fibers dropped after submersion in solutions with pH = 9.8. Based on these observations, a proof of concept for recycling of cellulose/epoxy composites and recovery of cellulose fibers is demonstrated after grinding and chemical treatment at a high pH. Full article

To fabricate multilayer ceramic capacitors (MLCCs) that can withstand external impacts, technologies to achieve excellent adhesion and mechanical strength of the cover layer should be essentially developed. Low adhesion and strength of the cover layer can lead to delamination and cracks in the MLCC, respectively. In this study, we present a method for applying polydopamine (PDA), a mussel-inspired adhesive protein, for as robust cover layer on an MLCC. Barium titanate (BT) particles treated with PDA increase the dispersion stability of the BT/PDA slurry, preventing re-agglomeration of the particles and enhancing the adhesiveness and strength owing to the cohesive properties of PDA. Compared to the BT layer, the adhesion of the BT/PDA layer was significantly enhanced by 217%; consequently, the compression modulus of the BT/PDA cover layer increased by 29.4%. After firing, the N-doped graphitic PDA played an important role in producing an MLCC cover layer with increased hardness and toughness. Furthermore, the N-doped graphitic PDA with a hydrophobic surface forms tortuous moisture paths in the cover layer, preventing the degradation of insulation resistance of the MLCC. Full article

The straightforward synthesis of polyamide-derived statistical copolymers with catechol, amine, amide and hydroxy residues via free radical polymerization is presented. In particular, catechol, amine and amide residues are present in natural mussel foot proteins, enabling strong underwater adhesion due to synergistic effects where cationic residues displace hydration and ion layers, followed by strong short-rang hydrogen bonding between the catechol or primary amides and SiO₂ surfaces. The present study is aimed at investigating whether such synergistic effects also exist for statistical copolymer systems that lack the sequence-defined positioning of functional groups in mussel foot proteins. A series of copolymers is established and the adsorption in saline solutions on SiO₂ is determined by quartz crystal microbalance measurements and ellipsometry. These studies confirm a synergy between cationic amine groups with catechol units and primary amide groups via an increased adsorptivity and increased polymer layer thicknesses. Therefore, the free radical polymerization of catechol, amine and amide monomers as shown here may lead to simplified mussel-inspired adhesives that can be prepared with the readily scalable methods required for large-scale applications. Full article

Given the widespread use of wood-based materials and that these materials are often damaged, an abundance of materials have been developed to repair and restore wood. Most of these materials treat the binder and filler as a single system; however, there is yet to be a system that has all the desired properties of an ideal wood-repair composite. Aiming for the goal of creating an ideal wood filler, this study proposed a wood-repair composite that combined epoxy resins, polyether amines, and poplar wood fibers. The materials were selected to mimic the hydrophobicity of lotus leaves and the strong adhesion of mussel proteins. The properties of the designed wood composites were characterized by various testing methods. The prepared fillers were then used to repair damaged poplar wood panels. The mechanical properties of the wood sample repaired with the optimal filler formulation reached 97% of those of the undamaged wood. In summary, the wood composites proposed in this study present a new means of repairing wooden relics, exposed outdoor wooden buildings, and household panels. Full article

Hemorrhagic shock is the primary cause of death in patients with severe trauma, and the development of rapid and efficient hemostatic methods is of great significance in saving the lives of trauma patients. In this study, a polycaprolactone (PCL) nanofiber membrane was prepared by electrospinning. A PCL–PDA loading system was developed by modifying the surface of polydopamine (PDA), using inspiration from mussel adhesion protein, and the efficient and stable loading of thrombin (TB) was realized to ensure the bioactivity of TB. The new thrombin loading system overcomes the disadvantages of harsh storage conditions, poor strength, and ease of falling off, and it can use thrombin to start a rapid coagulation cascade reaction, which has the characteristics of fast hemostasis, good biocompatibility, high safety, and a wide range of hemostasis. The physicochemical properties and biocompatibility of the PCL–PDA–TB membrane were verified by scanning electron microscopy, the cell proliferation test, the cell adhesion test, and the extract cytotoxicity test. Red blood cell adhesion, platelet adhesion, dynamic coagulation time, and animal models all verified the coagulation effect of the PCL–PDA–TB membrane. Therefore, the PCL–PDA–TB membrane has great potential in wound hemostasis applications, and should be widely used in various traumatic hemostatic scenarios. Full article

The regeneration of articular cartilage remains a serious problem in various pathological conditions such as osteoarthritis, due to the tissue’s low self-healing capacity. The latest therapeutic approaches focus on the construction of biomaterials that induce cartilage repair. This research describes the design, synthesis, and investigation of a safe, “smart”, fibrous scaffold containing a genetically incorporated active peptide for chondrogenic induction. While possessing specific sequences and the respective mechanical properties from natural fibrous proteins, the fibers also incorporate a Transforming Growth Factor-β1 (TGF-β1)-derived peptide (YYVGRKPK) that can promote chondrogenesis. The scaffold formed stable porous networks with shear-thinning properties at 37 °C, as shown by SEM imaging and rheological characterization, and were proven to be non-toxic to human dental pulp stem cells (hDPSCs). Its chondrogenic capacity was evidenced by a strong increase in the expression of specific chondrogenesis gene markers SOX9, COL2, ACAN, TGFBR1A, and TGFBR2 in cells cultured on “scaffold-TGFβ1” for 21 days and by increased phosphorylation of intracellular signaling proteins Smad-2 and Erk-1/2. Additionally, intense staining of glycosaminoglycans was observed in these cells. According to our results, “scaffold-TGFβ1” is proposed for clinical studies as a safe, injectable treatment for cartilage degeneration. Full article