Particle Hydrodynamics Research Articles

Copper-doped TiO2 nanocomposites: A dual functional nanoprobe for enhanced photodynamic therapy of breast tumor and antibacterial applications

Breast cancer is one of the most challenging malignancies in the present era, which continues to attract researchers to discover new therapeutic routes to combat tumors. Photodynamic therapy (PDT) has been promised to deal with malignancies as well as bacterial infections during surgery or afterward. In this study, copper doped titanium dioxide nanocomposites (Cu-TiO2 NCs) are synthesized and modified by an FDA-approved triblock polymer (Pluronic® F-127) to enhance the biocompatibility and stability of NCs. PF-127 coating increased the hydrodynamic particle sizes to 190 nm for 1Cu-TiO2@PF-127 and 220 nm for 10Cu-TiO2@PF-127, while Cu doping raised the zeta potential to 6.64 mV, which shifted to −6.64 mV and −0.08 mV after PF-127 functionalization, indicating effective surface modification. This nano-assembly generated significant amount of reactive oxygen species and demonstrated 90 % cancer cell death after low-intensity UV irradiation (5.6 mW·cm−2), while maintaining more than 70 % survival of normal L929 cells, indicating low toxicity to healthy cells. Moreover, antibacterial analysis against Escherichia coli and Staphylococcus aureus bacterial strains proved excellent antibacterial features of Cu-TiO2 NCs. Based on such outcomes, it can be expected that Cu-TiO2 NCs have potential for future nanomedicines.

Dispersion and particle pressure in sedimenting suspensions with hydrodynamic interactions and particle inertia

Particle inertia is a feature of suspension dynamics that is often neglected. However, its neglect changes the order of the governing equations of particle motion. In this work, we examine the impact of the inertia of particles over their velocity fluctuations and the resulting stresses. In order to observe effects of particle inertia, we consider dusty-gas suspensions of spherical weakly Brownian microparticles sedimenting in a Newtonian fluid at low Reynolds numbers. We first investigate the motion of a single spherical particle. The simulations for this simple case allow us to define the appropriate physical parameters of the flow and to validate the numerical calculation of velocity statistics over a range of Péclet and Stokes numbers. Next, we perform Langevin dynamics simulations with periodic boundary conditions to integrate the equations governing the translational and rotational motions of N hydrodynamically interacting particles suspended in the viscous fluid. The first aim of this paper is to examine the behavior of the velocity variance of inertial particles, with small fluctuations produced by Brownian motion at the moderate Péclet numbers. The interplay between mild Brownian forces and hydrodynamic interactions decreases the anisotropy of velocity fluctuations observed in non-Brownian suspensions (Pe≫1) of sedimenting particles. The simulation results suggest that particle inertia attenuates the magnitude of velocity fluctuations produced by both Brownian motion and viscous hydrodynamic interactions. Additionally, we study the long-time behavior of the velocity fluctuations by calculating their autocorrelation functions and the particle diffusivities. The numerical simulations show clear evidence of particle pressure arising from the flow disturbance produced by hydrodynamic interactions in a suspension. From the particle velocity variance obtained in the present numerical simulations, we propose a simple model for particle-phase pressure as a linear function of the particle volume fraction ϕ⩽5%, which is usually a closure quantity required in models of more complex particulate systems such as fluidized beds.

Delivering urokinase-type plasminogen activator using mulberry leaf exosomes enables thrombolysis and remodeling of venous microenvironments

In the treatment of thrombosis, conventional nanocarriers inevitably have problems, such as adverse reactions and difficulties in synthesis. Inspired by the concept of ‘medicine food homology,’ we extracted and purified natural exosomes from mulberry leaves as carriers for the delivery of urokinase-type plasminogen activator (uPA) for targeted therapy. The obtained mulberry leaf exosomes (MLE) possessed a desirable hydrodynamic particle size (119.4 nm), a uniform size distribution (polydispersity index = 0.174), and a negative surface charge (−23.3 mv). Before loading with uPA, MLE were grafted with cyclic RGD (cRGD) to selectively bind activated platelets for thrombus targeting. The cytometry studies revealed that MLE@cRGD has a high thrombus targeting ability about 74.3 %. Animal tests demonstrated that the delivered uPA could dissolve clots almost completely in femoral vein thrombosis models. In addition, MLE could remodel venous microenvironments by effectively eliminating reactive oxygen species (ROS) and promoting the phenotypic transformation of macrophages from M1 to M2 for venous tissue repair.

