Characterization of medaka (Oryzias latipes) AHRs and the comparison of two model fishes-Medaka vs. zebrafish: The subform-specific sensitivity to dioxin.

Dioxins and the emerging dioxin-like compounds (DLCs) have recruited increasing concerns about their environmental contamination, toxicity, health impacts, and mechanisms. Based on the structural similarity of dioxins and many DLCs, their toxicity was predominantly mediated by the dioxin receptor (aryl hydrocarbon receptor, AHR) in animals (including human), which can be different in expression and function among species and then possibly produce the species-specific risk or toxicity. To date, characterizing the AHR of additional species other than human and rodents can increase the accuracy of toxicity/risk evaluation and increase knowledge about AHR biology. As a key model, the medaka AHR has not been clearly characterized. Through genome survey and phylogenetic analysis, we identified four AHRs (olaAHR1a, olaAHR1b, olaAHR2a, and olaAHR2b) and two ARNTs (olaARNT1 and olaARNT2). The medaka AHR pathway was conserved in expression in nine tested tissues, of which olaAHR2a represented the predominant subform with greater abundance. Medaka AHRs and ARNTs were functional and could be efficiently transactivated by the classical dioxin congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), although olaAHR1a did not seem to cooperate with olaARNT2. In terms of function/sensitivity, the EC50 values of medaka olaAHR1a (9.01 ± 1.43 nM), olaAHR1b (4.00 ± 1.10 nM), olaAHR2a (8.75 ± 3.34 nM), and olaAHR2b (3.06 ± 0.81 nM) showed slight differences; however, they were all at the nM level. The sensitivity of four medaka AHRs to TCDD was similar to that of zebrafish dreAHR2 (the dominant form, EC50 = 3.14 ± 4.19 nM), but these medaka AHRs were more sensitive than zebrafish dreAHR1b (EC50 = 27.05 ± 18.51 nM). The additional comparison also indicated that the EC50 values in various species were usually within the nM range, but AHRs of certain subforms/species can vary by one or two orders of magnitude. In summary, the present study will enhance the understanding of AHR and help improve research on the ecotoxicity of dioxins/DLCs.

An n-Type Open-Shell Conjugated Polymer with High-Spin Ground-State and High Intrinsic Electrical Conductivity.

Open-shell conjugated polymers with a high intrinsic conductivity and high-spin ground state hold considerable promise for applications in organic electronics and spintronics. Herein, two novel acceptor-acceptor (A-A) conjugated polymers based on a highly electron-deficient quinoidal benzodifurandione unit have been developed, namely DPP-BFDO-Th and DPP-BFDO. The incorporation of the quinoidal moiety into the polymers backbones enables deeply aligned lower-lying lowest unoccupied molecular orbital (LUMO) levels of below -4.0 eV. Notably, DPP-BFDO exhibits an exceptionally low LUMO (-4.63 eV) and a high-spin ground state characterized by strong diradical characters. Moreover, a self-doping through intermolecular charge-transfer is observed for DPP-BFDO, as evidenced by X-ray photoelectron spectroscopy (XPS) studies. The high carrier concentration in combination with a planar and linear conjugated backbone yields a remarkable electrical conductivity (σ) of 1.04 S cm-1 in the "undoped" native form, ranking among the highest values reported for n-type radical-based conjugated polymers. When employed as an n-type thermoelectric material, DPP-BFDO achieves a power factor of 12.59 µW m-1 K-2. Furthermore, upon n-doping, the σ could be improved to 65.68 S cm-1. This study underscores the great potential of electron-deficient quinoidal units in constructing dopant-free n-type conductive polymers with a high-spin ground state and exceptional intrinsic conductivity.

A laboratory study of the increasing competitiveness of Karenia mikimotoi under rising CO2 scenario.

