Size Of MNPs Research Articles

Size-dependent deleterious effects of nano- and microplastics on sperm motility

IntroductionGrowing concerns regarding the reproductive toxicity associated with daily life exposure to micro-/nano-plastics (abbreviated as MNPs) have become increasingly prevalent. In reality, MNPs exposure involves a heterogeneous mixture of MNPs of different sizes rather than a single size. MethodsIn this study, an oral exposure mouse model was used to evaluate the effects of MNPs of four size ranges: 25–30 nm, 1–5 µm, 20–27 µm, and 125–150 µm. Adult male C57BL/6 J mice were administered environmentally relevant concentrations of 0.1 mg MNPs/day for 21 days. After that, open field test and computer assisted sperm assessment (CASA) were conducted. Immunohistochemical analyses of organ and cell type localization of MNPs were evaluated. Testicular transcriptome analysis was carried out to understand the molecular mechanisms. ResultsOur result showed that MNPs of different size ranges all impaired sperm motility, with a decrease in progressive sperm motility, linearity and straight-line velocity of sperm movement. Alterations did not manifest in animal locomotion, body weight, or sperm count. Noteworthy effects were most pronounced in the smaller MNPs size ranges (25–30 nm and 1–5 µm). Linear regression analysis substantiated a negative correlation between the size of MNPs and sperm curvilinear activity. Immunohistochemical analysis unveiled the intrusions of 1–5 µm MNPs, but not 20–27 µm and 125–150 µm MNPs, into Leydig cells and testicular macrophages. Further testicular transcriptomic analysis revealed perturbations in pathways related to spermatogenesis, oxidative stress, and inflammation. Particularly within the 1–5 µm MNPs group, a heightened perturbation in pathways linked to spermatogenesis and oxidative stress was observed. ConclusionsOur data support the size-dependent impairment of MNPs on sperm functionality, underscoring the pressing need for apprehensions about and interventions against the escalation of environmental micro-/nano-plastics contamination. This urgency is especially pertinent to small-sized MNPs.

Formation, behavior, properties and impact of micro- and nanoplastics on agricultural soil ecosystems (A Review)

Micro and nanoplastics (MPs and NPs, respectively) in agricultural soil ecosystems represent a pervasive global environmental concern, posing risks to soil biota, hence soil health and food security. This review provides a comprehensive and current summary of the literature on sources and properties of MNPs in agricultural ecosystems, methodology for the isolation and characterization of MNPs recovered from soil, MNP surrogate materials that mimic the size and properties of soil-borne MNPs, and transport of MNPs through the soil matrix. Furthermore, this review elucidates the impacts and risks of agricultural MNPs on crops and soil microorganisms and fauna. A significant source of MPs in soil is plasticulture, involving the use of mulch films and other plastic-based implements to provide several agronomic benefits for specialty crop production, while other sources of MPs include irrigation water and fertilizer. Long-term studies are needed to address current knowledge gaps of formation, soil surface and subsurface transport, and environmental impacts of MNPs, including for MNPs derived from biodegradable mulch films, which, although ultimately undergoing complete mineralization, will reside in soil for several months. Because of the complexity and variability of agricultural soil ecosystems and the difficulty in recovering MNPs from soil, a deeper understanding is needed for the fundamental relationships between MPs, NPs, soil biota and microbiota, including ecotoxicological effects of MNPs on earthworms, soil-dwelling invertebrates, and beneficial soil microorganisms, and soil geochemical attributes. In addition, the geometry, size distribution, fundamental and chemical properties, and concentration of MNPs contained in soils are required to develop surrogate MNP reference materials that can be used across laboratories for conducting fundamental laboratory studies.

ROS-Generating Amine-Functionalized Magnetic Nanoparticles Coupled with Carboxymethyl Chitosan for pH-Responsive Release of Doxorubicin.

