Polystyrene microplastics disturb maternal glucose homeostasis and induce adverse pregnancy outcomes.

Pregnant women are a special group that is sensitive to adverse external stimuli, causing metabolic abnormalities and adverse pregnancy outcomes. Microplastics (MPs), an environmental pollutant widely used in various fields, can induce a variety of toxic responses in mammals. Recent studies verified an association between MPs and metabolic disorders. Our research built a gestational mouse model in which polystyrene microplastics (PS-MPs) of 1 µm size were consumed at concentrations of 0.1, 1, and 10 mg/L during pregnancy. Results indicated that PS-MPs induced placental malfunction and fetal growth retardation. Significant glucose disorders, decreased liver function, hepatic inflammation, and oxidative stress were also observed after PS-MPs exposure. The hepatic SIRT1/IRS1/PI3K pathway was inhibited in the 10 mg/L PS-MPs exposure group. Our study found that PS-MPs activated inflammatory response and oxidative stress by increasing hepatic lipopolysaccharide (LPS) that inhibited the hepatic SIRT1/IRS1/PI3K pathway, ultimately leading to insulin resistance, glucose metabolism disorders, and adverse pregnancy outcomes. This study provides a basis for preventing environment-related gestational diabetes and concomitant adverse pregnancy outcomes.

Two effective clinical prediction models to screen for obstructive sleep apnoea based on body mass index and other parameters.

BACKGROUND AND OBJECTIVE: The diagnosis of obstructive sleep apnea (OSA) relies on polysomnography which is time-consuming and expensive. We therefore aimed to develop two simple, non-invasive models to screen adults for OSA. METHODS: The effectiveness of using body mass index (BMI) and a new visual prediction model to screen for OSA was evaluated using a development set (1769 participants) and confirmed using an independent validation set (642 participants). RESULTS: Based on the development set, the best BMI cut-off value for diagnosing OSA was 26.45 kg/m2, with an area under the curve (AUC) of 0.7213 (95% confidence interval (CI), 0.6861-0.7566), a sensitivity of 57% and a specificity of 78%. Through forward conditional logistic regression analysis using a stepwise selection model developed from observed data, seven clinical variables were evaluated as independent predictors of OSA: age, BMI, sex, Epworth Sleepiness Scale score, witnessed apnoeas, dry mouth and arrhythmias. With this new model, the AUC was 0.7991 (95% CI, 0.7668-0.8314) for diagnosing OSA (sensitivity, 75%; specificity, 71%). The results were confirmed using the validation set. A nomogram for predicting OSA was generated based on this new model using statistical software. CONCLUSIONS: BMI can be used as an indicator to screen for OSA in the community. We created an internally validated, highly distinguishable, visual and parsimonious prediction model comprising BMI and other parameters that can be used to identify patients with OSA among outpatients. Use of this prediction model may help to improve clinical decision-making.

The inhibition of enterovirus 71 induced apoptosis by Durvillaea antarctica through P53 and STAT1 signaling pathway.

The infection of enterovirus 71 (EV71) resulted in hand, foot, and mouth disease and may lead to severe nervous system damage and even fatalities. There are no effective drugs to treat the EV71 virus and it is crucial to find novel drugs against it. Polysaccharide isolated from Durvillaea antarctica green algae has an antiviral effect. In this study, D. antarctica polysaccharide (DAPP) inhibited the infection of EV71 was demonstrated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), reverse transcription polymerase chain reaction, flow cytometry, and western blot. MTT assay showed that DAPP had no toxicity on Vero cells at the concentration 250 µg/ml. Furthermore, DAPP significantly reduced the RNA level of EV71 in a dose-dependent manner. Moreover, DAPP inhibited the Vero cells apoptosis induced by EV71 via the P53 signaling pathway. Meanwhile, the expression of signal transducer and activator of transcription 1 and mammalian target of rapamycin were increased and the proinflammatory cytokines were significantly inhibited by DAPP. Taken together, these results suggested that DAPP could be a potential pharmaceutical against the infection of EV71 virus.

