From Preformulative Design to Tests: A Complex Path of Requisites and Studies for Nanoparticle Ocular Application. Part 2: , , and Studies.

The incidence of ocular pathologies is constantly increasing, as is the interest of the researchers in developing new strategies to ameliorate the treatment of these conditions. Nowadays, drug delivery systems are considered among the most relevant approaches due to their applicability in the treatment of a great variety of inner and outer eye pathologies through painless topical administrations. The design of such nanocarriers requires a deep study of many aspects related to the administration route but also a consideration of the authorities and pharmacopeial requirements, in order to achieve a clinical outcome.

Natural deep eutectic solvent-based dispersive liquid-liquid microextraction of pesticides in drinking waters combined with GC-MS/MS detection.

The current research aims to develop a new analytical method applying a dispersive liquid-liquid microextraction (DLLME) assisted by vortex and using an environmentally friendly extractant for the preconcentration of organochlorine and organophosphorus pesticides followed by gas chromatography-tandem mass spectrometry (GC-MS/MS) analysis. The extractant (i.e.

Tunable Properties of Non-Volatile Magnetic Mixtures on Different Surfaces.

In this work, the surface nature-dependent behaviors of magnetic deep eutectic solvents (MDESs) and magnetic low-transition-temperature non-volatile mixtures (MLTTMs) are reported for the first time. It has been observed that the surface of the material where the MDES or the MLTTM is placed could considerably affect the dispersion and the magnetic and structural properties of these magnetic mixtures. Different techniques and analyses have been carried out to highlight the differences observed in the properties depending on the material on which these magnetic mixtures are placed.

Determination of Fe, Cu, and Pb in edible oils using choline chloride:ethylene glycol deep eutectic solvent-based dispersive liquid-liquid microextraction associated with microwave-induced plasma optical emission spectrometry.

A new simple, fast and environmentally friendly deep eutectic solvent based dispersive liquid-liquid microextraction (DES-based DLLME) methodology assisted by vortex is presented for the separation and preconcentration of three elements (i.e., Fe, Cu and Pb) from edible oil samples (i.

Surface Potential Modulation in Boronate-Functionalized Magnetic Nanoparticles Reveals Binding Interactions: Toward Magnetophoretic Capture/Quantitation of Sugars from Extracellular Matrix.

Phenylboronic acids (BAs) are important synthetic receptors that bind reversibly to cis-diols enabling their use in molecular sensing. When conjugated to magnetic iron oxide nanoparticles, BAs have potential for application in separations and enrichment. Realizing this will require a new understanding of their inherent binding modes and measurement of their binding capacity and their stability in/extractability from complex environments.

Natural deep eutectic solvent-based microextraction for mercury speciation in water samples.

A new natural deep eutectic solvent (NADES)-based analytical method for mercury speciation in water samples is presented. A NADES (i.e.

A novel non-invasive colorectal cancer diagnostic method: Volatile organic compounds as biomarkers.

Introduction: Population-based fecal tests for colorectal cancer (CRC) screening have shown to reduce mortality thanks to the early detection of the disease. However, currently available fecal tests are limited in their sensitivity and specificity. Our aim is to look for volatile organic compounds in fecal samples as biomarkers for CRC detection.

Purinergic Receptors P2X7 and P2X4 as Markers of Disease Progression in the rd10 Mouse Model of Inherited Retinal Dystrophy.

The purinergic receptor P2X7 (P2X7R) is implicated in all neurodegenerative diseases of the central nervous system. It is also involved in the retinal degeneration associated with glaucoma, age-related macular degeneration, and diabetic retinopathy, and its overexpression in the retina is evident in these disorders. Retinitis pigmentosa is a progressive degenerative disease that ultimately leads to blindness.

Customized cationic nanoemulsions loading triamcinolone acetonide for corneal neovascularization secondary to inflammatory processes.

Customized cationic oil-in-water nanoemulsions (NEs) have been produced to improve the bioavailability of poorly water-soluble drugs, such as triamcinolone acetonide (TA). TA is a synthetic glucocorticoid with anti-inflammatory and antiangiogenic therapeutic properties and it is widely used as an effective treatment in ocular disorders. In this work, TA-NEs were characterized using two different custom-made cationic surfactants, showing a high positive surface charge favouring corneal penetration and a particle size below 300 nm.

Magnetic dispersive solid-phase extraction using ZSM-5 zeolite/FeO composite coupled with screen-printed electrodes based electrochemical detector for determination of cadmium in urine samples.

A novel, simple, fast, sensitive and environmentally friendly approach is presented to determine cadmium in urine samples, combining magnetic dispersive solid-phase extraction (MDSPE) for sample preparation and screen-printed carbon electrodes (SPCEs) for square-wave anodic stripping voltammetry. This association involves the miniaturization of sample preparation and measurement process. Firstly, cadmium was extracted directly from urine samples employing a ZSM-5/FeO, then, the composite enriched with cadmium was deposited onto the SPCE and finally covered with a suitable electrolyte for electrochemical detection.

