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1.
Sci Adv ; 10(6): eabd7904, 2024 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-38324682

RESUMEN

Effective therapeutic modalities and drug administration strategies for the treatment of chronic obstructive pulmonary disease (COPD) exacerbations are lacking. Here, mucus and biofilm dual-penetrating immunoantimicrobials (IMAMs) are developed for bridging antibacterial therapy and pro-resolving immunotherapy of COPD. IMAMs are constructed from ceftazidime (CAZ)-encapsulated hollow mesoporous silica nanoparticles (HMSNs) gated with a charge/conformation-transformable polypeptide. The polypeptide adopts a negatively charged, random-coiled conformation, masking the pores of HMSNs to prevent antibiotic leakage and allowing the nebulized IMAMs to efficiently penetrate the bronchial mucus and biofilm. Inside the acidic biofilm, the polypeptide transforms into a cationic and rigid α helix, enhancing biofilm retention and unmasking the pores to release CAZ. Meanwhile, the polypeptide is conditionally activated to disrupt bacterial membranes and scavenge bacterial DNA, functioning as an adjuvant of CAZ to eradicate lung-colonizing bacteria and inhibiting Toll-like receptor 9 activation to foster inflammation resolution. This immunoantibacterial strategy may shift the current paradigm of COPD management.


Asunto(s)
Nanopartículas , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Pulmón , Nanopartículas/química , Ceftazidima , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Péptidos
2.
Adv Mater ; 35(11): e2206821, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36574636

RESUMEN

Oral delivery of small interfering RNA (siRNA) provides a promising paradigm for treating diseases that require regular injections. However, the multiple gastrointestinal (GI) and systemic barriers often lead to inefficient oral absorption and low bioavailability of siRNA. Technologies that can overcome these barriers are still lacking, which hinders the clinical potential of orally delivered siRNA. Herein, small-sized, fluorinated nanocapsules (F-NCs) are developed to mediate efficient oral delivery of tumor necrosis factor α (TNF-α) siRNA for anti-inflammation treatment. The NCs possess a disulfide-cross-linked shell structure, thus featuring robust stability in the GI tract. Because of their small size (≈30 nm) and fluorocarbon-assisted repelling of mucin adsorption, the best-performing F3 -NCs show excellent mucus penetration and intestinal transport capabilities without impairing the intestinal tight junction, conferring the oral bioavailability of 20.4% in relative to intravenous injection. The disulfide cross-linker can be cleaved inside target cells, causing NCs dissociation and siRNA release to potentiate the TNF-α silencing efficiency. In murine models of acute and chronic inflammation, orally delivered F3 -NCs provoke efficient TNF-α silencing and pronounced anti-inflammatory efficacies. This study therefore provides a transformative strategy for oral siRNA delivery, and will render promising utilities for anti-inflammation treatment.


Asunto(s)
Nanocápsulas , Ratones , Animales , Nanocápsulas/química , ARN Interferente Pequeño/química , Factor de Necrosis Tumoral alfa/genética , Antiinflamatorios/química , Inflamación/tratamiento farmacológico
3.
Biomater Sci ; 10(21): 6258-6266, 2022 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-36111777

RESUMEN

Apoptosis of cardiomyocytes is a critical outcome of myocardial ischemia-reperfusion injury (MIRI), which leads to the permanent impairment of cardiac function. Upregulated E2F1 is implicated in inducing cardiomyocyte apoptosis, and thus intervention of the E2F1 signaling pathway via RNA interference may hold promising potential for rescuing the myocardium from MIRI. To aid efficient E2F1 siRNA (siE2F1) delivery into cardiomyocytes that are normally hard to transfect, a spherical, α-helical polypeptide (SPP) with potent membrane activity was developed via dendrimer-initiated ring-opening polymerization of N-carboxyanhydride followed by side-chain functionalization with guanidines. Due to its multivalent structure, SPP outperformed its linear counterpart (LPP) to feature potent siRNA binding affinity and membrane activity. Thus, SPP effectively delivered siE2F1 into cardiomyocytes and suppressed E2F1 expression both in vitro and in vivo after intramyocardial injection. The E2F1-miR421-Pink1 signaling pathway was disrupted, thereby leading to the reduction of MIRI-induced mitochondrial damage, apoptosis, and inflammation of cardiomyocytes and ultimately recovering the systolic function of the myocardium. This study provides an example of membrane-penetrating nucleic acid delivery materials, and it also provides a promising approach for the genetic manipulation of cardiomyocyte apoptosis for the treatment of MIRI.