Inhibition of enterovirus 71 infection by polysaccharides extracted from Picochlorum sp. 122 via the AKT and ATM/ATR signaling pathways.

Enterovirus 71 (EV71) poses a major threat to public health globally due to severe and even fatal hand, foot, and mouth disease (HFMD). However, no effective antiviral agents are available to treat HFMD caused by this virus. Polysaccharides have been shown to exhibit antiviral activity, and polysaccharides extracted from Picochlorum sp. 122 (PPE) could potentially be used to treat HFMD, but reports on their antiviral activity are limited. In this study, the antiviral activity of PPE against EV71 was verified in Vero cells. PPE was shown to limit EV71 infection, as demonstrated using an MTT assay and by observing the cellular cytopathic effect. In addition, a decrease in VP1 RNA and protein levels indicated that PPE effectively inhibits proliferation of EV71 in Vero cells. An annexin V affinity assay also indicated that PPE protects host cells from apoptosis through the AKT and ATM/ATR signalling pathways. These results demonstrate that PPE has potential as an antiviral drug to treat HFMD caused by EV71.

Selective Antifungal Activity and Fungal Biofilm Inhibition of Tryptophan Center Symmetrical Short Peptide.

Candida albicans, an opportunistic fungus, causes dental caries and contributes to mucosal bacterial dysbiosis leading to a second infection. Furthermore, C.albicans forms biofilms that are resistant to medicinal treatment. To make matters worse, antifungal resistance has spread (albeit slowly) in this species. Thus, it has been imperative to develop novel, antifungal drug compounds. Herein, a peptide was engineered with the sequence of RRFSFWFSFRR-NH2; this was named P19. This novel peptide has been observed to exert disruptive effects on fungal cell membrane physiology. Our results showed that P19 displayed high binding affinity to lipopolysaccharides (LPS), lipoteichoic acids (LTA) and the plasma membrane phosphatidylinositol (PI), phosphatidylserine (PS), cardiolipin, and phosphatidylglycerol (PG), further indicating that the molecular mechanism of P19 was not associated with the receptor recognition, but rather related to competitive interaction with the plasma membrane. In addition, compared with fluconazole and amphotericin B, P19 has been shown to have a lower potential for resistance selection than established antifungal agents.

First Report of Powdery Mildew Caused by Podosphaera xanthii on Ixeris denticulata in China.

