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Applications of nanoparticles and plants for efficient restoration of heavy metal-polluted water and soil are an emerging approach and need to be explored. Hydroponic study was performed to find the role of zinc oxide nanoparticles (ZnO NPs) in plant growth, antioxidative response, and lead (Pb) accumulation in Persicaria hydropiper. Seedlings were grown in Pb-polluted media amended with 5, 10, 15, and 20 mg L -1 ZnO NPs. Inductively coupled plasma spectroscopy (ICP) was used for Pb analysis in plant tissues. Pb significantly inhibited seedling growth, and ZnO NPs alleviated Pb-induced stress by promoting plant growth, and improved chlorophyll and carotenoid contents. Oxidative stress ameliorated in ZnO NPs exposed seedlings through enhanced production of free proline, phenolics, flavonoids, and activation of antioxidative enzymes. Pb accumulation boosted in ZnO NP treatments, and highly significant increase in Pb accumulation in roots (255.60±4.80 mg kg -1 ), stem (124.07±2.84 mg kg -1 ), and leaves (92.00±3.22 mg kg -1 ) was observed in T3 (15 mg L -1 ZnO NPs) for P. hydropiper. Contrarily, ZnO NPs at 20 mg L -1 dose suppressed plant growth, Pb accumulation, secondary metabolites, and antioxidative enzyme activities. Moreover, positive correlation was found in Pb accumulation with free proline and secondary metabolite contents in plant tissues. These results suggest that ZnO NPs at optimum concentration may augment efficacy of plants to remove heavy metal from polluted water through nanophytoremediation., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

An in vitro study was conducted to evaluate the effects of thidiazuron (TDZ) growth regulator and magnesium oxide (MgO) nanoparticles on radish (Raphanus sativus L.) under lead (Pb) stress. Effects of TDZ and MgO on seed germination, growth, biomass, total phenolics and flavonoids, antioxidant potential, and Pb phytoaccumulation in different plant parts were assessed. Nanoparticles of MgO were synthesized with leaf extract of Sageretia thea (Osbeck) plant. Thidiazuron and MgO nanoparticles were added to growth media in individual and in combinations. Lead (50 mg L -1 ) was added to growth media. Thidiazuron and MgO nanoparticles increased plant growth, phenolic and flavonoid contents, free radical scavenging activity, and lead phytoaccumulation. The increase was highly significant in TDZ and MgO nanoparticle combination treatments (T5, T6). Treatment (T6) showed a sixfold increase in Pb accumulation (1721.73 ± 17.4 μg g -1 dry biomass) as compared to control (274.29 ± 4.23 μg -1 g -1 ). Total phenolic and dry biomass showed significantly positive correlation in leaves (R 2 = 0.73), stem (R 2 = 0.58), and roots (R 2 = 0.72). The correlation of Pb accumulation and phenolic contents was significantly positive in root (R 2 = 0.80), stem (R 2 = 0.92), and leaves (R 2 = 0.69). Flavonoid showed a positive correlation with dry biomass and Pb accumulation. Antioxidant activity was highly increased in leaves followed by stem and root. Findings show that TDZ in combination with MgO nanoparticles can play a significant role in secondary metabolite production and Pb phytoaccumulation.

Aims: To predict the deposition of nanoparticles in a patient-specific arterial tree as a function of the vascular architecture, flow conditions, receptor surface density and nanoparticle properties., Materials & Methods: The patient-specific vascular geometry is reconstructed from computed tomography angiography images. The isogeometric analysis framework integrated with a special boundary condition for the firm wall adhesion of nanoparticles is implemented. A parallel plate flow chamber system is used to validate the computational model in vitro., Results: Particle adhesion is dramatically affected by changes in patient-specific attributes, such as branching angle and receptor density. The adhesion pattern correlates well with the spatial and temporal distribution of the wall shear rates. For the case considered, the larger (2.0 µm) particles adhere two-times more in the lower branches of the arterial tree, whereas the smaller (0.5 µm) particles deposit more in the upper branches., Conclusion: Our computational framework in conjunction with patient-specific attributes can be used to rationally select nanoparticle properties to personalize, and thus optimize, therapeutic interventions.