Asunto(s)
Dendrímeros , Daño por Reperfusión Miocárdica , Ratas , Animales , Daño por Reperfusión Miocárdica/genética , Daño por Reperfusión Miocárdica/tratamiento farmacológico , ARN Interferente Pequeño/farmacología , Dendrímeros/metabolismo , Ratas Sprague-Dawley , Apoptosis , Péptidos/genética , Péptidos/farmacología , Péptidos/metabolismo , Guanidinas/farmacología , Guanidinas/uso terapéutico , Proteínas Quinasas/metabolismo , Proteínas Quinasas/farmacología , Proteínas Quinasas/uso terapéutico , Factor de Transcripción E2F1/metabolismo , Factor de Transcripción E2F1/farmacología
4.
Nano Res ; 15(10): 9125-9134, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35915748

RESUMEN

Myocardial ischemia reperfusion (IR) injury is closely related to the overwhelming inflammation in the myocardium. Herein, cardiomyocyte-targeted nanotherapeutics were developed for the reactive oxygen species (ROS)-ultrasensitive co-delivery of dexamethasone (Dex) and RAGE small interfering RNA (siRAGE) to attenuate myocardial inflammation. PPTP, a ROS-degradable polycation based on PGE2-modified, PEGylated, ditellurium-crosslinked polyethylenimine (PEI) was developed to surface-decorate the Dex-encapsulated mesoporous silica nanoparticles (MSNs), which simultaneously condensed siRAGE and gated the MSNs to prevent the Dex pre-leakage. Upon intravenous injection to IR-injured rats, the nanotherapeutics could be efficiently transported into the inflamed cardiomyocytes via PGE2-assisted recognition of over-expressed E-series of prostaglandin (EP) receptors on the cell membranes. Intracellularly, the over-produced ROS degraded PPTP into small segments, promoting the release of siRAGE and Dex to mediate effective RAGE silencing (72%) and cooperative antiinflammatory effect. As a consequence, the nanotherapeutics notably suppressed the myocardial fibrosis and apoptosis, ultimately recovering the systolic function. Therefore, the current nanotherapeutics represent an effective example for the co-delivery and on-demand release of nucleic acid and chemodrug payloads, and might find promising utilities toward the synergistic management of myocardial inflammation. Electronic Supplementary Material: Supplementary material (experimental methods, RNA and primer sequences, 1H NMR spectra, FTIR spectrum, TEM images, zeta potential, drug loading content, RNA and drug release, cytotoxicity, etc.) is available in the online version of this article at 10.1007/s12274-022-4553-6.

5.
Adv Mater ; 34(35): e2110560, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35789055

RESUMEN

Protein drugs targeting intracellular machineries have shown profound therapeutic potentials, but their clinical utilities are greatly hampered by the lack of efficient cytosolic delivery techniques. Existing strategies mainly rely on nanocarriers or conjugated cell-penetrating peptides (CPPs), which often have drawbacks such as materials complexity/toxicity, lack of cell specificity, and endolysosomal entrapment. Herein, a unique carrier-free approach is reported for mediating cancer-selective and endocytosis-free cytosolic protein delivery. Proteins are sequentially modified with 4-nitrophenyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl) benzyl carbonate as the H2 O2 -responsive domain and 3,4-dihydroxy-l-phenylalanine as the substrate of l-type amino acid transporter 1 (LAT1). Thus, the pro-protein can be directly transported into tumor cells by overexpressed LAT1 on cell membranes, bypassing endocytosis and endolysosomal entrapment. In the cytosol, overproduced H2 O2 restores the protein structure and activity. Using this technique, versatile proteins are delivered into tumor cells with robust efficiency, including toxins, enzymes, CRISPR-Cas9 ribonucleoprotein, and antibodies. Furthermore, intravenously injected pro-protein of saporin shows potent anticancer efficacy in 4T1-tumor-bearing mice, without provoking systemic toxicity. Such a facile and versatile pro-protein platform may benefit the development of protein pharmaceuticals.