PurposeMagnetic nanoparticles have been used in diverse pharmaceutical applications because they can potentially be used to target specific sites. In the present work, a new type of nanocomposites is designed as a carrier of controlled bioactive agent delivery.MethodsAmine-functionalized magnetic nanoparticles (amine-MNPs) are coupled with carboxymethyl chitosan (CMC) to generate the nanocomposites, namely MNPs-CMC, which can be further loaded with doxorubicin (DOX) to produce MNPs-CMC-DOX. The generated nanocomposites are characterized by using various techniques (including FTIR, 1H-NMR, DSC, TGA, SEM, TEM and XRD). In vitro drug release studies are conducted in PBS with different pH values (1.2 and 6.8) at different temperatures (25°C and 37°C). The toxicity of the nanocomposites is tested in MCF-7 and 3T3 cells. The ROS-generating capacity of the nanocomposites is determined in treated cells using 2’,7’-dichlorodihydrofluorescein diacetate.ResultsThe structures of MNPs, CMC, and nanocomposites are confirmed by FTIR, XRD, and 1H-NMR data reveals the formation of CMC from chitosan (CS). The size of MNPs is estimated by TEM to be around 25 nm. After conjugation with CMC, the size of the nanocomposites increases to 46–57 nm. Based on the release profiles of MNPs-CMC-DOX, our nanocomposites are pH-responsive. In addition, our nanocomposites show reactive oxygen species (ROS)-generating capacity and cell type-dependent toxicity.ConclusionOur nanocomposites show high potential for use in bioactive agent delivery. Along with their ROS-generating capacity, they warrant further development as pH-responsive carriers for therapeutic applications.

Berberine Loaded Magnetic Nanoparticles for Breast Cancer Therapy on MDA-MB-231 Cells Lines

Berberine is an alkaloid naturally-derived from Berberis aristata and a family Berberidaceae exhibits a broad spectrum of pharmacological benefits, including antiviral and anticancer properties. The recent development of nanomedicine is an art of delivering drugs to the target-site by improving their safety and efficacy. In present study, four berberine-loaded magnetic nanoparticles (BBR/MNPs) were prepared using a modified co-precipitation method with calcination. The resulting BBR/MNPs were characterized by FTIR, XRD, HRSEM, zeta potential, VSM, loading efficiency, stability and in vitro release studies. The most proven magnetic nanoparticles formulation type in dissolution was followed by in vitro anticancer studies on MDA-MB-231 cells. XRD, FTIR and TGA results proved that the formed BBR/MNPs were ordered in their structure with iron, silanol groups and berberine moieties. The HRSEM reported the average particle size of MNPs varies from 100 to 250 nm after loading with berberine also had a regular spherical shape. The value of the zeta potential was -9 mV and 15 mV at pH 6 for bare MNPs and BBR/MNPs, respectively. Loading efficiency and stability were good at BBR/MCM-41MNP. The saturated magnetization (Ms) value of Fe-MCM-41 MNP (81.76 emu/g) was obtained by VSM analysis. In vitro dissolution studies of four BBR/MNPs at a three different pH 5.5, 6.5, 7.4 including BBR/MCM-41 MNP were 86%, 84% and 82%, respectively. In vitro anticancer studies with BBR/MCM-41-MNP on treated MDA-MB-231 breast cancer cells in comparison to standard doxorubicin. The MTT assay confirmed the cytotoxic effect of BBR/MCM-41-MNP in vitro. The resulting data were statistically analyzed using one-way Anova analysis with N = 3 replicates. The IC50 values (mean standard deviation) of BBR, BBR/MCM-41 MNP and standard doxorubicin were obtained as 16.754 ± 0.651, 6.750 ± 0.048, 4.955 ± 0.042 μg/mL with significant p < 0.0001. The best result was BBR/MCM-41 MNP with an average particle size 50 nm, which showed good drug loading efficiency and size stability above 7 days. Drug release was maximal (86%) at pH 5.5. The MTT-assay confirmed that BBR/MCM-41MNP exhibited more cytotoxicity on MDA-MB-231 cells than BBR, MCM-41MNP. The IC50 of BBR/MCM-41 was closed that of standard doxorubicin. The BBR/MCM-41MNP showed the optimum drug release with potent anticancer activity along with magnetic targeting.

Enhanced sensitivity and efficiency of detection of Staphylococcus aureus based on modified magnetic nanoparticles by photometric systems

