Fully Recycled Polyolefin Elastomer-Based Vitrimers with Ultra-High, Universal, Stable, and Switchable Adhesion.

Achieving both robust adhesion to arbitrary surfaces and thermal-switchable/recyclable properties has proven challenging, particularly for commodity polyolefins. Herein, a simple and effective route is reported to transform polyolefins elastomer (POE) into a fully recycled epoxy-functionalized POE vitrimers (E-POE vit) with ultra-high, universal, stable, and switchable adhesion via facile free radical grafting and dynamic cross-linking. The resultant E-POE vit exhibits increase in adhesion strength on glass exceeding three to ten times compared to those commonly used polymers, due to the synergy of dense hydrogen (H)-bonds and strong interfacial affinity. In addition, E-POE vit also displays strong adhesion on diverse surfaces ranging from inorganic to organic while maintaining good stability in various harsh environments. More importantly, temperature-sensitive H-bonds allow E-POE vit to switch between attachment-detachment at alternating temperatures, resulting in reversible adhesion without adhesion loss, even after 10 cycles. Moreover, E-POE vit is able to be fully recycled and reused more than ten times via thermo-activated transesterification reactions with negligible change in structure and performance. This work may unlock strategies to fabricate high-performance commercial polymer-based adhesives with adhesion and recyclable features for intelligent and sustainable applications.

Ocean acidificationf affects the bioenergetics of marine mussels as revealed by high-coverage quantitative metabolomics.

Ocean acidification has become a major ecological and environmental problem in the world, whereas the impact mechanism of ocean acidification in marine bivalves is not fully understood. Cellular energy allocation (CEA) approach and high-coverage metabolomic techniques were used to investigate the acidification effects on the energy metabolism of mussels. The thick shell mussels Mytilus coruscus were exposed to seawater pH 8.1 (control) and pH 7.7 (acidification) for 14 days and allowed to recover at pH 8.1 for 7 days. The levels of carbohydrates, lipids and proteins significantly decreased in the digestive glands of the mussels exposed to acidification. The 14-day acidification exposure increased the energy demands of mussels, resulting in increased electron transport system (ETS) activity and decreased cellular energy allocation (CEA). Significant carry-over effects were observed on all cellular energy parameters except the concentration of carbohydrates and cellular energy demand (Ec) after 7 days of recovery. Metabolomic analysis showed that acidification affected the phenylalanine, tyrosine and tryptophan biosynthesis, taurine and hypotaurine metabolism, and glycine, serine and threonine metabolism. Correlation analysis showed that mussel cell energy parameters (carbohydrates, lipids, proteins, CEA) were negatively/positively correlated with certain differentially abundant metabolites. Overall, the integrated biochemical and metabolomics analyses demonstrated the negative effects of acidification on energy metabolism at the cellular level and implicated the alteration of biosynthesis and metabolism of amino acids as a mechanism of metabolic perturbation caused by acidification in mussels.

Color-Tunable Binary Copolymers Manipulated by Intramolecular Aggregation and Hydrogen Bonding.

Construction of color-tunable luminescent polymeric materials with enhanced emission intensity and room-temperature phosphorescence (RTP) performance regulated by a single chromophore component is highly desirable in the scope of photoluminescent materials. Herein, a set of binary copolymers were facilely synthesized using free radical polymerization by selecting different types of polymer matrix and N-substituted naphthalimides (NPA) as chromophores. Surprisingly, the fluorescence emission of copolymers could be remarkably enhanced, because of the intramolecular aggregation of NPA manipulated by a single polymer chain in both solution and solid state. Moreover, RTP signals of binary copolymers were all clearly observed in the air without any processing procedure, because of the embedding of phosphors into hydrogen bonding networks after copolymerization with vinyl-based acrylamide monomers. Taking advantages of the synergistic effect of copolymerization-induced aggregation and copolymerization-induced rigidification to promote optical performance, UV stimulus-responsive luminescent polymer films with processability, flexibility, and adjustable emission wavelength were simply prepared using a drop-casting method in large scale, the setting of which is the basis for application in the fields of organic optoelectronics, information security, and bioimaging/sensing.

Tale of COF-on-MOF Composites with Structural Regulation and Stepwise Luminescence Enhancement.