Ixeris denticulata (Houtt.) Stebb is an annual herbaceous plant in the family of Asteraceae, which is native to Europe or central Asia. This plant is widely distributed in China and is commonly used for edible and medicinal purposes. In February 2019, typical symptoms of powdery mildew were observed on 70% of I. denticulata plants on the campus of Hainan University (20° 3' 25″ N; 110° 19' 4″ E) in Haikou, Hainan Province, China. White, superficial mycelia and conidia covered the leaf surfaces of affected plants, resulting in leaf curling, discoloration and defoliation. Hyphal appressoria were nipple-shaped, and solitary. Conidiophores were straight, cylindrical, 109 to 259 × 9 to 16 µm (n = 50), and produced 3 to 5 immature conidia in chains with a crenate outline. Foot cells were cylindrical, straight or sometimes constricted at the basal septum, 30 to 62 µm long (n = 100). Conidia were ellipsoid-ovoid to doliiform, 23 to 33 × 15 to 23 µm (n = 100) with a length/width ratio of 1.1 to 1.9, with well developed fibrosin bodies, and produced germ tubes from the lateral position. Based on these morphological characteristics, this pathogen was provisionally identified as Podosphaera xanthii (Braun and Cook 2012). The teleomorph was not detected. A specimen was deposited in the Hainan University Plant Pathology Herbarium as HNID-18. In order to confirm the identification, genomic DNA was extracted from mycelium and conidia collected from a single leaf using a fungal DNA kit (Omega Bio-Tek, USA). The rDNA internal transcribed spacer (ITS) region and 28S rDNA were amplified with the primer pairs ITS1 and ITS4 (White et al. 1990) and sequenced directly. The resulting 577-bp sequence was deposited in GenBank (Accession No. MT739423). The GenBank BLAST analysis of the ITS sequence showed 100% similarity with P. xanthii on Bidens sp. from Thailand (LC270780), as well as with P. xanthii from Eclipta prostrata (MT260063) and Cyanthillium cinereum (MN203658) from China. Additionally, the 28S rDNA region was amplified using the primer pairs NL1 and NL4 (O'Donnell 1993, Accession No. MT739424). The amplicon was sequenced in both directions and shared 100% similarity with P. xanthii (MK357436, LC371333 and MH137264). To fulfill Koch's postulates, five healthy potted plants of I. denticulata were inoculated by gently pressing a powdery mildew-infected leaf onto 15 young leaves. Five non-inoculated plants served as controls. All plants were maintained in a greenhouse at 24 to 30°C, 70% relative humidity and a 16-h photoperiod. After 7 days, inoculated leaves showed signs and symptoms of powdery mildew whereas no signs or symptoms were observed on the control plants. The fungus observed on the inoculated plants was identical morphologically to that on the originally infected leaves. Powdery mildew of I. chinensis caused by Golovinomyces sonchicola has been reported previously from Korea (Choi et al. 2014). Recently, P. xanthii was also shown to infect Ixeridium dentatum in Korea (Lee and Nguyen 2018). To our knowledge, this is the first record of P. xanthii infecting I. denticulata in China. We are concerned that the pathogen will cause severe damage and affect the yield and quality of the host, and even pose a threat to I. denticulata in the future.

Transcriptome analysis reveals the genetic basis underlying the seasonal development of keratinized nuptial spines in Leptobrachium boringii.

BACKGROUND: The expression of sexually selected traits often varies with populations' breeding cycles in many animals. The elucidation of mechanisms underlying the expression of such traits is a research topic in evolutionary biology; however, the genetic basis of the seasonal development of their expression remains unknown. Male Leptobrachium boringii develop keratinized nuptial spines on their upper jaw during the breeding season that fall off when the breeding season ends. To illuminate the genetic basis for the expression of this trait and its seasonal development, we assessed the de novo transcriptome for L. boringii using brain, testis and upper jaw skin and compared gene expression profiles of these tissues between two critical periods of the spine growth cycle. RESULTS: We identified 94,900 unigenes in our transcriptome. Among them, 2,131 genes were differentially expressed between the breeding period when the spines developed and the post-breeding period when the spines were sloughed. An increased number of differentially expressed genes (DEGs) were identified in the upper jaw skin compared with the testis and brain. In the upper jaw skin, DEGs were mainly enriched in cytosolic part, peptidase inhibitor activity and peptidase regulator activity based on GO enrichment analysis and in glycolysis/gluconeogenesis, ribosome biogenesis in eukaryotes and retinol metabolism based on KEGG enrichment analysis. In the other two tissues, DEGs were primarily involved in the cell cycle, DNA replication and melatonin production. Specifically, insulin/insulin-like growth factor and sex steroid hormone-related DEGs were identified in the upper jaw skin, indicating . The expression variation of IGF2 and estrogen-related genes may be the main factors regulating the seasonal development of the spines. CONCLUSIONS: Our study provides a list of potential genes involved in the regulation of seasonal development of nuptial spines in L. boringii. This is the first transcriptome survey of seasonally developed sexually selected traits for non-model amphibian species, and candidate genes provided here may provide valuable information for further studies of L. boringii.

A Novel Copolymer-Based Functional SPECT/MR Imaging Agent for Asialoglycoprotein Receptor Targeting.

