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Tamarind seed polysaccharide (TSP) is a galactoxyloglucan isolated from seed kernel of Tamarindus indica. TSP has already been used in the industrial fields, due to its physical, chemical, and biological properties (Shukla et al., 2018). It is a neutral and water-soluble polysaccharide; nonetheless, its high viscosity makes solubilization time consuming and feasible at low concentrations. Also, the absence of charges on the chain does not allow electrostatic interactions with charged biological or chemical molecules. For this reason, in this study we conducted a chemical modification of the polysaccharide adding sulphated groups on the TSP chain. The presence of negatively charged groups may allow a better solubilization of the polysaccharide and also specific binding to proteins or receptors, giving new biological properties to TSP (Wang et al., 2018) . The sulfation reaction of TSP was performed in one-step process, using dimethylformamide as a solvent, and sulfur trioxide pyridine complex as reagent. Characterization of the chemical-physical properties of the sulfated products are conducted through different analytical approaches to verify the successful synthesis. Studies of viscosity, morphology, chemical structure, and molecular weight distribution are performed to obtain the complete characterization of the synthesized products. The substitution degree is obtained by potentiometric titration, and the distribution of sulphated groups on the sugars chain is studied by NMR spectroscopy and mass spectrometry; specifically, the hydrolyzed sulfated TSP sample obtained by enzymatic degradation with cellulase and xyloglucanase were investigated. Sulphated TSP products have a molecular weight in the range of 400 kDa-1000 kDa compared to TSP which have a molecular weight of 600 kDa, a substitution degree on the repetitive unit of TSP in the range of 5-50% of the 21 hydroxyl groups that can be sulphated, exhibit lower viscosity than TSP and show higher solubility than pristine TSP.

Human transferrin (hTf) is an iron-binding glycoprotein (Mw 78 kDa) present in blood [1]. Two of its glycoforms, asialo- and disialo-hTF, named carbohydrate deficient transferrin (CDT), represent a well known biological marker of chronic alcohol abuse [2]. To determine CDT, one of the techniques used is capillary electrophoresis (CE). Since CE separations of macromolecules are spoiled by analyte interactions with the silica capillary, polysaccharides can be used as coatings to reduce these interactions [3]. Chitosan is a linear polysaccharide produced from chitin, by alkaline deacetylation [3]. It possesses reactive groups that can be exploited for production of derivatives, with increased solubility [4]. In the present work, chitosan derivatives were synthetized by chemical modification, including nucleophilic substitution, reductive amination, and Michael reaction. All chitosan derivatives were characterized by different techniques, including Nuclear Magnetic Resonance spectroscopy, Size Exclusion Chromatography-Triple Detector Array and Dynamic Light Scattering. The analysis highlighted a different chemical structure between chitosan and its derivatives. A preliminary evaluation of their application in CE showed effects on the streaming potential (an indirect parameter correlated with the interactions between capillary wall and electrolyte solution) with improvements in hTf peak resolution, in selected conditions. To conclude, polysaccharide derivatives have been successfully synthetized and characterized and a preliminary glimpse of their possible application to CE was given. References 1. Paterlini V.; Porpiglia N. M.; De Palo E. F.; Tagliaro F. Alcohol, 2019, Volum 78, 43. 2. Porpiglia N.M.; De Palo E. F.; Savchuk S. A.; Appolonova S. A.; Bortolotti F.; Tagliaro, Chim. Acta, 2018, Volum 486, 256. 3. Rinaudo M. Prog. Polym. Sci., 2006, Volum 31, 603. 4. Casettari L.; Vllasaliu S.; Castagnino E.; Stolnik S.; Howslw S.; Illum L. Prog. Polym. Sci, 2012, Volum 37, 659

The aim of this study was to carry out a quali-quantitative analysis of the presence of non-essential and essential trace elements in freshwater crayfish (Procambarus clarkii) edible tissues to establish the healthiness of this product and to evaluate the pollution status of the sampling sites included in the present study. P. clarkii is one of the most common species of freshwater crustaceans in Italy, regularly consumed by local people. Moreover, the crayfish, due to its trophic position and diet, can be considered as an excellent bioindicator of the health status of the ecosystem. We collected sixty crayfish samples from two different sites in Campania (Italy): Villa Literno and Sessa Aurunca. Concentrations of trace elements were determined by Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). Our data showed low concentrations of Cd, Hg and Pb, with values below the European Commission MRL (Commission Regulation (EC) 1881/2006). We suggest that data obtained from this study showed that crayfish collected from Villa Literno and Sessa Aurunca were safe for human consumption. Furthermore, the results of this research indicated mild contamination of heavy metals of the sampling sites, indicating a good health status of the area’s aquatic ecosystem.