Integrating metal-organic framework (MOF)-covalent organic framework (COF) allows versatile engineering of hybrid materials with properties superior to pristine components, especially COFs suffered from aggregation-caused quenching (ACQ), unlocking more possibilities to improve the luminescence of COFs. In this work, we prepared various MOF@COF composites with different COF layer thicknesses, in which stable UiO-66-NH2 served as the inner substrate and 1,3,5-benzenetricarboxaldehyde (BT), and 3,3'-dihydroxybenzidine (DH) were used to construct a COF layer. In addition to the conventional preparation method, we increased the ratio of BT and DH to be 1:2.5, and impressively, the morphologies of acquired UC (1:2.5) materials were quite different from the previous reticular structure and gradually extended from the spherical structure to the prickly structure with the increase of COF monomers. Remarkably, all of the UC materials possessed better luminescence properties than individual COF due to the limited COF layers. Meanwhile, UC-1 materials with an optimal COF layer displayed the strongest emission. In comparison with a single COF, the quantum yields of UC-1 and UC-1 (1:2.5) were increased nearly 7 times and 5 times, respectively. Moreover, the fluorescence of UC-1 materials was progressively enhanced via selective F- sensing. This work is expected to shed light on the potential hybridization of MOF-COF with structural adjustment, morphological design, and luminescence enhancement.

Tunable fluorescence emission based on multi-layered MOF-on-MOF.

Luminescent metal-organic frameworks (MOFs) have garnered considerable attention in various fields. Herein, we proposed a hierarchical confinement strategy based on MOF-on-MOF to tune luminescence emission ranging from blue to red including white light in a flexible way. The easily available ZIF-8 MOF was used as a host for the confinement of two kinds of size-matching dyes (perylene and rhodamine B) to obtain a layered ZIF-8@dye@ZIF-8@dye via in situ encapsulation and seed-mediated synthesis. ZIF-8@dye@ZIF-8@dye materials with different fluorescence emission in dispersed and solid states were both obtained by tuning the initial encapsulation concentration of dye and changing the structure of the inner and outer ZIF-8@dye layers. To our delight, ZIF-8@0.125perylene@ZIF-8@25RhB with white light emission in the dispersed state was obtained; meanwhile, ZIF-8@0.125perylene + 25RhB and mechanically mixed ZIF-8@0.125perylene + ZIF-8@25RhB could not realize white light emission under the same conditions, indicating that the proposed hierarchical confinement strategy facilitated white light regulation. Similarly, the emission of ZIF-8@dye@ZIF-8@dye in the solid state has also been investigated; ZIF-8@perylene@ZIF-8@3RhB with white light emission was obtained, while white light emission could not be achieved in ZIF-8@perylene + 3RhB and ZIF-8@perylene + ZIF-8@3RhB, which further indicated the importance of the hierarchical confinement strategy based on MOF-on-MOF. The proposed hierarchical confinement strategy may also inspire the development of other functional optical MOF materials.

Construction and Sensing Amplification of Raspberry-Shaped MOF@MOF.

MOFs@MOFs (metal-organic frameworks, MOFs) possess precise customized functionalities and predesigned structures that enable the implementation of structure and property regulation for specific functions in comparison to traditional single MOFs. However, the synthesis and fluorescence properties of multilayer MOFs@MOFs are still worth improving. Herein, a fluorescent raspberry-shaped MOF@MOF was constructed via optimized seed-mediated synthesis by tuning the reaction time, reaction mode, and reaction concentration, involving the initial synthesis of the UiO-66-NH2 core and then the coating of the UiO-67-bpy shell. The raspberry-shaped UiO-66@67-bpy showed stable fluorescence and desirable sensing selectivity for the Hg2+ ion under the interference of other ions; meanwhile, the raspberry-shaped UiO-66@67-bpy indicated amplified sensing performance than pure UiO-66-NH2, mechanically mixed UiO-66-NH2 + UiO-67-bpy, and UiO-66@UiO-67 counterpart due to the accumulation effect of outer UiO-67-bpy toward Hg2+. Density functional theory (DFT) calculations including adsorption energy calculations and electronic density difference analysis further showed that the enhanced fluorescence quenching was possibly attributed to the outer UiO-67-bpy enrichment promoting the charge transfer between Hg2+ and the ligands of fluorescent UiO-66@67-bpy. The synergistic effect of MOFs@MOFs unlocks more possibilities for the construction of enhanced sensors and other applications.

