Covalently Cross-Linked Nanoparticles Based on Ferulated Arabinoxylans Recovered from a Distiller’s Dried Grains Byproduct

The purpose of this investigation was to extract ferulated arabinoxylans (AX) from dried distillers’ grains with solubles (DDGS) plus to investigate their capability to form covalently cross-linked nanoparticles. AX registered 7.3 µg of ferulic acid/mg polysaccharide and molecular weight and intrinsic viscosity of 661 kDa and 149 mL/g, correspondingly. Fourier transform infrared spectroscopy (FTIR) was used to confirm the identity of this polysaccharide. AX formed laccase induced covalent gels at 1% (w/v), which registered an elastic modulus of 224 Pa and a content of FA dimers of 1.5 µg/mg polysaccharide. Scanning electron microscopy pictures of AX gels exhibited a microstructure resembling a rough honeycomb. AX formed covalently cross-linked nanoparticles (NAX) by coaxial electrospray. The average hydrodynamic diameter of NAX determined by dynamic light scattering was 328 nm. NAX presented a spherical and regular shape by transmission electron microscopy analysis. NAX may be an attractive material for pharmaceutical and biomedical applications and an option in sustainable DDGS use

Preparation methods of chitosan nanoparticles: a review

El quitosano es un polisacárido natural que ha sido utilizado frecuentemente en el desarrollo de distintos materiales, debido a sus excepcionales propiedades fisicoquímicas y biológicas. Las nanopartículas de quitosano son generalmente producidas por estrategias denominadas de construcción (del inglés “bottom up”), donde el ensamblado polimérico es promovido por distintas interacciones moleculares. Sin embargo, un grupo de estrategias llamadas de deconstrucción (del inglés “top-down”) basadas en la fragmentación de estructuras macroscópicas, han generado un gran interés recientemente como alternativa para la obtención de nanomateriales. El presente trabajo hace una revisión bibliográfica de los resultados obtenidos por distintas investigaciones sobre la producción de sistemas de nanopartículas basadas en quitosano durante las últimas décadas. Las evidencias demostraron que las nanopartículas de quitosano juegan un papel preponderante en la investigación de los nanomateriales poliméricos con aplicaciones biomédicas y farmacéuticas, debido a la gran diversidad de métodos de obtención existentes que determinan las propiedades de los materiales, tales como tamaño de partícula, capacidad de incorporación y liberación de compuestos bioactivos, carga superficial, mucoadhesividad, entre otras

Preparation of chitosan nanoparticles by nanoprecipitation and their ability as a drug nanocarrier

Polysaccharide-based nanoparticles represent a very promising drug delivery platform, particularly for the transmucosal delivery of bioactive macromolecules. Thus, the aim of this paper is to revisit the nanoprecipitation processes for preparing chitosan nanoparticles and to evaluate the influence of the process parameters on their characteristics. Chitosan was dissolved in water as N-(methylsulfonic acid) chitosan or directly in aqueous acetic acid. Methanol was used as the nonsolvent diffusing phase. Nanoparticles became smaller as the polymer concentration decreased or the nonsolvent to solvent volume ratio increased. Particles prepared in acidic media are slightly larger than those precipitated from N-(methylsulfonic acid) chitosan. Replacement of methanol by water in the suspension medium resulted in a notorious increase in their size. On the other hand, very little additions of Tween-80 to the nonsolvent phase render smaller nanoparticles, with a similar mean-size values. Nanoparticles precipitated in methanol have roughly the same dimensions, regardless of the ionic strength of the chitosan solution. These chitosan nanoparticles have good association and loading efficiency values of a model substance showing their ability as a nanocarrier for drug delivery systems

Synthesis of regioselective chitosan copolymers with β-cyclodextrin and poly(N-isopropyl acrylamide)