Ocean acidification (OA) driven by elevated carbon dioxide (CO2) levels is expected to disturb marine ecological processes, including the formation and control of harmful algal blooms (HABs). In this study, the effects of rising CO2 on the allelopathic effects of macroalgae Ulva pertusa to a toxic dinoflagellate Karenia mikimotoi were investigated. It was found that high level of CO2 (1000 ppmv) promoted the competitive growth of K. mikimotoi compared to the group of present ambient CO2 level (420ppmv), with the number of algal cell increased from 32.2 × 104 cells/mL to 36.75 × 104 cells/mL after 96 h mono-culture. Additionally, rising CO2 level weakened allelopathic effects of U. pertusa on K. mikimotoi, as demonstrated by the decreased inhibition rate (50.6 % under the original condition VS 34.3 % under the acidified condition after 96 h co-culture) and the decreased reactive oxygen species (ROS) level, malondialdehyde (MDA) content, antioxidant enzymes activity (superoxide dismutase (SOD), peroxidase (POD), glutathione peroxidase (GPX), glutathione reductase (GR) and catalase (CAT) and non-enzymatic antioxidants (glutathione (GSH) and ascorbic acid (ascorbate, vitamin C). Indicators for cell apoptosis of K. mikimotoi including decreased caspase-3 and -9 protease activity were observed when the co-cultured systems were under rising CO2 exposure. Furthermore, high CO2 level disturbed fatty acid synthesis in U. pertusa and significantly decreased the contents of fatty acids with allelopathy, resulting in the allelopathy weakening of U. pertusa. Collectively, rising CO2 level promoted the growth of K. mikimotoi and weakened allelopathic effects of U. pertusa on K. mikimotoi, indicating the increased difficulties in controlling K. mikimotoi using macroalgae in the future.

Turmeric-Derived Nanoparticles Functionalized Aerogel Regulates Multicellular Networks to Promote Diabetic Wound Healing.

Regulation of excessive inflammation and impaired cell proliferation is crucial for healing diabetic wounds. Although plant-to-mammalian regulation offers effective approaches for chronic wound management, the development of a potent plant-based therapeutic presents challenges. This study aims to validate the efficacy of turmeric-derived nanoparticles (TDNPs) loaded with natural bioactive compounds. TDNPs can alleviate oxidative stress, promote fibroblast proliferation and migration, and reprogram macrophage polarization. Restoration of the fibroblast-macrophage communication network by TDNPs stimulates cellular regeneration, in turn enhancing diabetic wound healing. To address diabetic wound management, TDNPs are loaded in an ultralight-weight, high swelling ratio, breathable aerogel (AG) constructed with cellulose nanofibers and sodium alginate backbones to obtain TDNPs@AG (TAG). TAG features wound shape-customized accessibility, water-adaptable tissue adhesiveness, and capacity for sustained release of TDNPs, exhibiting outstanding performance in facilitating in vivo diabetic wound healing. This study highlights the potential of TDNPs in regenerative medicine and their applicability as a promising solution for wound healing in clinical settings.

Binary Organic Solar Cells with over 19 % Efficiency and Enhanced Morphology Stability Enabled by Asymmetric Acceptors.

The simultaneous improvement of efficiency and stability of organic solar cells (OSCs) for commercialization remains a challenging task. Herein, we designed asymmetric acceptors DT-C8Cl and DT-C8BTz with functional haloalkyl chains, in which the halogen atoms could induce noncovalent interactions with heteroatoms like O, S, and Se, etc., thus leading to appropriately manipulated film morphology. Consequently, binary devices based on D18: DT-C8Cl achieved a champion power conversion efficiency (PCE) of 19.40 %. The higher PCE of D18: DT-C8Cl could be attributed to the enhanced π-π stacking, improved charge transport, and reduced recombination losses. In addition, the noncovalent interactions induced by haloalkyl chains could effectively suppress unfavorable morphology evolutions and thereby reduce trap density of states, leading to improved thermal and storage stability. Overall, our findings reveal that the rational design of asymmetric acceptors with functional haloalkyl chains is a novel and powerful strategy for simultaneously enhancing the efficiency and stability of OSCs.

