Biodegradable and Efficient Charge-Migrated Z-Scheme Heterojunction Amplifies Cancer Ferroptosis by Blocking Defensive Redox System.

Ferroptosis is an emerging non-apoptotic death process, mainly involving lipid peroxidation (LPO) caused by iron accumulation, which is potentially lethal to the intrinsically apoptotic-resistant malignant tumor. However, it is still restricted by the inherent antioxidant systems of tumor cells and the poor efficacy of traditional iron-based ferroptosis initiators. Herein, the study develops a novel ferroptosis-inducing agent based on PEGylated Cu+/Cu2+-doped black phosphorus@polypyrrole heterojunction (BP@CPP), which is constructed by utilizing the phosphate on the surface of BP to chelate Cu ions and initiating subsequent in situ polymerization of pyrrole. As a novel Z-scheme heterojunction, BP@CPP possesses an excellent photocatalytic activity in which the separated electron-hole pairs under laser irradiation endow it with powerful oxidizing and reducing capacities, which synergy with Cu+/Cu2+ self-cycling catalyzing Fenton-like reaction to further strengthen reactive oxygen species (ROS) accumulation, glutathione (GSH) depletion, and glutathione peroxidase 4 (GPX4) inactivation, ultimately leading to efficient ferroptosis. Systematic in vitro and in vivo evaluations demonstrate that BP@CPP effectively inhibit tumor growth by inducing desired ferroptosis while maintaining a favorable biosafety in the body. Therefore, the developed BP@CPP-based ferroptosis initiator provides a promising strategy for ferroptosis-like cancer therapy.

Genome wide analysis of dexamethasone stimulated mineralization in human dental pulp cells by RNA sequencing.

Human dental pulp cells (hDPCs) contain mesenchymal stem cells and are therefore indispensible for reparative dentin formation. Here, we present a pilot study of transcriptomic profiles of mineralized hDPCs isolated from sound human maxillary third molars. We observed altered gene expression of hDPCs between control (dexamethasone free) and experimental (dexamethasone 1 nm) groups. Differential expression analysis revealed up-regulation of several inflammation and mineralization-related genes in the experimental group. After a Gene Ontology analysis for predicting genes involved in biological process, cellular component and molecular function, we found enrichment of genes related to protein binding. Based on the results of Kyoto Encylopedia of Genes and Genomes pathway analysis, it is suggested up-regulated genes in mineralized hDPCs were mostly enriched in the mitogen-activated protein kinase (MAPK) signaling pathway, fluid shear stress and the atherosclerosis signaling pathway, etc. Importantly, Gene Set Enrichment Analysis revealed dexamethasone was positively related to the Janus kinase/signal transducer and activator of transcription, MAPK and Notch signaling pathway. Moreover, it was suggested that dexamethasone regulates signaling pathway in pluripotency of stem cells. Collectively, our work highlights transcriptome level gene regulation and intercellular interactions in mineralized hDPCs. The database produced in the present study paves the way for further investigations looking to explore genes that are involved in dental pulp cells mineralization.

High Heterotrophic Plasticity of Massive Coral Porites pukoensis Contributes to Its Tolerance to Bioaccumulated Microplastics.

Scleractinian corals have been observed to be capable of accumulating microplastics from reef environments; however, the tolerant mechanism is poorly known. Here, we examined the response of Porites pukoensis to microplastic pollution by analyzing algal symbiont density, energetic metabolism, and caspase3 activities (representing the apoptosis level) in the coral-Symbiodiniaceae association. The environments of three fringing reef regions along the south coast of Sanya City, Hainan Province of China, were polluted by microplastics (for example, microplastic concentrations in the seawater ranged from 3.3 to 46.6 particles L-1), resulting in microplastic accumulation in P. pukoensis (0.4-2.4 particles cm-2). The accumulation of microplastics was negatively correlated to algal symbiont density in the corals but not to caspase3 activities in the two symbiotic partners, demonstrating that P. pukoensis could tolerate accumulated microplastics despite the decrease of algal symbiont density. Furthermore, results from the carbon stable isotope and cellular energy allocation assay indicated that P. pukoensis obtained energy availability (mainly as lipid reserves) using the switch between heterotrophy and autotrophy to maintain energy balance and cope with accumulated microplastics. Collectively, P. pukoensis achieved tolerance to microplastic pollution by maintaining energy availability, which was largely attributed to its high heterotrophic plasticity.

