Targeted delivery of emamectin benzoate by functionalized polysuccinimide nanoparticles for the flowering cabbage and controlling Plutella xylostella

BACKGROUND

Plutella xylostella, one of the most destructive and cosmopolitan pests of cruciferous crops, is especially harmful to the young tissues of the flowering cabbage (Brassica campestris L.). Although emamectin benzoate (EB) has high insecticidal activity against P. xylostella, one major reason of low utilization for EB is the lack of internal transport in the young plants.

RESULTS

In this study, four kinds of functional EB/polysuccinimide (PSI) with glycine methylester nanoparticles (EB@PGA NPs) were prepared. The obtained EB@PGA NPs could effectively protect EB from photolysis, and the degradation rate of EB@PGA NPs was <30% in 24 h. Simulating the intestinal pH = 9 of P. xylostella, the highest cumulative release rate of EB@PGA NPs could reach 89.61% in 24 h. Furthermore, EB@PGA NPs could delivery EB into the young tissues of the flowering cabbage through the nanocarrier, and the highest transport efficiency of EB@PGA₂₅ reached 1.437%. The bioactivity of EB@PGA₂₅ against P. xylostella larvae (LC₅₀  = 0.34 μg mL^-1 ) was 1.6-fold higher than that of EB (LC₅₀  = 0.53 μg mL^-1 ). EB@PGA could easily become 'internalized' into the intestinal wall of P. xylostella, thus increasing the penetration of the drug and enhancing the insecticidal activity.

CONCLUSION

The accurate delivery of insecticides by PGA nanocarriers into young tissues of plants could be a promising new method for the efficient management of field pests and diseases. © 2021 Society of Chemical Industry.

Light-Interacting iron-based nanomaterials for localized cancer detection and treatment

To improve the prognosis of cancer patients, methods of local cancer detection and treatment could be implemented. For that, iron-based nanomaterials (IBN) are particularly well-suited due to their biocompatibility and the various ways in which they can specifically target a tumor, i.e. through passive, active or magnetic targeting. Furthermore, when it is needed, IBN can be associated with well-known fluorescent compounds, such as dyes, clinically approved ICG, fluorescent proteins, or quantum dots. They may also be excited and detected using well-established optical methods, relying on scattering or fluorescent mechanisms, depending on whether IBN are associated with a fluorescent compound or not. Systems combining IBN with optical methods are diverse, thus enabling tumor detection in various ways. In addition, these systems provide a wealth of information, which is inaccessible with more standard diagnostic tools, such as single tumor cell detection, in particular by combining IBN with near-field scanning optical microscopy, dark-field microscopy, confocal microscopy or super-resolution microscopy, or the highlighting of certain dynamic phenomena such as the diffusion of a fluorescent compound in an organism, e.g. using fluorescence lifetime imaging, fluorescence resonance energy transfer, fluorescence anisotropy, or fluorescence tomography. Furthermore, they can in some cases be complemented by a therapeutic approach to destroy tumors, e.g. when the fluorescent compound is a drug, or when a technique such as photo-thermal or photodynamic therapy is employed. This review brings forward the idea that iron-based nanomaterials may be associated with various optical techniques to form a commercially available toolbox, which can serve to locally detect or treat cancer with a better efficacy than more standard medical approaches. STATEMENT OF SIGNIFICANCE: New tools should be developed to improve cancer treatment outcome. For that, two closely-related aspects deserve to be considered, i.e. early tumor detection and local tumor treatment. Here, I present various types of iron-based nanomaterials, which can achieve this double objective when they interact with a beam of light under specific and accurately chosen conditions. Indeed, these materials are biocompatible and can be used/combined with most standard microscopic/optical methods. Thus, these systems enable on the one hand tumor cell detection with a high sensitivity, i.e. down to single tumor cell level, and on the other hand tumor destruction through various mechanisms in a controlled and localized manner by deciding whether or not to apply a beam of light and by having these nanomaterials specifically target tumor cells.