Novel approaches for fabricating safe- and sustainable-by-design coatings are being studied to replace perfluorooctanoic acid or other fluorinated substances that are raising concerns for their potential hazard for human health [1]. In this study, a chitosan-based coating with modified functionality is developed through a solvent-free deposition method. The chitosan backbone is modified with fatty acid side groups to change the polymer wettability from hydrophilic to hydrophobic [2]. The effective chitosan functionality modification with stearoyl groups is assessed and confirmed via combined by 1H and 13C DD-MAS Solid State NMR, FTIR and TGA analysis. The modified chitosan is then deposited by a solvent-free approach consisting of: i) freeze-drying, which allow safe long-term storage, ii) sieving, iii) thermal treatment (Figure 1a). Controlling the amount of deposited coating, transparency and superhydrophobicity can be tuned based on the desired characteristics. A superhydrophobic wetting state (θA = 150°, θR = 144°) is reached for coating amount of 4.8 mg/cm2, obtaining an opaque surface, whereas for lower amount of 0.8 mg/cm2, the coating is hydrophobic (θA = 108°, θR = 67°) with very good transparency (Figure 1b). A morphological characterization by SEM and optical microscope analyses of the coating provides evidence of increased roughness along with increased hydrophobicity. Our innovative and sustainable deposition method for modified chitosan is a simple procedure for creating bio-based transparent hydrophobic coatings, which is fluorine-free and does not require any solvent during deposition. As an outlook, we envision a further development of coatings to better control surface topography to decrease scattering and increase transmittance, and mechanical durability improvement using adhesion promoters or cross-linkers.

Non-covalent interactions in supramolecular chemistry provide useful systems to understand biological processes, and self-assembly systems are suitable assets to build-up innovative products for biomedical applications. In this field, polyelectrolyte complexes are interesting, especially when polysaccharides are involved, due to their non-toxicity and bio-absorbability. In this work, we investigated a polyelectrolyte formed by hyaluronic acid (HA), a negatively charged linear polysaccharide, with Chitlac (Ch), a positively charged lactose-modified chitosan. The aim of the study was the investigation of a novel Ch–HA polyelectrolyte complex, to understand the interaction between the two polysaccharides and the stability towards enzymatic activity. By means of gel permeation chromatography–triple detector array (GPC–TDA), nuclear magnetic resonance (NMR), dynamic viscosity, Zeta Potential and scanning electron microscopy (SEM), the polyelectrolyte complex properties were identified and compared to individual polysaccharides. The complex showed monodisperse molecular weight distribution, high viscosity, negative charge, and could be degraded by specific enzymes, such as hyaluronidase and lysozyme. The results suggest a close interaction between the two polysaccharides in the complex, which could be considered a self-assembly system.

A protocol based on the combination of different analytical methodologies is proposed to standardize the experimental conditions for reproducible formulations of hybrid hydrogels. The final hybrid material, based on the combination of gelatin and chitosan functionalized with methylfuran and cross-linked with 4-arm-PEG-maleimide, is able to mimic role, dynamism, and structural complexity of the extracellular matrix. Physical–chemical properties of starting polymers and finals constructs were characterized exploiting the combination of HP-SEC-TDA, UV, FT-IR, NMR, and TGA.

The development of 3D printable hydrogels based on the crosslinking between chitosan and gelatin is proposed. Chitosan and gelatin were both functionalized with methyl furan groups. Chemical modification was performed by reductive amination with methyl furfural involving the lysine residues of gelatin and the amino groups of chitosan to generate hydrogels with tailored properties. The methyl furan residues present in both polymers were exploited for efficient crosslinking via Diels-Alder ligation with PEG-Star-maleimide under cell-compatible conditions. The obtained chitosan-gelatin hybrid was employed to formulate hydrogels and 3D printable biopolymers and its processability and biocompatibility were preliminarily investigated.

Legionnaires' disease (LD) refers to a serious form of acute pneumonia caused by Legionella species. LD can be difficult to diagnose because the signs and symptoms are nonspecific, and therefore a rapid laboratory diagnosis is of paramount importance. In this study, a recently introduced immunochromatographic test (Immunocatch Legionella; Eiken Chemical Co., Ltd.) for Legionella pneumophila (serogroup 1) urinary antigen detection was compared with the Sofia Legionella fluorescent immunoassay (FIA) (Quidel) (routinely used in our laboratory) and with the widely used BinaxNOW Legionella assay (Alere). A total of 248 urine samples (60 frozen and 188 fresh) were evaluated. All of the samples were collected from patients with high clinical suspicion of Legionnaires' disease. The three assays were performed simultaneously according to the manufacturers' instructions. A total of 180 concordant negative and 66 concordant positive results were obtained. Only 2 discrepant results were registered. The sensitivity and specificity of Immunocatch compared with Sofia were, respectively, 98.5% and 99.4%. Cohen's kappa coefficient and overall percent agreement between Immunocatch and Sofia were also calculated and resulted in, respectively, 0.97 and 99.2%. These performances suggest that the Immunocatch test is a useful tool for Legionella pneumophila (serogroup 1) urinary antigen detection.

In the last decades, microelectromechanical systems have been increasing their number of degrees of freedom and their structural complexity. Hence, most recently designed MEMSs have required higher mobility than in the past and higher structural strength and stability. In some applications, device thickness increased up to the order of tens (or hundred) of microns, which nowadays can be easily obtained by means of DRIE Bosch process. Unfortunately, scalloping introduces stress concentration regions in some parts of the structure. Stress concentration is a dangerous source of strength loss for the whole structure and for comb-drives actuators which may suffer from side pull-in. This paper presents an analytical approach to characterize stress concentrations in DRIE micro-machined MEMS. The method is based on the linear elasticity equations, the de Saint-Venant Principle, and the boundary value problem for the case of a torsional state of the beam. The results obtained by means of this theoretical method are then compared with those obtained by using two other methods: one based on finite difference discretization of the equations, and one based on finite element analysis (FEA). Finally, the new theoretical approach yields results which are in accordance with the known value of the stress concentration factor for asymptotically null radius notches.