Synthesis, Characterization, and BSA Binding Properties of Carboxylated Merocyanine-Based Fluorophores.

This study describes the synthesis of new carboxylated merocyanine dyes by Knoevenagel condensation between 4-carboxybenzaldehyde and indolium/benzoindolium- and benzothiazolium-based coupling compounds. The condensations were performed in the presence of ammonium acetate, and the products were obtained in good yields after simple purification. These merocyanines exhibit UV-A-to-blue absorption and blue-to-green fluorescence emission, characterized by relatively large Stokes shift values (∼5000 cm).

Revealing the ESIPT process in benzoxazole fluorophores within polymeric matrices through theory and experiment.

The impact of the polymeric matrix on the photophysical characteristics of monomeric dyes responsive to excited-state intramolecular proton transfer (ESIPT) was investigated through UV-Vis absorption as well as steady-state and time-resolved emission spectroscopies. For this purpose, two benzoxazole monomers (M1 and M2) with acryloyl groups at different positions in their molecular structures were employed to facilitate covalent bonding within a styrene chain. Our findings reveal significant variations in their excited-state properties due to the proximity of the acryloyl groups, which affects the energy barrier of the ESIPT reaction, the emission wavelength, and the balance between the normal and tautomeric forms.

Accuracy improvement enzyme-linked immunosorbent assay using superparamagnetic/polyethylene glycol) nanoparticles for leishmaniasis diagnostic.

Serodiagnosis methods have been used as platforms for diagnostic tests for many diseases. Due to magnetic nanoparticles' properties to quickly detach from an external magnetic field and particle size effects, these nanomaterials' functionalization allows the specific isolation of target analytes, enhancing accuracy parameters and reducing serodiagnosis time. Superparamagnetic iron oxide nanoparticles (MNPs) were synthesized and functionalized with polyethylene glycol (PEG) and then associated with the synthetic Leishmaniosis epitope.

Vitamin D3 improves spatial memory and modulates cytokine levels in aged rats.

Vitamin D3 deficiency is associated with an increased risk of dementia. An association between vitamin D3 deficiency and subjective cognitive complaints in geriatric patients has been previously reported. This study aimed to evaluate the effects of two doses of vitamin D3 on spatial memory (using the Radial Maze) and cytokine levels [tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-10 (IL-10)] on 2-, 6-, 13-, 22-, and 31-month-old male Wistar rats.

The Protein Corona Conundrum: Exploring the Advantages and Drawbacks of its Presence around Amphiphilic Nanoparticles.

The success of targeted drug delivery systems still requires a detailed understanding about the biological consequences of self-developed biomolecular coronas around them, since this is the surface that interacts with living cells. Herein, we report the behavior of carbohydrate-decorated amphiphilic nanoparticles in a plasma environment with regard to the formation and biological consequences of the protein corona. Naked amphiphilic nanoparticles were produced through the self-assembly of azido-PEO-docosanoate molecules, and the coupling of -acetylglucosamine via click chemistry enabled the fabrication of the corresponding bioactive glyco-nanostructures.

Co-encapsulation of sodium diethyldithiocarbamate (DETC) and zinc phthalocyanine (ZnPc) in liposomes promotes increases phototoxic activity against (MDA-MB 231) human breast cancer cells.

There has been considerable interest in the development of novel photosensitisers for photodynamic therapy (PDT). The use of liposomes as drug delivery systems containing simultaneously two or more drugs is an attractive idea to create a new platform for PDT application. Therefore, the aim of this study was to evaluate the synergistic effect of diethyldithiocarbamate (DETC) and zinc phthalocyanine (PDT) co-encapsulated in liposomes.

Proton transfer in fluorescent secondary amines: synthesis, photophysics, theoretical calculation and preparation of photoactive phosphatidylcholine-based liposomes.

In this article, new fluorescent lipophilic based benzazoles were synthesized from the reaction between photoactive formyl derivatives and aliphatic amines followed by NaBH4 reduction with good yields. The photophysics of the benzazoles was investigated experimentally and theoretically. These compounds present absorption maxima in the UV region (∼339 nm) and fluorescence emission maxima in the cyan to green region with a large Stokes shift (∼175 nm) due to a proton transfer process in the excited state.

