Interkingdom assemblages in human saliva display group-level surface mobility and disease-promoting emergent functions.

Fungi and bacteria often engage in complex interactions, such as the formation of multicellular biofilms within the human body. Knowledge about how interkingdom biofilms initiate and coalesce into higher-level communities and which functions the different species carry out during biofilm formation remain limited. We found native-state assemblages of Candida albicans (fungi) and Streptococcus mutans (bacteria) with highly structured arrangement in saliva from diseased patients with childhood tooth decay. Further analyses revealed that bacterial clusters are attached within a network of fungal yeasts, hyphae, and exopolysaccharides, which bind to surfaces as a preassembled cell group. The interkingdom assemblages exhibit emergent functions, including enhanced surface colonization and growth rate, stronger tolerance to antimicrobials, and improved shear resistance, compared to either species alone. Notably, we discovered that the interkingdom assemblages display a unique form of migratory spatial mobility that enables fast spreading of biofilms across surfaces and causes enhanced, more extensive tooth decay. Using mutants, selective inactivation of species, and selective matrix removal, we demonstrate that the enhanced stress resistance and surface mobility arise from the exopolymeric matrix and require the presence of both species in the assemblage. The mobility is directed by fungal filamentation as hyphae extend and contact the surface, lifting the assemblage with a "forward-leaping motion." Bacterial cell clusters can "hitchhike" on this mobile unit while continuously growing, to spread across the surface three-dimensionally and merge with other assemblages, promoting community expansion. Together, our results reveal an interkingdom assemblage in human saliva that behaves like a supraorganism, with disease-causing emergent functionalities that cannot be achieved without coassembly.

Systemic Type 2 Inflammation-Associated Atopic Dermatitis Exacerbates Periodontitis.

INTRODUCTION: Atopic dermatitis (AD) is a prevalent and chronic inflammatory skin disease characterized by Th2 cell-mediated type 2 inflammation. Emerging evidence indicated that AD patients exhibit an increased incidence of oral disorders. In the present study, we sought mechanistic insights into how AD affects periodontitis. METHODS: Onset of AD was induced by 2,4-dinitrochlorobenzene (DNCB). Furthermore, we induced periodontitis (P) in AD mice. The effect of AD in promoting inflammation and bone resorption in gingiva was evaluated. Hematoxylin and eosin staining, tartrate-resistant acid phosphatase staining, immunofluorescence assay, and flow cytometry were used to investigate histomorphology and cytology analysis, respectively. RNA sequencing of oral mucosa is used tissues to further understand the dynamic transcriptome changes. 16S rRNA microbial analysis is used to profile oral microbial composition. RESULTS: Compared to control group, mice in AD group showed inflammatory signatures and infiltration of a proallergic Th2 (Th2A)-like subset in oral mucosa but not periodontitis, as identified by not substantial changes in mucosa swelling, alveolar bone loss, and TRAP+ osteoclasts infiltration. Similarly, more Th2A-like cell infiltration and interleukin-4 levels were significantly elevated in the oral mucosa of DNCB-P mice compared to P mice. More importantly, AD exacerbates periodontitis when periodontitis has occurred and the severity of periodontitis increased with aggravation of dermatitis. Transcriptional analysis revealed that aggravated periodontitis was positively correlated with more macrophage infiltration and abundant CCL3 secreted. AD also altered oral microbiota, indicating the re-organization of extracellular matrix. CONCLUSIONS: These data provide solid evidence about exacerbation of periodontitis caused by type 2 dermatitis, advancing our understanding in cellular and microbial changes during AD-periodontitis progression.

Cartilage-Inspired, High-Strength, and Heat-Tolerant Lubricating Hydrogels by Macrophase Separation.