Distribution characteristics of TiO2 NPs in Daihai lake and their stability regulated by abiotic factors

Accurate detection and stability analysis of titanium dioxide (TiO2 NPs) in surface water are critical for ecological risk assessment. Quantitative analysis of TiO2 NPs in water and sediment of Daihai Lake was performed and their occurrence forms was characterized by TEM, XRD and FTIR. Further investigation into the impact of pH, ionic strength (IS) and dissolved organic matter (DOM) on the stability of TiO2 NPs was carried out, along with a correlation analysis between abiotic factors and TiO2 NPs concentration. Results showed that TiO2 NPs in water and sediment are 1.01 × 105 and 5.66 × 105 particles/mL in July 2023, respectively. After transformed in water sample from Daihai Lake, the hydrodynamic particle (HDD) of TiO2 NPs reach 600–700 nm, with reduced crystallinity and observable characteristic peaks of NaCl, which is related to the high concentration of NaCl in Daihai Lake. Structural defects and changes in surface properties of TiO2 NPs are introduced due to the adsorption of organic matter, leading to higher aggregation and sedimentation rates. Specifically, Ca2+ promote the sedimentation of TiO2 NPs more than Na+. Conversely, A/A0 increased to 0.80–0.94 from 0.64 after humic acid (HA) and fulvic acid (FA) added. Hydroxyl and carboxyl groups of FA enhanced steric hindrance and inhibited TiO2 NPs sedimentation. While a strong promotion effect on the sedimentation of TiO2 NPs is detected when 10 mmol/L Ca2+ coexisted with 10 mg/L HA, with 70% of the TiO2 NPs settled within 120 min. Additionally, the concentration of TiO2 NPs in Daihai Lake is significantly positively correlated with dissolved organic carbon (DOC) and humification index, which might be relate to the enhancement of TiO2 NPs stability of aromatic organic matter. And the high concentration of DOC will also lead to the stable existence of TiO2 NPs in water and exacerbate aquatic toxicity.

Selenium nanoparticles stabilized with chitosan for fortifying dairy products

Relevance. One solution to the problem of selenium deficiency is the enrichment of socially important food products, in particular dairy products, with bioavailable forms of selenium. Such forms include selenium nanoparticles. The aim of the work is to develop a dairy product enriched with selenium nanoparticles stabilized with chitosan.Methods. According to dynamic light scattering spectroscopy, a sample of selenium nanoparticles stabilized with chitosan has a monomodal size distribution with an average hydrodynamic particle radius of 25 nm.Results. Quantum chemical modeling of selenium nanoparticles stabilized by chitosan has revealed that the most energetically favorable interaction is the interaction of the surface of selenium nanoparticles with the hydroxo group attached to the C3 glucosamine residue of chitosan. A study was conducted of the influence of technological parameters on the stability of selenium nanoparticles stabilized with chitosan. It was found that increasing the exposure time leads to an increase in the average hydrodynamic radius of selenium nanoparticles stabilized by chitosan. In the case of pH, an inverse relationship is observed: particles with the largest average hydrodynamic radius are found in samples with an acidic environment (pH ˂ 5). As part of a study of the influence of technological parameters on the stability of selenium nanoparticles stabilized by chitosan, it was found that selenium nanoparticles stabilized by chitosan can be used as a source of selenium for food products that have a neutral pH, but can be subjected to heat treatment at temperatures above 70 °C in for 5–15 minutes, in particular pasteurized milk. A study of pasteurized milk fortified with selenium nanoparticles stabilized by chitosan showed that there were no significant changes in titratable acidity, surface tension and pH of milk, as well as the average hydrodynamic radius of casein micelles after milk fortification. The value of antioxidant activity increases by 0.88% — from 6.50 to 7.38%.