Isolation and Enrichment of Extracellular Vesicles with Double-Positive Membrane Protein for Subsequent Biological Studies.

The isolation and enrichment of specific extracellular vesicle (EV) subpopulations are essential in the context of precision medicine. However, the current methods predominantly rely on a single-positive marker and are susceptible to interference from soluble proteins or impurities. This limitation represents a significant obstacle to the widespread application of EVs in biological research. Herein, a novel approach that utilizes proximity ligation assay (PLA) and DNA-RNA hybridization are proposed to facilitate the binding of two proteins on the EV membrane in advance enabling the isolation and enrichment of intact EVs with double-positive membrane proteins followed by using functionalized magnetic beads for capture and enzymatic cleavage for isolated EVs release. The isolated subpopulations of EVs can be further utilized for cellular uptake studies, high-throughput small RNA sequencing, and breast cancer diagnosis. Hence, developing and implementing a specialized system for isolating and enriching a specific subpopulation of EVs can enhance basic and clinical research in this field.

Design strategies and advanced applications of primer exchange reactions in biosensing: A review.

Early disease diagnosis relies on the sensitive detection and imaging of biomarkers. Signal amplification is one of the most commonly used methods to improve detection sensitivity. Primer exchange reaction (PER) is a novel signal amplification technique that has garnered attention because of its simple and sensitive features. The classical PER involves a single catalytic hairpin, which enables the attachment of custom sequences to the primer chain, generating a long repeat sequence that can bind numerous signaling molecules and achieve powerful signal amplification. Currently, numerous PER-based signal amplification strategies are available that can improve detection sensitivity and promote the development of the signal amplification field. This review focuses on the mechanism of typical PER, the diversification of PER, and PER-based biosensors for various targets. Finally, the challenges and prospects of PER development are discussed.

B─N Covalent Bond-Based Nonfullerene Electron Acceptors for Efficient Organic Solar Cells.

The optoelectronic properties and photovoltaic performance of nonfullerene electron acceptors (NFEAs) in organic solar cells (OSCs) are greatly influenced by the rational structure regulation of the central core unit. This study introduces a novel type of six-membered fused electron-donating core containing B─N covalent bonds to construct acceptor-donor-acceptor (A-D-A)-type NFEAs. By modulating the branching alkyl chains on the nitrogen atom, two NFEAs, BN910 and BN1014, are synthesized and characterized. Both molecules exhibit strong near-infrared absorption, narrow bandgaps (≈1.45 eV), appropriate energy levels, and tunable molecular packing behaviors, positioning them as promising candidates for efficient NFEAs in OSCs. The investigation reveals that BN1014, with longer and C2-branched alkyl chains, demonstrates superior intermolecular packing and morphology within active layers, leading to enhanced exciton dissociation, improved charge transfer, and reduced charge recombination in OSCs. As a result, a power conversion efficiency (PCE) of 10.02% is achieved for D18:BN1014-based binary OSCs. Notably, BN1014 can be utilized as the third component in the D18:DT-Y6 binary system to fabricate the ternary OSCs, and a PCE of 17.65% is achieved, outperforming 17.05% of D18:DT-Y6-based binary OSCs. These findings highlight the potential of heteroarenes featuring B─N covalent bonds for constructing high-efficiency NFEAs in OSCs.

Fluorescence-coded logarithmic-dilution digital droplet PCR for ultrawide-dynamic-range nucleic acid quantification.