Hydrogels are considered as a potential cartilage replacement material based on their structure being similar to natural cartilage, which are of great significance in repairing cartilage defects. However, it is difficult for the existing hydrogels to combine the high load bearing and low friction properties (37 °C) of cartilage through sample methods. Herein, we report a facile and new fabrication strategy to construct the PNIPAm/EYL hydrogel by using the macrophase separation of supersaturated N-isopropylacrylamide (NIPAm) monomer solution to promote the formation of liposomes from egg yolk lecithin (EYL) and asymmetric template method. The PNIPAm/EYL hydrogels possess a relatively high compressive strength (more than 12 MPa), fracture energy (9820 J/m2), good fatigue resistance, lubricating properties, and excellent biocompatibility. Compared with the PNIPAm hydrogel, the friction coefficient (COF 0.046) of PNIPAm/EYL hydrogel is reduced by 50%. More importantly, the COF (0.056) of PNIPAm/EYL hydrogel above lower critical solution temperature (LCST) does not increase significantly, exhibiting heat-tolerant lubricity. The finite element analysis further proves that PNIPAm/EYL hydrogel can effectively disperse the applied stress and dissipate energy under load conditions. This work not only provides new insights for the design of high-strength lubricating hydrogels but also lays a foundation for the treatment of cartilage injury as a substitute material.

Application of machine learning in the preoperative radiomic diagnosis of ameloblastoma and odontogenic keratocyst based on cone-beam CT.

OBJECTIVES: Preoperative diagnosis of oral ameloblastoma (AME) and odontogenic keratocyst (OKC) has been a challenge in dentistry. This study uses radiomics approaches and machine learning (ML) algorithms to characterize cone-beam CT (CBCT) image features for the preoperative differential diagnosis of AME and OKC and compares ML algorithms to expert radiologists to validate performance. METHODS: We retrospectively collected the data of 326 patients with AME and OKC, where all diagnoses were confirmed by histopathologic tests. A total of 348 features were selected to train six ML models for differential diagnosis by a 5-fold cross-validation. We then compared the performance of ML-based diagnoses to those of radiologists. RESULTS: Among the six ML models, XGBoost was effective in distinguishing AME and OKC in CBCT images, with its classification performance outperforming the other models. The mean precision, recall, accuracy, F1-score, and area under the curve (AUC) were 0.900, 0.807, 0.843, 0.841, and 0.872, respectively. Compared to the diagnostics by radiologists, ML-based radiomic diagnostics performed better. CONCLUSIONS: Radiomic-based ML algorithms allow CBCT images of AME and OKC to be distinguished accurately, facilitating the preoperative differential diagnosis of AME and OKC. ADVANCES IN KNOWLEDGE: ML and radiomic approaches with high-resolution CBCT images provide new insights into the differential diagnosis of AME and OKC.

The Coordination Nanocages-Integrated Polymer Brush Networks for Flexible Microporous Membranes with Exceptional H2 /CO2 Separation Performance.

The emergence of polymers with intrinsic microporosity provides solutions for flexible gas separation membranes with both high gas permeability and selectivity. However, their applications are significantly hindered by the costly synthetic efforts, limited availability of chemical systems, and narrow window of microporosity sizes. Herein, flexible mixed matrix membranes with tunable intrinsic microporosity can be facilely fabricated from the coordination assembly of polymer brushes and coordination nanocages. Polymer brushes bearing isophthalic acid side groups can coordinate with Cu2+ to assemble into polymer networks crosslinked by 2 nm nanocages. The semi-flexible feature of the polymer brush and the high crosslinking density of the network prevent the network from collapsing during solvent removal and the obtained aerogels demonstrate hierarchical structure with dual porosity from the crosslinked polymer network and coordination nanocage, respectively. The porosity can be facilely tuned via the amount of Cu2+ by regulating the network crosslinking density and nanocage loadings, and finally, optimized gas separation that surpasses Robeson upper bound for H2 /CO2 can be achieved. The coordination-driven assembly protocol paves a new avenue for the cost-effective synthesis of polymers with intrinsic microporosity and the fabrication of flexible gas separation membranes.

Spatial mapping of polymicrobial communities reveals a precise biogeography associated with human dental caries.