The aim of this study is to develop a copolymer-based single-photon emission computed tomography/magnetic resonance (SPECT/MR) dual-modality imaging agent that can be labeled with both technetium-99m (99mTc) and gadolinium (Gd) and target asialoglycoprotein receptor (ASGPR) via galactose. Monomers of N-p-vinylbenzyl-6-(2-(4-dimethylamino)benzaldehydehydrazono) nicotinate (VNI) for labeling of 99mTc, 5,8-bis(carboxymethyl)-3-oxo-11-(2-oxo-2-((4-vinylbenzyl)amino)ethyl)-1-(4-vinylphenzyl)-2,5,8,11-tetraazatridecan-13-oic acid (V2DTPA) for labeling of Gd, and vinylbenzyl-O-ß-d-galactopyranosyl-d-gluconamide (VLA) for targeting ASGPR were synthesized, respectively. Then the copolymer P(VLA-co-VNI-co-V2DTPA) (pVLND2) was synthesized and characterized by gel permeation chromatography, dynamic light scattering, and high-performance liquid chromatography analysis. After labeling with 99mTc and Gd simultaneously, the radiochemical purity, toxicity, relaxivity (r1), and in vivo SPECT/MR imaging in mice were evaluated. Single-photon emission computed tomography/magnetic resonance imaging and biodistribution results showed that pVLND2 could target ASGPR well. The significantly improved signal to noise ratio was observed in mice liver during MR imaging. All the results suggest that this novel kind of copolymer has the potential to be further developed as a functional SPECT/MR imaging agent.

Secular changes in eruption of primary teeth in Chinese infants and young children from three national cross-sectional surveys.

The eruption of primary teeth is a basic event during physical development of children, which is affected by heredity and environment. This study aimed to analyze the changes in primary teeth eruption among Chinese children with social development. A total of 249,264 healthy children under 2 years were extracted from the 1995, 2005, and 2015 National Survey on the Physical Growth and Development of Children in Nine Cities of China. Their primary teeth were examined and percentiles of primary teeth eruption age were calculated by probit analysis. The median primary teeth eruption age were 6.8 months, 6.7 months, 6.6 months in 1995, 2005 and 2015. Primary teeth eruption age of boys was 0.2 months, 0.3 months, 0.3 months earlier than that of girls in 1995, 2005 and 2015. Primary teeth eruption age was the earliest in children from northern region and was the latest in children from southern region, and this regional difference did not change over time. These findings suggest that primary teeth eruption age slightly advanced with social development, and their gender difference and regional difference have always existed, which supplied some data for understanding the secular trend of primary teeth development in stomatology, pediatrics, anthropology, and other related fields.

CD248 Regulates Inflammation and Encapsulation in Silicone-Related Capsule Formation.

BACKGROUND: Capsular contracture is the most common reason for having a secondary breast implant operation. The failure of the implanted device and discomfort are related to foreign body response, which involves a pathologic encapsulation. An up-regulated expression of CD248 was previously demonstrated to modulate inflammation and fibrosis. The authors hypothesized that CD248 contributes to foreign body reaction and contracture during silicone-stimulated capsule formation. METHODS: A murine capsular contracture model was established to correlate CD248 with capsular contracture. The timing and site of CD248 expression were characterized by protein analysis and histologic examination. The capsules between wild-type mice and CD248 knockout mice were compared in this model to verify the possible role of CD248 in silicone-related capsule formation. RESULTS: CD248 was expressed in the peri-silicone implant capsule by stromal fibroblast and perivascular fibroblast. CD248 was overexpressed on day 4 and down to a constant level, but it was still up-regulated through day 21 to day 56 after silicone implantation. The CD248 knockout mice showed a prolonged inflammation period, whereas the wild-type mice developed a thinner but more collagenous capsule. CONCLUSIONS: In conclusion, an effective murine capsular contracture model was established to study the relationship between CD248 and capsular contracture. CD248 may play a role in inflammation and encapsulation during silicone implantation. CD248 deletion in mice contributed to a loose and irregular collagen bundle in a capsule area, implying a decrease in contracture. Therefore, CD248 could be a potential therapeutic target in capsular contracture. CLINICAL RELEVANCE STATEMENT: CD248 may play a role in inflammation and encapsulation during silicone implantation. It could be a potential therapeutic target in clinical capsular contracture.