LAMA5-inspired adhesive dodecapeptide facilitates efficient dentine regeneration: An in vitro and in vivo study.

AIM: The primary goal of this study was to investigate the potential effects of A5G81 in inducing reparative dentine (RD) formation both in vitro and in vivo. METHODOLOGY: Cell adhesion was observed by crystal violet staining and quantified by Sodium Dodecyl Sulphate (SDS) extraction. Cell proliferation was investigated using Cell Counting Kit-8 (CCK-8) assay. Spreading of cytoskeleton was visualized using immunofluorescence staining. Protein expression level of Akt signalling pathway was compared in a human Akt pathway phosphorylation array. Genes that were up or downregulated by A5G81 were identified by RNA sequencing. The mRNA expression of odontoblastic markers was detected by quantitative real-time polymerase chain reaction (qPCR). Moreover, mineralization of human dental pulp cells (hDPCs) was visualized by alizarin red staining and quantified using cetylpyridinium chloride (CPC). A direct pulp-capping model was established in SD rats and the RD formation at 2 weeks after operation was observed using HE staining. RESULTS: A5G81 (optimal coating concentration: 0.5 mg/mL) promoted hDPCs adhesion and proliferation to a level that was similar to Type I collagen (COL-1). Meanwhile, A5G81 activated Akt signalling pathway, albeit to a lesser extent than COL-1. An inhibition test indicated that A5G81 induced hDPCs adhesion by activating PI3K pathway. A5G81 induced the expression of ECM remodelling genes and odontoblastic genes, which were demonstrated by RNA-seq and qPCR, respectively. In addition, A5G81 efficiently accelerated the mineralization of hDPCs in both immobilized and soluble forms, a property that makes it more applicable in dental clinic. Finally, the pulp-capping study in rats suggested that use of A5G81 could successfully induce the formation of RD within 2 weeks. CONCLUSION: Coating of A5G81 to non-tissue culture-treated polystyrene facilitates spreading, proliferation and differentiation of hDPCs, resulting in rapid RD formation in artificially exposed pulp.

Cu-Doped Polypyrrole with Multi-Catalytic Activities for Sono-Enhanced Nanocatalytic Tumor Therapy.

Nanocatalytic medicine is a burgeoning disease treatment model with high specificity and biosafety in which the nanocatalyst is the core of driving catalytic reaction to generate therapeutic outcomes. However, the robust defense systems in the pathological region would counteract nanocatalyst-initiated therapeutics. Here, a Cu-doped polypyrrole is innovatively developed by a facile oxidative polymerization reaction, which exhibits intriguing multi-catalytic activities, including catalyzing H2 O2 to generate O2 and · OH, and consuming reduced glutathione by a Cu(II)-Cu(I) transition approach. By decorating with sonosensitizers and DSPE-PEG, the obtained CuPPy-TP plus US irradiation can induce severe oxidative damage to tumor cells by amplifying oxidative stress and simultaneously relieving antioxidant capacity in tumors based on the highly effective sonochemical and redox reactions. The notable tumor-specific biodegradability, remarkable cell apoptosis in vitro, and tumor suppression in vivo are demonstrated in this work, which not only present a promising biocompatible antitumor nanocatalyst but also broaden the perspective in oxidative stress-based antitumor therapy.

Latitude-based approach for detecting aberrations of hand, foot, and mouth disease epidemics.