Tooth decay (dental caries) is a widespread human disease caused by microbial biofilms. Streptococcus mutans, a biofilm-former, has been consistently associated with severe childhood caries; however, how this bacterium is spatially organized with other microorganisms in the oral cavity to promote disease remains unknown. Using intact biofilms formed on teeth of toddlers affected by caries, we discovered a unique 3D rotund-shaped architecture composed of multiple species precisely arranged in a corona-like structure with an inner core of S. mutans encompassed by outer layers of other bacteria. This architecture creates localized regions of acidic pH and acute enamel demineralization (caries) in a mixed-species biofilm model on human teeth, suggesting this highly ordered community as the causative agent. Notably, the construction of this architecture was found to be an active process initiated by production of an extracellular scaffold by S. mutans that assembles the corona cell arrangement, encapsulating the pathogen core. In addition, this spatial patterning creates a protective barrier against antimicrobials while increasing bacterial acid fitness associated with the disease-causing state. Our data reveal a precise biogeography in a polymicrobial community associated with human caries that can modulate the pathogen positioning and virulence potential in situ, indicating that micron-scale spatial structure of the microbiome may mediate the function and outcome of host-pathogen interactions.

Comparisons of Different Bearing Surfaces in Cementless Total Hip Arthroplasty: A Systematic Review and Bayesian Network Analysis.

BACKGROUND: We aimed to make comparisons of different bearing surfaces in patients after cementless total hip arthroplasty. METHODS: The network meta-analysis was guided by the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guideline. The primary outcomes were implant survival and Harris hip score (HHS). Secondary outcomes included linear wear rates and serum level of metal ions. Subgroup analyses were performed by: (1) classifying head sizes as small and large; (2) femoral heads as ceramic and metal; and (3) liners as metal, ceramic, polyethylene, highly cross-linked polyethylene (HXP), or vitamin E-infused highly cross-linked polyethylene (HXPE). A total of 64 eligible RCTs with different bearings were assessed. Overall inconsistency and heterogeneity were acceptable. RESULTS: In the 10 years follow-up, metal-on-polythene and ceramic-on-polythene bearings with small heads showed higher risk for revisions compared with metal-on-HXP and ceramic-on-HXP bearings with small heads. Similarly, only metal or ceramic-on-polythene bearings with small heads showed inferiority in HHS compared with other bearings. Conventional polyethylene liners showed higher linear wear rates compared with HXP, HXPE, and ceramic liners at 5 and 10 years after surgery, while metal-on-metal and ceramic-on-metal bearings showed higher serum level of cobalt and chromium. CONCLUSION: Bearings containing HXP, HXPE, and ceramic liners showed comparable survivorship and hip function at follow-up of 5 and 10 years. Hard-on-hard bearings containing metal had higher serum level of metal ions than others. Bearings containing conventional polyethylene had worse performance in terms of implant survival, hip function, and wear rates. LEVEL OF EVIDENCE: Level I.

Investigation of interfacial adsorption between microplastics and methylparaben in aqueous solution.

Microplastics and parabens are considered to be a global contaminants, especially in the aquatic ecosystem. The interfacial interaction between four types of microplastics including polystyrene, polyethylene, polyethylene terephthalate, and polyvinyl chloride, and methylparaben were investigated in this study. The results showed that molecular layer dominates the adsorption, with the rate significantly affected by both internal diffusion and external diffusion. Among the four types, polystyrene and polyvinyl chloride showed the smallest and biggest adsorption capability, with the values were 0.656 and 1.269 mg g-1, respectively. For the adsorption capability, smaller particle size and higher pH value possessed positive effects. However, the existence of metal ions could inhibit the adsorption process, except for a weak promotion at low salinity. Physical adsorption effects, such as electrostatic interaction, hydrogen bond formation, and covalent bond formation, had been identified that dominated the adsorption. This finding could be served as a speculative foundation for the further study of the toxicity, migration, and ecological risk assessment of microplastics in aquatic ecosystem.

Nano-Bio Interactions in Cancer: From Therapeutics Delivery to Early Detection.

