Publications by authors named "Natalia Hassan"

Due to its high durability and transparency, soda lime glass holds a huge potential for several applications such as photovoltaics, optical instrumentation and biomedical devices, among others. The different technologies request specific properties, which can be enhanced through the modification of the surface morphology with a nanopattern. Here, we report a simple method to nanostructure a glass surface with soft lithography and wet-chemical etching in potassium hydroxide (KOH) solutions.

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The use of nanomaterials in medicine offers multiple opportunities to address neurodegenerative disorders such as Alzheimer's and Parkinson's disease. These diseases are a significant burden for society and the health system, affecting millions of people worldwide without sensitive and selective diagnostic methodologies or effective treatments to stop their progression. In this sense, the use of gold nanoparticles is a promising tool due to their unique properties at the nanometric level.

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Fenton-based electrochemical processes (FEPs) using newly engineered 3D photocatalyst nanocomposites have garnered significant attention owing to their ability to remove emerging contaminants. Despite the development of numerous materials, there is still a need to enhance their efficiency, stability, and recyclability to address the limitations of FEPs. This study seeks to address this issue by investigating sustainable methods to engineer novel 3D core-shell photocatalyst composites for application in FEPs.

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A sensitive electroanalytical method for the determination of arsenite, based on a heterostructure of aminated multiwalled carbon nanotubes and gold nanoparticles, was applied in an electrocoagulation (EC) treatment for the elimination of arsenite. A sensitive quantitative response was obtained in the determination of As in a secondary effluent from a wastewater treatment plant from Santiago (Chile). The preconcentration stage was optimized through a Central Composite Face design, and the most sensitive peak current was obtained at 200 s and -600 mV of time and accumulation potential, respectively, after a differential pulse voltammetry sweep.

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Bacterial infections have become one of the top ten public health concerns worldwide. These problems are aggravated with the emergence of multi-drug resistant bacterial strains. Thus, it is necessary to adopt novel technological strategies, such as development of bionanomaterials to prevent the infection, and treat this kind of bacteria.

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Gold nanoparticles (GNPs) are an attractive nanomaterial for potential applications in therapy and diagnostics due to their capability to direct toward specific sites in the organism. However, when exposed to plasma, GNPs can interact with different biomolecules that form a dynamic nano-bio interface called a "protein corona" (PC). Remarkably, the PC could affect multiple biological processes, such as cell targeting and uptake, cytotoxicity, and nanoparticle (NP) clearance.

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Nanoparticle-based drug delivery systems, in combination with high-affinity disease-specific targeting ligands, provide a sophisticated landscape in cancer theranostics. Due to their high diversity and specificity to target cells, antibodies are extensively used to provide bioactivity to a plethora of nanoparticulate systems. However, controlled and reproducible assembly of nanoparticles (NPs) with these targeting ligands remains a challenge.

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In the last decades, the incorporation of copper in polymeric membranes for water treatment has received greater attention, as an innovative potential solution against biofouling formation on membranes, as well as, by its ability to improve other relevant membrane properties. Copper has attractive characteristics: excellent antimicrobial activity, high natural abundance, low cost and the existence of multiple cost-effective synthesis routes for obtaining copper-based materials with tunable characteristics, which favor their incorporation into polymeric membranes. This study presents a comprehensive analysis of the progress made in the area regarding modified membranes for water treatment when incorporating copper.

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Ovarian cancer (OC) is the deadliest gynecological cancer. Standard treatment of OC is based on cytoreductive surgery followed by chemotherapy with platinum drugs and taxanes; however, innate and acquired drug-resistance is frequently observed followed by a relapse after treatment, thus, more efficient therapeutic approaches are required. Combination therapies involving phototherapies and chemotherapy (the so-called chemophototherapy) may have enhanced efficacy against cancer, by attacking cancer cells through different mechanisms, including DNA-damage and thermally driven cell membrane and cytoskeleton damage.

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Bioceramic nanoparticles have many potential applications within the biomedical device industry. However, these applications demand a precise control of their sizes, shapes and morphology which play a main role in most properties. In this work, we report a new route for the synthesis of hydroxyapatite nanoparticles using a microfluidic device.

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Copper oxide nanoparticles (CuO NPs) were synthesized in air by reducing copper (II) sulfate pentahydrate salt (CuSO₄·5H₂O) in the presence of sodium borohydride. The reaction was stabilized with Hexadecyltrimethylammonium bromide (CTAB) in a basic medium and using ultrasound waves. Different molar ratios of CTAB:Cu and NaBH₄:Cu were explored, to optimize the synthesis conditions, and to study the stability, size, and Zeta potential of the colloidal suspension.

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Background: Perinatal asphyxia interferes with neonatal development, resulting in long-term deficits associated with systemic and neurological diseases. Despite the important role of poly (ADP-ribose) polymerase 1 (PARP-1) in the regulation of gene expression and DNA repair, overactivation of PARP-1 in asphyxia-exposed animals worsens the ATP-dependent energetic crisis. Inhibition of PARP-1 offers a therapeutic strategy for diminishing the effects of perinatal asphyxia.

