Molecular Interaction Mechanisms Between Lubricant-Infused Slippery Surfaces and Mussel-Inspired Polydopamine Adhesive and DOPA Moiety.

Lubricant-infused slippery surfaces have recently emerged as promising antifouling coatings, showing potential against proteins, cells, and marine mussels. However, a comprehensive understanding of the molecular binding behaviors and interaction strength of foulants to these surfaces is lacking. In this work, mussel-inspired chemistry based on catechol-containing chemicals including 3,4-dihydroxyphenylalanine (DOPA) and polydopamine (PDA) is employed to investigate the antifouling performance and repellence mechanisms of fluorinated-based slippery surface, and the correlated interaction mechanisms are probed using atomic force microscopy (AFM). Intermolecular force measurements and deposition experiments between PDA and the surface reveal the ability of lubricant film to inhibit the contact of PDA particles with the substrate. Moreover, the binding mechanisms and bond dissociation energy between a single DOPA moiety and the lubricant-infused slippery surface are quantitatively investigated employing single-molecule force spectroscopy based on AFM (SM-AFM), which reveal that the infused lubricant layer can remarkably influence the dissociation forces and weaken the binding strength between DOPA and underneath per-fluorinated monolayer surface. This work provides new nanomechanical insights into the fundamental antifouling mechanisms of the lubricant-infused slippery surfaces against mussel-derived adhesive chemicals, with important implications for the design of lubricant-infused materials and other novel antifouling platforms for various bioengineering and engineering applications.

Bio-based microplastic polylactic acid exerts the similar toxic effects to traditional petroleum-based microplastic polystyrene in mussels.

Microplastics (MPs) have accumulated in the oceans, causing adverse effects on marine organisms and the environment. Biodegradable polylactic acid (PLA) is considered as an excellent substitute for traditional petroleum-based plastics, but it is difficult to degrade completely and easily become MPs in the marine environment. To test the ecological risk of bio-based PLA, we exposed thick-shelled mussels (Mytilus coruscus) to bio-based PLA and petroleum-based polystyrene (PS) (at 102, 104, and 106 particles/L) for 14 days. The significant increase in enzyme activities related to oxidative stress and immune response showed that mussels were under physiological stress after MP ingestion. While enzyme activities of nerve conduction and energy metabolism were significantly disturbed after exposure. Meanwhile, normal physiological activities in respiration, ingestion and assimilation were also suppressed in association with enzyme changes. The negative effects of PS and PLA in mussels were not differentiated, and further integration analysis of integrated biomarker response (IBR) and principal component analysis (PCA) also showed that PLA would induce adverse effects in mussels and ecological risks as PS, especially at environmental concentrations. Therefore, it is necessary to pay more attention to the environmental and ecological risk of bio-based MP PLA accumulating in the marine environment.

Molecular Characterization and Antibacterial Resistance Determination of Escherichia coli Isolated from Fresh Raw Mussels and Ready-to-Eat Stuffed Mussels: A Major Public Health Concern.

Our study focused exclusively on analyzing Escherichia coli (E. coli) contamination in fresh raw mussels and ready-to-eat (RTE) stuffed mussels obtained from authorized and regulated facilities. However, it is critical to recognize that such contamination represents a significant public health threat in regions where unauthorized harvesting and sales practices are prevalent. This study aimed to comprehensively assess the prevalence, molecular characteristics, and antibacterial resistance profiles of E. coli in fresh raw mussels and RTE stuffed mussels. E. coli counts in fresh raw mussel samples ranged from 1 to 2.89 log CFU/g before cooking, with a significant reduction observed post-cooking. RTE stuffed mussel samples predominantly exhibited negligible E. coli presence (<1 log CFU/g). A phylogenetic analysis revealed a dominance of phylogroup A, with variations in the distribution observed across different sampling months. Antibacterial resistance was prevalent among the E. coli isolates, notably showing resistance to ampicillin, streptomycin, and cefotaxime. Extended-spectrum ß-lactamase (ESßL) production was rare, with only one positive isolate detected. A variety of antibacterial resistance genes, including tetB and sul1, were identified among the isolates. Notably, virulence factor genes associated with pathogenicity were absent. In light of these findings, it is imperative to maintain rigorous compliance with quality and safety standards at all stages of the mussel production process, encompassing harvesting, processing, cooking, and consumption. Continuous monitoring, implementation of rigorous hygiene protocols, and responsible antibacterial drug use are crucial measures in mitigating food safety risks and combating antibacterial resistance. Stakeholders, including seafood industry players, regulatory agencies, and healthcare professionals, are essential to ensure effective risk mitigation and safeguard public health in the context of seafood consumption.