BACKGROUND: Epidemics of hand, foot and mouth disease (HFMD) among children in East Asia have been a serious annual public health problem. Previous studies in China and island-type territories in East Asia showed that the onset of HFMD epidemics evolved with increased latitude. Based on the natural characteristics of the epidemics, we developed regression models for issuing aberration alerts and predictions. METHODS: HFMD sentinel surveillance data from 2008 to 2014 in Japan are used in this study, covering 365 weeks and 47 prefectures between 24 and 46° of north latitude. Average HFMD cases per sentinel are standardized as Z rates. We fit weekly Z rate differences between prefectures located in the south and north of a designated prefecture with linear regression models to detect the surging trend of the epidemic for the prefecture. We propose a rule for issuing an aberration alert determined by the strength of the upward trend of south-north Z rate differences in the previous few weeks. In addition to the warning, we predict a Z rate for the next week with a 95% confidence interval. RESULTS: We selected Tokyo and Kyoto for evaluating the proposed approach to aberration detection. Overall, the peaks of epidemics in Tokyo mostly occurred in weeks 28-31, later than in Kyoto, where the disease peaked in weeks 26-31. Positive south-north Z rate differences in both prefectures were clearly observed ahead of the HFMD epidemic cycles. Aberrations in the major epidemics of 2011 and 2013 were successfully detected weeks earlier. The prediction also provided accurate estimates of the epidemic's trends. CONCLUSIONS: We have used only the latitude, one geographical feature affecting the spatiotemporal distribution of HFMD, to develop rules for early aberration detection and prediction. We have also demonstrated that the proposed rules performed well using real data in terms of accuracy and timeliness. Although our approach may provide helpful information for controlling epidemics and minimizing the impact of diseases, the performance could be further improved by including other influential meteorological factors in the proposed latitude-based approach, which is worth further investigation.

Transcriptome analysis of human dental pulp cells cultured on a novel cell-adhesive fragment by RNA sequencing.

AIM: The aim of the present work was to find an efficient method for safe and reliable expansion of human dental pulp cells (hDPCs) in vitro. Here, we examined the effect of a novel recombinant E8 fragment of Laminin-511 (iMatrix-511) in hDPCs regarding viability and cell spreading. Further, we investigated the underlying mechanisms governing its effects in hDPCs using RNA sequencing (RNA-seq). METHODOLOGY: hDPCs were obtained from caries-free maxilla third molars (n = 3). CCK-8 assay was conducted to measure the viability of cells cultured on iMatrix-511 and two other ECM proteins. Cell morphology was observed by phase contrast microscope. RNA-seq of hDPCs cultured on iMatrix-511 or noncoated control was performed on Illumina NovaseqTM 6000 platform. RESULTS: iMatrix-511 (0.5 µg/cm2) enhanced the viability of hDPCs to an extent better than COL-1 and gelatin. Short term culture of hDPCs on iMatrix-511 resulted in 233 differentially expressed genes (DEGs). The top 12 most upregulated genes were XIAP, AL354740, MRFAP1, AC012321, KCND3, TMEM120B, AC009812, GET1-SH3BGR, CNTN3, AC090409, GEN1 and PIK3IP1, whereas the top 12 most downregulated genes were SFN, KRT17, RAB4B-EGLN2, CSTA, KCTD11, ATP6V1G2-DDX39B, AC010323, SBSN, LYPD3, FOSB, AC022400 and CHI3L1. qPCR validation confirmed the significant upregulation of GEN1, KCND3, PIK3IP1 and MRFAP1. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed, with genes enriched in various extracellular matrix interaction, estrogen and fat metabolism-related functions and pathways. CONCLUSIONS: iMatrix-511 facilitated spreading and proliferation of hDPCs. It enhances expression of anti-apoptotic genes, while inhibits expression of epidermis development-related genes.

Transparent biodegradable composite plastic packaging film from TEMPO-oxidized cellulose nanofibers.

In this research, we develop a method to create biodegradable food packaging films. Initially, TEMPO-oxidized cellulose nanofiber (TOCNF) undergoes sonication to produce well-dispersed single-strain nanofibers. These nanofibers are then blended with waterborne polyurethane (WPU) to enhance their extensibility. To further enhance compatibility between these two components, a non-ionic surfactant, Tween 80, is introduced into the TOCNF/WPU mixture to improve the dispersion of the WPU within the blend. The addition of Tween 80 significantly increases the transparency of the resulting film (Transmittance: 89.4 %, Haze: 2.2 %). Furthermore, the incorporation of the surfactant effectively reduces the formation of wrinkles and cracks during the film drying process, preventing adverse impacts on the film's barrier properties. The thin film further undergoes esterification crosslinking with citric acid to remove its hydrophilic groups for better water vapor barrier properties. The resulting bio-based packaging film exhibits remarkable transparency, strong biodegradability, and superior gas-barrier properties (water vapor and oxygen) compared to commonly used food packaging.

Selective enrichment of bacteria and antibiotic resistance genes in microplastic biofilms and their potential hazards in coral reef ecosystems.

