Nanotechnology in Agriculture: Manganese Ferrite Nanoparticles as a Micronutrient Fertilizer for Wheat

Limited research has focused on nanoparticle (NP) applications' impact on edible wheat parts in a field environment. Here, we studied the nutritional quality of edible parts of wheat (Triticum aestivum L.) with a field experiment by spraying MnFe2O4 nanoparticles. Wheat was foliar sprayed with 0, 25, 50, and 100 mg/L composite manganese ferrite (MnFe2O4) NPs during 220 d of a growth period. Ionic controls were prepared using the conventional counterparts (MnSO4·H2O and FeSO4·7H2O) to compare with the 100 mg/L MnFe2O4 NPs. After three consecutive foliar applications, nanoparticles demonstrated a substantial elevation in grain yield and harvest index, exhibiting a noteworthy increase to 5.0 ± 0.12 t/ha and 0.46 ± 0.001 in the 100 mg/L NP dose, respectively, concomitant with a 14% enhancement in the grain number per spike. Fe, Mn, and Ca content in grain increased to 77 ± 2.7 mg/kg, 119 ± 2.8 mg/kg, and 0.32 ± 7.9 g/kg in the 100 mg/L NPs, respectively. Compared to the ion treatment, the 100 mg/L NP treatments notably boosts wheat grain crude protein content (from 13 ± 0.79% to 15 ± 0.58%) and effectively lowers PA/Fe levels (from 11 ± 0.7 to 9.3 ± 0.5), thereby improving Fe bioavailability. The VSM results exhibited a slight superparamagnetic behavior, whereas the grains and stems exhibited diamagnetic behavior. The results indicate that the nanomaterial did not accumulate in the grains, suggesting its suitability as an Fe and Mn-rich fertilizer in agriculture. Above all, the foliar application of nanocomposites increased the concentrations of Fe, Mn, and Ca in wheat grains, accompanied by a significant enhancement in grain yield. Therefore, the research results indicate that the foliar application of MnFe2O4 NPs can positively regulate wheat grains' nutritional quality and yield.

The modified biochar from wheat straw by the combined composites of MnFe2O4 nanoparticles and chitosan Schiff base for enhanced removal of U(VI) ions from aqueous solutions

In the last few decades, U(VI) is a significant environmental threat. The innovative and environmentally friendly adsorbent materials for U(VI) removal were urgent. Preparation of the modified biochar from wheat straw by combined composites of MnFe2O4 nanoparticles and chitosan Schiff base (MnFe2O4@CsSB/BC) was characterized, and adsorption experiments were carried out to investigate the performance and interfacial mechanism of U(VI) removal. The results showed that MnFe2O4@CsSB/BC exhibited high adsorption capacity of U(VI) compared with BC. The adsorption process of U(VI) removal by MnFe2O4@CsSB/BC could be ascribed as pseudo-second-order model and Langmuir model. The maximum adsorption capacity of U(VI) removal by MnFe2O4@CsSB/BC reached 19.57 mg/g at pH4.0, 30 mg/L of U(VI), and 25 °C. The possible mechanism was a chemical adsorption process, and it mainly contained electrostatic attraction and surface complexation. Additionally, it also was an economic and environmental friendly adsorbent.

A novel Anti-ROS osteoblast-specific delivery system for ankylosing spondylitis treatment via suppression of both inflammation and pathological new bone formation

Ankylosing spondylitis (AS) is a common rheumatic disorder distinguished by chronic inflammation and heterotopic ossification at local entheses sites. Currently available medications, including nonsteroidal anti-inflammatory drugs (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs) and TNF inhibitors, are limited by side effects, high costs and unclear inhibitory effects on heterotopic ossification. Herein, we developed manganese ferrite nanoparticles modified by the aptamer CH6 (CH6-MF NPs) that can efficiently scavenge ROS and actively deliver siRNA into hMSCs and osteoblasts in vivo for effective AS treatment. CH6-MF NPs loaded with BMP2 siRNA (CH6-MF-Si NPs) effectively suppressed abnormal osteogenic differentiation under inflammatory conditions in vitro. During their circulation and passive accumulation in inflamed joints in the Zap70^mut mouse model, CH6-MF-Si NPs attenuated local inflammation and rescued heterotopic ossification in the entheses. Thus, CH6-MF NPs may be an effective inflammation reliever and osteoblast-specific delivery system, and CH6-MF-Si NPs have potential for the dual treatment of chronic inflammation and heterotopic ossification in AS.