Intelligent breast cancer diagnosis with two-stage using mammogram images.

Breast cancer (BC) significantly contributes to cancer-related mortality in women, underscoring the criticality of early detection for optimal patient outcomes. Mammography is a key tool for identifying and diagnosing breast abnormalities; however, accurately distinguishing malignant mass lesions remains challenging. To address this issue, we propose a novel deep learning approach for BC screening utilizing mammography images. Our proposed model comprises three distinct stages: data collection from established benchmark sources, image segmentation employing an Atrous Convolution-based Attentive and Adaptive Trans-Res-UNet (ACA-ATRUNet) architecture, and BC identification via an Atrous Convolution-based Attentive and Adaptive Multi-scale DenseNet (ACA-AMDN) model. The hyperparameters within the ACA-ATRUNet and ACA-AMDN models are optimized using the Modified Mussel Length-based Eurasian Oystercatcher Optimization (MML-EOO) algorithm. The performance is evaluated using a variety of metrics, and a comparative analysis against conventional methods is presented. Our experimental results reveal that the proposed BC detection framework attains superior precision rates in early disease detection, demonstrating its potential to enhance mammography-based screening methodologies.

BDNF-loaded chitosan-based mimetic mussel polymer conduits for repair of peripheral nerve injury.

Care for patients with peripheral nerve injury is multifaceted, as traditional methods are not devoid of limitations. Although the utilization of neural conduits shows promise as a therapeutic modality for peripheral nerve injury, its efficacy as a standalone intervention is limited. Hence, there is a pressing need to investigate a composite multifunctional neural conduit as an alternative treatment for peripheral nerve injury. In this study, a BDNF-loaded chitosan-based mimetic mussel polymer conduit was prepared. Its unique adhesion characteristics allow it to be suture-free, improve the microenvironment of the injury site, and have good antibacterial properties. Researchers utilized a rat sciatic nerve injury model to evaluate the progression of nerve regeneration at the 12-week postoperative stage. The findings of this study indicate that the chitosan-based mimetic mussel polymer conduit loaded with BDNF had a substantial positive effect on myelination and axon outgrowth. The observed impact demonstrated a favorable outcome in terms of sciatic nerve regeneration and subsequent functional restoration in rats with a 15-mm gap. Hence, this approach is promising for nerve tissue regeneration during peripheral nerve injury.

Species-specific differences and temperature-dependence of Na+/K+-ATPase in freshwater mussels Anodonta anatina and Unio tumidus (Bivalvia: Unionidae).

The predicted global warming of surface waters can be challenging to aquatic ectotherms like freshwater mussels. Especially animals in northern temperate latitudes may face and physiologically acclimate to significant stress from seasonal temperature fluctuations. Na+/K+-ATPase enzyme is one of the key mechanisms that allow mussels to cope with changing water temperatures. This enzyme plays a major role in osmoregulation, energy control, ion balance, metabolite transport and electrical excitability. Here, we experimentally studied the effects of temperature on Na+/K+-ATPase activity of gills in two freshwater mussel species, Anodonta anatina and Unio tumidus. The study animals were acclimated to three ambient temperatures (+4, +14, +24 °C) and Na+/K+-ATPase activity was measured at those temperatures for each acclimation group. Both species had their highest gill Na+/K+-ATPase activity at the highest acclimation temperature. Na+/K+-ATPase activity of gills exhibited species-specific differences, and was higher in A. anatina than U. tumidus in all test groups at all test temperatures. Temperature dependence of Na+/K+-ATPase was confirmed in both species, being highest at temperatures between +4 and + 14 °C when Q10 values in the acclimation groups varied between 5.06 and 6.71. Our results underline the importance of Na+/K+-ATPase of gills for the freshwater mussels in warming waters. Because Na+/K+-ATPase is the driving force behind ciliary motion, our results also suggest that in warming waters A. anatina may be more tolerant at sustaining vigorous ciliary action (associated with elevated respiration rates and filter-feeding) than U. tumidus. Overall, our results indicate great flexibility of the mussel's ecophysiological characteristics as response to changing conditions.