Asunto(s)
Transportador de Aminoácidos Neutros Grandes 1 , Neoplasias Cutáneas , Animales , Transporte Biológico , Citosol/metabolismo , Endocitosis , Transportador de Aminoácidos Neutros Grandes 1/metabolismo , Ratones
6.
Bioact Mater ; 17: 320-333, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35386446

RESUMEN

Ischemia-reperfusion (IR) injury represents a major cause of myocardial dysfunction after infarction and thrombolytic therapy, and it is closely related to the free radical explosion and overwhelming inflammatory responses. Herein, macrophage-targeting nanocomplexes (NCs) are developed to mediate efficient co-delivery of siRNA against MOF (siMOF) and microRNA-21 (miR21) into myocardial macrophages, cooperatively orchestrating the myocardial microenvironment against IR injury. Bioreducible, branched poly(ß-amino ester) (BPAE-SS) is designed to co-condense siMOF and miR21 into NCs in a multivalency-reinforced approach, and they are surface-decorated with carboxylated mannan (Man-COOH) to shield the positive surface charges and enhance the serum stability. The final MBSsm NCs are efficiently internalized by myocardial macrophages after systemic administration, wherein BPAE-SS is degraded into small segments by intracellular glutathione to promote the siMOF/miR21 release, finally provoking efficient gene silencing. Thus, cardiomyocyte protection and macrophage modulation are realized via the combined effects of ROS scavenging, inflammation inhibition, and autophagy attenuation, which ameliorates the myocardial microenvironment and restores the cardiac function via positive cellular crosstalk. This study renders promising solutions to address the multiple systemic barriers against in vivo nucleic acid delivery, and it also offers new options for IR injury by manipulating multiple reciprocal bio-reactions.

7.
Acta Biomater ; 143: 344-355, 2022 04 15.
Artículo en Inglés | MEDLINE | ID: mdl-35189380

RESUMEN

Neutrophils serve as a key contributor to the pathophysiology of myocardial ischemia reperfusion injury (MIRI), because the unregulated activation and infiltration of neutrophils lead to overwhelming inflammation in the myocardium to cause tissue damage. Herein, endothelial cell-targeting and  reactive oxygen species (ROS)-ultrasensitive nanocomplexes (NCs) were developed to mediate efficient co-delivery of VCAM-1 siRNA (siVCAM-1) and dexamethasone (DXM), which cooperatively inhibited neutrophil recruitment by impeding neutrophil migration and adhesion. RPPT was first synthesized via crosslinking of PEI 600 with ditellurium followed by modification with PEG and the endothelial cell-targeting peptide cRGD. RPPT was allowed to envelope the DXM-loaded PLGA nanoparticles and condense the siVCAM-1. After systemic administration in rats experiencing MIRI, the cRGD-modified NCs efficiently targeted and entered the inflamed endothelial cells, wherein RPPT was sensitively degraded by over-produced ROS to trigger intracellular siVCAM-1 release and potentiate the VCAM-1 silencing efficiency. As a consequence of the complementary function of DXM and siVCAM-1, the NCs notably mitigated neutrophil infiltration into ischemic myocardium, provoking potent anti-inflammatory efficacy to reduce MIRI and recover cardiac function. The present study offers an effective approach for the controlled co-delivery of siRNA and drug cargoes, and it also highlights the importance of multi-dimensional manipulation of neutrophils in anti-inflammatory treatment. STATEMENT OF SIGNIFICANCE: The unregulated activation and infiltration of neutrophils lead to overwhelming inflammation in the myocardium after myocardial ischemia reperfusion injury (MIRI). Here, endothelial cell-targeting and ROS-ultrasensitive nanocomplexes (NCs), comprised of PLGA NPs decorated with cRGD-poly(ethylene glycol) (PEG)-modified, ditellurium-crosslinked PEI (RPPT), were developed to mediate efficient co-delivery of VCAM-1 siRNA (siVCAM-1) and dexamethasone (DXM). DXM and siVCAM-1 with complementary functions inhibited both the migration and adhesion of neutrophils, efficiently interventing the neutrophil recruitment and interrupting the self-amplified inflammation cascade in the injured myocardium. The molecular design of RPPT renders an effective example for constructing polymeric materials with high ROS sensitivity, and it resolves the critical dilemma related to polycation-mediated siRNA delivery, such as siRNA encapsulation versus release, and transfection efficiency versus toxicity.