Nanoparticles for cancer therapy and imaging are designed to accumulate in the diseased tissue by exploiting the Enhanced Permeability and Retention (EPR) effect. This limits their size to about 100nm. Here, using intravital microscopy and elemental analysis, we compare the in vivo localization of particles with different geometries and demonstrate that plateloid particles preferentially accumulate within the tumor vasculature at unprecedented levels, independent of the EPR effect. In melanoma-bearing mice, 1000×400nm plateloid particles adhered to the tumor vasculature at about 5% and 10% of the injected dose per gram organ (ID/g) for untargeted and RGD-targeted particles respectively, and exhibited the highest tumor-to-liver accumulation ratios (0.22 and 0.35). Smaller and larger plateloid particles, as well as cylindroid particles, were more extensively sequestered by the liver, spleen, and lungs. Plateloid particles appeared well-suited for taking advantage of hydrodynamic forces and interfacial interactions required for efficient tumoritropic accumulation, even without using specific targeting ligands., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Background: This study aims to evaluate the antibacterial activity of chitosan-coated iron oxide nanoparticles (Chi-IONP) by agar direct diffusion method and determine the minimum inhibitory concentration and minimum bactericidal concentration (MIC/MBC) of this nanosolution against E.faecalis, S.mutans and Candida albicans the three oral microorganisms commonly isolated from endodontic infections. Methods: The nanoparticles solution was prepared by functionalizing the 8nm iron oxide nanoparticles with glycine and coating them by chitosan dissolved in 0.25% v/v acetic acid. E.faecalis, S.mutans and candida albicans were isolated and identified with Vitek 2 system. Agar diffusion method was used to test three groups of materials, NaOCl 5.25% serve as positive control, 0.25% Acetic acid as negative control and Chi-IONP as experimental material. Broth microdilution method used to determine the MIC/MBC of the experimental material. Statistical analysis used: Statistical analysis was conducted by independent variables t-test performed by using IBM-SPSS program version 22. Result: The used microbial isolates were confirmed with Vitek 2 system with excellent confidence level of diagnosis. Chi-IONP showed antifungal activity higher than NaOCl 5.25%, and comparable effect to NaOCl 5.25% against E.faecalis and S.mutans. The negative group showed no effect on the tested microorganisms. The MIC/MBC were determined as following 125/250 μg/ml for E.faecalis, 250/ 500μg/ml for S.mutans and the MIC/MFC was 62.5/ 125 μg/ml for C.albicans. Conclusion: Chi-IONP was a powerful antimicrobial agent against the tested microorganisms, and this test results shows antifungal activity of Chi-IONP higher than NaOCl 5.25% and comparable antibacterial effect to NaOCl 5.25%. [ABSTRACT FROM AUTHOR]

The use of chitosan nanoparticles (CNPs) will improve anti-microbial efficacy, mechanical integrity of diseased dentin matrix and tissue regeneration. Mechanical preparation in root canal treatment leads to the formation of smear layer. The aim of this study was to evaluate the effectiveness of chitosan nanoparticles in combination with Glyde gel in removing of smear layer. Twenty-five extracted maxillary single-rooted premolars were selected, and divided into five groups according to irrigation material used, (GI=Glyde gel, GII=2: 1 (Glyde-CNPs) gel, GIII=NaOCl gel 5.25%, GIV=NaOCl gel 2%, GV=Saline only). The teeth were instrumented using ProTaper Next System (X1-X4) when one of five irrigant materials used as a lubricant during instrumentation. A scoring system was used to conduct the SEM assessment in coronal, middle and apical part. The statistical analysis was done with Chi square test at (P<0.05). The smear layer was significantly reduced in all groups except the control and NaOCl groups (P>0.05). Chitosan nanoparticles could enhance the activity of Glyde gel in removing the smear layer. [ABSTRACT FROM AUTHOR]

