Formation and properties of a novel complex composed of an amylose-grafted chitosan derivative and single-walled carbon nanotubes

Preparation and characterization of cationic hyperbranched maltodextrins as potential carrier for siRNA encapsulation

The present study sought to investigate the physicochemical properties of cationic branched maltodextrins with similar degrees of substitution but different degrees of branching and their siRNA delivery capacity. The results showed that the ratio of α-1,6 glycosidic bonds was significantly increased in the sample treated with dual enzymes. The structural characterization results showed that abundant short chains reassembled by 1,4-α-glucan branching enzyme (GBEs) hydrolysis formed hyperbranched short clustered structure. The absorption peaks that appeared in the FT-IR spectrum confirmed the occurrence of quaternization. The complexes formed by self-assembly of cationic maltodextrins and siRNA were verified by the gel retardation assay and atomic force microscopy, demonstrating a uniform spherical structure with a size close to 300-350 nm. Meanwhile, cationic branched maltodextrins could effectively reduce the change of secondary structure of siRNA. Overall, the results suggested that branched maltodextrins with a cationic surface had significant potential as siRNA carriers.

Crosslinked chitosan nanoparticle-anchored magnetic multi-wall carbon nanotubes: a bio-nanoreactor with extremely high activity toward click-multi-component reactions

In the present study, we have designed a procedure for the synthesis of a bio-nanoreactor catalyst, crosslinked chitosan nanoparticle-anchored magnetic multi-wall carbon nanotubes (CS NPs/MWCNT@Fe₃O₄), via an in situ ionotropic gelation method.

Antioxidant Nanocomplexes for Delivery of Epigallocatechin-3-gallate

Modification of chitosan (CS) through grafting with caffeic acid (CA, CA-g-CS) and ferulic acid (FA, FA-g-CS) significantly improved its solubility under neutral and alkaline environments. Spherical and physicochemically stable nanocomplexes assembled from the phenolic acid grafting CS and caseinophosphopeptide (CPP) were obtained with particle size <300 nm and zeta potential of <+30 mV. The net polymer nanocomplexes composed with the phenolic acid grafting CS and CPP showed strong antioxidant activity. The encapsulation efficiencies of epigallocatechin-3-gallate (EGCG) in the CA-g-CS-CPP nanocomplexes and FA-g-CS-CPP nanocomplexes were 88.1 ± 6.7 and 90.4 ± 4.2%, respectively. Improved delivery properties of EGCG were achieved after loading with the antioxidant nanocomplexes, including controlling release of EGCG under simulated gastric environments and preventing its degradation under neutral and alkaline environments.

Copper supported on MWCNT-guanidine acetic acid@Fe3O4: synthesis, characterization and application as a novel multi-task nanocatalyst for preparation of triazoles and bis(indolyl)methanes in water

The synthesis of a new supported copper (Cu) nanocatalyst, with highly dispersed particles, based on magnetic guanidine acetic acid (GAA) functionalized multi-wall carbon nanotubes (MWCNT), Cu/MWCNT-GAA@Fe₃O₄, is reported.

Enzymatic synthesis of amylose nanocomposite microbeads using amylosucrase from Deinococcus geothermalis

This communication reports a biological approach to synthesize pure amylose microbeads and amylose–SWCNT composite microbeads using the amylosucrase from Deinococcus geothermalis.

Covalently Bonded Chitosan on Graphene Oxide via Redox Reaction

Carbon nanostructures have played an important role in creating a new field of materials based on carbon. Chemical modification of carbon nanostructures through grafting has been a successful step to improve dispersion and compatibility in solvents, with biomolecules and polymers to form nanocomposites. In this sense carbohydrates such as chitosan are extremely valuable because their functional groups play an important role in diversifying the applications of carbon nanomaterials. This paper reports the covalent attachment of chitosan onto graphene oxide, taking advantage of this carbohydrate at the nanometric level. Grafting is an innovative route to modify properties of graphene, a two-dimensional nanometric arrangement, which is one of the most novel and promising nanostructures. Chitosan grafting was achieved by redox reaction using different temperature conditions that impact on the morphology and features of graphene oxide sheets. Transmission Electron Microscopy, Fourier Transform Infrared, Raman and Energy Dispersive spectroscopies were used to study the surface of chitosan-grafted-graphene oxide. Results show a successful modification indicated by the functional groups found in the grafted material. Dispersions of chitosan-grafted-graphene oxide samples in water and hexane revealed different behavior due to the chemical groups attached to the graphene oxide sheet.