Lipid Nanoparticles as Carriers for the Treatment of Neurodegeneration Associated with Alzheimer's Disease and Glaucoma: Present and Future Challenges.

Glaucoma constitutes the second cause of blindness worldwide and it is considered a neurodegenerative disorder. In this sense, Alzheimer's disease, which is the most common type of dementia, also causes neurodegeneration. The association between both diseases remains unknown although it has been hypothesised that a possible connection might exist and it will be analysed throughout the review.

Magnetic dispersive solid-phase extraction using a zeolite-based composite for direct electrochemical determination of lead(II) in urine using screen-printed electrodes.

Magnetic dispersive solid-phase extraction (MDSPE) is combined with electrochemical detection by using a screen-printed carbon electrode modified with gold nanoparticles to determine lead(II). A zeolite-based magnetic composite was used as sorbent during sample preparation, thus combining the unique properties of zeolites as sorbent materials with the remarkable advantages provided by magnetic materials. Three different zeolite-based magnetic composites were initially investigated and characterized.

Determination of four bisphenols in water and urine samples by magnetic dispersive solid-phase extraction using a modified zeolite/iron oxide composite prior to liquid chromatography diode array detection.

A novel approach is presented to determine four bisphenols in water and urine samples, employing magnetic dispersive solid-phase extraction combined with liquid chromatography and diode array detection. A modified zeolite-based magnetic composite was used as an efficient sorbent, combining the advantages of magnetic materials with the remarkable properties of zeolites. A multivariate optimization design was employed to optimize some experimental factors affecting magnetic dispersive solid-phase extraction.

A modified zeolite/iron oxide composite as a sorbent for magnetic dispersive solid-phase extraction for the preconcentration of nonsteroidal anti-inflammatory drugs in water and urine samples.

This study is the first to use a new ZSM-5 zeolite-based composite decorated with iron oxide magnetic nanoparticles and modified with hexadecyltrimethylammonium bromide surfactant (i.e., HDTMA-ZSM-5/FeO) as an efficient sorbent for magnetic dispersive solid-phase extraction (MDSPE) of nonsteroidal anti-inflammatory drugs in water and urine samples with subsequent measurement by liquid chromatography diode array detection.

Zeolites and zeolite-based materials in extraction and microextraction techniques.

Zeolites are ordered crystalline materials with a promising performance for a wide range of applications such as catalysis, petrochemistry, environmental remediation, and medicine, but have scarcely been evaluated in Analytical Chemistry. Their unique and fascinating properties such as their high surface area, high adsorption capacity and molecular selectivity, chemical and thermal stability, ion-exchange capacity, low cost extraction and synthesis, and their easy modification, which provides a wide range of zeolite-based materials, make zeolites potential sorbents for extraction procedures. Therefore, in this review, we provide an overview of the current status of zeolites and zeolite-based materials used in extraction and microextraction techniques with reference to recent applications and highlight some of the novel advances.

Determination of siloxanes in water samples employing graphene oxide/Fe O nanocomposite as sorbent for magnetic solid-phase extraction prior to GC-MS.

A new, fast, simple, and environmentally friendly analytical method has been developed to determine six siloxanes in water samples: octamethyltrisiloxane, octamethylcyclotetrasiloxane, decamethyltetrasiloxane, decamethylcyclopentasiloxane, dodecamethylpentasiloxane and dodecamethylcyclohexasiloxane. The analytical method consists of magnetic solid-phase extraction employing graphene oxide/Fe O as sorbent for the separation and preconcentration of siloxanes prior to GC-MS determination. The extraction procedure was optimized by means of a Plackett-Burman design.

Rapid determination of hydrophilic phenols in olive oil by vortex-assisted reversed-phase dispersive liquid-liquid microextraction and screen-printed carbon electrodes.

A novel approach is presented to determine hydrophilic phenols in olive oil samples, employing vortex-assisted reversed-phase dispersive liquid-liquid microextraction (RP-DLLME) for sample preparation and screen-printed carbon electrodes for voltammetric analysis. The oxidation of oleuropein, hydroxytyrosol, caffeic acid, ferulic acid and tyrosol was investigated, being caffeic acid and tyrosol selected for quantification. A matrix-matching calibration using sunflower oil as analyte-free sample diluted with hexane was employed to compensate matrix effects.

Hydrophilic magnetic ionic liquid for magnetic headspace single-drop microextraction of chlorobenzenes prior to thermal desorption-gas chromatography-mass spectrometry.

