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1.
ACS Appl Mater Interfaces ; 15(1): 1843-1858, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36539955

RESUMO

Environmental contamination by intense insecticide usage is consistently proposed as a significant contributor to major hazards; further, disturbing non-target populations provoke a grave concern worldwide as they play essential roles in ecosystems. Pyriproxyfen is one of the most widely used pesticides; however, due to its probable toxicity, its global application in large amounts may result in water concentrations that exceed regulatory pollution thresholds. Herein, we describe nanopyriproxyfen-loaded sago beads (PPX-NCB) designed for the slow release of pyriproxyfen (PPX). Our design is inspired by the composite structure of sago beads, composed of several small beads resembling a pomegranate. The microscopic beads accumulate chitosan-PPX-nanomicelles cross-linked with tripolyphosphate via physical absorption, offering adequate room for water absorption and subsequent PPX release. PPX-NCB had distinct effects on the immature egg and larva of Anopheles stephensi, limiting embryonic development in the eggs while enhancing bioactivity. It affects the integument of larvae and alters the surface hydrocarbons of eggs and larvae. In addition, PPX-NCB demonstrates an improved safety profile in non-target Daphnia magna.


Assuntos
Praguicidas , Punica granatum , Animais , Amido , Ecossistema , Praguicidas/toxicidade , Água , Larva
2.
NanoImpact ; 28: 100431, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36206944

RESUMO

Bio-inspired nanoparticles, including metallic, micelles, and polymeric, have been explored as a novel tool in the quest for effective and safe agrochemicals. Although nanoparticles (NPs) are being rapidly investigated for their usefulness in agricultural production and protection, little is known about the behaviour and interaction of oil-in-water micelle nanoparticles or nano-micelles (NM) with plants. We loaded a bio-based resin inherent of tree from the Pinaceae family as active material and produced stable nano-micelles using a natural emulsifier system. Here, we show that foliar-applied nano-micelle can translocate in two dicot plants belonging to diverse families (Coriandrum sativum -Apiaceae and Trigonella foenumgraecum -Fabaceae) via similar mode. Fluorescent-tagged NM (average diameter 11.20nm) showed strong signals and higher intensities as revealed by confocal imaging and exhibited significant adhesion in leaf compared to control. The NM subsequently translocates to other parts of the plants. As observed by SEM, the leaf surface anatomies revealed higher stomata densities and uptake of NM by guard cells; furthermore, larger extracellular spaces in mesophyll cells indicate a possible route of NM translocation. In addition, NM demonstrated improved wetting-spreading as illustrated by contact angle measurement. In a field bioassay, a single spray application of NM offered protection from aphid infestation for at least 9 days. There were no signs of phytotoxicity in plants post-application of NM. We conclude that pine resin-based nano-micelle provides an efficient, safe, and sustainable alternative for agricultural applications.


Assuntos
Micelas , Folhas de Planta , Humanos
3.
Sci Rep ; 10(1): 14107, 2020 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-32839484

RESUMO

The use pesticide is one of the indispensable means to combat mosquito borne diseases. However, the repeated use of synthetic pesticides has induced resistance in the vector pest along with undesirable impact on the environment. The biodegradability, non-persistent and user's safety are the root cause to prefer plant-derived pesticides to synthetic ones. The botanical based pesticides tend to degrade rapidly under the influence of several environmental factors. For the feasible application as pesticides, the plant products are formulated either as liquid or as purely solid. Despite well-established formulation technology in pesticide delivery, their handling trouble is being ignored. There is difficulty in liquid formulation of pesticide products, as they are prone to splashing and spillage, resulting in contamination, wastage and direct exposure to skin; whereas a solid formulation tends to produce dust. In the present work, cedarwood (Cedrus deodara) essential oil embedded pectin nanocapsules were produced. The nanocapsules were characterized according to their morphology, size, encapsulation efficiency and thermal stability. Furthermore, the nanocapsules were impregnated onto mini cotton tea bags to be employed as RTU (ready to use) formulation for treating the breeding sites of mosquitoes. The larvicidal activity of the bags treated with pectin-cedar wood nanocapsules was assessed against malaria vector, Anopheles culicifacies and 98% mortality was recorded till 4 weeks, this suggests its potential and hassle free applications in controlling mosquito vector.