Microplastics become hotspots for bacteria to trigger a series of ecological effects, but few studies have focused on the potential impacts of microplastic biofilms in coral reef ecosystems. Here, we measured the bacterial communities and antibiotic resistance genes (ARGs) in the seawater and microplastic biofilms. Results showed that microbial biofilms were formed on the surface of microplastics. The alpha diversity of the bacterial community in the microplastic biofilms was lower than that in the seawater, and the bacterial communities were distinct between the two. Further analysis revealed that several bacteria in the microplastic biofilms carried ARGs, and the proportion of which was correlated to the concentration of antibiotics in the seawater. Specifically, Vibrio was positively correlated to sul1 in the microplastic biofilms under higher concentrations of sulfonamides. Pathway analysis reflected significant overrepresentation of human disease related pathways in the bacterial community of microplastic biofilms. These results suggest that the microplastic biofilms could selectively enrich bacteria from the reef environments, causing the development of ARGs under antibiotic driving. This may pose a serious threat to coral reef ecosystems and human health. Our study provides new insights into the ecological impacts of microplastic biofilms in coral reef ecosystems.

Characterization of the microplastic photoaging under the action of typical salt ions of biological nitrogen removal processes.

Microplastics (MPs) are one of the most prevalent and diverse contaminants, and wastewater treatment plants are significant MP aggregators. Controlling the pollution caused by microplastics requires an understanding of how they age. The properties of the MPs photoaging process under the influence of salt ions typical of biological nitrogen elimination processes were disclosed in this work. The aging process of polyvinyl chloride microplastics (PVC-MPs) was greatly slowed down by greater HCO3- and NO2- concentrations, according to a comparison of the carbonyl index changes that occurred during photoaging. The carbonyl index had a negative correlation with the thermal stability of the photo-aged PVC-MPs, and aging accelerated the elimination of chlorine from the water. The samples were aged by UV radiation after 36 h at 40 °C, and the amount of chlorine eliminated was 10.13 times greater than that of the original MPs samples. It was discovered that the leachate concentration of aged MPs dramatically increased with decreasing particle size and was positively connected with the level of aging by comparing the concentration of leachate for two particle sizes (1 mm and 100 m). Photoaging caused MPs to become rougher, which in turn improved the NO3--N, NH4+-N, and NO2--N adsorption by PVC-MPs.

[Effect of Low-density Polyethylene Microplastics on Natural Attenuation of Oxygenated Polycyclic Aromatic Hydrocarbons in Soil].

The continuous accumulation of microplastics in agricultural soils may affect the natural attenuation of oxygen-containing polycyclic aromatic hydrocarbons (OPAHs). The effects of low-density polyethylene (LDPE) microplastics with the spiking proportion of 1 % and 0.01 % in soils on the natural attenuation of OPAHs were investigated via soil microcosm experiments. The relation between the response of bacterial communities and OPAHs dissipation was also explored. The initial content of OPAHs in the soil was 34.6 mg·kg-1. The dissipation of OPAHs in the soil on day 14 was inhibited by LDPE. The contents of OPAHs in LDPE groups were higher than that in the control by 0.9-1.6 mg·kg-1, and the inhibition degree increased with the proportion of LDPE. The contents of OPAHs were not significantly different among groups on day 28, indicating that the inhibitory effect of LDPE disappeared. LDPE did not change the composition of the dominant taxa in the OPAHs-contaminated soil community but influenced the relative abundances of some dominant taxa. LDPE increased the relative abundance of Proteobacteria and Actinobacteria at the phylum level and decreased that of Bacillus and increased those of Micromonospora, Sphingomonas, and Nitrospira (potential degrading bacteria of LDPE and endogenous substances) at the genus level, all four of which were the main genera dominating intergroup community differences. LDPE changed the α and ß diversity of bacterial communities, but the extents were not significant. LDPE affected the function of the bacterial community, reducing the total abundance of PAHs-degrading genes and some degrading enzymes, inhibiting the growth of PAHs-degrading bacteria and thus interfering with the natural decay of OPAHs.

Hyperthermia-triggered NO release based on Cu-doped polypyrrole for synergistic catalytic/gas cancer therapy.