Electrospun high hydrophilicity antimicrobial poly (lactic acid)/silk fibroin nanofiber membrane for wound dressings.

Antimicrobial wound dressings can aid wound healing by preventing bacterial infection. This is particularly true of electrospun ones, which have a porous structure and can be easily loaded with antimicrobial drugs. Here, Poly lactic acid (PLA), Silk Fibroin (SF) and antimicrobial agents of Silver nanoparticles (Ag NPs) and Silver oxide (Ag2O) to prepare the PLA/SF composites antimicrobial nanofiber membrane by electrospinning. The PLA with 30 % SF nanofiber membrane show the water vapor permeability (WVP) and the liquid absorption of 36 g·mm/(m2·d·kPa) and 1721 %. With the increasing of SF contents, the degradation rate and surface hydrophilicity of the nanofiber membrane increase significantly. The nanofiber membrane exhibited excellent antimicrobial activity against Pseudomonas aeruginosa (P. aeruginosa) with the inhibition circle reach at 18.2 mm. The resultant nanofiber membrane showed high cytosolic activity, good cytocompatibility and strong antimicrobial ability, which laid a theoretical foundation for the construction of a new PLA/SF composites antimicrobial fiber membrane.

Fabrication and characterization of natural polyphenol and ZnO nanoparticles loaded protein-based biopolymer multifunction electrospun nanofiber films, and application in fruit preservation.

To extend the shelf life of sweet cherries (Prunus avium L.) and considering the environmental problems caused by traditional packaging materials, novel Zein/Gelatin-proanthocyanidins-zinc oxide nanoparticles (ZE/GE-PC-ZnO) and Zein/Gelatin-gallic acid-zinc oxide nanoparticles (ZE/GE-GA-ZnO) protein-based composite nanofiber films were prepared by electrospinning. According to the results, ZE/GE-PC-ZnO and ZE/GE-GA-ZnO films' contact angles were higher than those of Zein/Gelatin film by 28.91% and 21.27%, and their antioxidant activities were 5 and 9 times higher, respectively. Moreover, ZE/GE-PC-ZnO film showed good inhibitory activity against B. cinerea. On the eleventh day of the cherry packaging test, compared to unwrapped cherries, the losses of weight and firmness of wrapped fruit were reduced by more than 20% and 60%, respectively. Respiration time was delayed by 5 days, and the peak of ethylene release was decreased by nearly half. In conclusion, these two nanofiber films were viable packaging materials that fulfilled global strategies for green development.

Effects of food emulsifiers on high fat-diet-induced obesity, intestinal inflammation, changes in bile acid profile, and liver dysfunction.

Obesity has become one of the most prevalent health concerns of our time. A long-term high-fat diet is closely related to obesity. Food emulsifiers are incorporated into high-fat foods to enhance the texture and stability. Whether food emulsifiers exacerbate obesity and metabolic disorders induced by a high-fat diet remains unclear. This study aimed to investigate the effects of polysorbate-80 (P80) and polyglycerol polyricinoleate (PGPR) on lipid metabolism, bile acid profile, and gut microbiota in normal and high-fat-diet-induced obesity in mice. The results of this study showed that P80 and PGPR had little effect on body weight but significantly increased epididymal-fat weight, total energy intake, and blood lipid levels. P80 and PGPR stimulated colon inflammation and improved the expression of inflammatory factors in the colon and liver significantly. P80 and PGPR changed the bile acid profile. However, P80 and PGPR did not aggravate inflammation, obesity and alter bile acid profile by altering the composition of the gut microbiota. The results of this study provide an experimental reference for the rational use of food additives and the adjustment of dietary structure, which are important and have application value.