Understanding the interactions between nanomaterials and biological systems plays a pivotal role in enhancing the efficacy of nanomedicine and advancing the disease diagnosis. The nanoparticle-protein corona, an active biomolecular layer, is formed around nanoparticles (NPs) upon mixing with biological fluid. The surface layer which consists of rapidly exchanged biomolecules is called the "soft" corona. The inner layer which is more stable and tightly packed is called the "hard" corona. It has been suggested that the NP-protein corona has a decisive effect on the in vivo fate of nanomedicine upon intravenously administration into the mouse. Furthermore, the features of the NP-protein corona make it a powerful platform to enrich low-abundance proteins from serum/plasma for downstream mass-spectrometry (MS)-based proteomics for biomarker discovery and disease diagnosis.Herein, we summarize our recent work on the development of nanomedicine and disease detection from the level of nano-bio interactions between nanoparticles and biological systems. Nanomedicine has made substantial progress over the past two decades. However, the significant enhancement of overall patient survival by nanomedicine remains a challenge due to the lack of a deep understanding of nano-bio interactions in the clinical setting. The pharmacokinetic effect of the protein corona on PEGylated NPs during blood circulation indicated that the adsorbed apolipoproteins could prolong the circulation time of NPs. This mechanistic understanding of the protein corona (active biomolecule) formed around polymeric NPs offered insights into enhancing the efficacy of nanomedicine from the biological interactions point of view. Moreover, we discuss the basic rationale for developing bioresponsive cancer nanomedicine by exploiting the pathophysiological environment around the tumor, typically the pH, reactive oxygen species (ROS), and redox-responsive supramolecular motifs based on synthetic amphiphilic polymers. The protein corona in vivo determines the biological fate of NPs, whereas it opens a new avenue to enrich low abundant proteins in a biospecimen ex vivo to render them "visible" for downstream analytical workflows, such as MS-based proteomics. Blood serum/plasma, due to easy accessibility and great potential to uncover and monitor physiological and pathological changes in health and disease, has remained a major source of detecting protein biomarker candidates. Inspired by the features of the NP-protein corona, a Proteograph platform, which integrates multi-NP-protein coronas with MS for large-scale efficient and deep proteome profiling has been developed. Finally, we conclude this Account with a better understanding of nano-bio interactions to accelerate the nanomedicine translation and how MS-based proteomics can boost our understanding of the corona composition and facilitate the identification of disease biomarkers.

Aquapteridospora jiangxiensis, a new aquatic hyphomycetous fungus from a freshwater habitat in China.

During an investigation of freshwater fungi in Jiangxi province, China, a new hyphomycetous fungus, Aquapteridospora jiangxiensis, was collected and isolated. Aquapteridospora jiangxiensis is characterized by its unbranched and guttulate conidiophores with multi-septa swollen at the base, polyblastic conidiogenous cells with sympodial proliferations, and denticles, and guttulate conidia with a sheath. A photo plate of the macro- and micro-morphology and a muti-loci (ITS, LSU, SSU, TEF1 and RPB2) phylogenetic tree are provided. A key to the species of Aquapteridospora is also presented in this paper.

Photoaging of Baby Bottle-Derived Polyethersulfone and Polyphenylsulfone Microplastics and the Resulting Bisphenol S Release.

This study evaluated the release of bisphenol S (BPS) from polyethersulfone (PES) and polyphenylsulfone microplastics (MPs) derived from baby bottles under UV irradiation. Released BPS fluctuates over time because it undergoes photolysis under UV254 irradiation. Under UV365 irradiation, the highest released concentration at 50 °C was 1.7 and 3.2 times that at 35 and 25 °C, respectively, as the activation energy of the photochemical reactions responsible for MP decay was reduced at high temperatures. Low concentrations of humic acid (HA, ≤10 mg·L-1) promote BPS release because HA acts as a photosensitizer. A high concentration of HA (10∼50 mg·L-1) decreases the BPS release because HA shields MPs from light and scavenges reactive radicals that are produced via photochemical reactions. For example, under UV irradiation, hydroxyl radicals (•OH) attack results in the breakage of ether bonds and the formation of phenyl radicals (Ph•) and phenoxy radicals (Ph-O•).The•OH addition and hydrogen extractions further produce BPS from the decayed MPs. A leaching kinetics model was developed and calibrated by the experimental data. The calibrated model predicts the equilibrium level of BPS release from MPs that varies with the surface coverage density of BPS and leaching rate constants. This study provides groundwork that deepens our understanding of environmental aging and the chemical release of MPs.