Structure, Evolution, and Mitochondrial Genome Analysis of Mussel Species (Bivalvia, Mytilidae).

Based on the nucleotide sequences of the mitochondrial genome (mitogenome) of specimens taken from two mussel species (Arcuatula senhousia and Mytilus coruscus), an investigation was performed by means of the complex approaches of the genomics, molecular phylogenetics, and evolutionary genetics. The mitogenome structure of studied mussels, like in many other invertebrates, appears to be much more variable than in vertebrates and includes changing gene order, duplications, and deletions, which were most frequent for tRNA genes; the mussel species' mitogenomes also have variable sizes. The results demonstrate some of the very important properties of protein polypeptides, such as hydrophobicity and its determination by the purine and pyrimidine nucleotide ratio. This fact might indirectly indicate the necessity of purifying natural selection for the support of polypeptide functionality. However, in accordance with the widely accepted and logical concept of natural cutoff selection for organisms living in nature, which explains its action against deleterious nucleotide substitutions in the nonsynonymous codons (mutations) and its holding of the active (effective) macromolecules of the polypeptides in a population, we were unable to get unambiguous evidence in favor of this concept in the current paper. Here, the phylogeny and systematics of mussel species from one of the largest taxons of bivalve mollusks are studied, the family known as Mytilidae. The phylogeny for Mytilidae (order Mytilida), which currently has no consensus in terms of systematics, is reconstructed using a data matrix of 26-27 mitogenomes. Initially, a set of 100 sequences from GenBank were downloaded and checked for their gender: whether they were female (F) or male (M) in origin. Our analysis of the new data confirms the known drastic differences between the F/M mitogenome lines in mussels. Phylogenetic reconstructions of the F-lines were performed using the combined set of genetic markers, reconstructing only protein-coding genes (PCGs), only rRNA + tRNA genes, and all genes. Additionally, the analysis includes the usage of nucleotide sequences composed of other data matrices, such as 20-68 mitogenome sequences. The time of divergence from MRCA, estimated via BEAST2, for Mytilidae is close to 293 Mya, suggesting that they originate in the Silurian Period. From all these data, a consensus for the phylogeny of the subfamily of Mytilinae and its systematics is suggested. In particular, the long-debated argument on mussel systematics was resolved as to whether Mytilidae, and the subfamily of Mytilinae, are monophyletic. The topology signal, which was strongly resolved in this paper and in the literature, has refuted the theory regarding the monophyly of Mytilinae.

Mussel-inspired chitosan and its applications in the biomedical field.

Chitosan (CS) has physicochemical properties including solubility, crystallinity, swellability, viscosity, and cohesion, along with biological properties like biocompatibility, biodegradation, antioxidant, antibacterial, and antitumor effects. However, these characteristics of CS are greatly affected by its degree of deacetylation, molecular weight, pH and other factors, which limits the application of CS in biomedicine. The modification of CS with catechol-containing substances inspired by mussels can not only improve these properties of CS, but also endow it with self-healing property, providing an environmentally friendly and sustainable way to promote the application of CS in biomedicine. In this paper, the properties of CS and its limitation in the biomedical filed are introduced in detail. Then, the modification methods and properties of substances with catechol groups inspired by mussels on CS are reviewed. Finally, the applications of modified CS in the biomedical field of wound healing, drug delivery, anticancer therapy, biosensor and 3D printing are further discussed. This review can provide valuable information for the design and exploitation of mussel-inspired CS in the biomedical field.

In situ visualization of the cellular uptake and sub-cellular distribution of mussel oligosaccharides.