Antibacterial activity of oregano essential oils against Streptococcus mutans in vitro and analysis of active components.

BACKGROUND: Streptococcus mutans (S. mutans) is considered the most relevant bacteria during the transition of the non-pathogenic commensal oral microbial community to plaque biofilms that promote the development of dental caries. Oregano (Origanum vulgare L.), is a universally natural flavoring and its essential oil has been demonstrated to have good antibacterial effects. However, the specific antibacterial mechanism of oregano essential oil (OEO) against S. mutans is still not completely understood. METHODS: In this work, the composition of two different OEOs was determined by GC‒MS. Disk-diffusion method, minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined to assess their antimicrobial effect on S. mutans. The inhibition of acid production, hydrophobicity, biofilm formation and real-time PCR for gtfB/C/D, spaP, gbpB, vicR, relA and brpA mRNA expression by S. mutans were assessed to preliminarily investigate the mechanisms of action. Molecular docking was performed to simulate the interactions with the virulence proteins and active constituents. MTT test using immortalized human keratinocytes cells was also performed to investigate cytotoxicity. RESULTS: Compared with the positive drug Penicillin /streptomycin 100X (DIZ: 34.13 ± 0.85 mm, MIC: 0.78125 µL/mL, MBC: 6.25 µL/mL), the essential oils of Origanum vulgare L. (DIZ: 80 mm, MIC: 0.625µL/mL, MBC:2.5µL/mL) and Origanum heracleoticum L. (DIZ: 39.67 ± 0.81 mm, MIC: 0.625µL/mL, MBC: 1.25µL/mL) could also exhibit similar effects to inhibit the acid production and reduce the hydrophobicity and biofilm formation of S. mutans at 1/2-1MIC concentration. And gene expression of gtfB/C/D, spaP, gbpB, vicR and relA were found to be downregulated. Due to the composition of essential oils from different sources being highly variable, through effective network pharmacology analysis, we found that OEOs contained many effective compounds, like carvacrol and its biosynthetic precursors γ-terpinene and p-cymene, which may directly target several virulence proteins of S. mutans. Besides, no toxic effect was instigated by OEOs at 0.1 µL/mL in the immortalized human keratinocytes cells. CONCLUSION: The integrated analysis in the present study suggested that OEO might be a potential antibacterial agent for the prevention of dental caries.

Acute impact of salinity and C/N ratio on the formation and properties of soluble microbial products from activated sludge.

The present study investigated the shock of NaCl and C/N ratio on properties of soluble microbial products (SMPs), focusing on their sized fractions. The results indicated that the NaCl stress increased the content of biopolymers, humic substances, building blocks, and LMW substances in SMPs, while the addition of 40 g NaCl L-1 significantly changed their relative abundance in SMPs. The acute impact of both N-rich and N-deficient conditions accelerated the secretion of SMPs, but the characteristics of LMW substances differed. Meanwhile, the bio-utilization of SMPs has been enhanced with the increase of NaCl dosage but decreased with the increase of the C/N ratio. The mass balance of sized fractions in SMPs + EPS could be set up when NaCl dosage <10 g/L and C/N ratio >5, which indicates the hydrolysis of sized fractions in EPS mainly compensated for their increase/reduction in SMPs. Besides, the results of the toxic assessment indicated that the oxidative damage caused by the NaCl shock was an important factor affecting the property of SMPs, and the abnormal expression of DNA transcription cannot be neglected for bacteria metabolisms with the change of C/N ratio.

Six Spain Thymus essential oils composition analysis and their in vitro and in silico study against Streptococcus mutans.

