Temporal stability and assembly mechanisms of gut microbiota in sea cucumbers response to nanoplastics treatment.

Aquaculture provides essential food for humans, and the health of farmed species is particularly important for the aquaculture industry. Aquaculture environment could be a sink of plastic debris (PDs) due to the enclosed character and heavy use of plastics. Gut microbiota of aquaculture species could respond to the exogenous pollutants and regulate the health of hosts. Here, variations in gut microbiota of Apostichopus japonicus induced by the ingested nanoplastics (NPs) were investigated by a lab experiment. We selected a NPs concentration gradient of 100 mg/kg and 500 mg/kg to simulate microplastic pollution to A. japonicus, and the significant differences in gut microbiota composition after 21 days of NP exposure were evaluated. According to the high-throughput sequencing from time series samples, a decrease of diversity in gut microbiota of A. japonicus with dietary NPs was observed. In addition, the gut microbiota compositions of sea cucumbers with and without NPs exposure were also distinct, expressing as enrichment of Bacteroidota while reducement of Proteobacteria under NPs stresses. Combined the results of network analysis, the less complexity and stability of gut microbiota in sea cucumbers with dietary NPs were proved. Based on the neutral community model, the ingested NPs elevated the contribution of stochastic processes for the gut microbiota assembly in sea cucumbers. Our study showed that substantial variations in gut microbiota of A. japonicus under NPs stresses, and also explored the underlying mechanisms regulating these changes. This research would offer new meaningful insights into the toxicity of NPs on sea cucumbers, contributing a solid fundament to improve the health of sea cucumbers under NPs stresses.

Preparation of environment-friendly SiO2 aerogel based on waste boron mud and its adsorption behavior for toluene.

To mitigate the environmental hazards of boron mud waste accumulation, we prepared environmental-friendly SiO2 aerogels by extracting them through alkaline leaching treatment and optimized the experimental conditions. The optimum process parameters for alkaline leaching solution NaOH concentration, leaching temperature, solid-to-liquid ratio, and leaching time were 2 mol/L, 95 °C, 1:4, and 3 h, respectively. In this work, cheap and non-toxic hydroxy silicone oil (PDMS-OH) and hydrogen-containing silicone oil (PMHS) were used as surface modifiers instead of toxic and expensive trimethylchlorosilane (TMCS) in the SiO2 aerogel modification process. The best performance under the optimum conditions was achieved with 60% PDMS-OH-modified SiO2 aerogel. Organic liquid spills, represented by toluene, pose a great danger to the environment and water bodies. We treated free toluene on the water surface with the aerogel mentioned above and its adsorption capacity was up to 2,655 mg/g. After the adsorption of toluene, the aerogels coalesced into agglomerates for subsequent collection and handling. Furthermore, after five repeated applications, the adsorption capacity remained at 91.43% of the initial application. Overall, this research provided an inexpensive and simple solution for the treatment of organic liquids in wastewater.

Can we enhance osteoporotic metaphyseal fracture healing through enhancing ultrastructural and functional changes of osteocytes in cortical bone with low-magnitude high-frequency vibration?

Fragility fractures are related to the loss of bone integrity and deteriorated morphology of osteocytes. Our previous studies have reported that low-magnitude high-frequency vibration (LMHFV) promoted osteoporotic fracture healing. As osteocytes are known for mechanosensing and initiating bone repair, we hypothesized that LMHFV could enhance osteoporotic fracture healing through enhancing morphological changes in the osteocyte lacuna-canalicular network (LCN) and mineralization. A metaphyseal fracture model was established in female Sprague-Dawley rats to investigate changes in osteocytes and healing outcomes from early to late phase post-fracture. Our results showed that the LCN exhibited an exuberant outgrowth of canaliculi in the osteoporotic fractured bone at day 14 after LMHFV. LMHFV upregulated the E11, dentin matrix protein 1 (DMP1), and fibroblast growth factor 23 (FGF23), but downregulated sclerostin (Sost) in osteocytes. Moreover, LMHFV promoted mineralization with significant enhancements of Ca/P ratio, mineral apposition rate (MAR), mineralizing surface (MS/BS), and bone mineral density (BMD) in the osteoporotic group. Consistently, better healing was confirmed by microarchitecture and mechanical properties, whereas the enhancement in osteoporotic group was comparable or even greater than the normal group. This is the first report to reveal the enhancement effect of LMHFV on the osteocytes' morphology and functions in osteoporotic fracture healing.