Source Apportionment, Hydrodynamic Influence, and Environmental Stress of Pharmaceuticals in a Microtidal Estuary with Multiple Outlets in South China.

Pharmaceutical residues in the environment are of great concern as ubiquitous emerging contaminants. This study investigated the presence of 40 pharmaceuticals in water and sediment of the Pearl River Estuary (PRE) in the wet season of 2020. Among psychiatric drugs, only diazepam was found in water samples while six of them were detected in the sediment. The Σantibiotics levels ranged from 6.18 to 35.9 ng/L and 2.63 to 140 ng/g dry weight in water and sediment samples, respectively. Fluoroquinolones and tetracyclines were found well settling in the outlet sediment, while sulfonamides could be released from disturbed sediment under stronger tidal wash-out conditions. After entering the marine waters, pharmaceuticals tended to deposit at the PRE mouth by the influence of the plume bulge and onshore invasion of deep shelf waters. Low ecological risks to the aquatic organisms and of causing antimicrobial resistance were identified. Likewise, hydrological modeling results revealed insignificant risks: erythromycin-H2O and sulfamethoxazole discharged through the outlets constituted 30.8% and 6.74% of their environmental capacity, respectively. Source apportionment revealed that pharmaceutical discharges through the Humen and Yamen outlets were predominantly of animal origin. Overall, our findings provide strategic insights on environmental regulations to further minimize the environmental stress of pharmaceuticals in the PRE.

A Rare Case of Craniocervical Penetrating Injury by a Steel Bar.

RATIONALE: Non-missile penetrating injuries caused by foreign bodies, such as knives or sharp wood, are infrequent. We report a 49-year-old male suffering from severe craniocervical penetrating injury by a steel bar was successfully treated by surgery. CHIEF COMPLAINT: The male patient was a 49-year-old builder. Although working on the construction site, an approximately 60 cm steel bar penetrated the patient's brain vertically through the left top of the head presenting with unconsciousness and intermittent irritability. DIAGNOSIS: Computed tomography of the head showed the entrance and exit of the skull damaged by the steel bar. Three-dimensional reconstruction showed that the steel bar entered the skull from the posterior left coronal suture and penetrated the ipsilateral occipital bone, about 5 cm into the neck soft tissue. INTERVENTION: We successfully performed the operation and removed the steel bar. OUTCOMES: The patient was followed up for 5 years; muscle strength returned to normal. LESSONS: Penetrating injuries caused by steel bars are rare, which always cause severe intracranial injury combined with peripheral tissue injury, by sharing our experience in the treatment of this rare case, we hope to provide a reference for similar injuries in the future.

Ferumoxytol Nanoparticles Target Biofilms Causing Tooth Decay in the Human Mouth.

Severe tooth decay has been associated with iron deficiency anemia that disproportionally burdens susceptible populations. Current modalities are insufficient in severe cases where pathogenic dental biofilms rapidly accumulate, requiring new antibiofilm approaches. Here, we show that ferumoxytol, a Food and Drug Administration-approved nanoparticle formulation for treating iron deficiency, exerts an alternative therapeutic activity via the catalytic activation of hydrogen peroxide, which targets bacterial pathogens in biofilms and suppresses tooth enamel decay in an intraoral human disease model. Data reveal the potent antimicrobial specificity of ferumoxytol iron oxide nanoparticles (FerIONP) against biofilms harboring Streptococcus mutans via preferential binding that promotes bacterial killing through in situ free-radical generation. Further analysis indicates that the targeting mechanism involves interactions of FerIONP with pathogen-specific glucan-binding proteins, which have a minimal effect on commensal streptococci. In addition, we demonstrate that FerIONP can detect pathogenic biofilms on natural teeth via a facile colorimetric reaction. Our findings provide clinical evidence and the theranostic potential of catalytic nanoparticles as a targeted anti-infective nanomedicine.