Asunto(s)
Daño por Reperfusión Miocárdica , Animales , Antiinflamatorios/metabolismo , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Dexametasona/farmacología , Células Endoteliales , Inflamación/tratamiento farmacológico , Inflamación/metabolismo , Daño por Reperfusión Miocárdica/tratamiento farmacológico , Daño por Reperfusión Miocárdica/genética , Daño por Reperfusión Miocárdica/metabolismo , Infiltración Neutrófila , Neutrófilos/metabolismo , Copolímero de Ácido Poliláctico-Ácido Poliglicólico , ARN Interferente Pequeño/genética , Ratas , Especies Reactivas de Oxígeno/metabolismo , Molécula 1 de Adhesión Celular Vascular/metabolismo
8.
J Exp Zool B Mol Dev Evol ; 338(5): 301-313, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35226401

RESUMEN

Activating transcription factor 5 (Atf5) is a member of the ATF/CREB family of transcription factors and involved in diverse cellular functions and diseases in mammals. However, the function of atf5 remains largely unknown in fish. Here, we report the expression pattern and function of duplicated atf5 genes in zebrafish. The results showed that the gene structures of zebrafish atf5a and atf5b were similar to their mammalian orthologs. Zebrafish Atf5a and Atf5b shared an amino acid sequence identity of 40.7%. Zebrafish atf5a and atf5b had maternal origin with dynamic expression during embryonic development. Zebrafish atf5a mRNA is mainly enriched in olfactory epithelium, midbrain, and hindbrain, while zebrafish atf5b mRNA is mainly detected in midbrain, hindbrain, and liver during embryogenesis. The results of acute hypoxia experiment showed that atf5a mRNA was significantly upregulated in the brain, liver, and muscle, while atf5b mRNA was just increased significantly in the brain. Functional analysis showed that knockdown of atf5a affects the development of the ciliated neurons in zebrafish embryos. The effect was enhanced when atf5a MO was co-injected with atf5b MO. The development of ciliated neurons in zebrafish embryos was not affected by injection of atf5b MO alone. atf5a knockdown also affects the development of early-born olfactory neurons. The effects caused by atf5a knockdown could be rescued by atf5b mRNA. These results suggest that the duplicated atf5 genes may have evolved divergently and play redundant biological roles in the development of olfactory sensory neurons in zebrafish.


Asunto(s)
Duplicación de Gen , Pez Cebra , Factores de Transcripción Activadores/genética , Factores de Transcripción Activadores/metabolismo , Animales , Regulación del Desarrollo de la Expresión Génica , Mamíferos/genética , ARN Mensajero/metabolismo , Proteínas de Pez Cebra/genética , Proteínas de Pez Cebra/metabolismo
9.
Adv Mater ; 34(12): e2108817, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35044010

RESUMEN

Overactivated T cells and overproduced pro-inflammatory cytokines form a self-amplified signaling loop to continuously exacerbate the dysregulated inflammatory response and propel the progression of autoimmune diseases (AIDs). Herein, immuno-engineered nanodecoys (NDs) based on poly(lactic-co-glycolic acid) nanoparticles coated with programmed death-ligand 1 (PD-L1)-expressing macrophage membrane (PRM) are developed to mediate multi-target interruption of the self-promoted inflammatory cascade in AIDs. The PRM collected from IFN-γ-treated RAW 264.7 cells possesses elevated surface levels of adhesion molecule receptors and pro-inflammatory cytokine receptors, and, thus, systemically administered PRM NDs afford higher accumulation level in inflamed tissues and stronger scavenging efficiency toward multiple pro-inflammatory cytokines. More importantly, IFN-γ treatment induces remarkable PD-L1 expression on PRM, thereby allowing PRM NDs to bind membrane-bound programmed death-1 (PD-1) on CD4+ T cell surfaces or neutralize free soluble PD-1, which reconstructs the PD-1/PD-L1 inhibitory axis to suppress CD4+ T cell activation and restore immune tolerance. As such, PRM NDs provoke potent and cooperative anti-inflammatory and immune-suppressive efficacies to alleviate autoimmune damages in Zymosan A-induced arthritis mice and dextran sulfate sodium-induced ulcerative colitis mice. This study provides an enlightened example for the immuno-engineering of cell-membrane-based NDs, rendering promising implications into the treatment of AIDs via multi-target immune-modulation.