Integrated Three-Dimensional Microdevice with a Modified Surface for Enhanced DNA Separation from Biological Samples.

Functional interfaces and devices for rapid adsorption and immobilization of nucleic acids (NAs) are significant for relevant bioengineering applications. Herein, a microdevice with poly(acrylic acid) (PAA) photosensitive resin was integrated by three-dimensional (3D) printing, named DPAA for short. Precise microscale structures and abundant surface carboxyl functional groups were fabricated for fast and high-throughput deoxyribonucleic acid (DNA) separation. Surface modification was then done using polydopamine (PDA) and poly(ethylene glycol) (PEG) to obtain modified poly(acrylic acid) (PAA)-based devices DPDA-PAA and DPEG-PAA rich in amino and hydroxyl groups, respectively. The fabricated device DPAA possessed superior printing accuracy (40-50 µm). Functionalization of amino and hydroxyl was successful, and the modified devices DPDA-PAA and DPEG-PAA maintained a high thermal stability like DPAA. Surface potential analysis and molecular dynamics simulation indicated that the affinity for DNA was in the order of DPDA-PAA > DPEG-PAA > DPAA. Further DNA separation experiments confirmed the high throughput and high selectivity of DNA separation performance, consistent with the predicted affinity results. DPDA-PAA showed relatively the highest DNA extraction yield, while DPEG-PAA was the worst. An acidic binding system is more favorable for DNA separation and recovery. DPDA-PAA showed significantly better DNA extraction performance than DPAA in a weakly acidic environment (pH 5.0-7.0), and the average DNA yield of the first elution was 2.16 times that of DPAA. This work validates the possibility of modification on integrated 3D microdevices to improve their DNA separation efficiency effectively. It also provides a new direction for the rational design and functionalization of bioengineering separators based on nonmagnetic methods. It may pave a new path for the highly efficient polymerase chain reaction diagnosis.

Adverse effects of polystyrene nanoplastics on sea cucumber Apostichopus japonicus and their association with gut microbiota dysbiosis.

The mariculture environment is a sink of microplastics (MPs) due to its enclosed nature and mass use of plastics. Nanoplastics (NPs) are MPs with a diameter <1 µm that have a more toxic effect on aquatic organisms than other MPs. However, little is known about the underlying mechanisms of NP toxicity on mariculture species. Here, we performed a multi-omics investigation to explore gut microbiota dysbiosis and associated health problems induced by NPs in juvenile sea cucumber Apostichopus japonicus, a commercially and ecologically important marine invertebrate. We observed significant differences in gut microbiota composition after 21 days of NP exposure. Ingestion of NPs significantly increased core gut microbes, especially Rhodobacteraceae and Flavobacteriaceae families. Additionally, gut gene expression profiles were altered by NPs, especially those related to neurological diseases and movement disorders. Correlation and network analyses indicated close relationships between transcriptome changes and gut microbiota variation. Furthermore, NPs induced oxidative stress in sea cucumber intestines, which may be associated with intraspecies variation in Rhodobacteraceae in the gut microbiota. The results suggested that NPs were harmful to the health of sea cucumbers, and they highlighted the importance of the gut microbiota in the responses to NP toxicity in marine invertebrates.

Evaluation of immunogenicity and protective efficacy of a novel Senecavirus A strain-based inactivated vaccine in mice.