BACKGROUND: Streptococcus mutans is a well-known oral pathogen that plays a critical role in the development of dental caries. Many studies have been directed to discover the chemical compounds present in natural products to inhibit the growth and biofilm formation activity of S. mutans. Thymus essential oils exhibit good inhibition on the growth and pathogenesis of S. mutans. However, details about the active compounds in Thymus essential oil and the inhibition mechanism still remain unclear. The aim of this study was to investigate the antimicrobial activity of 6 Thymus species (Three samples of Thymus vulgaris, two samples of Thymus zygis, and one sample of Thymus satureioides essential oils) on S. mutans, to identify the potential active components, and to reveal the underlying mechanism. METHODS: The composition of Thymus essential oils was analyzed by gas chromatography-mass spectrometry. And its antibacterial effect was evaluated based on the bacterial growth, acid production, biofilm formation and genetic expression of virulence factors by S. mutans. Potential active components of the Thymus essential oil were identified using molecular docking and correlation analysis. RESULTS: GC-MS analysis showed that the major components in the 6 Spain Thymus essential oils were linalool, α-terpineol, p-cymene, thymol and carvacrol. MIC and MBC analysis showed that 3 Thymus essential oils showed very sensitive antimicrobial activity, and were chosen for further analysis. The 3 Thymus essential oil exhibited a significant inhibitory effect on acid production, adherence and biofilm formation of S. mutans and the expression of virulence genes, such as brpA, gbpB, gtfB, gtfC, gtfD, vicR, spaP and relA. Correlation analysis showed that phenolic components, such as carvacrol and thymol, were positively related to DIZ value, which suggests that they are the potential antimicrobial components. Molecular docking between the Thymus essential oil components and virulence proteins also found that carvacrol and thymol exhibited strong binding affinity with functional domains of virulence genes. CONCLUSIONS: Thymus essential oil showed significant inhibition against the growth and pathogenesis of S. mutans depending on their composition and concentration. And phenolic compounds, such as carvacrol and thymol, are the major active components. Thymus essential oil could be used in oral healthcare products as a potential anti-caries ingredient.

Fabrication of thermoplastic polyurethane with functionalized MXene towards high mechanical strength, flame-retardant, and smoke suppression properties.

Recently, two-dimensional MXene demonstrated promising advantages to improve the flame-retardant performance of composites; however, its compatibility with polymer matrix is a great concern. In this study, MXene was first functionalized with phosphorylated chitosan (PCS) to obtain the PCS-MXene nanohybrid. The resulting nanohybrid was introduced into the thermoplastic polyurethane (TPU) matrix via solution mixing followed by the hot-pressing method, affording TPU/PCS-MXene nanocomposite. The resulting nanohybrid exhibited superior compatibility with the TPU matrix, enhancing mechanical performance of the TPU/PCS-MXene nanocomposite compared to the pristine TPU and TPU/MXene nanocomposite. Besides, the flame-retardant performance of TPU/PCS-MXene nanocomposite was greatly enhanced, while the smoke emission was effectively suppressed. As only 3 wt% PCS-MXene was introduced, peak heat release rate, total heat release, and total smoke production of the composite decreased by 66.7%, 21.0%, and 27.7%, respectively, compared to the pristine TPU. Systematical characterization was then carried out to investigate the enhancement mechanism of PCS-MXene, highlighting the crucial role of PCS combined with the catalytic effect of MXene. In brief, the compatibility issues of MXene were effectively addressed, and its flame-retardancy enhanced greatly via the PCS modification, the bio-based characteristic of which, in turn greatly benefits the further development of MXene-polymer composite.

Directing Transition of Synthetic Protocell Models via Physicochemical Cues-Triggered Interfacial Dynamic Covalent Chemistry.