Staphylococcus aureus is an important infectious factor in the food industry and hospital infections. Many methods are used for detecting bacteria but they are mostly time-consuming, poorly sensitive. In this study, a nano-biosensor based on iron nanoparticles (MNPs) was designed to detect S. aureus. MNPs were synthesized and conjugated to Biosensors. Then S. aureus was lysed and nano-biosensor (MNP-TiO2-AP-SMCC-Biosensors) was added to the lysed bacteria. After bonding the bacterial genome to the nano-biosensor, MNPs were separated by a magnet. Bacterial DNA was released from the surface of nano-biosensor and researched by Nano-drop spectrophotometry. The results of SEM and DLS revealed that the size of MNPs was 20–25 nm which increased to 38–43 nm after modification and addition of biosensors. The designed nano-biosensor was highly sensitive and specific for the detection of S. aureus. The limit of detection (LOD) was determined as 230 CFU mL−1. There was an acceptable linear correlation between bacterial concentration and absorption at 3.7 × 102–3.7× 107 whose linear diagram and regression was Y = 0.242X + 2.08 and R 2 = .996. Further, in the presence of other bacteria as a negative control, it was absolutely specific. The sensitivity of the designed nano-biosensor was investigated and compared through PCR.

Solvatochromism of a highly conjugated novel donor-π-acceptor dipolar fluorescent probe and its application in surface-energy transfer with gold nanoparticles

A novel highly conjugated donor-π-acceptor (D-π-A) fluorescent probe 4-((1E,3E)-4-(4-(5-(4-tert-butylphenyl)-1,3,4-oxadiazol-2-yl)phenyl)buta-1,3-dienyl)-N,N-dimethylbenzenamine (3TVPO) is synthesized using a Wittig reaction and characterized by 1H, 13C NMR, FT-IR spectroscopy and high-resolution mass spectrometry (HR-MS). The photophysical properties have been studied to understand the intramolecular charge-transfer (ICT) character of the compound. The solvatochromism of 3TVPO has been explored in polar protic/aprotic/weakly polar solvents. Various solvent correlation techniques such as Lippert–Mataga, Bilot–Kawski, Kawski–Chamma–Viallet, Bakhshiev, and Reichardt methods were employed to estimate the singlet ground- and excited-state dipole moment and are compared and discussed with those obtained computationally. The specific and non-specific solute-solvent interactions were analyzed using Kamlet–Taft and Catalán solvent parameters by means of a multiple-linear-regressions (MLR) method. In addition, surface-energy transfer (SET) has been studied using this optoelectronically important 3TVPO molecule as efficient donor and gold nanoparticles (Au MNPs) as excellent acceptors employing steady-state and time-resolved spectroscopic techniques. The size- and distance-dependent SET between 3TVPO and Au MNPs was explored. It is demonstrated that the quenching efficiency increases as the size of Au MNPs increases from 40 to 53 nm. The super-quenching effect and nonradiative energy transfer were analyzed using Stern–Volmer plots. The impact of the present investigation about the super-quenching effect of the Au MNPs can be exploited for biosensing applications owing to its acute sensitivity.

Characterization of solid magnetic nanoparticles by means of solid sampling high resolution continuum source electrothermal atomic absorption spectrometry

Direct determination of iron concentration and particle size of solid MNPs using HR CS GFAAS.

Preparation of fatty acids coated Fe3O4 nanoparticles for adsorption and determination of benzo(a)pyrene in environmental water samples

A range of fatty acids (C6–C11) coated magnetic nanoparticles were synthesized. The particle size and crystal phase of MNPs were characterized by transmission electron microscope and X-ray diffraction, respectively. The synthesized MNPs were used for adsorption of benzo(a)pyrene from water samples, the study showed that a proper chain length may accommodate BaP and/or provide enough Van der Waals interactions, so decanoic acid coated MNPs (Fe3O4@C10) were selected for the adsorption experiments. The influences of amount of sorbent, the pH and ionic strength of sample matrix, temperature and sorption time on adsorption efficiency were investigated. The study showed that the characteristics of adsorption isotherms corresponded well with Freundlich model (R2=0.988), and the theoretical maximum adsorption capacity was 63.90ngmg−1 calculated by Langmuir model. Combined with high-performance liquid chromatography and fluorescence detection (HPLC–FLD), a simple and effective method for adsorption and determination of BaP in water samples was developed.