Synergistic Effect of Co-Delivering Ciprofloxacin and Tetracycline Hydrochloride for Promoted Wound Healing by Utilizing Coaxial PCL/Gelatin Nanofiber Membrane.

Combining multiple drugs or biologically active substances for wound healing could not only resist the formation of multidrug resistant pathogens, but also achieve better therapeutic effects. Herein, the hydrophobic fluoroquinolone antibiotic ciprofloxacin (CIP) and the hydrophilic broad-spectrum antibiotic tetracycline hydrochloride (TH) were introduced into the coaxial polycaprolactone/gelatin (PCL/GEL) nanofiber mat with CIP loaded into the PCL (core layer) and TH loaded into the GEL (shell layer), developing antibacterial wound dressing with the co-delivering of the two antibiotics (PCL-CIP/GEL-TH). The nanostructure, physical properties, drug release, antibacterial property, and in vitro cytotoxicity were investigated accordingly. The results revealed that the CIP shows a long-lasting release of five days, reaching the releasing rate of 80.71%, while the cumulative drug release of TH reached 83.51% with a rapid release behavior of 12 h. The in vitro antibacterial activity demonstrated that the coaxial nanofiber mesh possesses strong antibacterial activity against E. coli and S. aureus. In addition, the coaxial mats showed superior biocompatibility toward human skin fibroblast cells (hSFCs). This study indicates that the developed PCL-CIP/GEL-TH nanofiber membranes hold enormous potential as wound dressing materials.

Dual-Functional Nanofibrous Patches for Accelerating Wound Healing.

Bacterial infections and inflammation are two main factors for delayed wound healing. Coaxial electrospinning nanofibrous patches, by co-loading and sequential co-delivering of anti-bacterial and anti-inflammation agents, are promising wound dressing for accelerating wound healing. Herein, curcumin (Cur) was loaded into the polycaprolactone (PCL) core, and broad-spectrum antibacterial tetracycline hydrochloride (TH) was loaded into gelatin (GEL) shell to prepare PCL-Cur/GEL-TH core-shell nanofiber membranes. The fibers showed a clear co-axial structure and good water absorption capacity, hydrophilicity and mechanical properties. In vitro drug release results showed sequential release of Cur and TH, in which the coaxial mat showed good antioxidant activity by DPPH test and excellent antibacterial activity was demonstrated by a disk diffusion method. The coaxial mats showed superior biocompatibility toward human immortalized keratinocytes. This study indicates a coaxial nanofiber membrane combining anti-bacterial and anti-inflammation agents has great potential as a wound dressing for promoting wound repair.

Predicting membrane fouling in a high solid AnMBR treating OFMSW leachate through a genetic algorithm and the optimization of a BP neural network model.

Anaerobic membrane bioreactors are a promising technology in the treatment of high-strength wastewater; however, unpredictable membrane fouling largely limits their scale-up application. This study, therefore, adopted a backpropagation neural network model to predict the membrane filtration performance in a submerged system, which treats leachate from the organic fraction of municipal solid waste. Duration time, water yield flow, influent COD, pH, bulk sludge concentration, and the ratio of ΔTMP to filtration time were selected as input variables to simulate membrane permeability. The membrane pressure slightly increased by 1.1 kPa within 62 days of operation. The results showed that the AnMBR membrane filtration performance was acceptable when treating OFMSW leachate under a flux of 6 L/(m2·h). The model results indicated that the sludge concentration largely determined the membrane fouling with a contribution of 33.8%. Given the local minimization problem in the BP neural network process, a genetic algorithm was introduced to optimize the simulation process, and the relative error of the results was reduced from 5.57% to 3.57%. Conclusively, the artificial neural network could be a useful tool for the prediction of an AnMBR that is so far under development.

Comparative analysis of the surface properties and corrosion resistance of Co-Cr dental alloys fabricated by different methods.