Digital PCR (dPCR) is considered the next generation of nucleic acid detection for its ability of absolute quantification and high sensitivity. However, when compared to the current gold standard, quantitative PCR (qPCR), dPCR is falling behind by several orders of magnitude in dynamic range, which limits its clinical applicability. Here we present fluorescence-coded logarithmic-dilution digital droplet PCR (Flodd-PCR) that features a dynamic range across 7 orders of magnitude, over 2 orders higher than conventional dPCR (4-5 log range) and approaching that of qPCR (7-8 log range). Flodd-PCR realizes such a wide dynamic range by dividing ∼20,000 droplets into 4 groups, each featuring a unique dilution factor of the loaded DNA template and thus a shifted dynamic range. This is achieved by a microfluidic chip that performs multi-step serial dilution (20-925 folds) and droplet generation. The post-PCR droplets can be clustered in silico based on their dilution indicator fluorescence and analyzed independently. Experimentally, Flodd-PCR can detect 4-20,000,000 copies/µL (cp./µL) of the synthetic human papillomavirus (HPV) DNA and outperforms standard dPCR when analyzing clinical HPV samples. Furthermore, Flodd-PCR can be implemented with existing dPCR system set-up with minimal adjustment, and therefore will also have wide practicality in different applications which conventional dPCR has already demonstrated.

Engineered Enzyme-Loaded Erythrocyte Vesicles Precisely Deprive Tumoral Nutrients to Induce Synergistic Near-Infrared-II Photothermal Therapy and Immune Activation.

Starvation therapy has been considered a promising strategy in cancer treatment for altering the tumor microenvironment (TME) and causing a cascade of therapeutic effects. However, it is still highly challenging to establish a therapeutic strategy for precisely and potently depriving tumoral nutrition. In this study, a glucose oxidase (GOx) and thrombin-incorporated erythrocyte vesicle (EV) with cyclic (Arg-Gly-Asp) (cRGD) peptide modification, denoted as EV@RGT, were synthesized for precisely depriving tumoral nutrition and sequentially inducing second near-infrared region (NIR-II) photothermal therapy (PTT) and immune activation. The EV@RGT could specifically accumulate at the tumor site and release the enzymes at the acidic TME. The combination of GOx and thrombin exhausts tumoral glucose and blocks the nutrition supply at the same time, resulting in severe energy deficiency and reactive oxygen species (ROS) enrichment within tumor cells. Subsequently, the abundant clotted erythrocytes in tumor vessels present outstanding localized NIR-II PTT for cancer eradication owing to the hemoglobin. Furthermore, the abundant ROS generated by enhanced starvation therapy repolarizes resident macrophages into the antitumor M1 phenotype via a DNA damage-induced STING/NF-κB pathway, ultimately contributing to tumor elimination. Consequently, the engineered EV@RGT demonstrates powerful antitumor efficiency based on precise nutrition deprivation, sequential NIR-II PTT, and immune activation effect. This work provides an effective strategy for the antitumor application of enzyme-based reinforced starvation therapy.

NIR-II Responsive Nanohybrids Incorporating Thermosensitive Hydrogel as Sprayable Dressing for Multidrug-Resistant-Bacteria Infected Wound Management.

Developing an effective dressing against bacterial infection and synchronously addressing wound complications, such as bleeding, long-term inflammation, and reinfection, are highly desirable in clinical practice. In this work, a second near-infrared (NIR-II) responsive nanohybrid consisting of imipenem encapsulated liposome with gold-shell and lipopolysaccharide (LPS)-targeting aptamer, namely ILGA, is constructed for bacteria elimination. Benefiting from the delicate structure, ILGA exhibits strong affinity and a reliable photothermal/antibiotic therapeutic effect toward multidrug-resistant Pseudomonas aeruginosa (MDR-PA). Furthermore, by incorporating ILGA with a thermosensitive hydrogel poly(lactic-co-glycolic acid)-polyethylene glycol-poly(lactic-co-glycolic acid) (PLGA-PEG-PLGA), a sprayable dressing ILGA@Gel was prepared, which enables a quick on-demand gelation (10 s) for wound hemostasis and offers excellent photothermal/antibiotic efficacy to sterilize the infected wound. Additionally, ILGA@Gel provides satisfactory wound-healing environments by reeducating wound-associated macrophages for inflammation alleviation and forming a gel layer to block exogenous bacterial reinfection. This biomimetic hydrogel reveals excellent bacteria eradication and wound recovery effectiveness, demonstrating its promising potential for managing complicated infected wounds.