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Biomacromolecules structures and their interaction between different systems have been extensively studied in the last years. Nevertheless, in the medicinal context, it has not been studied deeply. For this reason, the interest to investigate the behavior of different biomacromolecules such us proteins, organelles, phospholipids, etc.

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The properties of nanometric materials make nanotechnology a promising platform for tackling problems of contemporary medicine. In this work, gold nanorods were synthetized and stabilized with polyethylene glycols and modified with two kinds of peptides. The D1 peptide that recognizes toxic aggregates of Aβ, a peptide involved in Alzheimer's disease (AD); and the Angiopep 2 that can be used to deliver nanorods to the mammalian central nervous system.

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In recent years, advances in nanotechnology have raised the specter of developing effective agents for the treatment of high-impact diseases, like gastric cancer, which remains one of the major causes of cancer deaths worldwide. This article reviews advances in the treatment of this pathology using several types of nanoparticles. First, we start with an overview of gastric cancer, its prevention, detection and the available treatments.

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The spontaneous aggregation of α-cyclodextrin (α-CD) molecules in the bulk aqueous solution and the interactions of the resulting aggregates at the liquid/air interface have been studied at 283 K using a battery of techniques: transmission electron microscopy, dynamic light scattering, dynamic surface tensiometry, Brewster angle microscopy, neutron reflectometry, and ellipsometry. We show that α-CD molecules spontaneously form aggregates in the bulk that grow in size with time. These aggregates adsorb to the liquid/air interface with their size in the bulk determining the adsorption rate.

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In this article, we describe how nanoparticles work in photothermally triggered drug delivery, starting with a description of the plasmon resonance and the photothermal effect, and how this is used to release a drug. Then, we describe the four major functionalization strategies and each of their different applications. Finally, we discuss the biodistribution and toxicity of these systems and the necessary requirements for the use of gold nanoparticles for spatially and temporally controlling drug release through the photothermal effect.

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In this article we review the flow chemistry methodologies for the controlled synthesis of different kind of nano and microparticles for biomedical applications. Injection mechanism has emerged as new alternative for the synthesis of nanoparticles due to this strategy allows achieving superior levels of control of self-assemblies, leading to higher-ordered structures and rapid chemical reactions. Self-assembly events are strongly dependent on factors such as the local concentration of reagents, the mixing rates, and the shear forces, which can be finely tuned, as an example, in a microfluidic device.

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Pure decahedral anatase TiO(2) particles with high content of reactive {001} facets were obtained from titanium(IV) tetrachloride (TiCl(4)) using a microemulsions droplet system at specific conditions as chemical microreactor. The product was systematically characterized by X-ray diffraction, field-emission scanning and transmission electron microscopy (FE-SEM, TEM), N(2) adsorption-desorption isotherms, FT-IR and UV-vis spectroscopy, and photoluminescence studies. The obtained cuboids around 90 nm in size have a uniform and dense surface morphology with a BET specific surface area of 11.

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Magneto-plasmonic microcapsules were prepared by the assembly of gold and γ-Fe(2)O(3) magnetic nanoparticles at the oil-water interface of microdroplets generated in a microfluidic device.

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The structure and physicochemical properties of the nanoparticles spontaneously formed within aqueous mixtures of the hydrogenated/fluorinated catanionic surfactant cetyltrimetylammonium perfluorooctanoate in the absence of counterions as a function of its concentration are investigated by a combined experimental/computational study at room temperature. Apparent molar volumes, isentropic apparent molar compressibilities, and dynamic light scattering measurements together with transmission and cryo-scanning electron as well as confocal laser microscopy images, and computational molecular dynamics simulations indicate that a variety of structures of different sizes coexist in solution with vesicles of ∼160 nm diameter. Interestingly, the obtained nanostructures were observed to self-assemble from a random distribution of monomers in a time scale easily accessible by atomistic classical molecular dynamics simulations, allowing to provide a comprehensive structural and dynamic characterization of the surfactant molecules at atomic level within the different aggregates.

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Propanolol is a betablocker drug used in the treatment of arterial hypertension related diseases. In order to achieve an optimal performance of this drug it is important to consider the possible interactions of propanolol with plasma proteins. In this work, we have used several experimental techniques to characterise the effect of addition of the betablocker propanolol on the properties of bovine plasma fibrinogen (FB).

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Differential scanning calorimetry (DSC), circular dichroism (CD), difference spectroscopy (UV-vis), Raman spectroscopy, and small-angle X-ray scattering (SAXS) measurements have been performed in the present work to provide a quantitatively comprehensive physicochemical description of the complexation between bovine fibrinogen and the sodium perfluorooctanoate, sodium octanoate, and sodium dodecanoate in glycine buffer (pH 8.5). It has been found that sodium octanoate and dodecanoate act as fibrinogen destabilizer.

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