Nitric oxide (NO) is a crucial gaseous medium for tumor growth and progression, but it may also cause mitochondrial disorder and DNA damage by drastically increasing its concentration in tumor. Due to its challenging administration and unpredictable release, NO based gas therapy is difficult to eliminate malignant tumor at low safe doses. To address these issues, herein, we develop a multifunctional nanocatalyst called Cu-doped polypyrrole (CuP) as an intelligent nanoplatform (CuP-B@P) to deliver the NO precursor BNN6 and specifically release NO in tumors. Under the aberrant metabolic environment of tumors, CuP-B@P catalyzes the conversion of antioxidant GSH into GSSG and excess H2O2 into ·OH through Cu+/Cu2+ cycle, which results in oxidative damage to tumor cells and the concomitant release of cargo BNN6. More importantly, after laser exposure, nanocatalyst CuP can absorb and convert photons into hyperthermia, which in turn, accelerates the aforesaid catalytic efficiency and pyrolyzes BNN6 into NO. Under the synergistic effect of hyperthermia, oxidative damage, and NO burst, almost complete tumor elimination is achieved in vivo with negligible toxicity to body. Such an ingenious combination of NO prodrug and nanocatalytic medicine provides a new insight into the development of NO based therapeutic strategies. STATEMENT OF SIGNIFICANCE: A hyperthermia-responsive NO delivery nanoplatform (CuP-B@P) based on Cu-doped polypyrrole was designed and fabricated, in which CuP catalyzed the conversion of H2O2 and GSH into ·OH and GSSG to induce intratumoral oxidative damage. After laser irradiation, hyperthermia ablation and responsive release of NO further coupled with oxidative damage to eliminate malignant tumors. This versatile nanoplatform provides new insights into the combined application of catalytic medicine and gas therapy.

(3-Chloro-2-hydroxypropyl) trimethylammonium chloride and polyethyleneimine co-modified pomelo peel cellulose-derived aerogel for remelt syrup decolorization in sugar refining.

The crucial need for quality refined sugar has led to the development of advanced adsorbents, with a focus on the decolorization of remelt syrup. In this study, (3-chloro-2-hydroxypropyl) trimethylammonium chloride and polyethyleneimine co-modified pomelo peel cellulose-derived aerogel (CP-PPA) was fabricated, and synthetic melanoidins were used as model colorants of remelt syrup to evaluate the validity and practicality of CP-PPA for eliminating colored impurities. Integrating abundant amine-functionalized groups (quaternary ammonium and protonated amine) within the pomelo peel-derived aerogel directionally captured electronegative melanoidins via electrostatic interactions. Furthermore, the active sites, types, and relative strength of the weak interactions between CP-PPA and melanoidins were determined using density functional theory simulations. CP-PPA exhibited an excellent equilibration adsorbing capacity for capturing melanoidins of 749.51 mg/g, and a removal efficiency of 93.69 %. Additionally, the adsorption mechanism was thoroughly examined in an effort to improve the economy of the sugar refinement industry.

Hyperbranched polyethyleneimine-functionalised chitosan aerogel for highly efficient removal of melanoidins from wastewater.

Melanoidins are hazardous dark-coloured substances contained in molasses-based distillery wastewater. Adsorption is an effective approach to eliminate melanoidins from wastewater. However, melanoidin adsorption capacities of available adsorbents are unsatisfactory, which seriously limits their practical application. A hyperbranched polyethyleneimine-functionalised chitosan aerogel (HPCA) was fabricated as an effective adsorbent for melanoidin scavenging. HPCA demonstrated superior melanoidin adsorption efficiency because of its high specific surface area, abundant amino functional groups, and high hydrophilicity. Melanoidin removal rate of HPCA was 94.95%, which remained at 91.45% after 5 cycles. Notably, using the Langmuir isothermal model, the maximum melanoidin adsorption capacity of HPCA was determined to be 868.36 mg/g, surpassing those of most of previously reported adsorbents. Toxicity experiments indicated that HPCA can be considered a safe adsorbent with excellent biocompatibility that hardly threatens aquatic organisms. The efficient melanoidin removal of HPCA was attributed to electrostatic attraction, H-bonding, and van der Waals force. However, the adsorption might be predominantly controlled by electrovalent interaction between protonated amino groups of HPCA and carboxyl/carboxylate groups of melanoidins. Two novel models, namely, external diffusion resistance-internal diffusion resistance mixed model and adsorption on active site model, were employed to describe the dynamic mass transfer characteristics of melanoidin adsorption by HPCA.

Os odontoideum associated with a retro-odontoid cyst treated with posterior C1-C3 fixation: A case report and literature review.

