Lignin-based porous junction for silver-silver chloride reference electrodes

Carbonized lignin powder was used as a salt bridge for a silver-silver chloride reference electrode. This easy-to-prepare reference electrode exhibited excellent stability in saturated potassium chloride solution. In addition, the electrochemical impedance spectra showed that the prepared reference electrode is stable in acidic, neutral, and basic aqueous solutions (pH 1 - 12) and has similar impedances to its glass frit equivalent

Magnetic Accumulation of SPIONs under Arterial Flow Conditions: Effect of Serum and Red Blood Cells

Magnetic drug targeting utilizes an external magnetic field to target superparamagnetic iron oxide nanoparticles (SPIONs) and their cargo to the diseased vasculature regions. In the arteries, the flow conditions affect the behavior of magnetic particles and the efficacy of their accumulation. In order to estimate the magnetic capture of SPIONs in more physiological-like settings, we previously established an ex vivo model based on human umbilical cord arteries. The artery model was employed in our present studies in order to analyze the effects of the blood components on the efficacy of magnetic targeting, utilizing 2 types of SPIONs with different physicochemical characteristics. In the presence of freshly isolated human plasma or whole blood, a strong increase in iron content measured by AES was observed for both particle types along the artery wall, in parallel with clotting activation due to endogenous thrombin generation in plasma. Subsequent studies therefore utilized SPION suspensions in serum and washed red blood cells (RBCs) at hematocrit 50%. Interestingly, in contrast to cell culture medium suspensions, magnetic accumulation of circulating SPION-3 under the external magnet was achieved in the presence of RBCs. Taken together, our data shows that the presence of blood components affects, but does not prevent, the magnetic accumulation of circulating SPIONs

Highly Porous Cellulose-Based Carbon Fibers as Effective Adsorbents for Chlorpyrifos Removal: Insights and Applications

The extensive utilization of the organophosphate pesticide chlorpyrifos, combined with its acute neurotoxicity, necessitates the development of effective strategies for its environmental removal. While numerous methods have been explored for chlorpyrifos removal from water, adsorption is the most promising. We investigated the potential of two cellulose-derived porous carbons as adsorbents for chlorpyrifos removal from water, prepared by either CO2 or H2O activation, resulting in similar morphologies and porosities but different amounts of heteroatom functionalities. The kinetics of batch adsorption removal from water fits well with the pseudo-first-order and pseudo-second-order kinetic models for both materials. The Freundlich, Langmuir, Dubinin–Radushkevich, and Sips isotherm models described the process of chlorpyrifos adsorption very well in all investigated cases. The maximum adsorption capacity determined from the Sips isotherm model gave values of 80.8 ± 0.1 mg g−1 and 132 ± 3 mg g−1 for the H2O and CO2 activated samples, respectively, reflecting the samples’ differences in heteroatom functionalities. Additionally, the application of either adsorbent led to reduced toxicity levels in all tested samples, implying that no harmful byproducts were generated during adsorption. Comparative analysis with the existing literature further validates the study’s findings, suggesting the efficacy and applicability of cellulose-based porous carbons for sustainable chlorpyrifos remediation

Surface modifcation of SPIONs in PHBV microspheres for biomedical applications

Surface modification of superparamagnetic iron oxide nanoparticles (SPIONs) has been introduced with lauric acid and oleic acid via co-precipitation and thermal decomposition methods, respectively. This modification is required to increase the stability of SPIONs when incorporated in hydrophobic, biodegradable and biocompatible polymers such as poly (3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). In this work, the solid-in-oil-in-water (S/O/W) emulsion-solvent extraction/evaporation method was utilized to fabricate magnetic polymer microspheres incorporating SPIONs in PHBV. The prepared magnetic PHBV microspheres exhibited particle sizes <1 µm. The presence of functional groups of lauric acid, oleic acid and iron oxide in the PHBV microspheres was confirmed by Fourier Transform Infrared spectroscopy (FTIR). X-ray diffraction (XRD) analysis was performed to further confirm the success of the combination of modified SPIONs and PHBV. Thermogravimetric analysis (TGA) indicated that PHBV microspheres were incorporated with SPIONsLauric as compared with SPIONsOleic. This was also proven via magnetic susceptibility measurement as a higher value of this magnetic property was detected for PHBV/SPIONsLauric microspheres. It was revealed that the magnetic PHBV microspheres were non-toxic when assessed with mouse embryotic fibroblast cells (MEF) at different concentrations of microspheres. These results confirmed that the fabricated magnetic PHBV microspheres are potential candidates for use in biomedical applications