Immunologically modified MnFe2O4 nanoparticles to synergize photothermal therapy and immunotherapy for cancer treatment

Immunotherapy has been a promising candidate for cancer treatment. The combination of photothermal therapy (PTT) and immunotherapy have shown to cause tumor ablation and induce host immune response. However, this strategy is often hampered by a limited immune response and undesirable immunosuppression. In this work, we developed an immunologically modified nanoplatform, using ovalbumin (OVA)-coated PEGylated MnFe₂O₄ nanoparticles (NPs) loaded with R837 immunoadjuvant (R837-OVA-PEG-MnFe₂O₄ NPs) to synergize PTT and immunotherapy for the treatment of breast cancer. The designed R837-OVA-PEG-MnFe₂O₄ NPs are able to elicit significant immune responses in vitro and in vivo. MnFe₂O₄ NPs also allowed for a reduction of systemic immunosuppression through downregulation of M2-associated cytokines. More importantly, the R837-OVA-PEG-MnFe₂O₄ NPs under laser irradiation effectively inhibited tumor growth and prevented lung metastases, leading to a prolonged survival time and improved survival rate. In addition, the designed multitasking MnFe₂O₄ NPs showed as a good contrast agent for magnetic resonance (MR) imaging to detect orthotopic breast tumor in vivo. Our work provides a novel strategy for combined PTT and improved immunotherapy in the treatment of breast and other metastatic cancers.

Biodistribution and acute toxicity of a nanofluid containing manganese iron oxide nanoparticles produced by a mechanochemical process

Superparamagnetic iron oxide nanoparticles are candidate contrast agents for magnetic resonance imaging and targeted drug delivery. Biodistribution and toxicity assessment are critical for the development of nanoparticle-based drugs, because of nanoparticle-enhanced biological reactivity. Here, we investigated the uptake, in vivo biodistribution, and in vitro and in vivo potential toxicity of manganese ferrite (MnFe2O4) nanoparticles, synthesized by an original high-yield, low-cost mechanochemical process. Cultures of murine Balb/3T3 fibroblasts were exposed for 24, 48, or 72 hours to increasing ferrofluid concentrations. Nanoparticle cellular uptake was assessed by flow-cytometry scatter-light measurements and microscopy imaging after Prussian blue staining; cytotoxicity was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and colony-forming assays. After a single intravenous injection, in vivo nanoparticle biodistribution and clearance were evaluated in mice by Mn spectrophotometric determination and Prussian blue staining in the liver, kidneys, spleen, and brain at different posttreatment times up to 21 days. The same organs were analyzed for any possible histopathological change. The in vitro study demonstrated dose-dependent nanoparticle uptake and statistically significant cytotoxic effects from a concentration of 50 μg/mL for the MTT assay and 20 μg/mL for the colony-forming assay. Significant increases in Mn concentrations were detected in all analyzed organs, peaking at 6 hours after injection and then gradually declining. Clearance appeared complete at 7 days in the kidneys, spleen, and brain, whereas in the liver Mn levels remained statistically higher than in vehicle-treated mice up to 3 weeks postinjection. No evidence of irreversible histopathological damage to any of the tested organs was observed. A comparison of the lowest in vitro toxic concentration with the intravenously injected dose and the administered dose of other ferrofluid drugs currently in clinical practice suggests that there might be sufficient safety margins for further development of our formulation.

Synthesis and Characterization of Multifunctional Chitosan- MnFe₂O4 Nanoparticles for Magnetic Hyperthermia and Drug Delivery

Multifunctional nanoparticles composed of MnFe₂O₄ were encapsulated in chitosan for investigation of system to combine magnetically-triggered drug delivery and localized hyperthermia for cancer treatment with the previously published capacity of MnFe₂O₄ to be used as an efficient MRI contrast agent for cancer diagnosis. This paper focuses on the synthesis and characterization of magnetic MnFe₂O₄ nanoparticles, their dispersion in water and their incorporation in chitosan, which serves as a drug carrier. The surface of the MnFe₂O₄ nanoparticles was modified with meso-2,3-di-mercaptosuccinic acid (DMSA) to develop stable aqueous dispersions. The nanoparticles were coated with chitosan, and the magnetic properties, heat generation and hydrodynamic size of chitosan-coated MnFe₂O₄ were evaluated for various linker concentrations and in a range of pH conditions.