STATEMENT OF PROBLEMS: The complex oral environment leads to the corrosion of dental alloy materials and the release of metal ions that may have a negative impact on health. Digital manufacturing is increasingly being used in dentistry, but whether digitally manufactured prostheses have better resistance to corrosion than traditional cast prostheses is unclear. PURPOSE: The purpose of this in vitro study was to determine the surface properties and corrosion resistance of dental cobalt-chromium (Co-Cr) alloys fabricated by lost-wax casting (CAST), selective laser melting (SLM), and computer numerical control milling (CNC). MATERIAL AND METHODS: The surface characteristics of the specimens were analyzed via scanning electron microscopy and energy-dispersive spectroscopy (SEM-EDS), metallurgical observation, and X-ray diffraction (XRD). For corrosion resistance, the specimens were immersed in artificial saliva at a pH 2.3 and 6.8 for 1, 4, and 7 weeks. Then, inductively coupled plasma-mass spectrometry (ICP-MS) was used to detect the main metal ion. Electrochemical impedance spectroscopy (EIS) was conducted based on a 3-electrode system to assess the electrochemical corrosion resistance. An ANOVA test was used to evaluate statistically significant differences among the groups (α=.05). RESULTS: The SLM and CNC specimens showed more homogenous microstructures, less ion release at different times and pH, and more charge transfer resistance than CAST specimens. CONCLUSIONS: Compared with casting, SLM-printing and CNC-milling have advantages in terms of surface properties and corrosion resistance.

Effects of garbage salvaging and suspended crossbar on microplastic pollution along a typical urban river.

Microplastic pollution has been considered as a global environmental issue that potentially threatens human health. However, research about microplastic pollution in urban rivers is still insufficient. This study analyzed the abundance and distribution of microplastics in surface water of the Nanfei River in Hefei, China. Microplastic concentrations ranged from 0.8 to 27 items/L along the studied river. The small size (50-333 µm) (47.58-84.89%) and white (55.65-88.89%) were predominant among all samples, except that collected from the source reach. Pellet was a typical and abundant microplastic type and accounted for 60.30%. PE and PP were the major polymers, occupying 55.24% and 22.86%, respectively. The results showed that traditional environmental management practices including salvaging surface garbage regularly and setting wooden suspended crossbars at tributary confluences could significantly mitigate the pollution degree of microplastics. The polymer risk index was calculated to describe the potential risk of microplastics, and the pollution level was still at high risk under various management practices. This study provides a valuable finding for future research on microplastics in urban city rivers, which may improve the knowledge that how to control and prevent microplastic pollution.

Pressure-Controlled Encapsulation of Graphene Quantum Dots into Liposomes by the Reverse-Phase Evaporation Method.

Ultrasmall nanoparticles (USNPs) with sizes below 10 nm have shown great potentials in medical applications owing to their outstanding physical, chemical, optical, and biological properties. However, they suffer from a rapid renal clearance and biodegradation rate in the biological environment due to the small size. Liposomes are one of the most promising delivery nanocarriers for loading USNPs because of their excellent biocompatibility and lipid bilayer structure. Encapsulation of USNPs into liposomes in an efficient and controllable manner remains a challenge. In this study, we achieved a high loading of graphene quantum dots (GQDs, ∼4 nm), a typical USNP, into the aqueous core of liposomes (45.68 ± 1.44%), which was controllable by the pressure. The GQDs-loaded liposomes (GQDs-LPs) exhibited a very good aqueous stability for over a month. Furthermore, indocyanine green (ICG), an efficient near-infrared (NIR) photothermal agent, was introduced in the GQDs-LP system that could convert NIR laser energy into thermal energy and break down the liposomes, causing the release of GQDs in 6 min. Moreover, this NIR light-controlled release system (GQDs-ICG-LPs) also exhibited a good photothermal therapeutic performance in vitro, and 75% of cancer cells were killed at a concentration of 200 µg/mL. Overall, the successful development of the NIR light-controlled release system has laid a solid foundation for the future biomedical application of USNPs-loaded liposomes.