Unlike chemosynthetic drugs designed for specific molecular and disease targets, active small-molecule natural products typically have a wide range of bioactivities and multiple targets, necessitating extensive screening and development. To address this issue, we propose a strategy for the direct in situ microdynamic examination of potential drug candidates to rapidly identify their effects and mechanisms of action. As a proof-of-concept, we investigated the behavior of mussel oligosaccharide (MOS-1) by tracking the subcellular dynamics of fluorescently labeled MOS-1 in cultured cells. We recorded the entire dynamic process of the localization of fluorescein isothiocyanate (FITC)-MOS-1 to the lysosomes and visualized the distribution of the drug within the cell. Remarkably, lysosomes containing FITC-MOS-1 actively recruited lipid droplets, leading to fusion events and increased cellular lipid consumption. These drug behaviors confirmed MOS-1 is a candidate for the treatment of lipid-related diseases. Furthermore, in a high-fat HepG2 cell model and in high-fat diet-fed apolipoprotein E (ApoE) -/- mice, MOS-1 significantly promoted triglyceride degradation, reduced lipid droplet accumulation, lowered serum triglyceride levels, and mitigated liver damage and steatosis. Overall, our work supports the prioritization of in situ visual monitoring of drug location and distribution in subcellular compartments during the drug development phase, as this methodology contributes to the rapid identification of drug indications. Collectively, this methodology is significant for the screening and development of selective small-molecule drugs, and is expected to expedite the identification of candidate molecules with medicinal effects.

Local differences in robustness to ocean acidification.

Ocean acidification (OA) caused by increased atmospheric carbon dioxide is affecting marine systems a globally and is more extreme in coastal waters. A wealth of research to determine how species will be affected by OA, now and in the future, is emerging. Most studies are discrete and generally do not include the full life cycle of animals. Studies that include the potential for adaptation responses of animals from areas with different environmental conditions and the most vulnerable life stages are needed. Therefore, we conducted experiments with the widely-distributed blue mussel, Mytilus edulis, from populations regularly exposed to different OA conditions. Mussels experienced experimental conditions prior to spawning, through embryonic and larval development, a highly vulnerable stage. Survivorship to metamorphosis of larvae from all populations was negatively affected by extreme OA conditions (pH 7.3, Ωar, 0.39, pCO2 2479.74), but, surprisingly, responses to Mid OA (pH 7.6, Ωar 0.77, pCO21167.13) and Low OA (pH 7.9, Ωar 1.53, pCO2 514.50) varied among populations. Two populations were robust and showed no effect of OA on survivorship in this range. One population displayed the expected negative effect on survivorship with increased OA. Unexpectedly survivorship in the fourth population was highest under Mid OA conditions. There were also significant differences in development time among populations that were unaffected by OA. These results suggest that adaptation to OA may already be present in some populations and emphasizes the importance of testing animals from different populations to see the potential for adaptation to OA.

Changes in the composition of invertebrate assemblages from wave-exposed intertidal mussel stands along the Nova Scotia coast, Canada.

Rocky intertidal habitats occur worldwide and are mainly characterized by primary space holders such as seaweeds and sessile invertebrates. Some of these organisms are foundation species, as they can form structurally complex stands that host many small invertebrates. The abundance of primary space holders is known to vary along coastlines driven directly or indirectly by environmental variation. However, it is less clear if the invertebrate assemblages associated to a foundation species may remain relatively unchanged along coastlines, as similar stands of a foundation species can generate similar microclimates. We examined this question using abundance data for invertebrate species found in mussel stands of a similar structure in wave-exposed rocky habitats at mid-intertidal elevations along the Atlantic coast of Nova Scotia (Canada). While the most abundant invertebrate species were found at three locations spanning 315 km of coastline, species composition (a combined measure of species identity and their relative abundance) differed significantly among the locations. One of the species explaining the highest amount of variation among locations (a barnacle) exhibited potential signs of bottom-up regulation involving pelagic food supply, suggesting benthic-pelagic coupling. The abundance of the species that explained the highest amount of variation (an oligochaete) was positively related to the abundance of their predators (mites), further suggesting bottom-up forcing in these communities. Overall, we conclude that species assemblages associated to structurally similar stands of a foundation species can show clear changes in species composition at a regional scale.

Modelling and mapping carbon capture potential of farmed blue mussels in the Baltic Sea region.