The combined effects of polystyrene nanoplastics and dissolved organic matter on the environmental bioavailability of carbamazepine

The bioavailability of active pharmaceutical ingredients (APIs) plays a crucial role in determining the toxicity and risk of contaminants in the environment. However, the bioavailability of APIs in complex environmental matrices is still unclear. In this study, the combined effects of polystyrene nanoplastics (PS NPs) with various particle sizes (50, 100, and 1000 nm) and fulvic acid (FA) on the bioavailability of carbamazepine (CBZ) were investigated via negligible depletion solid-phase microextraction (nd-SPME) and Daphnia magna (D. magna) accumulation. The uptake kinetic study revealed that both PS NPs and FA reduced the elimination rate (k2) in most cases. The availability of CBZ to nd-SPME was determined by the hydrodynamic particle size of PS NPs, whereas the bioavailability to D. magna depended on the intrinsic particle size. The CBZ bioavailability was greater in co-exposed matrices due to the attenuated sorption of PS NPs to CBZ by FA modification. Notably, co-exposure of PS NPs and FA resulted in a higher bioaccumulation factor (BAF) of CBZ, probably due to the desorption and reabsorption of particle-associated CBZ. This study demonstrated that both PS NP particle size and FA binding affect the bioavailability of CBZ, and nd-SPME can mimic only the bioaccumulation of CBZ via diffusion.

Multi-objective Bayesian shape optimization of an industrial hydrodynamic separator using unsteady Eulerian-Lagrangian simulations

AbstractThe shape of a hydrodynamic particle separator has been optimized using a parallelized and robust formulation of Bayesian optimization, with data from an unsteady Eulerian flow field coupled with Lagrangian particle tracking. The uncertainty due to the mesh, initial conditions, and stochastic dispersion in the Eulerian-Lagrangian simulations was minimized and quantified. This was then translated across to the error term in the Gaussian process model and the minimum probability of improvement infill criterion. An existing parallelization strategy was modified for the infill criterion and customized to prefer exploitation in the decision space. In addition, a new strategy was developed for hidden constraints using Voronoi penalization. In the approximate Pareto Front, an absolute improvement over the base design of$$14\%$$14%in the underflow collection efficiency and$$10\%$$10%in the total collection efficiency was achieved, which resulted in the filing of a patent.* The corresponding designs were attributed to the effective distribution of residence time between the trays via the removal of a vertical plume. The plume also reduced both efficiencies by creating a flow path in a direction that acted against effective settling. The concave down and offset tray shapes demonstrated the value of Bayesian optimization in producing useful and non-intuitive designs.Graphic abstract

Non-Debye Behavior of the Néel and Brown Relaxation in Interacting Magnetic Nanoparticle Ensembles.

We used ac-susceptibility measurements to study the superspin relaxation in Fe3O4/Isopar M nanomagnetic fluids of different concentrations. Temperature-resolved data collected at different frequencies, χ″ vs. T|f, reveal magnetic events both below and above the freezing point of the carrier fluid (TF = 197 K): χ″ shows peaks at temperatures Tp1 and Tp2 around 75 K and 225 K, respectively. Below TF, the Néel mechanism is entirely responsible for the superspin relaxation (as the carrier fluid is frozen), and we found that the temperature dependence of the relaxation time, τN(Tp1), is well described by the Dorman-Bessais-Fiorani (DBF) model: τNT=τrexp⁡EB+EadkB T. Above TF, both the internal (Néel) and the Brownian superspin relaxation mechanisms are active. Yet, we found evidence that the effective relaxation times, τeff, corresponding to the Tp2 peaks observed in the denser samples do not follow the typical Debye behavior described by the Rosensweig formula 1τeff=1τN+1τB. First, τeff is 5 × 10-5 s at 225 K, almost three orders of magnitude more that its Néel counterpart, τN~8 × 10-8 s, estimated by extrapolating the above-mentioned DBF analysis. Thus, 1τN≫1τeff, which is clearly not consistent with the Rosensweig formula. Second, the observed temperature dependence of the effective relaxation time, τeff(Tp2), is excellently described by τB-1T=Tγ0exp⁡-E'kBT-T0', a model solely based on the hydrodynamic Brown relaxation, τB(T)=3ηTVHkBT, combined with an activation law for the temperature variation of the viscosity, ηT=η0exp⁡E'/kB(T-T0'. The best fit yields γ0=3ηVHkB = 1.6 × 10-5 s·K, E'/kB = 312 K, and T0' = 178 K. Finally, the higher temperature Tp2 peaks vanish in the more diluted samples (δ ≤ 0.02). This indicates that the formation of larger hydrodynamic particles via aggregation, which is responsible for the observed Brownian relaxation in dense samples, is inhibited by dilution. Our findings, corroborating previous results from Monte Carlo calculations, are important because they might lead to new strategies to synthesize functional magnetic ferrofluids for biomedical applications.