Background: Os odontoideum is a rare abnormality of the upper cervical spine, and os odontoideum associated with a retro-odontoid cyst has been described as a marker of local instability. Case description: This paper reports a case of a 52-year-old female patient who was diagnosed with os odontoideum associated with a retro-odontoid cyst. The patient underwent posterior C1-C3 fixation without surgical removal of the cyst. Magnetic resonance imaging (MRI) two days later revealed that the retro-odontoid cyst was still present and that there were no significant changes to it when compared with the preoperative MRI. Conclusion: Retro-odontoid cysts associated with unstable os odontoideum can lead to symptomatic spinal cord compression. Posterior C1-C3 fixation can restore atlantoaxial stability by allowing the gradual resorption of the cyst and ensuring spinal cord decompression. Fixation can also avoid the surgical risk associated with a high-riding vertebral artery.

Species-specific microplastic enrichment characteristics of scleractinian corals from reef environment: Insights from an in-situ study at the Xisha Islands.

The microplastic pollution has become a worldwide ecological concerns and imposed negative impacts on the coral reef ecosystems. In the present study, the distribution and characteristics of microplastics in the seawater, marine sediment and three scleractinian coral species (Pocillopora damicornis, Galaxea fascicularis, and Porites lutea) at five representative atolls in the Xisha Islands were investigated. The average microplastic abundances in the seawater and marine sediment were 9.5 ± 3.7 particles L-1 and 280.9 ± 231.9 particles kg-1 (dry weight), and the average contents of microplastics in P. damicornis, G. fascicularis and P. lutea were 0.9 ± 0.5 particles cm-2, 1.2 ± 0.6 particles cm-2, and 2.5 ± 1.6 particles cm-2, respectively. There were no significant correlations for the microplastic concentration between the reef environment and the corals. These results infer that the microplastic pollution is severe in the coral reef ecosystem in the Xisha Islands, and scleractinian corals could enrich microplastics from the reef environment. In addition, more than 80% of the microplastics in the seawater, marine sediment and corals were smaller than 2 mm, and the most common types of microplastics were cellophane (61.13%) and polyethylene terephthalate (33.49%). Black and fibers were the most common color and shape of the microplastics in the seawater and marine sediment, respectively. The microplastics in transparent color, film shape and small size (<2 mm) were highly accumulated in corals. Besides, cluster analysis showed that significant difference of microplastic characteristics existed between the corals and the reef environment, and the features of enriched microplastics among three coral species were also different. Moreover, P. lutea exhibited a stronger ability in enriching microplastics than G. fascicularis and P. damicornis. These results suggest that the microplastic-enriching capacities of scleractinian corals are species-specific, and species acclimated to microplastic pollution might become predominant in future coral community.

Ingested microplastics impair the metabolic relationship between the giant clam Tridacna crocea and its symbionts.

Microplastics are emerging as widespread pollutants in coral reef ecosystems worldwide; however, there is limited knowledge regarding their impact on giant clams, which are important reef builders. In the present study, the cytological, physiological, and molecular response of the giant clam Tridacna crocea to a 5 d exposure of microplastics was investigated. The concentration of microplastics in the intestine and outer mantle increased significantly and gradually after the exposure to microplastics. There were no significant changes in the density of symbiotic Symbiodiniaceae throughout the exposure period, but symbiont chlorophyll content increased significantly after 1 d of exposure. There was a significant increase in symbiont superoxide dismutase (SOD) activity, but a decrease in giant clam SOD activity and symbiont glutathione S-transferase (GST) activity. No significant changes in catalase (CAT) activity and caspase3 activation level were observed in the two symbiotic partners. Transcriptomic analysis of the giant clam revealed 138 significantly upregulated and 1390 significantly downregulated genes after 5 d of microplastic exposure. The top 20 GO terms overrepresented by these significantly downregulated genes were related to primary metabolic processes and cellular metabolic processes. No significantly upregulated genes were observed in symbionts, but 28 genes were significantly downregulated, including chloroplast oxygen-evolving enhancer, photosystem I reaction center subunit II, peptide/nitrate transporter, sodium-coupled neutral amino acid transporter, beta-glucosidase, and TPA: lipase. These results suggest that T. crocea ingests microplastics through the outer mantle and intestine, and these microplastics can suppress the photosynthesis, organic nutrient transportation, and detoxification ability of the symbionts, as well as the primary metabolism of the giant clam. This eventually could threaten their metabolic relationship and long-term survival.