Asunto(s)
Enfermedades Autoinmunes , Linfocitos T CD4-Positivos , Animales , Antiinflamatorios/metabolismo , Enfermedades Autoinmunes/tratamiento farmacológico , Enfermedades Autoinmunes/metabolismo , Citocinas/metabolismo , Activación de Linfocitos , Ratones
10.
Sci Adv ; 7(48): eabl6432, 2021 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-34818042

RESUMEN

Imbalance between osteoblasts and osteoclasts accounts for the incidence and deterioration of postmenopausal osteoporosis. Abnormally elevated RANKL and TNF-α levels after menopause promote osteoclast formation and inhibit osteoblast differentiation, respectively. Here, nanodecoys capable of scavenging RANKL and TNF-α were developed from preosteoclast (RAW 264.7 cell) membrane­coated poly(lactic-co-glycolic acid) (PLGA) nanoparticles, which inhibited osteoporosis and maintained bone integrity. The nanodecoys effectively escaped from macrophage capture and enabled prolonged blood circulation after systemic administration. The abundant RANK and TNF-α receptor (TNF-αR) on the cell membranes effectively neutralized RANKL and TNF-α to prevent osteoclastogenesis and promote osteoblastogenesis, respectively, thus reversing the progression of osteoporosis in the ovariectomized (OVX) mouse model. These biomimetic nanodecoys provide an effective strategy for reconstructing the osteoclast/osteoblast balance and hold great potentials for the clinical management of postmenopausal osteoporosis.

11.
Biomater Sci ; 9(13): 4639-4647, 2021 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-34036971

RESUMEN

Cytosolic protein delivery holds great potential for the development of protein-based biotechnologies and therapeutics. Currently, cytosolic protein delivery is mainly achieved with the assistance of various carriers. Herein, we present a universal and effective strategy for carrier-free cytosolic protein delivery via metabolic glycoengineering and bioorthogonal click reactions. Ac4ManNAz (AAM), an azido-modified N-acetylmannosamine analogue, was first employed to label tumor cell surfaces with abundant azido groups via glycometabolism. Then, proteins including RNase A, cytochrome C (Cyt C), and bovine serum albumin (BSA) were covalently modified with dibenzocyclooctyne (DBCO). Based on the highly efficient bioorthogonal click reactions between DBCO and azido, DBCO-modified proteins could be efficiently internalized by azido-labeled cancer cells. RNase A-DBCO could largely maintain its enzymatic activity and, thus, led to notable anti-tumor efficacy in HeLa and B16F10 cells in vitro and in B16F10 xenograft tumors in vivo. This study therefore provides a simple and powerful approach for carrier-free protein delivery and would have broad applicability in anti-tumor protein therapy.


Asunto(s)
Química Clic , Neoplasias , Humanos , Neoplasias/tratamiento farmacológico
12.
Biomaterials ; 255: 120166, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32544718

RESUMEN

The anticancer performance of nanomedicine is largely impeded by insufficient intratumoral penetration. Herein, tumor microenvironment (TME)-amendatory and self-adaptive nanoclusters (NCs) capable of cancer-associated fibroblasts (CAFs) depletion and size/charge conversion were engineered to mediate light-assisted, hierarchical intratumoral penetration. Particularly, large-sized NCs (~50 nm) were prepared via self-assembly of FAP-α-targeting peptide-modified, 1O2-sensitive polymers, which were further used to envelope small-sized dendrimer (~5 nm) conjugated with Ce6 and loaded with DOX (DC/D). After systemic administration, the NCs efficiently targeted CAFs and generated lethal levels of 1O2 upon light irradiation, which depleted CAFs and concomitantly dissociated the NCs to liberate small-sized, positively charged DC/D. Such stroma attenuation and NCs transformation collectively facilitated the delivery of DC/D into deeper regions of CAF-rich tumors, where DOX and 1O2 provoked synergistic anti-cancer efficacies. This study provides an effective approach to facilitate the tumor penetration of nanomedicine by concurrently and spatiotemporally reconfiguring the nano-properties and remodeling the TME.