Investigating the Adsorption Kinetics of Dimethoate, Malathion and Chlorpyrifos on Cellulose-Derived Activated Carbons: Understanding the Influence of Physicochemical Properties

In light of the escalating environmental concerns regarding pesticide accumulation, it is imperative to devise efficient strategies for their removal. Among the various options, activated carbons have emerged as promising candidates for adsorptive pesticide removal due to their many advantages, such as large surface area, well-developed porosity, and cost-effectiveness. However, the intricate relationship between the properties of these materials and their performance in pesticide adsorption remains largely unexplored. This study primarily focuses on examining the adsorption kinetics of three organophosphate pesticides: dimethoate, malathion (aliphatic), and chlorpyrifos (aromatic), using a range of cellulose-based activated carbon fibers with diverse specific surface areas, pore size distributions, and elemental compositions. By employing sophisticated data analysis tools, principal component analysis, and semi-empirical quantum chemical calculations, this study uncovers the importance of these distinct properties in efficiently removing structurally diverse pesticides. The results of the adsorption experiments suggested that these processes can be described using a pseudo-second-order kinetic model, which is confirmed via multiple linear regression. The obtained data suggest that the most effective carbon material for pesticide removal should have a pore diameter of approximately 4 nm, low oxygen content, a unimodal pore size distribution, and a high presence of sp2 domains. The insights from this research have the potential to guide the development of improved adsorbents and facilitate the rational selection of adsorbents tailored to specific pollutants based on their physicochemical properties and the pollutants’ chemical structure. By shedding light on the vital connection between adsorbent properties and performance, our findings significantly advance sustainable and effective pesticide removal, thereby fostering a cleaner and healthier environment

Genotoxicity of Superparamagnetic Iron Oxide Nanoparticles in Granulosa Cells

Nanoparticles that are aimed at targeting cancer cells, but sparing healthy tissue provide an attractive platform of implementation for hyperthermia or as carriers of chemotherapeutics. According to the literature, diverse effects of nanoparticles relating to mammalian reproductive tissue are described. To address the impact of nanoparticles on cyto- and genotoxicity concerning the reproductive system, we examined the effect of superparamagnetic iron oxide nanoparticles (SPIONs) on granulosa cells, which are very important for ovarian function and female fertility. Human granulosa cells (HLG-5) were treated with SPIONs, either coated with lauric acid (SEONLA) only, or additionally with a protein corona of bovine serum albumin (BSA;SEONLA-BSA),or with dextran (SEONDEX). Both micronuclei testing and the detection of H2A.X revealed no genotoxic effects of SEONLA-BSA, SEONDEX or SEONLA. Thus, it was demonstrated that different coatings of SPIONs improve biocompatibility, especially in terms of genotoxicity towards cells of the reproductive system

Functionalization Of T Lymphocytes With Citrate-Coated Superparamagnetic Iron Oxide Nanoparticles For Magnetically Controlled Immune Therapy

Purpose: Immune activation with T cell tumor infiltration is beneficial for the prognosis of patients suffering from solid cancer. Depending on their immune status, solid tumors can be immunologically classified into three groups: “hot” tumors are infiltrated with T lymphocytes, “cold” tumors are not infiltrated and “immune excluded” tumors are only infiltrated in the peripheral tumor tissue. Checkpoint inhibitors provide new therapeutic options for “hot” tumors by triggering the immune response of T cells. In order to enable this for cold tumors as well, T cells must be enriched in the tumor. Therefore, we use the principle of magnetic targeting to guide T cells loaded with citrate-coated superparamagnetic iron oxide nanoparticles (SPIONCitrate) to the tumor by an externally applied magnetic field. Methods: SPIONCitrate were produced by alkaline coprecipitation of iron(II) and iron(III) chloride and in situ coating with sodium citrate. The concentration-dependent cytocompatibility of the particles was determined by flow cytometry and blood stability assays. Atomic emission spectroscopy was used for the quantification of the particle uptake into T lymphocytes. The attractability of the loaded cells was observed by live-cell imaging in the presence of an externally applied magnetic field. Results: SPIONCitrate displayed good cytocompatibility to T cells and did not show any sign of aggregation in blood. Finally, SPIONCitrate-loaded T cells were strongly attracted by a small external magnet. Conclusion: T cells can be “magnetized” by incorporation of SPIONCitrate for magnetic targeting. The production of the particle-cell hybrid system is straightforward, as the loading process only requires basic laboratory devices and the loading efficiency is sufficient for cells being magnetically controllable. For these reasons, SPIONCitrate are potential suitable candidates for magnetic T cell targeting