Elucidating Bauhinia variegata lectin/phosphatidylcholine interactions in lectin-containing liposomes.

Investigations focused on the interactions of nanoparticles with lectins are relevant since it is well accepted that such proteins can be recognized by carbohydrates as parts of cell membranes. This can ultimately enhance the cellular uptake of the produced assemblies. In this framework, the physical interactions of phosphatidylcholine (PC) liposomes and the Bauhinia variegate lectin (BVL) are reported here.

Self-assembled carbohydrate-based vesicles for lectin targeting.

This study examined the physicochemical interactions between vesicles formed by phosphatidylcholine (PC) and glycosylated polymeric amphiphile N-acetyl-β-d-glucosaminyl-PEG-docosanate (CPEGGlcNAc) conjugated with Bauhinia variegata lectin (BVL). Lectins are proteins or glycoproteins capable of binding glycosylated membrane components. Accordingly, the surface functionalization by such entities is considered a potential strategy for targeted drug delivery.

New glycosylated conjugate copolymer N-acetyl-β-D-glucosaminyl-pluronic: Synthesis, self-assembly and biological assays.

This work describes the synthesis of a new glycosylated conjugate copolymer, GlcNAc-PEO75-PPO30-PEO75-GlcNAc (GlcNAc-PluronicF68-GlcNAc), using click chemistry from Pluronic(®) F68 and propargyl-2-N-acetamido-2-deoxy-β-D-glucopyranoside. Micelles were prepared by the self-assembly of GlcNAc-PluronicF68-GlcNAc in phosphate-buffered solution. The critical micelle concentration was determined by fluorescence spectroscopy, and the value was found to be equal to 5.

Gold nanoparticles and/or N-acetylcysteine mediate carrageenan-induced inflammation and oxidative stress in a concentration-dependent manner.

We report the effect of gold nanoparticles (AuNP) in an acute inflammation model induced by carrageenan (CG) and compared this effect with those induced by the antioxidant N-acetylcysteine (NAC) alone and by the synergistic effect of NAC and AuNP together. Male Wistar rats received saline or saline containing CG administered into the pleural cavity, and some rats also received NAC (20 mg/kg) subcutaneously and/or AuNP administered into the pleural cavity immediately after surgery. Four hours later, the rats were sacrificed and pleural exudates obtained for evaluation of cytokine levels and myeloperoxidase activities.

Synthesis, micellization and lectin binding of new glycosurfactants.

Here we report the preparation and physico-chemical characterization of carbohydrate-decorated micelles and their interaction with lectins. A library of biosourced amphiphiles was prepared by copper-catalyzed azide-alkyne cycloaddition (CuAAC) between alkynyl sugars (lactose, N-acetyl-D-glucosamine) and azido-functionalized poly(ethylene glycol) esters (N3-PEG900-decanoate (C10) and -dodecanoate (C12)). In water, these glycoconjugates self-assemble into micelles of homogeneous nanometric size (11 nm) as evidenced by scattering techniques (DLS for light, and SAXS for X-ray).

Self-association of sodium deoxycholate with EHEC cellulose cooperatively induced by sodium dodecanoate.

Some aspects of ethyl (hydroxyethyl) cellulose (EHEC) aqueous behavior in the presence of ionic surfactants are described in the literature; however, most of the studies reported address moderately concentrated solutions. Few studies have been carried out in the dilute regime using mixtures of biosurfactants. The main purpose of this work is to investigate the interaction of EHEC in the dilute regime and to verify the mixture of two surfactants: sodium deoxycholate (NaDC) and sodium dodecanoate (SDoD).

Self-assembly of amphiphilic glycoconjugates into lectin-adhesive nanoparticles.

This work describes the synthesis and self-assembly of carbohydrate-clicked rod-coil amphiphilic systems. Copper-catalyzed Huisgen cycloaddition was efficiently employed to functionalize the hydrophilic extremity of PEG-b-tetra(p-phenylene) conjugates by lactose and N-acetyl-glucosamine ligands. The resulting amphiphilic systems spontaneously self-assembled into nanoparticles when dissolved in aqueous media, as evidenced by dynamic light scattering (DLS), transmission electron microscopy (TEM), and small-angle X-ray scattering (SAXS).