Closing Editorial: Research Progress on Chitosan Applications.

Chitosan has attracted significant attention due to its versatile properties, which make it an ideal candidate for varied biomedical and industrial applications [...

NMR Fingerprinting of Conventional and Genetically Modified Soybean Plants with AtAREB1 Transcription Factors.

Drought stress impacts soybean yields and physiological processes. However, the insertion of the activated form of the AtAREB1 gene in the soybean cultivar BR16, which is sensitive to water deficit, improved the drought response of the genetically modified plants. Thus, in this study, we used H NMR in solution and solid-state NMR to investigate the response of genetically modified soybean overexpressing AtAREB1 under water deficiency conditions.

Antimicrobial and Photoantimicrobial Activities of Chitosan/CNPPV Nanocomposites.

Multidrug-resistant bacteria represent a global health and economic burden that urgently calls for new technologies to combat bacterial antimicrobial resistance. Here, we developed novel nanocomposites (NCPs) based on chitosan that display different degrees of acetylation (DAs), and conjugated polymer cyano-substituted poly(-phenylene vinylene) (CNPPV) as an alternative approach to inactivate Gram-negative () and Gram-positive () bacteria. Chitosan's structure was confirmed through FT-Raman spectroscopy.

Head-to-Tail and Head-to-Head Molecular Chains of Poly(-Anisidine): Combined Experimental and Theoretical Evaluation.

Poly(-anisidine) (PPA) is a polyaniline derivative presenting a methoxy (-OCH) group at the position of the phenyl ring. Considering the important role of conjugated polymers in novel technological applications, a systematic, combined experimental and theoretical investigation was performed to obtain more insight into the crystallization process of PPA. Conventional oxidative polymerization of -anisidine monomer was based on a central composite rotational design (CCRD).

Insight into morphological, physicochemical and spectroscopic properties of β-chitin nanocrystalline structures.

We systematically investigated the effect of β-chitin (BCH) particle size on the preparation of nanocrystals/nanowhiskers (CWH) by acid hydrolysis. Regardless this variable, CWH aqueous suspension exhibited outstanding stability and the average degree of acetylation remained nearly constant after the acid treatment. In contrast, the morphology, dimensions, crystallinity, and molecular weight of CHW were significantly affect by the particle size.

Clotrimazole-loaded N-(2-hydroxy)-propyl-3-trimethylammonium, O-palmitoyl chitosan nanoparticles for topical treatment of vulvovaginal candidiasis.

Vulvovaginal candidiasis (VVC) represents a considerable health burden for women. Despite the availability of a significant array of antifungal drugs and topical products, the management of the infection is not always effective, and new approaches are needed. Here, we explored cationic N-(2-hydroxy)-propyl-3-trimethylammonium, O-palmitoyl chitosan nanoparticles (NPs) as carriers of clotrimazole (CLT) for the topical treatment of VVC.

N-(2-hydroxy)-propyl-3-trimethylammonium, O-palmitoyl chitosan: Synthesis, physicochemical and biological properties.

Two samples of N-(2-hydroxy)-propyl-3-trimethylammonium, O-palmitoyl chitosan (DPCat) with different average degrees of quaternization named as DPCat35 (DQ¯ = 35%) and DPCat80 (DQ¯ = 80%), were successfully synthesized by reacting glycidyltrimethylammonium chloride (GTMAC) with O-palmitoyl chitosan (DPCh) derivative (DS¯ = 12%). Such amphiphilic derivatives of chitosan were fully water-soluble at 1.0 < pH < 12.

Fast-forward approach of time-domain NMR relaxometry for solid-state chemistry of chitosan.

Chitosans with different average degrees of acetylation and weight molecular weight were analyzed by time-domain NMR relaxometry using the recently proposed pulse sequence named Rhim and Kessemeier - Radiofrequency Optimized Solid-Echo (RK-ROSE) to acquire H NMR signal of solid-state materials. The NMR signal decay was composed of faster (tenths of μs) and longer components, where the mobile-part fraction exhibited an effective relaxation transverse time assigned to methyl hydrogens from N-acetyl-d-glucosamine (GlcNAc) units. The higher intrinsic mobility of methyl groups was confirmed via DIPSHIFT experiments by probing the H-C dipolar interaction.

Evaluation of chitosan crystallinity: A high-resolution solid-state NMR spectroscopy approach.

We propose a novel approach relied on high-resolution solid-state C NMR spectroscopy to quantify the crystallinity index of chitosans (Ch) prepared with variable average degrees of acetylation (DA¯) from 5% to 60 % and average weight molecular weight (M¯) ranged in 0.15 × 10 g mol-1.2 × 10 g mol.

Effect of amylolysis on the formation, the molecular, crystalline and thermal characteristics and the digestibility of retrograded starches.

This study evaluated the effect of amylases on the formation, and characteristics of retrograded starches using sweet potato (SPS), cassava (CAS) and high amylose maize (HAS) starches. The starches were gelatinized, hydrolyzed with fungal or maltogenic α-amylase, de-branched and retrograded. The modified starches were then analyzed for digestibility, chain size distribution, relative crystallinity and crystallite size, thermal properties and the proportion of double helices.

Bioproduction of N-acetyl-glucosamine from colloidal α-chitin using an enzyme cocktail produced by Aeromonas caviae CHZ306.

N-acetyl-D-glucosamine (GlcNAc) is an important amino-monosaccharide with great potential for biotechnological applications. It has traditionally been produced by the chemical hydrolysis of chitin, despite certain industrial and environmental drawbacks, including acidic wastes, low yields and high costs. Therefore, enzymatic production has gained attention as a promising environmentally-friendly alternative to the chemical processes.

Characterization and physical-chemistry of methoxypoly(ethylene glycol)-g-chitosan.

Methoxypoly(ethyleneglycol)-graft-chitosan (PEG-g-Ch) was prepared by grafting polyethyleneglycol into chitosans (Ch) exhibiting different average degree of deacetylation (60% < DD¯ < 95%). H NMR showed that PEG-g-Ch derivatives presented high average degree of N-substitution (DS¯ ≈ 40%) and such derivatives exhibited full water solubility at 1.0 < pH < 11.

Self-aggregates of 3,6-O,O'-dimyristoylchitosan derivative are effective in enhancing the solubility and intestinal permeability of camptothecin.

The aim of this work was to investigate the potential of a new 3,6-O,O'-dimyristoyl derivative amphiphilic chitosan (DMCh), in improving the solubility of camptothecin (CPT), a hydrophobic anticancer drug, and its potential oral delivery. FTIR, H NMR and solid-state C NMR spectroscopy were used to characterize DMCh and to determine its average degree of substitution (DS¯=6.8%).