A functionalized fluorescent dendrimer as a pesticide nanocarrier: application in pest control

Nanoscale ◽  
2015 ◽  
Vol 7 (2) ◽  
pp. 445-449 ◽  
Author(s):  
Xiaoxia Liu ◽  
Bicheng He ◽  
Zejun Xu ◽  
Meizhen Yin ◽  
Wantai Yang ◽  
...  

A water-soluble fluorescent cationic dendrimer can efficiently deliver a pesticide into the insect cells and largely increase the cytotoxicity of the drug.

Biomolecules ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1031
Author(s):  
Umut Toprak ◽  
Cansu Doğan ◽  
Dwayne Hegedus

Calcium (Ca2+) homeostasis is vital for insect development and metabolism, and the endoplasmic reticulum (ER) is a major intracellular reservoir for Ca2+. The inositol 1,4,5- triphosphate receptor (IP3R) and ryanodine receptor (RyR) are large homotetrameric channels associated with the ER and serve as two major actors in ER-derived Ca2+ supply. Most of the knowledge on these receptors derives from mammalian systems that possess three genes for each receptor. These studies have inspired work on synonymous receptors in insects, which encode a single IP3R and RyR. In the current review, we focus on a fundamental, common question: “why do insect cells possess two Ca2+ channel receptors in the ER?”. Through a comparative approach, this review covers the discovery of RyRs and IP3Rs, examines their structures/functions, the pathways that they interact with, and their potential as target sites in pest control. Although insects RyRs and IP3Rs share structural similarities, they are phylogenetically distinct, have their own structural organization, regulatory mechanisms, and expression patterns, which explains their functional distinction. Nevertheless, both have great potential as target sites in pest control, with RyRs currently being targeted by commercial insecticide, the diamides.


1938 ◽  
Vol 16 (3) ◽  
pp. 177-180 ◽  
Author(s):  
Enid M. Smedley

Since 1935 a large number of chemicals including chloro-acetic acid and various water-soluble chloro-acetates, received from the Pest Control Committee of Imperial Chemical Industries, have been tested for their value in controlling the potato strain of Heterodera schachtii under the direction of Prof. R. T. Leiper, F.R.S.Soils from Yorkshire and Ayrshire were used in the experiments, as they are of very different types, and might conceivably respond differently to chemical treatment.


2001 ◽  
Vol 29 (4) ◽  
pp. 571-577 ◽  
Author(s):  
J. Li ◽  
D. J. Derbyshire ◽  
B. Promdonkoy ◽  
D. J. Ellar

Crystal structures combined with biochemical data show that the δ-endotoxins from Bacillus thuringiensis are structurally poised towards large-scale, irreversible conformational changes that transform them from the soluble protein bound at the cell surface into a membrane-embedded form causing lysis of susceptible insect cells. Cry δ-endotoxins are made of a helix bundle, a β-prism and a β-sandwich. The conformational change involves an umbrella-like opening between the helix-4,5-hairpin and the remaining helices, and between the helical domain and the two sheet domains. Comparison of Cry1Ac structures with and without the bound receptor ligand GalNAc associates occupation of the high-affinity site on the β-sandwich with an increase of temperature factors in the helical, pore-forming domain, which may indicate how receptor binding could trigger the required major conformational change. The structure of Cyt δ-endotoxins indicates that the surface helix hairpins must peel away to expose the β-strands for membrane attack. Single amino acid substitutions in hinge residues or the core can restore activity following an inhibitory mutation.


Molecules ◽  
2020 ◽  
Vol 25 (10) ◽  
pp. 2290 ◽  
Author(s):  
Mariano Cáceres ◽  
Eduardo Guzmán ◽  
Agustín Alvarez-Costa ◽  
Francisco Ortega ◽  
Ramón G. Rubio ◽  
...  

Synthetic insecticides have been used for a long time as one of the most effective tools for insect pest control. However, the re-emergence of insect pests and their fast development of resistance, as has occurred for pyrethroid-resistant bed bugs Cimex lectularius L., make it necessary to develop new and safe strategies for effective pest control. This has fostered the research on new eco-sustainable formulations based on essential oils, which allows reducing the impact associated with the intensive use of synthetic insecticides on the environment and their effects on human health. This research explores the stability of water/eugenol/ethanol surfactantless emulsions loaded with imidacloprid (0.003 wt%), and their toxicity against a resistant bed bug strain. The results have shown that these emulsions enable the solubilization of a poorly water-soluble drug, such as the imidacloprid, without any significant modification of their stability. Furthermore, the application of the obtained formulations against the pyrethroid-resistant bed bug results in mortality in the 50–85% range upon topical and spray applications, with the increase of the eugenol content enhancing the effectiveness of the formulations. It may be expected that the ternary water/eugenol/ethanol mixtures could be further developed in the preparation of ready to use formulations, enabling the dispersion of insecticides for pest control.