Magnetic-guided nanocarriers for ionizing/non-ionizing radiation synergistic treatment against triple-negative breast cancer

BackgroundTriple-negative breast cancer (TNBC) is a subtype of breast cancer with the worst prognosis. Radiotherapy (RT) is one of the core modalities for the disease; however, the ionizing radiation of RT has severe side effects. The consistent development direction of RT is to achieve better therapeutic effect with lower radiation dose. Studies have demonstrated that synergistic effects can be achieved by combining RT with non-ionizing radiation therapies such as light and magnetic therapy, thereby achieving the goal of dose reduction and efficacy enhancement.MethodsIn this study, we applied FeCo NPs with magneto thermal function and phototherapeutic agent IR-780 to construct an ionizing and non-ionizing radiation synergistic nanoparticle (INS NPs). INS NPs are first subjected to morphology, size, colloidal stability, loading capacity, and photothermal conversion tests. Subsequently, the cell inhibitory and cellular internalization were evaluated using cell lines in vitro. Following comprehensive assessment of the NPs’ in vivo biocompatibility, tumor-bearing mouse model was established to evaluate their distribution, targeted delivery, and anti-tumor effects in vivo.ResultsINS NPs have a saturation magnetization exceeding 72 emu/g, a hydrodynamic particle size of approximately 40 nm, a negatively charged surface, and good colloidal stability and encapsulation properties. INS NPs maintain the spectral characteristics of IR-780 at 808 nm. Under laser irradiation, the maximum temperature was 92 °C, INS NPs also achieved the effective heat temperature in vivo. Both in vivo and in vitro tests have proven that INS NPs have good biocompatibility. INS NPs remained effective for more than a week after one injection in vivo, and can also be guided and accumulated in tumors through permanent magnets. Later, the results exhibited that under low-dose RT and laser irradiation, the combined intervention group showed significant synergetic effects, and the ROS production rate was much higher than that of the RT and phototherapy-treated groups. In the mice model, 60% of the tumors were completely eradicated.ConclusionsINS NPs effectively overcome many shortcomings of RT for TNBC and provide experimental basis for the development of novel clinical treatment methods for TNBC.

Climate‐influenced phenology of larval fish transport in a large lake

AbstractElucidating physical transport phenologies in large lakes can aid understanding of larval recruitment dynamics. Here, we integrate a series of climate, hydrodynamic, biogeochemical, and Lagrangian particle dispersion models to: (1) simulate hatch and transport of fish larvae throughout an illustrative large lake, (2) evaluate patterns of historic and potential future climate‐induced larval transport, and (3) consider consequences for overlap with suitable temperatures and prey. Simulations demonstrate that relative offshore transport increases seasonally, with shifts toward offshore transport occurring earlier during relatively warm historic and future simulations. Intra‐ and inter‐annual trends in transport were robust to assumed pelagic larval duration and precise location and timing of hatching. Larvae retained nearshore generally encountered more favorable temperatures and zooplankton densities compared to larvae transported offshore. Larval exploitation of nearshore resources under climate change may depend on a concomitant shift to earlier spawning and hatch times in advance of earlier offshore transport.