This study applies a regional Dynamic Energy Budget (DEB) model, enhanced to include biocalcification processes, to evaluate the carbon capture potential of farmed blue mussels (Mytilus edulis/trossulus) in the Baltic Sea. The research emphasises the long-term capture of carbon associated with shell formation, crucial for mitigating global warming effects. The model was built using a comprehensive pan-Baltic dataset that includes information on mussel growth, filtration and biodeposition rates, and nutrient content. The study also examined salinity, temperature, and chlorophyll a as key environmental factors influencing carbon capture in farmed mussels. Our findings revealed significant spatial and temporal variability in carbon dynamics under current and future environmental conditions. The tested future predictions are grounded in current scientific understanding and projections of climate change effects on the Baltic Sea. Notably, the outer Baltic Sea subbasins exhibited the highest carbon capture capacity with an average of 55 t (in the present scenario) and 65 t (under future environmental conditions) of carbon sequestrated per farm (0.25 ha) over a cultivation cycle - 17 months. Salinity was the main driver of predicted regional changes in carbon capture, while temperature and chlorophyll a had more pronounced local effects. This research advances our understanding of the role low trophic aquaculture plays in mitigating climate change. It highlights the importance of developing location-specific strategies for mussel farming that consider both local and regional environmental conditions. The results contribute to the wider discourse on sustainable aquaculture development and environmental conservation.

Mussel shell-derived biogenic hydroxyapatite as reinforcement on chitosan-loaded gentamicin composite for antibacterial activity and bone regeneration.

In this study, hydroxyapatite (HAp) was synthesized from natural biowaste materials, specifically mussel shells, and combined with chitosan (CS) and gentamicin sulfate antibiotic (GA) using an in-situ method. The resulting composite material, designated HAp/CS-GA, has its physicochemical and structural properties characterized by Fourier transform infrared spectroscopy (FTIR) analysis. The drug-loaded structure was confirmed by UV-visible absorption spectroscopy (UV-Vis) and X-ray diffraction (XRD) analysis. Additionally, field emission scanning electron microscopy (FE-SEM) equipped with the energy dispersive X-ray spectroscopic (EDX) technique was used to determine the surface topography and main components. The composite of HAp/CS-GA was analyzed using a drug release profile and UV-visible spectroscopy (UV-Vis). The fabricated composites antimicrobial behavior was examined against bone infection-causing Gram-positive and Gram-negative bacteria, showing potential activity against Klebsiella pneumoniae, Pseudomonas aeruginosa, and Staphylococcus aureus compared to Escherichia coli, respectively. Simultaneously, the cytotoxicity of the composite was evaluated by MTT assay using an MG-63 osteoblast-like cell line that exhibited no toxicity in the prepared composite. After a 24 h incubation period, the MG-63 cells on the HAp/CS-GA composite showed good proliferation, according to Hoechst 33258 fluorescence staining results. The results suggested that the composite had excellent biocompatibility and antibacterial activity and enhanced the osteoblast cell proliferation. Therefore, the designed HAp/CS-GA composite would be a promising candidate for bone tissue engineering.

Redox-triggered debonding of mussel-inspired pressure sensitive adhesives: Improving efficiency through functional design.

Debondable pressure-sensitive adhesives (PSAs) promise access to recyclability in microelectronics in the transition toward a circular economy. Two PSAs were synthesized from a tetravalent thiol star-polyester forming thiol-catechol-connectivities (TCC) with either biorelated DiDopa-bisquinone (BY*Q) or fossil-based bisquinone A (BQA). The PSAs enable debonding by oxidation of TCC-catechols to quinones. The extent of debonding efficiency depends on the interaction modes, which are determined by the chemical structure differences of both TCC-motifs. BY*Q-TCC-PSA debonds with exceptional loss of 99% of its approx. 2 MPa shear strength. For BQA-TCC-PSA, a debonding efficiency of only approx. 60% was found, irrespective of its initial shear strength, which could be tuned up to approx. 7 MPa. The efficiency of debonding for BY*Q-TCC-PSA after TCC-oxidation is linked to the loss of synergistic interactions without strongly affecting the bulk glue properties, outperforming the purely catechol-based BQA-analogue.

Different parts of the mussel Gigantidas haimaensis holobiont responded differently to deep-sea sampling stress.

