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Functionalization of starch with oxidative cleavage reaction to yield the corresponding dialdehyde derivatives has been employed as an approach for gel formation via Schiff's base reaction. However, this reaction is known as reversible and hydrolysable in aqueous solutions. In this study, the potential of hydrazone chemistry to be used in the synthesis of stimuli‐free and stable hydrogels is investigated. Soluble starch is selectively oxidized to give aldehydic‐starch with different aldehyde contents 39.9, 34.6, and 22.6 aldehyde group/100 anhydroglucose unit (AGU). Adipic dihydrazide was used as an α‐effect nucleophile to react with the dialdehyde starch and obtain stable hydrazone‐based and stimuli‐free hydrogels. Hydrazone chemistry of aldehydic‐starch and adipic dihydrazide (AD) is demonstrated by spectral analysis. As well, the biocompatibility with human skin fibroblasts cells is investigated using a cytotoxicity assay. SEM images show the pore sizes vary from 575 to 4752 nm related to AD concentrations. The swelling degree recorded an increase of 900%, 500%, and 600% at pH 4, pH 7, and pH 9, respectively. Hydrogels showed varied mechanical behavior as a function of AD concentrations.

Nowadays, encapsulated dyes in a polymeric matrix have opened up new perspectives in many applications such as filtration of subatomic particles, composite reinforcement, multifunctional membranes, tissue engineering scaffolds, wound dressing, coatings, medical purposes as well as sensors. In the presented work, we report on electrospinning neat peryelene dianhydride based thermoplastic elastomers. Perylene-3, 4,9, 10-tetracarboxylic dianhydride (PDA) is encapsulated into cellulose acetate (CA) electrospun fibers, which was prepared from 12 % cellulose acetate solution, at 20 kV with a distance of 10 cm. The flow rate was 0.2 ml·h–1. These water repellent nanofibrous coatings are anticipated to serve as hydrophobic coatings. Scanning electron microscope is used to study the properties of the electrospun PDA-CA nanofibers.

Background Micronutrient deficiencies among pregnant women are widespread in low-income countries, including Egypt. Iron deficiency anemia (IDA) is the most frequent nutritional deficiency during pregnancy, with an impact on maternal and fetal morbidity and mortality. We aimed to evaluate the effect of maternal IDA and nutritional status on birth anthropometry, cord blood iron profile and breast milk micronutrients in 50 anemic (hemoglobin

Starch derivatives with anionic functional groups have attracted a lot of attention because of their potentials in the industrial applications. Commonly anionic starch derivatives possess gelatinization temperatures lower than that of native starch that is broadening its applications in industrial processes operated at low temperature. In this work, new starch derivatives containing sulfonated functional groups were prepared through intermediate triazinyl compounds. Four different bridging compounds were synthesized and characterized via spectral analysis. The sulfonated triazinyl compounds were reacted with native starch to obtain different density of sulfonic acid groups on starch backbone. Native starch was reacted with mono/dichlorotriazine-4-aminobenzene-sulfonic acid and mono/dichlorotriazine-4-aminobenzene 1,3-disulfonic acid. The sulfonic acid groups were introduced in different degree of substitutions (0.043, 0.032, 0.006 and 0.008) which caused charge repulsion along the starch chains and resulted in keeping chains stretched and therefore less affected with pH and temperature. Ultimately, the produced anionic starch derivatives possess gelatinization temperatures lower than that of native starch that is broadening its applications in industrial processes operated at low temperature.

Injectable hydrogels have attracted a great deal of attention as cell carriers and bioactive agents in regenerative medicine due to their ability to fill complex three-dimensional (3D) tissue gaps and relative ease of in vivo administration. Polysaccharide-based hydrogels can provide microenvironments that favor tissue regeneration and biocompatibility due to their chemical similarities with native extracellular matrix components. This manuscript reports the in vitro application of an injectable chitosan-based polysaccharide hydrogel for cell and protein delivery. Crosslinked hydrogels were produced by the reaction between the amino functionality of chitosan and the aldehyde of dextran aldehyde resulting in an imine bond (Schiff's base) formation in aqueous solutions. This approach eliminated the use of additional crosslinking agents which may pose undesired side effects regarding cytotoxicity and biocompatibility. Additionally, we demonstrate versatility of the gel in terms of its fabrication, and ability to alter mechanical properties by changing the crosslinking extent due to aldehyde content. Bovine serum albumin (BSA), used as a model protein, followed a steady release pattern from the gel. BSA release was dependent on the extent of hydrogel crosslinking. Increase in crosslinking extent resulted in improved mechanical properties and sustained release of BSA. Human fetal osteoblasts encapsulated into the hydrogel showed at least 70% viability and continued to proliferate under in vitro culture. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39934.