The manipulation of matter at the nanoscale has unleashed a great potential for engineering biomedical drug carriers, but the transport of nanoparticles (NPs) under nanoscale confinement is still poorly understood. Using colloidal physics to describe NP interactions, we have computationally studied the passive transport of NPs using experimentally relevant conditions from bulk into a nanochannel of 60-90 nm height. NP size, channel height, and the Debye length are comparable so that changes in nanoscale dimensions may induce substantial changes in NP transport kinetics. We show that subtle changes in nanochannel dimensions may alter the energy barrier by about six orders of magnitude resulting in different NP penetration depths and diffusion mechanisms: ballistic, first-order and quasi zero-order transport regimes. The analysis of NP diffusion by continuum methods reveals that apparent diffusivity is reduced by decreasing channel size. The continuum finite element (FE) numerical method reproduced the colloidal model results only when surface interactions were accounted for. These results give a new insight into NP passive transport at the boundaries of nanoconfined domains, and have implications on the design of nanoscale fluidics and NP systems for biomedical and engineering applications. [ABSTRACT FROM AUTHOR]

This paper is primarily focused in studying the effects of nanoclay particles such as montmorillonite on improving mechanical and thermal properties of fiber reinforced polymer matrix composite materials. Basic correlations between polymer morphology, strength, modulus, toughness, and thermal stability of thermoset nanocomposites were investigated as a function of layered silicate content. S2-glass/epoxy-clay nanocomposites were manufactured through an affordable vacuum assisted resin infusion method (VARIM). The nanocomposites are formed during polymerization when the adsorbing monomer separates the clay particles into nanometer scales. Transmission electron microscopy (TEM) and wide angle X-ray diffraction(WAXD) were used to characterize the morphology of the dispersed clay particles. The thermal properties such as onset of decomposition and glass transition temperatures were determined by Thermo Gravimetric Analysis (TGA) and Dynamic Modulus Analyzer (DMA). Mechanical properties such as interlaminar shear strength, flexural properties and fracture toughness are also determined for both conventional S2-glass/epoxy composites and S2-glass fiber reinforced nanocomposites. The results show significant improvements in mechanical and thermal properties of conventional fiber reinforced composites with low loading of organo silicate nanoparticles. By dispersing 1% by weight nanosilicates, S2-glass/epoxy-clay nanocomposites attributed to almost 44. 24 and 23% improvement in interlaminar shear strength, flexural strength and fracture toughness in comparison to conventional S2-glass/epoxy composites. Similarly. the nanocomposites exhibit approximately 26 Celsius higher decomposition temperatures than that of conventional composites. This improved properties of fiber reinforced polymer nanocomposites are... [ABSTRACT FROM AUTHOR]

Abstract: Carboxymethyl chitin (CMC) nanoparticles were prepared by cross-linking of CMC solution with CaCl2 and FeCl3. The cytotoxicity of the CMC nanoparticles was evaluated using MTT assay and they were found to be non-toxic into L929 mouse cells. The antibacterial and magnetic properties of the CMC nanoparticles were also studied. The prepared CMC nanoparticles were characterized using SEM and FTIR. The model hydrophobic anticancer drug 5-fluorouracil (5-Fu) was loaded into CMC nanoparticles via emulsion cross-linking method. The encapsulation efficiency and in-vitro drug release behaviour of drug-loaded nanoparticles were studied by UV spectrophotometer. Drug release studies showed that the CMC nanoparticles showed controlled and sustained drug release at pH 6.8. Moreover, the prepared nanoparticles were also found to be antibacterial and their magnetic properties reveals for their potential use in drug tracking. These results indicated that CMC nanoparticles are a promising carrier system for controlled drug delivery. [Copyright &y& Elsevier]