Nano-Size Effect of Hyperbranched Polyglycerol-Grafted Fe3O4 Nanoparticles

Hyperbranched polyglycerol-grafted Fe3O4 nanoparticles (HPG-grafted MNPs) are newly developed MRI contrast agents with good stability, dispersibility, and biocompatibility. Their magnetic, cell uptake properties may be changed when their size varies. In this study, HPG-grafted MNPs with their size ranging from 8 to 10, 13, and 15 nm were successfully synthesized via a facile one-pot reaction using ferric oxalate pentahydrate as the precursor. With the increase of particle size, HPG-grafted MNPs show increasing trends in saturation magnetization, transverse relaxivities (R2), R2/R1 ratio, and cell uptake. MTT assays indicated that nanoparticles with defferent sizes did not possess significant cytotoxicity toward mouse macrophages and 3T3 fibroblasts. Furthermore, in vivo MRI experiments were carried out with the 8-nm HPG-grafted MNPs injected into a live rabbit. Our results demonstrate that the size of HPG-grafted MNPs, which can be synthetically controlled, played an important role in tuning their magnetic and cell uptake properties. This allows HPG-grafted MNPs exhibit optional and designable properties for their application as an efficient MRI contrast agent.

Size-regulated group separation of CoFe2O4 nanoparticles using centrifuge and their magnetic resonance contrast properties

Magnetic nanoparticle (MNP)-based magnetic resonance imaging (MRI) contrast agents (CAs) have been the subject of extensive research over recent decades. The particle size of MNPs varies widely and is known to influence their physicochemical and pharmacokinetic properties. There are two commonly used methods for synthesizing MNPs, organometallic and aqueous solution coprecipitation. The former has the advantage of being able to control the particle size more effectively; however, the resulting particles require a hydrophilic coating in order to be rendered water soluble. The MNPs produced using the latter method are intrinsically water soluble, but they have a relatively wide particle size distribution. Size-controlled water-soluble MNPs have great potential as MRI CAs and in cell sorting and labeling applications. In the present study, we synthesized CoFe2O4 MNPs using an aqueous solution coprecipitation method. The MNPs were subsequently separated into four groups depending on size, by the use of centrifugation at different speeds. The crystal shapes and size distributions of the particles in the four groups were measured and confirmed by transmission electron microscopy and dynamic light scattering. Using X-ray diffraction analysis, the MNPs were found to have an inverse spinel structure. Four MNP groups with well-selected semi-Gaussian-like diameter distributions were obtained, with measured T2 relaxivities (r2) at 4.7 T and room temperature in the range of 60 to 300 mM−1s−1, depending on the particle size. This size regulation method has great promise for applications that require homogeneous-sized MNPs made by an aqueous solution coprecipitation method. Any group of the CoFe2O4 MNPs could be used as initial base cores of MRI T2 CAs, with almost unique T2 relaxivity owing to size regulation. The methodology reported here opens up many possibilities for biosensing applications and disease diagnosis.PACS75.75.Fk, 78.67.Bf, 61.46.Df

Synthesis of PEGylated Magnetic Nanoparticles With Different Core Sizes

Tailoring the properties of superparamagnetic nanoparticles (MNPs) is essential for various nano-based biological applications. Having control over the properties of the MNPs permits a maximum flexibility. Starting from monodisperse iron oxide MNPs produced by thermal decomposition, we report on the optimization and characterization of a first and second seed mediated growth step by varying the surfactant amount and by optimizing the heating steps. We demonstrate the ability to gradually increase the size of crystalline MNPs from 6 over 9 to 12 nm with an improving monodispersity as demonstrated by Transmission Electron Microscopy, Dynamic Light Scattering and X-ray diffraction. The magnetic properties of the MNPs, studied by Vibrating Sample Magnetometry, were in concert with their size increase. We also show the functionalization of these particles with polyethylene glycolated silanes, to render the MNPs stable in water. Different characterization techniques, namely Transmission Electron Microscopy, Dynamic Light Scattering, Fourier-transform InfraRed, Thermo gravimetric analysis and X-ray Photoelectron Spectroscopy, confirmed the successful engraftment of the silanes on the MNP's surface. In conclusion, the proposed route of step-wise synthesis in combination with silane functionalization allows fine tuning the physical properties of iron oxide MNPs for applications in an aqueous environment.

Study of superparamagnetic nanoparticles as labels in the quantitative lateral flow immunoassay

The superparamagnetic nanoparticles (MNPs) with a series of sizes and magnetite contents are designed and prepared as labels used in lateral flow immunoassay (LFIA) to test if the size and magnetite content of MNPs can affect the performance of LFIA. The result showed that detection time was mainly determined by the size of MNPs, while the signal intensity was closely correlated to the magnetite content of the MNPs. In addition, the magnetic signals intensity remained stable over a long time period. Smaller MNPs with higher magnetite content are first choices as labels to construct a rapid and high-sensitive quantitative LFIA.