Oxygen-Tolerant RAFT Polymerization Catalyzed by a Recyclable Biomimetic Mineralization Enhanced Biological Cascade System.

An enzyme cascade system including glucose oxidase (GOx) and iron porphyrin (DhHP-6) is encapsulated in a metal-organic framework called zeolitic imidazolate framework-8 (ZIF-8) through one-step facile synthesis. The composite (GOx&DhHP-6@ZIF-8) is then used to initiate oxygen-tolerant reversible addition-fragmentation chain-transfer polymerization for different methacrylate monomers, such as 2-diethylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, and poly(ethylene glycol) methyl ether methacrylate (Mn = 500 g mol-1 ). The composite shows the robustness toward solvent and temperatures, all polymerizations using above monomers and catalyzing by GOx&DhHP-6@ZIF-8 exhibits high monomer conversion (>85%) and narrow molar mass dispersity (<1.3). Besides, acrylic and acrylamide monomers such as 2-hydroxyethyl acrylate and N,N-dimethylacrylamide are also carried to demonstrate the broad applicability. Proton nuclear magnetic resonance characterization and chain extension experiments confirm the retaining end groups of the resultant polymers, which is a significant feature of living polymerization. More importantly, the process of recycling the composite through a centrifuge is simplistic, and the composite still maintains similar activity compared to the original composites after five times. This low-cost and easily separated composite catalyst represents a versatile strategy to synthesize well-defined functional polymers suitable for industrial-scale production.

Oxidative stress induced by nanoplastics in the liver of juvenile large yellow croaker Larimichthys crocea.

There are many toxicological studies on microplastics, but little is known about the effect of nanoplastics (NPs). Here, we evaluated the oxidative stress responses induced by NPs (10, 104 and 106 particles/l) in juvenile Larimichthys crocea during 14-d NPs exposure followed by a 7-d recovery. After exposure, the activities of antioxidant enzymes (SOD, CAT, GPx) and MDA levels increased in the liver of fish at the highest NPs concentration. SOD and CAT activities remained elevated above the baseline after recovery under high-concentration NPs but returned to the baseline in two other NP treatments. Although lipid peroxidation in liver was reversible, juvenile fish in NPs treatments exhibited a lower survival rate than the control during both exposure and recovery. Furthermore, IBR value and PCA analysis showed the potential adverse effects of NPs. Considering that NPs can reduce the survival of fish juveniles, impacts of NPs on fishery productivity should be considered.

Toxicity mechanisms of polystyrene microplastics in marine mussels revealed by high-coverage quantitative metabolomics using chemical isotope labeling liquid chromatography mass spectrometry.

Marine microplastic has become an important environmental issue of global concern due to its wide distribution and harmful impacts. However, there is still insufficient information on the toxicity mechanism of microplastics to marine organisms. In this study, we developed and applied a high-coverage quantitative metabolomics technique to investigate the toxicity mechanisms of the polystyrene microspheres (micro-PS) on marine mussels (Mytilus coruscus). A total of 3599 metabolites were quantified, including 163 positively identified metabolites, 318 high-confident putatively identified metabolites, and 2602 mass-matched metabolites from the hemolymph of mussels. Metabolomics analysis indicated that micro-PS disrupted the amino acid metabolism, particularly phenylalanine metabolism, which may lead to oxidative stress and neurotoxicity. Micro-PS at environmentally relevant concentrations induced oxidative stress and immunotoxicity in mussels. After 7 days of recovery, along with the significant clearance of micro-PS by mussels, both metabolite levels and biochemical indicators generally returned to the same level as the control group. Overall, the results showed that microplastics at environmentally-relevant concentrations can cause toxic effects on mussels but these influences are reversible. We envisage the usages of high-coverage metabolomics for investigating the toxicity of various types of microplastics under many different conditions, including those relevant to the marine environment.

Ocean acidification but not hypoxia alters the gonad performance in the thick shell mussel Mytilus coruscus.

Ocean acidification and hypoxia have become increasingly severe in coastal areas, and their co-occurrence poses emerging threats to coastal ecosystems. Here, we investigated the combined effects of ocean acidification and hypoxia on the reproductive capacity of the thick-shelled mussel Mytilus coruscus. Our results demonstrated low pH but not low oxygen induced decreased gonadosomatic index (GSI) in mussels. Male mussels had a lower level of sex steroids (estradiol, testosterone, and progesterone) when kept at low pH. Expression of genes related to reproduction were also impacted by low pH with a downregulation of genes involved in gonad development in males (ß-catenin and Wnt-7b involved in males) and an upregulation of testosterone synthesis inhibition-related gene (Wnt-4) in females. Overall, our results suggest that ocean acidification has an impact on the gonadal development through an alternation of gene expression and level of steroids while hypoxia had no significant effect.