Acute environmental changes cause stress during conventional deep-sea biological sampling without in situ fixation and affect gene expressions of samples collected. However, the degree of influence and underlying mechanisms are hardly investigated. Here, we conducted comparative transcriptomic analyses between in situ and onboard fixed gills and between in situ and onboard fixed mantles of deep-sea mussel Gigantidas haimaensis to assess the effects of incidental sampling stress. Results showed that transcription, translation, and energy metabolism were upregulated in onboard fixed gills and mantles, thereby mobilizing rapid gene expression to tackle the stress. Autophagy and phagocytosis that related to symbiotic interactions between the host and endosymbiont were downregulated in the onboard fixed gills. These findings demonstrated that symbiotic gill and nonsymbiotic mantle responded differently to sampling stress, and symbiosis in the gill was perturbed. Further comparative metatranscriptomic analysis between in situ and onboard fixed gills revealed that stress response genes, peptidoglycan biosynthesis, and methane fixation were upregulated in the onboard fixed endosymbiotic Gammaproteobacteria inside the gills, implying that energy metabolism of the endosymbiont was increased to cope with sampling stress. Furthermore, comparative analysis between the mussel G. haimaensis and the limpet Bathyacmaea lactea transcriptomes resultedidentified six transcription factor orthologs upregulated in both onboard fixed mussel mantles and limpets, including sharply increased early growth response protein 1 and Kruppel-like factor 5. They potentially play key roles in initiating the response of sampled deep-sea macrobenthos to sampling stress. Our results clearly show that in situ fixed biological samples are vital for studying deep-sea environmental adaptation.

Mussel-Bioinspired Lignin Adhesive for Wearable Bioelectrodes.

As a natural "binder," lignin fixes cellulose in plants to foster growth and longevity. However, isolated lignin has a poor binding ability, which limits its biomedical applications. In this study, inspired by mussel adhesive proteins, acidic/basic amino acids (AAs) are introduced in alkali lignin (AL) to form ionic-π/spatial correlation interactions, followed by demethylation to create catechol residues for enhanced adhesion activity. Atomic force microscopy reveals that catechol residues are the primary adhesion structures, with basic AAs exhibiting superior synergistic effects compared to acidic AAs. Demethylated lysine-grafted AL exhibits the strongest adhesion force toward skin tissue. Molecular dynamic simulation and density functional theory calculations indicate that adhesion against skin tissue mainly results from hydrogen bonds and cation-π interactions, with the adhesion mechanism being based on the Gibbs free energy of the Schiff base reaction. In summary, a biomimetic electrode based on lignin inspired by mussel adhesive proteins is prepared; the presented method offers a straightforward strategy for the development of biomimetic adhesives. Furthermore, this mussel-inspired adhesive can be used as a wearable bioelectrode in biomedical applications.

Biomonitoring of human activities recovery following lockdown in a highly touristic Mediterranean Island using Mytilus galloprovincialis.

Coastal waters face significant anthropogenic stress, particularly from tourism, exacerbating pollution, especially in areas like touristic islands. Ischia, the largest island in the Gulf of Naples and part of the Regno di Nettuno Marine Protected Area, suffers from pollution due to tourism and maritime traffic. During the initial SARS-CoV-2 lockdown from March to June 2020, Ischia was isolated, providing a unique opportunity to study pollutant release and its impact on coastal ecosystems. Adult Mytilus galloprovincialis mussels were transplanted to three sites on the island for active biomonitoring. Accumulation of chemicals in tissues and biomarkers related to metabolism, detoxification, and oxidative stress were measured. Results indicated that pollutants from daily activities entered the sea, affecting filter feeders. Translocated organisms showed modulated metabolic functions and biochemical changes, highlighting coastal vulnerability and calling for conservation efforts.

Biofiltering capacity of Chambardia rubens (Bivalvia: Unionidae) may modulate expression of stress and growth genes inhibited by the neonicotinoid insecticide acetamiprid in zebrafish.