Optical-Based (Bio) Sensing Systems Using Magnetic Nanoparticles

In recent years, various reports related to sensing application research have suggested that combining the synergistic impacts of optical, electrical or magnetic properties in a single technique can lead to a new multitasking platform. Owing to their unique features of the magnetic moment, biocompatibility, ease of surface modification, chemical stability, high surface area, high mass transference, magnetic nanoparticles have found a wide range of applications in various fields, especially in sensing systems. The present review is comprehensive information about magnetic nanoparticles utilized in the optical sensing platform, broadly categorized into four types: surface plasmon resonance (SPR), surface-enhanced Raman spectroscopy (SERS), fluorescence spectroscopy and near-infrared spectroscopy and imaging (NIRS) that are commonly used in various (bio) analytical applications. The review also includes some conclusions on the state of the art in this field and future aspects.

Enhanced In Vitro Biocompatibility and Water Dispersibility of Magnetite and Cobalt Ferrite Nanoparticles Employed as ROS Formation Enhancer in Radiation Cancer Therapy

Efficient magnetic reactive oxygen species (ROS) formation enhancing agents after X-ray treatment are realized by functionalizing superparamagnetic magnetite (Fe₃ O₄ ) and Co-ferrite (CoFe₂ O₄ ) nanoparticles with self-assembled monolayers (SAMs). The Fe₃ O₄ and CoFe₂ O₄ nanoparticles are synthesized using Massart's coprecipitation technique. Successful surface modification with the SAM forming compounds 1-methyl-3-(dodecylphosphonic acid) imidazolium bromide, or (2-{2-[2-hydroxy-ethoxy]-ethoxy}-ethyl phosphonic acid provides biocompatibility and long-term stability of the Fe₃ O₄ and CoFe₂ O₄ nanoparticles in cell media. The SAM-stabilized ferrite nanoparticles are characterized with dynamic light scattering, X-ray powder diffraction, a superconducting quantum interference device, Fourier transform infrared attenuated total reflectance spectroscopy, zeta potential measurements, and thermogravimetric analysis. The impact of the SAM-stabilized nanoparticles on the viability of the MCF-7 cells and healthy human umbilical vein endothelial cells (HUVECs) is assessed using the neutral red assay. Under X-ray exposure with a single dosage of 1 Gy the intracellular SAM stabilized Fe₃ O₄ and CoFe₂ O₄ nanoparticles are observed to increase the level of ROS in MCF-7 breast cancer cells but not in healthy HUVECs. The drastic ROS enhancement is associated with very low dose modifying factors for a survival fraction of 50%. This significant ROS enhancement effect by SAM-stabilized Fe₃ O₄ and CoFe₂ O₄ nanoparticles constitutes their excellent applicability in radiation therapy.

Recent Progress in Synthesis and Functionalization of Multimodal Fluorescent-Magnetic Nanoparticles for Biological Applications

There is a great interest in the development of new nanomaterials for multimodal imaging applications in biology and medicine. Multimodal fluorescent-magnetic based nanomaterials deserve particular attention as they can be used as diagnostic and drug delivery tools, which could facilitate the diagnosis and treatment of cancer and many other diseases. This review focuses on the recent developments of magnetic-fluorescent nanocomposites and their biomedical applications. The recent advances in synthetic strategies and approaches for the preparation of fluorescent-magnetic nanocomposites are presented. The main biomedical uses of multimodal fluorescent-magnetic nanomaterials, including biological imaging, cancer therapy and drug delivery, are discussed, and prospects of this field are outlined.