Comparison of the toxic effects of polystyrene and sulfonated polystyrene on wheat under cadmium stress

With advances in plastic resource utilization technologies, polystyrene (PS) and sulfonated polystyrene (SPS) microplastics continue to be produced and retained in environmental media, potentially posing greater environmental risks. These plastics, due to their different physicochemical properties, may have different environmental impacts when compounded with other pollutants. The objective of this study was to investigate the combined toxic effects of PS and SPS on wheat using cadmium (Cd) as a background contaminant. The results demonstrated that Cd significantly impeded the normal growth of wheat by disrupting root development. Both PS and SPS exhibited hormesis at low concentrations and promoted wheat growth. Under combined toxicity, PS reduced oxidative stress and promoted the uptake of essential metal elements in wheat. Additionally, KEGG pathway analysis revealed that PS facilitated the repair of Cd-induced blockage of the TCA cycle and glutathione metabolism. However, high concentrations of SPS in combined toxicity not only enhanced oxidative stress and interfered with the uptake of essential metal elements, but also exacerbated the blocked TCA cycle and interfered with pyrimidine metabolism. These differences are related to the different stability (Zeta potential, Hydrodynamic particle size) of the two microplastics in the aquatic environment and their ability to carry heavy metal ions, especially Cd. The results of this study provide important insights into understanding the effects of microplastics on crops in the context of Cd contamination and their environmental and food safety implications.

Complex patterns of genetic structure in the sea cucumber Holothuria (Metriatyla) scabra from the Philippines: implications for aquaculture and fishery management

The sandfish Holothuria (Metriatyla) scabra, is a high-value tropical sea cucumber harvested from wild stocks for over four centuries in multi-species fisheries across its Indo-Pacific distribution, for the global bêche-de-mer (BDM) trade. Within Southeast Asia, the Philippines is an important centre of the BDM trade, however overharvesting and largely open fishery management have resulted in declining catch volumes. Sandfish mariculture has been developed to supplement BDM supply and assist restocking efforts; however, it is heavily reliant on wild populations for broodstock supply. Consequently, to inform fishery, mariculture, germplasm and translocation management policies for both wild and captive resources, a high-resolution genomic audit of 16 wild sandfish populations was conducted, employing a proven genotyping-by-sequencing approach for this species (DArTseq). Genomic data (8,266 selectively-neutral and 117 putatively-adaptive SNPs) were used to assess fine-scale genetic structure, diversity, relatedness, population connectivity and local adaptation at both broad (biogeographic region) and local (within-biogeographic region) scales. An independent hydrodynamic particle dispersal model was also used to assess population connectivity. The overall pattern of population differentiation at the country level for H. scabra in the Philippines is complex, with nine genetic stocks and respective management units delineated across 5 biogeographic regions: (1) Celebes Sea, (2) North and (3) South Philippine Seas, (4) South China and Internal Seas and (5) Sulu Sea. Genetic connectivity is highest within proximate marine biogeographic regions (mean Fst=0.016), with greater separation evident between geographically distant sites (Fst range=0.041–0.045). Signatures of local adaptation were detected among six biogeographic regions, with genetic bottlenecks at 5 sites, particularly within historically heavily-exploited locations in the western and central Philippines. Genetic structure is influenced by geographic distance, larval dispersal capacity, species-specific larval development and settlement attributes, variable ocean current-mediated gene flow, source and sink location geography and habitat heterogeneity across the archipelago. Data reported here will inform accurate and sustainable fishery regulation, conservation of genetic diversity, direct broodstock sourcing for mariculture and guide restocking interventions across the Philippines.

Berberine encapsulated phenylboronic acid-conjugated pullulan nanoparticles: Synthesis, characterization and anticancer activity validated in A431 skin cancer cells and 3D spheroids

Polysaccharide-based drug delivery systems are in high demand due to their biocompatibility, non-toxicity, and low-cost. In this study, sialic acid receptor targeted 4-carboxy phenylboronic acid modified pullulan-stearic acid conjugate (4-cPBA-PUL-SA) was synthesized and characterized for the delivery of Berberine (BBR). BBR-loaded 4-cPBA-PUL-SA nanoparticles (BPPNPs) were monodispersed (PDI: 0.238 ± 0.07), with an average hydrodynamic particle size of 191.6 nm and 73.6 % encapsulation efficiency. BPPNPs showed controlled BBR release and excellent colloidal stability, indicating their potential for drug delivery application. The cytotoxicity results indicated that BPPNPs exhibited dose and time-dependent cytotoxicity against human epidermoid carcinoma cells (A431) as well as 3D spheroids. Targeted BPPNPs demonstrated significantly higher anticancer activity compared to BBR and non-targeted BPNPs. The IC50 values for BPPNPs (2.29 μg/ml) were significantly lower than BPNPs (4.13 μg/ml) and BBR (19.61 μg/ml), indicating its potential for skin cancer treatment. Furthermore, CSLM images of A431 cells and 3D spheroids demonstrated that BPPNPs have higher cellular uptake and induced apoptosis compared to free BBR and BPNPs. In conclusion, BPPNPs demonstrate promising potential as an effective drug delivery system for skin cancer therapy.