2014 ◽  
Vol 2 (29) ◽  
pp. 4653-4659 ◽  
Author(s):  
Dongxu Shen ◽  
Fan Zhou ◽  
Zejun Xu ◽  
Bicheng He ◽  
Miao Li ◽  
...  

A water-soluble, fluorescent, cationic dendrimer systemically delivers dsRNA into insect cells and tissues, resulting in the suppression of the immune gene.


Author(s):  
J. G. Robertson ◽  
D. F. Parsons

The extraction of lipids from tissues during fixation and embedding for electron microscopy is widely recognized as a source of possible artifact, especially at the membrane level of cell organization. Lipid extraction is also a major disadvantage in electron microscope autoradiography of radioactive lipids, as in studies of the uptake of radioactive fatty acids by intestinal slices. Retention of lipids by fixation with osmium tetroxide is generally limited to glycolipids, phospholipids and highly unsaturated neutral lipids. Saturated neutral lipids and sterols tend to be easily extracted by organic dehydrating reagents prior to embedding. Retention of the more saturated lipids in embedded tissue might be achieved by developing new cross-linking reagents, by the use of highly water soluble embedding materials or by working at very low temperatures.


Author(s):  
J. D. McLean ◽  
S. J. Singer

The successful application of ferritin labeled antibodies (F-A) to ultrathin sections of biological material has been hampered by two main difficulties. Firstly the normally used procedures for the preparation of material for thin sectioning often result in a loss of antigenicity. Secondly the polymers employed for embedding may non-specifically absorb the F-A. Our earlier use of cross-linked polyampholytes as embedding media partially overcame these problems. However the water-soluble monomers used for this method still extract many lipids from the material.


Author(s):  
D.R. Mattie ◽  
J.W. Fisher

Jet fuels such as JP-4 can be introduced into the environment and come in contact with aquatic biota in several ways. Studies in this laboratory have demonstrated JP-4 toxicity to fish. Benzene is the major constituent of the water soluble fraction of JP-4. The normal surface morphology of bluegill olfactory lamellae was examined in conjunction with electrophysiology experiments. There was no information regarding the ultrastructural and physiological responses of the olfactory epithelium of bluegills to acute benzene exposure.The purpose of this investigation was to determine the effects of benzene on the surface morphology of the nasal rosettes of the bluegill sunfish (Lepomis macrochirus). Bluegills were exposed to a sublethal concentration of 7.7±0.2ppm (+S.E.M.) benzene for five, ten or fourteen days. Nasal rosettes were fixed in 2.5% glutaraldehyde and 2.0% paraformaldehyde in 0.1M cacodylate buffer (pH 7.4) containing 1.25mM calcium chloride. Specimens were processed for scanning electron microscopy.


Author(s):  
H. J. Arnott ◽  
M. A. Webb ◽  
L. E. Lopez

Many papers have been published on the structure of calcium oxalate crystals in plants, however, few deal with the early development of crystals. Large numbers of idioblastic calcium oxalate crystal cells are found in the leaves of Vitis mustangensis, V. labrusca and V. vulpina. A crystal idioblast, or raphide cell, will produce 150-300 needle-like calcium oxalate crystals within a central vacuole. Each raphide crystal is autonomous, having been produced in a separate membrane-defined crystal chamber; the idioblast''s crystal complement is collectively embedded in a water soluble glycoprotein matrix which fills the vacuole. The crystals are twins, each having a pointed and a bidentate end (Fig 1); when mature they are about 0.5-1.2 μn in diameter and 30-70 μm in length. Crystal bundles, i.e., crystals and their matrix, can be isolated from leaves using 100% ETOH. If the bundles are treated with H2O the matrix surrounding the crystals rapidly disperses.


Author(s):  
B. J. Grenon ◽  
A. J. Tousimis

Ever since the introduction of glutaraldehyde as a fixative in electron microscopy of biological specimens, the identification of impurities and consequently their effects on biologic ultrastructure have been under investigation. Several reports postulate that the impurities of glutaraldehyde, used as a fixative, are glutaric acid, glutaraldehyde polymer, acrolein and glutaraldoxime.Analysis of commercially available biological or technical grade glutaraldehyde revealed two major impurity components, none of which has been reported. The first compound is a colorless, water-soluble liquid with a boiling point of 42°C at 16 mm. Utilizing Nuclear Magnetic Resonance (NMR) spectroscopic analysis, this compound has been identified to be — dihydro-2-ethoxy 2H-pyran. This impurity component of the glutaraldehyde biological or technical grades has an UV absorption peak at 235nm. The second compound is a white amorphous solid which is insoluble in water and has a melting point of 80-82°C. Initial chemical analysis indicates that this compound is an aldol condensation product(s) of glutaraldehyde.


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