Supramolecular Engineering of Efficient Artificial Light-Harvesting Systems from Cyanovinylene Chromophores and Pillar[5]arene-Based Polymer Hosts.

Enhanced emission and adjustable wavelength for single luminogen systems are highly desirable in the scope of photoluminescent materials. Herein, a supramolecular strategy has been proposed for supramolecular assembly-induced enhanced emission and valid emission manipulation by fabricating an amphiphilic copolymer host material with pillar[5]arene units as the side chains, whereby cyanovinylene-based (CV) derivatives are anchored to the polymer hosts via host-guest interactions. The guest-bearing copolymers can further form luminescent supramolecular polymer nanoparticles (SPNs). Remarkably, the as-prepared SPNs exhibit dramatic emission enhancement and tunable fluorescence wavelength, ascribing to the synergetic effects involving the restriction of intramolecular motions and the prevented excimer formation for CV moieties, as endowed by host-guest interactions and the entanglement of the polymer chains. Furthermore, the SPNs can be established as efficient artificial light-harvesting systems via the inclusion of Nile red into the particles for broadened emission spectra. As a proof-of-concept study, the use of pillar[5]arene-containing polymer hosts largely facilitates the emission enhancement and wavelength adjustment for the inherent luminogens, setting the basis for the supramolecular design of highly tunable luminescent systems.

Antioxidant responses of the mussel Mytilus coruscus co-exposed to ocean acidification, hypoxia and warming.

In the present study, the combined effects of pH, dissolved oxygen (DO) and temperature levels on the antioxidant responses of the mussel Mytilus coruscus were evaluated. Mussels were exposed to two pH (8.1, 7.7-acidification), two DO (6 mg L-1, 2 mg L-1-hypoxia) and two temperature levels (20 °C, 30 °C-warming) for 30 days. SOD, CAT, MDA, GPx, GSH, GST, TAOC, AKP, ACP, GPT, AST levels were measured in the gills of mussels. All tested biochemical parameters were altered by these three environmental stressors. Values for all the test parameters except GSH first increased and then decreased at various experimental treatments during days 15 and 30 as a result of acidification, hypoxia and warming. GSH content always increased with decreased pH, decreased DO and increased temperature. PCA showed a positive correlation among all the measured biochemical indexes. IBR results showed that M. coruscus were adversely affected by reduced pH, low DO and elevated temperature.

Physiological effects of plastic particles on mussels are mediated by food presence.

Plastic particles cause toxic effects on marine organisms but whether food particles can affect the toxic effects of plastic particles on filter feeding animals remains unknown. To evaluate the intake and physiological effects of different size particles and their exposure ways, the thick shell mussels Mytilus coruscus were exposed to polystyrene (PS) nanoplastics (NPs, 70 nm) and microplastics (MPs, 10 µm) respectively for two weeks by mixing NPs/MPs with microalgae or exposed to MNPs individually after feeding. Intake of particles and their physiological effects including energy budget, digestive enzymes and oxidative responses were assessed after exposure. Results indicated food presence mediate the effects while MPs decrease the energy budget and increase the catalase activity and malondialdehyde levels. Moreover, exposure way significantly affected energy budget and size of particle had a significant impact on enzyme activities. Our results showed MPs induce more significant effects than NPs on mussels, emphasized the importance of particle exposure way and suggested that mixture exposure with microalgae alleviate the influences on mussels caused by plastic particles alone. This study emphasized that we need to take the food particles into account for evaluating the toxic effects of plastic particles on filter feeding animals in the natural environment.

Short-term exposure to norfloxacin induces oxidative stress, neurotoxicity and microbiota alteration in juvenile large yellow croaker Pseudosciaena crocea.