Decitabine-based nanoparticles for enhanced immunotherapy of hepatocellular carcinoma via DNA hypermethylation reversal

DNA methyltransferase (DNMT) inhibitor represents the first clinical breakthrough via targeting aberrant cancer epigenomes. Demethylation drugs such as decitabine can restore tumor suppressor gene (TSG) expression and function to achieve anti-tumor effect. Despite DNMT inhibitors have shown significant efficacy for treating leukemia, their application in solid tumor such as HCC is limited due to short in vivo half-lives. In this study, the DNMT1 inhibitor decitabine was first loaded into the Polylactic-co-glycolic acid (PLGA) spherical nanoparticles (Dec@PLGA). The vesicle of PD-L1 antibody and macrophage membrane (aMM) was further coated onto the surface of Dec@PLGA to finally synthesize Dec@PLGA@aMM. Dec@PLGA@aMM was in uniformed spherical structure with hydrodynamic particle size of 95.7 ± 9.1 nm and surface zeta potential of −15.1 ± 3.3 mV. Dec@PLGA@aMM significantly increased the expression of both p14 and p16 in a concentration-dependent manner. Dec@PLGA@aMM could enhance the tumor suppression through restoration of TSGs, which were epigenetically silenced by DNA hypermethylation. The Dec@PLGA@aMM group showed significantly (P < 0.05) less tumor volume than PBS group, PLGA@MM group, aPD-L1 group, PLGA@aMM group, decitabine group, Dec + aPD-L1 group, and Dec@PLGA@MM group. The decitabine could enhance aPD-L1-mediated immunotherapy of HCC via epigenetic alteration. This novel targeted PLGA NPs are aimed to treat HCC by decreasing DNA methylation and blocking PD-L1, thus providing new ideas for effective treatments via epigenetic alteration for HCC patients clinically.

Tailoring micellar nanocarriers for pemetrexed in breast cancer: design, fabrication and in vitro evaluation.

Aim: To investigate the pemetrexed encapsulated polymeric mixed micelles (PMMs) against breast cancer treatment.Methods: We meticulously optimized the formulation and conducted extensive characterizations, including photon correlation spectroscopy for micellization, advanced analytical techniques and in vitro cell line assessments.Results: The PMM exhibited favorable characteristics, with a spherical morphology, hydrodynamic particle size of 19.58±0.89nm, polydispersity index of 0.245±0.1, and a surface charge of -9.70±0.61mV. Encapsulation efficiency and drug payload reached 96.16±0.37% and 4.5±0.32%, respectively. Cytotoxicity analysis indicated superior efficacy of the PMM over the drug solution.Conclusion: The PMM formulation exhibited controlled release of the drug, and demonstrated enhanced cytotoxicity against breast cancer cells, highlighting its therapeutic promise.

Transport and retention of sinking microplastics in a well-mixed estuary

Estuaries have been shown to be potential hotspots of microplastic accumulation, but the hydrodynamic conditions and particle properties that control this process need further investigation. We have designed a series of numerical particle-tracking experiments to examine the sensitivity of retention in estuaries to particle size, particle density and varying tides and freshwater flow. At the end of the simulation, over 90 % of sinking particles are retained in the estuary, and the retention rate is further increased by high river runoff. In contrast, increased river discharge increases the number of marginally-buoyant (i.e. density close to estuarine water) particles that escape the estuary. Larger particle size tends to limit the downstream transport of sinking particles but can facilitate the transport of marginally-buoyant particles. Tidal asymmetry, vertical turbulent mixing and the vertical structure of the subtidal circulation are proposed as the underlying mechanisms controlling the fate of particles.