A new, fast, easy to handle, and environmentally friendly magnetic headspace single-drop microextraction (Mag-HS-SDME) based on a magnetic ionic liquid (MIL) as an extractant solvent is presented. A small drop of the MIL 1-ethyl-3-methylimidazolium tetraisothiocyanatocobaltate(II) ([Emim][Co(NCS)]) is located on one end of a small neodymium magnet to extract nine chlorobenzenes (1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,3-trichlorobenzene, 1,2,4-trichlorobenzene, 1,3,5-trichlorobenzene, 1,2,3,4-tetrachlorobenzene, 1,2,4,5-tetrachlorobenzene, and pentachlorobenzene) as model analytes from water samples prior to thermal desorption-gas chromatography-mass spectrometry determination. A multivariate optimization strategy was employed to optimize experimental parameters affecting Mag-HS-SDME.

Magnetic headspace adsorptive extraction of chlorobenzenes prior to thermal desorption gas chromatography-mass spectrometry.

This study presents a new, user-friendly, cost-effective and portable headspace solid-phase extraction technique based on graphene oxide decorated with iron oxide magnetic nanoparticles as sorbent, located on one end of a small neodymium magnet. Hence, the new headspace solid-phase extraction technique has been called Magnetic Headspace Adsorptive Extraction (Mag-HSAE). In order to assess Mag-HSAE technique applicability to model analytes, some chlorobenzenes were extracted from water samples prior to gas chromatography-mass spectrometry determination.

Complexation-mediated electromembrane extraction of highly polar basic drugs-a fundamental study with catecholamines in urine as model system.

Complexation-mediated electromembrane extraction (EME) of highly polar basic drugs (log P < -1) was investigated for the first time with the catecholamines epinephrine, norepinephrine, and dopamine as model analytes. The model analytes were extracted as cationic species from urine samples (pH 4), through a supported liquid membrane (SLM) comprising 25 mM 4-(trifluoromethyl)phenylboronic acid (TFPBA) in bis(2-ethylhexyl) phosphite (DEHPi), and into 20 mM formic acid as acceptor solution. EME was performed for 15 min, and 50 V was used as extraction voltage across the SLM.

Graphene oxide/FeO as sorbent for magnetic solid-phase extraction coupled with liquid chromatography to determine 2,4,6-trinitrotoluene in water samples.

A fast, simple, economical, and environmentally friendly magnetic solid-phase extraction (MSPE) procedure has been developed to preconcentrate 2,4,6-trinitrotoluene (TNT) from water samples prior to determination by liquid chromatography-UV-Vis employing graphene oxide/FeO nanocomposite as sorbent. The nanocomposite synthesis was investigated, and the MSPE was optimized by a multivariate approach. The optimum MSPE conditions were 40 mg of nanocomposite, 10 min of vortex extraction, 1 mL of acetonitrile as eluent, and 6 min of desorption in an ultrasonic bath.

Zeolite/iron oxide composite as sorbent for magnetic solid-phase extraction of benzene, toluene, ethylbenzene and xylenes from water samples prior to gas chromatography⬜mass spectrometry.

This study reports a new composite based on ZSM-5 zeolite decorated with iron oxide magnetic nanoparticles as a valuable sorbent for magnetic solid-phase extraction (MSPE). A proposal is made to determine benzene, toluene, ethylbenzene and xylenes (BTEX) as model analytes in water samples using gas chromatography-mass spectrometry. A two-step multivariate optimization strategy, using Plackett⬜Burman and circumscribed central composite designs, was employed to optimize experimental parameters affecting MSPE.

Mercury determination in urine samples by gold nanostructured screen-printed carbon electrodes after vortex-assisted ionic liquid dispersive liquid-liquid microextraction.

A novel approach is presented to determine mercury in urine samples, employing vortex-assisted ionic liquid dispersive liquid-liquid microextraction and microvolume back-extraction to prepare samples, and screen-printed electrodes modified with gold nanoparticles for voltammetric analysis. Mercury was extracted directly from non-digested urine samples in a water-immiscible ionic liquid, being back-extracted into an acidic aqueous solution. Subsequently, it was determined using gold nanoparticle-modified screen-printed electrodes.

Tungsten coil atomic emission spectrometry combined with dispersive liquid-liquid microextraction: A synergistic association for chromium determination in water samples.

A novel and environment friendly analytical method is reported for total chromium determination and chromium speciation in water samples, whereby tungsten coil atomic emission spectrometry (WCAES) is combined with in situ ionic liquid formation dispersive liquid-liquid microextraction (in situ IL-DLLME). A two stage multivariate optimization approach has been developed employing a Plackett-Burman design for screening and selection of the significant factor involved in the in situ IL-DLLME procedure, which was later optimized by means of a circumscribed central composite design. The optimum conditions were complexant concentration: 0.

Microwave-Assisted Extraction of Phenolic Compounds from Almond Skin Byproducts (Prunus amygdalus): A Multivariate Analysis Approach.

A microwave-assisted extraction (MAE) procedure to isolate phenolic compounds from almond skin byproducts was optimized. A three-level, three-factor Box-Behnken design was used to evaluate the effect of almond skin weight, microwave power, and irradiation time on total phenolic content (TPC) and antioxidant activity (DPPH). Almond skin weight was the most important parameter in the studied responses.