All-Polymer Solar Cells and Photodetectors with Improved Stability Enabled by Terpolymers Containing Antioxidant Side Chains.

It is of vital importance to improve the long-term and photostability of organic photovoltaics, including organic solar cells (OSCs) and organic photodetectors (OPDs), for their ultimate industrialization. Herein, two series of terpolymers featuring with an antioxidant butylated hydroxytoluene (BHT)-terminated side chain, PTzBI-EHp-BTBHTx and N2200-BTBHTx (x = 0.05, 0.1, 0.2), are designed and synthesized. It was found that incorporating appropriate ratio of benzothiadiazole (BT) with BHT side chains on the conjugated backbone would induce negligible effect on the molecular weight, absorption spectra and energy levels of polymers, however, which would obviously enhance the photostability of these polymers. Consequently, all-polymer solar cells (all-PSCs) and photodetectors were fabricated, and the all-PSC based on PTzBI-EHp-BTBHT0.05: N2200 realized an optimal power conversion efficiency (PCE) approaching ~ 10%, outperforming the device based on pristine PTzBI-EHp: N2200. Impressively, the all-PSCs based on BHT-featuring terpolymers displayed alleviated PCEs degradation under continuous irradiation for 300 h due to the improved morphological and photostability of active layers. The OPDs based on BHT-featuring terpolymers achieved a lower dark current at - 0.1 bias, which could be stabilized even after irradiation over 400 h. This study provides a feasible approach to develop terpolymers with antioxidant efficacy for improving the lifetime of OSCs and OPDs.

Furan Donor for NIR-II Molecular Fluorophores with Enhanced Bioimaging Performance.

The second near-infrared (NIR-II, 1,000 to 1,700 nm) molecular fluorophores containing donor-acceptor-donor conjugated backbone have attracted substantial attention due to their outstanding advantages, such as stable emission and facilely tuned photophysical properties. However, it is still challenging for them to simultaneously achieve high brightness and red-shifted absorption and emission. Herein, furan is adopted as the D unit to construct NIR-II fluorophores, demonstrating red shift of absorption, enhanced absorption coefficient, and fluorescent quantum yield when compared with the generally used thiophene counterparts. The high brightness and desirable pharmacokinetics of the optimized fluorophore, IR-FFCHP, endows improved performance for angiography and tumor-targeting imaging. Furthermore, dual-NIR-II imaging of tumor and sentinel lymph nodes (LNs) has been achieved with IR-FFCHP and PbS/CdS quantum dots, enabling the in vivo imaging navigated LN surgery in tumor-bearing mice. This work demonstrates the potential of furan for constructing bright NIR-II fluorophores for biological imaging.

Regional distribution of the plastic additive tris(butoxyethyl) phosphate in Nanyang Lake estuary, China, and toxic effects on Cyprinus carpio.

There is increasing concern regarding the toxicological effects of plastic additives on humans and aquatic organisms. This study investigated effects of the plastic additive tris(butoxyethyl) phosphate (TBEP) on Cyprinus carpio by measuring concentration distribution of TBEP in the Nanyang Lake estuary, as well as toxic effects of varying doses of TBEP exposure on carp liver. This also included measuring responses of superoxide dismutase (SOD), malondialdehyde (MDA), tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and cysteinyl aspartate-specific protease (caspase). Concentrations of TBEP in the polluted water environment (water company inlets, urban sewage pipes, etc.) in the survey area were as high as 76.17-3875.29 µg/L, and 3.12 µg/L in the river flowing through the urban area, and 1.18 µg/L in the estuary of the lake. In the subacute toxicity test, SOD activity in liver tissue with an increase in TBEP concentration was reduced significantly, while the MDA content continued to increase with an increase in TBEP concentration. Inflammatory response factors (TNF-α and IL-1ß) and apoptotic proteins (caspase-3 and caspase-9) gradually increased with increasing concentrations of TBEP. Additionally, reduced organelles, increased lipid droplets, swelling of mitochondria, and disorder of mitochondrial cristae structure were observed in liver cells of TBEP-treated carp. Generally, TBEP exposure induced severe oxidative stress in carp liver tissue, resulting in release of inflammatory factors and inflammatory response, mitochondrial structure changes, and the expression of apoptotic proteins. These findings benefit our understanding about the toxicological effects of TBEP in aquatic pollution.