Asunto(s)
Nanomedicina , Microambiente Tumoral , Línea Celular Tumoral , Polímeros
13.
J Exp Zool B Mol Dev Evol ; 334(2): 77-87, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-31990140

RESUMEN

Arginine methylation is an important posttranslational modification and catalyzed by a family of protein arginine methyltransferases (PRMTs). PRMT7 is the type III PRMT and produces solely monomethylarginine products. PRMT7 has been found to play important roles in multiple biological processes in mammals. However, the expression pattern and function of Prmt7 remain largely unknown in fish. In this study, we characterized the medaka prmt7 gene and determined its expression pattern and function during embryogenesis and germ cell development. The results showed that the chromosomal location and gene structure of medaka prmt7 were similar to its mammalian orthologs. Comparisons of deduced amino acid sequences indicated that medaka Prmt7 was a homolog of human PRMT7 with two methyltransferase domains. Reverse transcription-polymerase chain reaction (RT-PCR) and real time RT-PCR revealed that medaka prmt7 had maternal origin with continuous and dynamical expression during embryonic development. Whole-mount in situ hybridization analysis observed that the transcripts of prmt7 were ubiquitous at morula and gastrula stage, and were later riched in the brain and otic vesicles during embryogenesis. In the adult stage, prmt7 messenger RNA was detected in all examined tissues with the high levels in the ovary and testis. The expression of prmt7 in the gonads was restricted to oocytes of the ovary and spermatids/sperm of the testis. Functional analysis showed that knockdown of medaka prmt7 did not reduce the total number of primordial germ cells (PGCs) in vivo but significantly affected PGCs distribution during embryonic development. These results indicate that prmt7 may be involved in germ cell development in medaka.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica/fisiología , Regulación Enzimológica de la Expresión Génica/fisiología , Oryzias/metabolismo , Proteína-Arginina N-Metiltransferasas/metabolismo , Secuencia de Aminoácidos , Animales , Oryzias/embriología , Oryzias/genética , Filogenia , Proteína-Arginina N-Metiltransferasas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo
14.
J Sep Sci ; 36(19): 3242-8, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23897627

RESUMEN

Graphene-grafted ferroferric oxide microspheres were used as the adsorbent to extract some pyrethroid pesticides (bifenthrin, λ-cyhalothrin, cyfluthrin, cypermethrin, fenvalerate, and deltamethrin) from orange and lettuce samples prior to their determination by GC-MS. The main variables that could affect the extraction, including the amount of the adsorbent, pH of the sample solution, extraction time, concentration of salt, and desorption conditions, were investigated and optimized. Under the optimized conditions, a linear response was obtained in the concentration range of 0.3-100.0 ng/g for the analytes with the coefficients of determination ranging from 0.9877 to 0.9925. The LODs for the pyrethroids ranged from 0.01 to 0.02 ng/g. The method provided a good repeatability with RSDs < 10.6%. The recoveries for the six pyrethroid pesticides were in the range from 90.0 to 103.7%. The method was applied to the determination of the pesticides in orange and lettuce samples with a satisfactory result.


Asunto(s)
Citrus sinensis/química , Grafito/química , Lactuca/química , Residuos de Plaguicidas/aislamiento & purificación , Piretrinas/aislamiento & purificación , Dióxido de Silicio/química , Adsorción , Cromatografía de Gases y Espectrometría de Masas , Campos Magnéticos , Microesferas , Tamaño de la Partícula , Propiedades de Superficie
15.
Anal Sci ; 29(3): 325-31, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23474722

RESUMEN

In this paper, a sensitive analytical method for four fungicides (procymidone, folpet, vinclozolin and ditalimfos) in environmental water and juice samples was developed by using magnetic solid-phase extraction (MSPE) with magnetic graphene nanocomposite (G-Fe3O4) as the adsorbent, followed by determination with gas chromatography and electron capture detection. Parameters such as the amount of G-Fe3O4, extraction time, ionic strength and pH of the sample solution, desorption solvent and desorption time were optimized. Under the optimum conditions, the enrichment factors of the method for the analytes were in the range from 1495 to 1849. The limits of detection for the fungicides ranged from 1.0 to 7.0 ng L(-1). The recoveries of the method for the analytes were in the range from 79.2 to 102.4%. The developed G-Fe3O4-MSPE method was simple and efficient for the extraction and determination of the four fungicides in water and grape juice samples.


Asunto(s)
Bebidas/análisis , Grafito/química , Imidas/química , Imidas/aislamiento & purificación , Nanopartículas de Magnetita/química , Extracción en Fase Sólida/métodos , Agua/química , Adsorción , Cromatografía de Gases , Electrones , Contaminantes Ambientales/análisis , Contaminantes Ambientales/química , Contaminantes Ambientales/aislamiento & purificación , Fungicidas Industriales/análisis , Fungicidas Industriales/química , Fungicidas Industriales/aislamiento & purificación , Concentración de Iones de Hidrógeno , Imidas/análisis , Concentración Osmolar , Factores de Tiempo
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