As the preliminary synthetic analogs of living cells, protocells with life-like features serve as a versatile platform to explore the origin of life. Although protocells constructed from multiple components have been developed, the transition of primitive cellular compartments toward structural complexity and advanced function remains a scientific challenge. Herein, a programmable pathway is established to exploit a simple chemistry to construct structural transition of protocell models from emulsion droplets, nanocapsules to molecularly crowded droplets. The transitional process toward distinct cell-like compartments is driven by interfacial self-assembly of simple components and regulated by physicochemical cues (e.g., mechanical force, solvent evaporation, acid/base equilibrium) triggered dynamic covalent chemistry. These protocell models are further studied by comparing their compartmentalization behavior, sequestration efficiency, and the ability to enrich biomolecules (e.g., enzyme and substrate) toward catalytic reaction or biological activity within the compartments. The results showcase physiochemical cues-driven programmable transition of life-like compartments toward functionalization, and offer a new step toward the design of living soft materials.

A three-tiered colloidosomal microreactor for continuous flow catalysis.

Integrative colloidosomes with hierarchical structure and advanced function may serve as biomimetic microreactors to carry out catalytic reactions by compartmentalizing biological species within semipermeable membranes. Despite of recent progress in colloidosome design, integration of biological and inorganic components into tiered structures to tackle the remaining challenges of biocatalysis is highly demanded. Here, we report a rational design of three-tiered colloidosomes via the Pickering emulsion process. The microreactor consists of crosslinked amphiphilic silica-polymer hybrid nanoparticles as the semipermeable shell, an enzyme-incorporated catalytic sub-layer, and a partially-silicified adsorptive lumen. By leveraging confinement and enrichment effect, we demonstrate the acceleration of lipase-catalyzed ester hydrolysis within the microcompartment of organic-inorganic hybrid colloidosomes. The catalytic colloidosomes are further assembled into a closely packed column for enzymatic reactions in a continuous flow format with enhanced reaction rates. The three-tiered colloidosomes provide a reliable platform to integrate functional building blocks into a biomimetic compartmentalized microreactor with spatially controlled organization and high-performance functions.

Recombinant thrombomodulin lectin-like domain attenuates Porphyromonas gingivalis lipopolysaccharide-induced osteoclastogenesis and periodontal bone resorption.

BACKGROUND: Evidence demonstrates that the thrombomodulin (TM) lectin domain (TMD1) exerts anti-inflammatory functions. Lipopolysaccharides derived from Porphyromonas gingivalis (Pg-LPS) are considered a major pathogenic factor for chronic periodontitis, promoting inflammation, osteoclastogenesis and alveolar bone resorption. Herein, we aimed to evaluate the potential therapeutic effect of recombinant TMD1 (rTMD1) in suppression of Pg-LPS-induced osteoclastogenesis and periodontal bone loss. METHODS: In vitro, the effects of Pg-LPS, tumor necrosis factor (TNF)-α and rTMD1 on osteoclast differentiation were investigated using receptor activator of nuclear factor-κB ligand (RANKL)-stimulated RAW 264.7 macrophages. In vivo, the effects of rTMD1 treatment were evaluated in a model of experimental periodontitis induced by direct injection of Pg-LPS into the vestibular gingiva. RESULTS: Administration of Pg-LPS to RANKL-stimulated RAW 264.7 macrophages resulted in upregulation of CD86 and osteoclast marker (eg, Dc-stamp and Trap) gene expression and increase of pro-inflammatory cytokine production (e.g., TNF-α) during osteoclast differentiation, and rTMD1 can attenuate these effects. Also, rTMD1 inhibited Pg-LPS-enhanced in vitro bone resorption in a dose-dependent manner. Moreover, TNF-α promoted phosphorylation of p38 and ERK during osteoclast differentiation, and the signal activation can be inhibited by rTMD1. Finally, treatment with rTMD1 hindered Pg-LPS-induced alveolar bone loss in experimental periodontitis in mice. CONCLUSION: Our study demonstrated that rTMD1 attenuates Pg-LPS-enhanced M1 macrophage polarization, osteoclastogenesis and periodontal bone resorption and thus holds therapeutic promise for periodontitis.