Metabolites and metabolic pathways associated with allelochemical effects of linoleic acid on Karenia mikimotoi.

Linoleic acid (LA) shows great potential in inhibiting the growth of multiple red tide microalgae by disturbing algal physio-biochemical processes. However, our knowledge on the mechanisms of algal mortality at metabolic level remains limited. Herein, the response of K. mikimotoi to LA was evaluated using metabolomics, stable isotope techniques (SIT), and physiological indicators. Results showed that 100 µg/L LA promoted the growth of K. mikimotoi, which was significantly inhibited by 500 µg/L LA, along with a significant reduction of photosynthetic pigments and a significant increase of reactive oxygen species (ROS). SIT showed that LA entered algal cells, and 56 isotopologues involved in ferroptosis, carotenoid biosynthesis, and porphyrin metabolism were identified. Non-targeted metabolomics identified 90 and 111 differential metabolites (DEMs) belonging to 11 metabolic pathways under the 500 µg/L and 100 µg/L LA exposure, respectively. Among them, 34 DEMs were detected by SIT. Metabolic pathway analysis showed that 500 µg/L LA significantly promoted ferroptosis, and significantly inhibited carotenoid biosynthesis, porphyrin metabolism, sphingolipid metabolism, and lipopolysaccharide biosynthesis, presenting changes opposite to those observed in 100 µg/L LA-treated K. mikimotoi. Overall, this study revealed the metabolic response of K. mikimotoi to LA, enriching our understanding on the allelochemical mechanism of LA on K. mikimotoi.

Dietary nutrition regulates intestinal stem cell homeostasis.

Intestinal stem cells (ISCs), which locate at the base of intestinal crypts, are key determinants of governing proliferation and differentiation of the intestinal epithelium. The surrounding cells of ISCs and their related growth factors form ISC niche, supporting ISC function and self-renewal. ISC has an underappreciated but emerging role as a sensor of dietary nutrients, which fate decisions is adjusted in response to nutritional states to regulate gut homeostasis. Here, we review endogenous and exogenous factors, such as caloric restriction, fasting, fat, glucose and trace element. They instruct ISCs via mTORC1, PPAR/CPT1α, PPARγ/ß-catenin, Wnt/GSK-3ß pathway, respectively, jointly affect intestinal homeostasis. These dietary responses regulate ISC regenerative capacity and may be a potential target for cancer prevention. However, without precise definitions of nutrition intervene, it will be difficult to generate sufficient data to extending our knowledge of the biological response of ISC on nutrients. More accurately modeling organoids or high-throughput automated organoid culture in microcavity arrays have provided unprecedented opportunities for modeling diet-host interactions. These major advances collectively provide new insights into nutritional regulation of ISC proliferation and differentiation and drive us ever closer to breakthroughs for regenerative medicine and disease treatment by nutrition intervention in the clinic.

Photocatalytic degradation effect and mechanism of Karenia mikimotoi by non-noble metal modified TiO2 loading onto copper metal organic framework (SNP-TiO2@Cu-MOF) under visible light.