This work aimed to design a synthetic route under mild conditions allowing the main chitosan chain to be grafted with β-cyclodextrin (β-CD) and poly(N-isopropyl acrylamide) (PNIPAm), at C2 and C6 positions, respectively. For this reason, the regioselectivity of proposed reactions is an important factor to be considered. β-CD is an oligosaccharide with a cyclic structure capable of forming inclusion complexes with hydrophobic molecules. Grafting β-CD onto the chitosan backbone by reductive N-alkylation at C2 position was carried out. With this purpose, the previous preparation of β-CD monoaldehyde was required. PNIPAm is a thermosensitive polymer with a transition temperature near 33 °C. To regioselectively anchor poly(N-isopropyl acrylamide) chains onto chitosan at C6 position, it was required to attach at the C6 position of chitosan an alkyl group for the subsequent grafting of PNIPAm-N3 by means of copper-catalyzed azide-alkyne cycloaddition click reaction. To guarantee the regioselectivity of the functionalization of chitosan with a C6 terminal alkyne, its oxyalkylation with glycidyl propargyl ether in a solvent composed of LiOH/KOH/urea was used. The structure of all derivatives was confirmed by FT-IR and 1H-NMR spectroscopy

Production and characterization of supercritical CO₂ dried chitosan nanoparticles as novel carrier device

The materials produced by the supercritical CO₂ drying have outstanding properties that allow the incorporation of molecules in their porous structure. In this context, dried chitosan nanoparticles including β-lactoglobulin were obtained. First, the nanoparticles in water suspension were produced by ionotropic gelation incorporating the protein with high loading efficiency. Later, solvent exchange and CO₂ supercritical drying procedures were performed. The physicochemical characteristics and structural properties were determined, demonstrating a stable porous structure in the dried materials and corroborating the presence of the protein after the drying. The CO₂ supercritical dried chitosan nanoparticles can be effectively resuspended in acidic aqueous medium remaining in the nanoscale with minimum effect on the loading parameters. The release of the β-lactoglobulin was highly influenced by the pH, reaching around 40% under acidic conditions in ten hours. The obtained results demonstrate the possibility to apply these chitosan materials as a controlled release material

Enzymatically cross-linked arabinoxylan microspheres as oral insulin delivery system

Arabinoxylans (AX) microspheres with different insulin/AX mass ratio were prepared by formation of phenoxy radical issued from the ferulic acid by enzymatic oxidation (entrapped in situ of insulin). Phenolic acid content and FT-IR spectrum of unloaded and insulin-loaded AX microspheres revealed that the phenoxy radical issued from the ferulic acid by enzymatic oxidation did not interact covalently with insulin. The microspheres showed a spherical shape, smooth surface and an average diameter of particles of 320 μm. In vitro control release found that AX microspheres minimized the insulin loss in the upper GI tract, retaining high percentage (~75%) of insulin in its matrix. The stability of the secondary structure of insulin was studied by dichroism circular (CD). The CD spectra of insulin released from AX microspheres did not change according to the insulin/AX mass ratio of the microsphere. Significant hypoglycemic effects with improved insulin-relative bioavailability tested on an in vivo murine model revealed the efficacy of these enzymatically cross-linked arabinoxylans microspheres as a new oral insulin carrier

Quorum sensing interruption as a tool to control virulence of plant pathogenic bacteria

Pathogenic bacteria use Quorum sensing (QS) to regulate the expression of virulence factors involved in plant tissue infection. Some of these factors are the production of biofilm, hydrolytic enzymes, toxins, and plasmids; therefore, the interruption of this system could be a useful tool to control plant tissue infections. This review analyzes the potential treatments to interrupt QS and control the infection of plant tissues

Covalently Cross-Linked Nanoparticles Based on Ferulated Arabinoxylans Recovered from a Distiller’s Dried Grains Byproduct

The purpose of this investigation was to extract ferulated arabinoxylans (AX) from dried distillers’ grains with solubles (DDGS) plus to investigate their capability to form covalently cross-linked nanoparticles. AX registered 7.3 µg of ferulic acid/mg polysaccharide and molecular weight and intrinsic viscosity of 661 kDa and 149 mL/g, correspondingly. Fourier transform infrared spectroscopy (FTIR) was used to confirm the identity of this polysaccharide. AX formed laccase induced covalent gels at 1% (w/v), which registered an elastic modulus of 224 Pa and a content of FA dimers of 1.5 µg/mg polysaccharide. Scanning electron microscopy pictures of AX gels exhibited a microstructure resembling a rough honeycomb. AX formed covalently cross-linked nanoparticles (NAX) by coaxial electrospray. The average hydrodynamic diameter of NAX determined by dynamic light scattering was 328 nm. NAX presented a spherical and regular shape by transmission electron microscopy analysis. NAX may be an attractive material for pharmaceutical and biomedical applications and an option in sustainable DDGS use