Assuntos
Anopheles/efeitos dos fármacos , Inseticidas/farmacologia , Malária/prevenção & controle , Mosquitos Vetores/efeitos dos fármacos , Óleos Voláteis/farmacologia , Animais , Agentes de Controle Biológico/farmacologia , Cedrus/química , Nanocápsulas , Pectinas , Chá/química
4.
Colloids Surf B Biointerfaces ; 181: 789-797, 2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31238211

RESUMO

Chitosan nanocapsules, containing lemongrass (Cymbopogon citratus) oil (LGO), have been developed in gel form in which acrylate (Ac) was incorporated as a thickener and fabric binder. The gel was impregnated on fabric to achieve long-lasting and wash-durable mosquito repellency. The interaction between cotton fibers and gel was investigated by FTIR and XRD. Wash durability of gel was compared with chitosan nanocapsules without acrylate (LGO-encap) using SEM and GC-MS. The SEM analyses revealed that acrylate containing nanocapsules retains on fabric after a series of washing. The GC-MS results indicated that the relative amount of deducible oil components from fabric was found to be higher after the series of washing in acrylate containing nanocapsules (LGO-encap-Ac), which further points to the improved wash durability and retention of capsules on fabric. The bio-efficacy results of post-fifteen washing turned out was 75% of repellency against mosquitoes with the use of acrylate; while in nanocapsules without acrylate, only 51% of repellency was achieved. Furthermore, the 36 days repeated application of nanogel on Swiss albino mice did not show any signs of dermal toxicity. The formulation is, thus, suitable to impregnate dress of the military personals and individuals who have to perform field duty and where risk of mosquito bites is probably more.


Assuntos
Acrilatos/farmacologia , Quitosana/farmacologia , Culicidae/efeitos dos fármacos , Polietilenoglicóis/farmacologia , Polietilenoimina/farmacologia , Pele/efeitos dos fármacos , Acrilatos/química , Animais , Quitosana/química , Fibra de Algodão , Feminino , Camundongos , Nanogéis/química , Tamanho da Partícula , Polietilenoglicóis/química , Polietilenoimina/química , Propriedades de Superfície
5.
Echocardiography ; 25(10): 1138-44, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18986398

RESUMO

Five adult patients with Takotsubo cardiomyopathy (TC) diagnosed by usual criteria were studied with velocity vector imaging (VVI) on admission and at follow-up, when their LV function had improved, as assessed by 2D TTE wall-motion score (WMS) index. Averaged peak segmental longitudinal strain (S) in systole, and velocity (V) and strain rate (SR) in both systole and diastole were measured from apical 4- (A4C) and 2-chamber views (A2C) in all patients. The data obtained by VVI were analyzed separately for involved and uninvolved segments, which were independently assessed by WMS. In the involved segments, systolic S, V, SR, and diastolic SR improved (P-value < 0.05) on follow-up. Diastolic V showed a trend toward improvement but did not reach statistical significance. In the uninvolved segments, none of the parameters improved significantly either during systole or diastole. In three of these five patients, left atrial (LA) walls were also studied by placing region of interest (ROI) points in the middle of each wall. Peak segmental LA systolic and diastolic V and SR as well as systolic S were obtained for both involved and uninvolved LA walls which were assessed independently using WMS similar to LV. In the involved LA walls, none of the atrial systolic and diastolic parameters changed significantly but all parameters with the exception of systolic V showed a tendency toward improvement during follow-up. Among the uninvolved LA walls, none changed significantly but atrial systolic SR and, diastolic V and SR tended to increase during follow-up. Our retrospective study using VVI demonstrates that TC patients also have LV systolic and diastolic longitudinal dysfunction, not just systolic radial dysfunction as assessed by traditional 2D TTE indices. Longitudinal LA dysfunction may also be present.


Assuntos
Função do Átrio Esquerdo , Velocidade do Fluxo Sanguíneo/fisiologia , Ventrículos do Coração/diagnóstico por imagem , Cardiomiopatia de Takotsubo/diagnóstico por imagem , Ultrassonografia , Idoso , Diástole/fisiologia , Seguimentos , Humanos , Pessoa de Meia-Idade , Sístole/fisiologia , Ultrassonografia/métodos
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