Modeling the fate of microplastics in the Sengkarang Estuary, Pekalongan City, Central Java, Indonesia

AbstractPlastic‐containing waste generated from industrial and household activities is usually discharged into rivers. Pekalongan Regency has several rivers that flow into the Java Sea, one of which is the Sengkarang River. Microplastic is a serious pollutant that has prompted enhanced research and experimentation. This study aims to determine the concentration and distribution of microplastics in water and sediment at the mouth of the Sengkarang River, Pekalongan. A total of 10 water samples and five sediment samples were collected from the river body to the deep water area around the Sengkarang River. Modeling of microplastic distribution is made using hydrodynamic modeling and particle tracking models using two‐dimensional mathematical model. The results showed that the abundance of microplastics ranged from 131 to 360 particle/m3 in water samples and 552.5–972.5 particle/kg in sediment samples. The most common types of microplastics found were fibers and fragments. The greatest abundance and distribution of microplastics are found in coastal areas in water samples and mangrove areas in sediment samples. The distribution of microplastics is influenced by tidal currents, wind directions, and also river water discharge.

Tuning Surface, Phase, and Magnetization of Superparamagnetic Magnetite by Ionic Liquids: Single-Step Microwave-Assisted Synthesis.

Achieving colloidal and chemical stability in ferrofluids by surface modification requires multiple steps, including purification, ex situ modification steps, and operation at high temperatures. In this study, a single-step microwave-assisted methodology is developed for iron oxide nanoparticle (IONP) synthesis utilizing a series of imidazolium-based ionic liquids (ILs) with chloride, bis(trifluoromethylsulfonyl)imide, and pyrrolide anions as the reaction media, thus eliminating the use of volatile organics while enabling rapid synthesis at 80 °C as well as in situ surface functionalization. The characterized surface functionality, hydrodynamic particle size, magnetization, and colloidal stability of the IONPs demonstrate a strong dependence on the IL structure, ion coordination strength, reactivity, and hydrophilicity. The IONPs present primarily a magnetite (Fe3O4) phase with superparamagnetism with the highest saturation magnetization at 81 and 73 emu/g at 10 and 300 K, respectively. Depending on the IL coating, magnetization and exchange anisotropy decrease by 20 and 2-3 emu/g (at 35 wt % IL), respectively, but still represent the highest magnetization achieved for coated IONPs by a coprecipitation method. Further, the surface-functionalized superparamagnetic magnetite nanoparticles show good dispersibility and colloidal stability in water and dimethyl sulfoxide at 0.1 mg/mL concentration over the examined 3 month period. This study reports on the intermolecular and chemical interactions between the particle surface and the ILs under synthetic conditions as they relate to the magnetic and thermal properties of the resulting IONPs that are well suited for a variety of applications, including separation and catalysis.

Particle hydrodynamics in acoustic fields: Unifying acoustophoresis with streaming

Particle hydrodynamics in acoustic fields: Unifying acoustophoresis with streaming

Natural alkaloids from Dicranostigma leptopodum (Maxim.) Fedde and their G5. NHAc-PBA dendrimer-alkaloid complexes for targeting chemotherapy in breast cancer MCF-7 cells.

Herein, we isolated five natural alkaloids, iso-corydine (iso-CORY), corydine (CORY), sanguinarine (SAN), chelerythrine (CHE) and magnoflorine (MAG), from traditional medicinal herb Dicranostigma leptopodum (Maxim.) Fedde (whole herb) and elucidated their structures. Then we synthesised G5. NHAc-PBA as targeting dendrimer platform to encapsulate the alkaloids into G5. NHAc-PBA-alkaloid complexes, which demonstrated alkaloid-dependent positive zeta potential and hydrodynamic particle size. G5. NHAc-PBA-alkaloid complexes demonstrated obvious breast cancer MCF-7 cell targeting effect. Among the G5. NHAc-PBA-alkaloid complexes, G5.NHAc-PBA-CHE (IC50=13.66 μM) demonstrated the highest MCF-7 cell inhibition capability and G5.NHAc-PBA-MAG (IC50=24.63 μM) had equivalent inhibitory effects on cell proliferation that comparable to the level of free MAG (IC50=23.74 μM), which made them the potential breast cancer targeting formulation for chemotherapeutic application. This work successfully demonstrated a pharmaceutical research model of 'natural bioactive product isolation-drug formulation preparation-breast cancer cell targeting inhibition'.