Polypyrrole Nanoenzymes as Tumor Microenvironment Modulators to Reprogram Macrophage and Potentiate Immunotherapy.

Nanozyme-based tumor catalytic therapy has attracted widespread attention in recent years, but its therapeutic outcome is drastically diminished by species of nanozyme, concentration of substrate, pH value, and reaction temperature, etc. Herein, a novel Cu-doped polypyrrole nanozyme (CuP) with trienzyme-like activities, including catalase (CAT), glutathione peroxidase (GPx), and peroxidase (POD), is first proposed by a straightforward one-step procedure, which can specifically promote O2 and ·OH elevation but glutathione (GSH) reduction in tumor microenvironment (TME), causing irreversible oxidative stress damage to tumor cells and reversing the redox balance. The PEGylated CuP nanozyme (CuPP) has been demonstrated to efficiently reverse immunosuppressive TME by overcoming tumor hypoxia and re-educating macrophage from pro-tumoral M2 to anti-tumoral M1 phenotype. More importantly, CuPP exhibits hyperthermia-enhanced enzyme-mimic catalytic and immunoregulatory activities, which results in intense immune responses and almost complete tumor inhibition by further combining with αPD-L1. This work opens intriguing perspectives not only in enzyme-catalytic nanomedicine but also in macrophage-based tumor immunotherapy.

Intervention of Polydopamine Assembly and Adhesion on Nanoscale Interfaces: State-of-the-Art Designs and Biomedical Applications.

The translation of mussel-inspired wet adhesion to biomedical engineering fields have catalyzed the emergence of polydopamine (PDA)-based nanomaterials with privileged features and properties of conducting multiple interfacial interactions. Recent concerns and progress on the understanding of PDA's hierarchical structure and progressive assembly are inspiring approaches toward novel nanostructures with property and function advantages over simple nanoparticle architectures. Major breakthroughs in this field demonstrated the essential role of π-π stacking and π-cation interactions in the rational intervention of PDA self-assembly. In this review, the recently emerging concepts in the preparation and application of PDA nanomaterials, including 3D mesostructures, low-dimensional nanostructures, micelle/nanoemulsion based nanoclusters, as well as other multicomponent nanohybrids by the segregation and organization of PDA building blocks on nanoscale interfaces are outlined. The contribution of π-electron interactions on the interfacial loading/release of π electron-rich molecules (nucleic acids, drugs, photosensitizers) and the exogenous coupling of optical energy, as well as the impact of wet-adhesion interactions on the nano-bio interface interplay, are highlighted by discussing the structure-property relationships in their featured applications including fluorescent biosensing, gene therapy, drug delivery, phototherapy, combined therapy, etc. The limitations of current explorations, and future research directions are also discussed.

Interfacial Engineering of Hybrid Polydopamine/Polypyrrole Nanosheets with Narrow Band Gaps for Fluorescence Sensing of MicroRNA.

Nanoquencher-based biosensors have emerged as powerful tools for the detection of tumor markers, where challenges in efficiently docking the π-electron interaction interface toward nucleic acid probes containing π-electron-rich units of bases and fluorescent dyes still remain. Herein, we present hybrid polydopamine/polypyrrole nanosheets (PDA-PPy-NS) with π electron coupling and ultranarrow band gap (0.29 eV) by interfacial engineering of polymer hybrids at the nanoscale. PDA-PPy-NS were first prepared through oxidant-induced polymerization of pyrrole on PDA nanosheets. By utilizing fluorescent-dye-labeled single-stranded DNA as a probe, the hybrid nanoquencher showed ultrahigh fluorescence quenching ability, i.e., a Cy5-ssDNA/nanoquencher mass ratio of 36.9 under the complete quenching condition, which is comparable to that of graphene oxide. It was demonstrated that the energy level coupling of nanosheets and nucleic acid dye (Cy5) was the key factor contributing to the efficient photoinduced electron transfer (PET). Subsequently, the nanoquencher/DNA probe was proved to possess superior sensitivity and selectivity for efficient and reliable detection of miRNA-21 with a detection limit of 23.1 pM. Our work proves that the π-electron-rich biosensor interface can significantly enhance the PET efficiency, providing a theoretical basis for developing novel high-performance sensors.