Neonicotinoid insecticides specifically target insect subtypes of nicotinic acetylcholine receptors. Acetamiprid (ACE: C10H11ClN4), the neonicotinoid insecticide, is used to control crop insect pests worldwide. It is a nitrile, monochloropyridine, and carboxamidine that is highly soluble and accessible to waterways. There, it causes neurotoxic and oxidative perturbance to non-target organisms. The unionid mussel Chamabradia rubens is a common Northern River Nile suspension feeder. The current study aimed to assess ACE filtration from waters by C. rubens, and whether this biological power can reduce ACE effects on fish. Removal of ACE by C. rubens was assessed using LC-MS/MS. Zebrafish Danio rerio adults were exposed to different sublethal doses of ACE in the presence or absence of C. rubens in their aquaria. The results showed that mussels could remove significant ACE amounts from water, where it accumulated mostly in the digestive gland. The presence of C.rubens in zebrafish aquaria having ACE was accompanied by significant upregulation of antioxidant enzyme gene transcripts and total H2O2 scavenging, in contrast to mussel-free ACE-exposed groups. Meanwhile, liver triglycerides rose 5-6-fold in response to ACE in the "Fish-Only" groups, indicating an ACE-induced hepatotoxicity. Also, Insulin-like growth factor 1 (igf1) and fish body mass increased more in "Fish + Mussel" groups than in the "Fish-Only" ones. In aggregate, these findings suggest that the Nile mussel could reduce the oxidative stress and metabolic changes induced in fish by ACE. This can contribute valuable environmental and economic benefits upon the use of this mussel as a biofilter.

Mussel-inspired immunomodulatory and osteoinductive dual-functional hydroxyapatite nanoplatform for promoting bone regeneration.

Simultaneously modulating the inflammatory microenvironment and promoting local bone regeneration is one of the main challenges in treating bone defects. In recent years, osteoimmunology has revealed that the immune system plays an essential regulatory role in bone regeneration and that macrophages are critical components. In this work, a mussel-inspired immunomodulatory and osteoinductive dual-functional hydroxyapatite nano platform (Gold/hydroxyapatite nanocomposites functionalized with polydopamine - PDA@Au-HA) is developed to accelerate bone tissues regeneration by regulating the immune microenvironment. PDA coating endows nanomaterials with the ability to scavenge reactive oxygen species (ROS) and anti-inflammatory properties, and it also exhibits an immunomodulatory ability to inhibit M1 macrophage polarization and activate M2 macrophage secretion of osteogenesis-related cytokines. Most importantly, this nano platform promotes the polarization of M2 macrophages and regulates the crosstalk between macrophages and pre-osteoblast cells to achieve bone regeneration. Au-HA can synergistically promote vascularized bone regeneration through sustained release of Ca and P particles and gold nanoparticles (NPs). This nano platform has a synergistic effect of good compatibility, scavenging of ROS, and anti-inflammatory and immunomodulatory capability to accelerate the bone repair process. Thus, our research offers a possible therapeutic approach by exploring PDA@Au-HA nanocomposites as a bifunctional platform for tissue regeneration.

Mussel-Derived and Bioclickable Peptide Mimic for Enhanced Interfacial Osseointegration via Synergistic Immunomodulation and Vascularized Bone Regeneration.

Inadequate osseointegration at the interface is a key factor in orthopedic implant failure. Mechanistically, traditional orthopedic implant interfaces fail to precisely match natural bone regeneration processes in vivo. In this study, a novel biomimetic coating on titanium substrates (DPA-Co/GFO) through a mussel adhesion-mediated ion coordination and molecular clicking strategy is engineered. In vivo and in vitro results confirm that the coating exhibits excellent biocompatibility and effectively promotes angiogenesis and osteogenesis. Crucially, the biomimetic coating targets the integrin α2ß1 receptor to promote M2 macrophage polarization and achieves a synergistic effect between immunomodulation and vascularized bone regeneration, thereby maximizing osseointegration at the interface. Mechanical push-out tests reveal that the pull-out strength in the DPA-Co/GFO group is markedly greater than that in the control group (79.04 ± 3.20 N vs 31.47 ± 1.87 N, P < 0.01) and even surpasses that in the sham group (79.04 ± 3.20 N vs 63.09 ± 8.52 N, P < 0.01). In summary, the novel biomimetic coating developed in this study precisely matches the natural process of bone regeneration in vivo, enhancing interface-related osseointegration and showing considerable potential for clinical translation and applications.