In this study, the SNP-TiO2@Cu-MOF composite was prepared successfully by loading non-noble metal modified TiO2 (SNP-TiO2) on the surface of copper metal organic skeleton (Cu-MOF), and compared the inactivation efficiency of different photocatalysts to Karenia mikimotoi (K. mikimotoi) under visible light. The obtained photocatalyst had the characteristic crystal faces of Cu-MOF and SNP- TiO2, and contained functional groups such as Cu-O, -COOH, N-O, P-O, etc., which indicated the structural stability of the photocatalyst. The band gap of SNP-TiO2@Cu-MOF composite was 2.82 eV, and it had great light absorption ability in visible light region. It was proved to be a mesoporous adsorption material, which had a huge specific surface area (245 m2/g). Compared with other photocatalysts, SNP-TiO2@Cu-MOF composite showed the strongest photocatalytic activity. When the concentration of composite material was set to 100 mg/L and the exposure time was 6 h, the visible light photocatalytic inactivation efficiency of K. mikimotoi was 93.75 %. By measuring various metabolic indexes of K. mikimotoi under the action of different photocatalysts for 1 h, it was confirmed that cell inactivation was due to the increased membrane permeability and degradation of photosynthetic pigments and main life proteins. This research showed that SNP-TiO2@Cu-MOF composite material was full of great potential and application prospect in controlling the outbreak of eutrophication.

Acidification of seawater attenuates the allelopathic effects of Ulva pertusa on Karenia mikimotoi.

Acidification of seawater resulting from absorption of excessive carbon dioxide from the atmosphere is posing a serious threat to marine ecosystem. In this study, we hypothesized that acidified seawater attenuates allelopathic effects of macroalgae on red tide algae because the increase of dissolved carbon dioxide benefits algal growth, and investigated the allelopathic effects of Ulva pertusa on Karenia mikimotoi in response to seawater acidification by determining cell density, photosynthetic pigment content, chlorophyll fluorescence parameters, and chloroplast structure of K. mikimotoi under U. pertusa stress in original (pH=8.2) and acidified (pH=7.8) seawater. U. pertusa inhibited the growth of K. mikimotoi in the original and acidizing seawater, and the inhibition rate was positively correlated with treatment time and concentration of U. pertusa. However, acidizing condition significantly weakened the inhibition degree of U. pertusa on K. mikimotoi (P < 0.05), with the inhibition rates decreased from 51.85 to 43.16% at 10 gFW/L U. pertusa for 96 h. U. pertusa reduced contents of chlorophyll a, chlorophyll c, and carotenoid, maximum photochemical quantum yield (Fv/Fm), actual quantum yield, maximum relative electron transfer efficiency (rETRmax) of PSII, real-time fluorescence value (F), and maximum fluorescence value (Fm') of PSII of K. mikimotoi under original and acidified conditions. And, the inhibition degree of U. pertusa under acidizing condition was significantly lower than that of original seawater group. Furthermore, the damage degree of chloroplast structure of K. mikimotoi under U. pertusa stress was more serious under original seawater condition. These results indicate that acidification of seawater attenuates the allelopathic effects of U. pertusa on K. mikimotoi.

Poly-ß-hydroxybutyrate alleviated diarrhea and colitis via Lactobacillus johnsonii biofilm-mediated maturation of sulfomucin.

Maintainance of sulfomucin is a key end point in the treatment of diarrhea and inflammatory bowel disease (IBD). However, the mechanisms underlying the microbial sense to sulfomucin are poorly understood, and to date, there are no therapies targeting the secretion and maturation of sulfomucin in IBD. Herein, we biosynthesized poly-ß-hydroxybutyrate (PHB) and found that PHB could alleviate inflammation caused by diarrhea and colitis by enhancing the differentiation of sulfomucin. Microbiota transplantation and clearance together demonstrate that PHB promoting sulfomucin is mediated by Lactobacillus johnsonii (L. johnsonii). Further studies revealed that PHB provides a favorable niche for L. johnsonii biofilm formation to resist disturbance and support its growth. L. johnsonii-biofilm alleviates colitis by regulating fucose residues to promote goblet cell differentiation and subsequent sulfomucin maturation. Importantly, PHB alleviates colitis by enhancing sulfomucin secretion and maturation in a L. johnsonii-dependent manner. PHB represents a class of guardians, acting as a safe probiotic-biofilm delivery system that significantly promotes probiotic proliferation. Altogether, this study adds weight to the possible role of probiotics and functional materials in the treatment of intestinal inflammation. The application of PHB and biofilm self-coating L. johnsonii carries high translational potential and may be of clinical relevance.