In recent years, antibiotics have been widely detected in coastal waters of China, which raising concerns for coastal biodiversity and aquaculture. This study evaluated the effects of short-term exposure of norfloxacin (NOR) on oxidative stress and intestinal health of the large yellow croaker Pseudosciaena crocea. Juvenile fish were exposed to four concentrations of NOR (0.1, 10, 100 and 1000 µg/L) for 14 days. The results showed that NOR inhibited growth and threatened the survival of juveniles. According to the changes of intestinal microbiota, we found that NOR led to a significant decrease in intestinal microbiota diversity, with the decreased relative abundance of Proteobacteria, but the increased Tenericutes. From the perspective of microbial function, NOR inhibited metabolism, cellular defence mechanism and information transduction process. In terms of biochemical indicators, NOR caused an increase in malondialdehyde (MDA) level and inhibited superoxide dismutase (SOD) and acetyl cholinesterase (AChE) activities. Catalase (CAT) activity was activated at low concentration but significantly inhibited at high concentration of NOR. Moreover, there was a high correlation between change in biochemical indicators and change in the microbial community. Overall, environmentally relevant concentrations (0.1 µg/L) and high concentrations (10, 100 and 1000 µg/L) of NOR have negative effects on the defence function and intestinal health of large yellow croaker juveniles.

Strengthened, Antibacterial, and Conductive Flexible Film for Humidity and Strain Sensors.

With the development of artificial intelligence, people are not satisfied with the traditional conductive materials and tend to focus on stretchable and flexible electronic systems. Flexible conductive rubbers have great potential applications in wearable strain sensors. However, the rapid propagation of bacteria during the use of wearable sensors may be an ineluctable threat to humans' health. Herein, a conductive rubber film is fabricated based on carboxylic styrene-butadiene rubber (XSBR), citric acid (CA), and silver nitrate (AgNO3) via a convenient approach, where Ag nanoparticles (Ag NPs) are in situ reduced without sintering at elevated temperatures. The resultant films exhibit many desirable and impressive features, such as strengthened mechanical properties, flexibility, and conductivity. More importantly, the Ag NP flexible conductive films exhibit excellent antibacterial activity against Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria), which have potential applications as flexible antibacterial materials to monitor movements of the human body in real time. Also, because of the hygroscopicity of CA, the resistance of our conductive film is sensitive to various humidities, which can be applied in the humidity sensor.

Nanoplastics impair the intestinal health of the juvenile large yellow croaker Larimichthys crocea.

Microplastics (MPs) have become a severe concern in marine environment worldwide. Micro-polystyrene particles have been proved to accumulate in vivo and caused disorders of digestion, antioxidant system, immunity and intestinal microflora, but little is known about the effects of nano-polystyrene (nano-PS). In order to understand response mechanism of marine fish to nano-PS, the effects of nanoplastics on the intestinal health and growth performance of the juvenile Larimichthys crocea were investigated. After 14-d exposure, the reduced digestive enzyme activities indicated that nano-PS had a negative impact on the digestion and absorption of juvenile fish. Moreover, analysis of the intestinal microbiota showed that the proportion of the three-dominant bacterial phyla (Bacteroidetes, Proteobacteria and Firmicutes) in the gut changed significantly, accompanied by a significant increase of potentially pathogenic bacteria (Parabacteroides and Alistipes). In addition, lysozyme activity and specific growth rate (SGR) were significantly reduced, and total mortality of juvenile fish was significantly increased. Overall, nano-PS exposure was harmful for the health of juvenile fish, which might threaten their population in the long term.

Microplastics aggravate the adverse effects of BDE-47 on physiological and defense performance in mussels.

The highly hydrophobic surfaces make microplastics a potential carrier of organic pollutants in the marine environment. In order to explore the toxic effects of polybrominated diphenyl ethers (BDE-47) combined with microplastics on marine organisms, we exposed the marine mussel Mytilus coruscus to micro-PS combined with BDE-47 for 21 days to determine the immune defense, oxidative stress and energy metabolism of the mussels. The results showed that the clearance rate (CR) of mussels exposed to single micro-PS, single BDE-47 or both was lower than control group. In general, compared to single BDE-47 exposure, the combination of micro-PS and BDE-47 significantly increased respiration rate (RR), activities of acid phosphatase (ACP) and alkaline phosphatase (ALP), reactive oxygen species (ROS) production and malondialdehyde (MDA) concentrations, but significantly decreased lactate dehydrogenase (LDH) activity and the relative expression of heat shock protein (Hsp70 and 90). Overall, combined stress has more adverse effects on defense performance and energy metabolism in mussels and micro-PS seem to exacerbate the toxicological effects of BDE-47. As microplastics pollution may deteriorate in the future, the health of mussels may be threatened in organically polluted environment, which eventually change the stability of the structure and function of intertidal ecosystem.