Resveratrol-Loaded Albumin Nanoparticles with Prolonged Blood Circulation and Improved Biocompatibility for Highly Effective Targeted Pancreatic Tumor Therapy

Human serum albumin (HSA) is an intrinsic protein and important carrier that transports endogenous as well as exogenous substances across cell membranes. Herein, we have designed and prepared resveratrol (RV)-loaded HSA nanoparticles conjugating RGD (arginine-glycine-aspartate) via a polyethylene glycol (PEG) "bridge" (HRP-RGD NPs) for highly effective targeted pancreatic tumor therapy. HRP-RGD NPs possess an average size of 120 ± 2.6 nm with a narrow distribution, a homodisperse spherical shape, a RV encapsulation efficiency of 62.5 ± 4.21%, and a maximum RV release ratio of 58.4.2 ± 2.8% at pH 5.0 and 37 °C. In vitro biocompatibility of RV is improved after coating with HSA and PEG. Confocal fluorescence images show that HRP-RGD NPs have the highest cellular uptake ratio of 47.3 ± 4.6% compared to HRP NPs and HRP-RGD NPs with free RGD blocking, attributing to an RGD-mediated effect. A cell counting kit-8 (CCK-8) assay indicates that HRP-RGD NPs without RV (HP-RGD NPs) have nearly no cytotoxicity, but HRP-RGD NPs are significantly more cytotoxic to PANC-1 cells compared to free RV and HRP NPs in a concentration dependent manner, showing apoptotic morphology. Furthermore, with a formulated PEG and HSA coating, HRP-RGD NPs prolong the blood circulation of RV, increasing approximately 5.43-fold (t1/2). After intravenous injection into tumor-bearing mice, the content of HRP-RGD NPs in tumor tissue was proven to be approximately 3.01- and 8.1-fold higher than that of HRP NPs and free RV, respectively. Based on these results, HRP-RGD NPs were used in an in vivo anti-cancer study and demonstrated the best tumor growth suppression effect of all tested drugs with no relapse, high in vivo biocompatibility, and no significant systemic toxicity over 35 days treatment. These results demonstrate that HRP-RGD NPs with prolonged blood circulation and improved biocompatibility have high anti-cancer effects with promising future applications in cancer therapy.

Maghemite nanoparticles coated with human serum albumin: combining targeting by the iron-acquisition pathway and potential in photothermal therapies

Human serum albumin (HSA), the most abundant plasma protein in human blood, is a natural transport vehicle with multiple ligand binding sites. It, therefore, constitutes an attractive candidate for drug delivery. Targeting may occur via the most known interaction of the protein with the neonatal Fc receptor (FcRn). Here, we investigate another HSA delivery path, involving the transferrin receptor, and we elaborate a maghemite-HSA nanohybrid, opening up new opportunities for medical applications. Fluorescence spectrophotometric titration and size-exclusion chromatography were used to substantiate, in cell-free assays, an interaction between HSA and the transferrin receptor R1. This occurs with a dissociation constant, K_D of 6.7 nM. This interaction was confirmed in HeLa cell culture where, by confocal microscopy, rhodamine-labeled HSA is shown to be internalized. HSA was then covalently conjugated onto maghemite nanoparticles (NPs) to give a NP-HSA nanohybrid. The therapeutic potential of this hybrid was demonstrated through its heating capacity in magnetic hyperthermia (MH) and near-infrared (NIR) photothermia (PT). In particular, the Specific Absorption Rate (SAR) in the PT Therapy (PTT) mode, using a 808 nm NIR-LASER (1 W cm^-2) and at iron concentration as low as 2.5 mM, was found to be very high, equal to 1870 W g^-1 with a temperature increment of 9.2 °C. The nanohybrids incubated with HeLa cells were mainly localized at the cell surface. When the PTT mode was applied under the same conditions as in vitro, mortality was higher in HeLa cells than in fibroblasts (non-malignant cells). Cytotoxicity was checked in both cell lines without the PTT mode; the nanohybrids do not seem to affect cell viability. These results make the nanohybrids very promising agents for NIR-PT and for targeting in cancer therapy, since non-malignant cells were not damaged.