Senecavirus A (SVA) is an emerging picornavirus associated with porcine idiopathic vesicular disease (PIVD), which is clinically indistinguishable from foot-and-mouth disease and other vesicular diseases in pigs. In recent years, the wide spread of SVA has caused huge economic losses to the world's pig industry. However, there are no vaccines currently available to prevent and control the infection of SVA due to the extensive diversity of SVA isolates and high cost of the pig model for vaccine evaluation. In the present study, a novel SVA CH-HNCY-2019 strain with unique amino-acid mutations in VP1, VP3 and 3C was isolated from the central part of China. A mouse model was proposed to for evaluation of the immunogenicity and protective efficacy of the inactivated CH-HNCY-2019 vaccine. The results indicated that one dose immunization of 107TCID50 inactivated CH-HNCY-2019 vaccine in mice induced a high titer of neutralizing antibody and complete protection. After challenging with the homologous virus, no viral RNA or histopathological damages were detected in the heart, liver, spleen, lung, kidney, intestine and brain tissues of the immunized mice. However, viral RNA and different degrees of histopathological damages were observed in all corresponding tissues of the unimmunized mice. In summary, the present study proved that mouse is a candidate animal model for the primary evaluation of the immunogenicity and protection efficacy of SVA vaccines for the first time. In addition, the inactivated SVA CH-HNCY-2019 vaccine was immunogenic and could protect mice against homologous viral challenges.

The (PrS/HGF-pDNA) multilayer films for gene-eluting stent coating: Gene-protecting, anticoagulation, antibacterial properties, and in vivo antirestenosis evaluation.

Vascular gene-eluting stents (GES) is a promising strategy for treatment of cardiovascular disease. Very recently, we have proved that the (protamine sulfate/plasmid DNA encoding hepatocyte growth factor) (PrS/HGF-pDNA) multilayer can serve as a powerful tool for enhancing competitiveness of endothelial cell over smooth muscle cell, which opens perspectives for the regulation of intercellular competitiveness in the field of interventional therapy. However, before the gene multilayer films could be used in vascular stents for real clinical application, the preservation of gene bioactivity during the industrial sterilization and the hemocompatibility of film should be taken into account. Actually, both are long been ignored issues in the field of gene coating for GES. In this study, we demonstrate that the (PrS/HGF-pDNA) multilayer film exhibits the good gene-protecting abilities, which is confirmed by using the industrial sterilizations (gamma irradiation and ethylene oxide) and a routine storage condition (dry state at 4°C for 30 days). Furthermore, hemocompatible measurements (such as platelet adhesion and whole blood coagulation) and antibacterial assays (bacteria adhesion and growth inhibition) indicate the good anticoagulation and antibacterial properties of the (PrS/HGF-pDNA) multilayer film. The in vivo preliminary data of angiography and histological analysis suggest that the (PrS/HGF-pDNA) multilayer coated stent can reduce the in-stent restenosis. This work reveals that the (PrS/HGF-pDNA) multilayer film could be a promising candidate as coating for GES, which is of great potential in future clinic application.

Fast and long-acting antibacterial properties of chitosan-Ag/polyvinylpyrrolidone nanocomposite films.

Infection associated with medical devices is one of the most frequent complications of modern medical biomaterials. Preparation of antibacterial films on the medical devices is a great challenge owing to bactericidal efficiency, long acting and biocompatibility. In this study, silver nanoparticles (Ag NPs) doped chitosan/polyvinylpyrrolidone (PVP) films were successfully prepared by dip coating method. The nanocomposite films with spherical Ag NPs (diameters in 10-50 nm) were stable after being immersed in PBS for 35 days. Through regulating the concentration of AgNO3, the nanocomposite films showed good cell compatibility. The nanocomposite films could eliminate 100% Staphylococcus aureus (ATCC 6538) and Escherichia coli (ATCC 8739) in 5 min and had favorable long-acting antibacterial property. The increase of PVP amount obviously enhanced anti-adhesion activity of the nanocomposite film. Such nanocomposite films can be expected to have good potential in biomaterials applications.