Ocean acidification, hypoxia and warming impair digestive parameters of marine mussels.

Global change and anthropogenic activities have driven marine environment changes dramatically during the past century, and hypoxia, acidification and warming have received much attention recently. Yet, the interactive effects among these stressors on marine organisms are extremely complex and not accurately clarified. Here, we evaluated the combined effects of low dissolved oxygen (DO), low pH and warming on the digestive enzyme activities of the mussel Mytilus coruscus. In this experiment, mussels were exposed to eight treatments, including two degrees of pH (8.1, 7.7), DO (6, 2 mg/l) and temperature (30 °C and 20 °C) for 30 days. Amylase (AMS), lipase (LPS), trypsin (TRY), trehalase (TREH) and lysozyme (LZM) activities were measured in the digestive glands of mussels. All the tested stress conditions showed significant effects on the enzymatic activities. AMS, LPS, TRY, TREH showed throughout decreased trend in their activities due to low pH, low DO, increased temperature and different combinations of these three stressors with time but LZM showed increased and then decreased trend in their activities. Hypoxia and warming showed almost similar effects on the enzymatic activities. PCA showed a positive correlation among all measured biochemical parameters. Therefore, the fitness of mussel is likely impaired by such marine environmental changes and their population may be affected under the global change scenarios.

Diel-cycling seawater acidification and hypoxia impair the physiological and growth performance of marine mussels.

Ocean acidification and hypoxia are concurrent in some coastal waters due to anthropogenic activities in the past decades. In the natural environment, pH and dissolved oxygen (DO) may fluctuate and follow diel-cycling patterns, but such effects on marine animals have not been comprehensively studied compared to their constant effects. In order to study the effects of diel-cycling seawater acidification and hypoxia on the fitness of marine bivalves, the thick shell mussels Mytilus coruscus were exposed to two constant levels of dissolved oxygen (2 mg/L, 8 mg/L) under two pH treatments (7.3, 8.1), as well as single diel fluctuating pH or DO, and the combined diel fluctuating of pH and DO for three weeks. The experimental results showed that constant acidification and hypoxia significantly reduced the extracellular pH (pHe) and condition index (CI) of mussels, and significantly increased HCO3-, pCO2 and standard metabolic rate (SMR). Diel fluctuating hypoxia and acidification also significantly reduced the pHe and CI, and significantly increased pCO2 and SMR, but had no significant effects on HCO3-. However, the diel-cycling acidification and hypoxia resulted in a higher CI compared to continuous exposure. In general, continuous and intermittent stress negatively impact the hemolymph and growth performance of mussels. However, mussels possess a little stronger resistance to diel-cycling seawater acidification and hypoxia than sustained stress.

Microplastics impair digestive performance but show little effects on antioxidant activity in mussels under low pH conditions.

In the marine environment, microplastic contamination and acidification may occur simultaneously, this study evaluated the effects of ocean acidification and microplastics on oxidative stress responses and digestive enzymes in mussels. The thick shell mussels Mytilus coruscus were exposed to four concentrations of polystyrene microspheres (diameter 2 µm, 0, 10, 104 and 106 particles/L) under two pH levels (7.7 and 8.1) for 14 days followed by a 7-day recovery acclimation. Throughout the experiment, we found that microplastics and ocean acidification exerted little oxidative stress to the digestive gland. Only catalase (CAT) and glutathione (GSH) showed a significant increase along with increased microplastics during the experiment, but recovered to the control levels once these stressors were removed. No significant effects of pH and microplastics on glutathione peroxidase (GPx) and superoxide dismutase (SOD) were observed. The responses of digestive enzymes to both stressors were more pronounced than antioxidant enzymes. During the experiment, pepsin (PES), trypsin (TRS), alpha-amylase (AMS) and lipase (LPS) were significantly inhibited under microplastics exposure and this inhibition was aggravated by acidification conditions. Only PES and AMS tended to recover during the recovery period. Lysozyme (LZM) increased significantly under microplastic exposure conditions, but acidification did not exacerbate this effect. Therefore, combined stress of microplastics and ocean acidification slightly impacts oxidative responses but significantly inhibits digestive enzymes in mussels.