Choline chloride-based deep eutectic solvents as plasticizer and active agent in chitosan films.

The growing concern over extending the shelf life of food products, coupled with the escalating environmental impact of synthetic plastic waste, has fuelled a quest for bio-based alternatives in packaging research. In response to this pressing need, our study delves into the synthesis of chitosan-based films incorporating a deep eutectic solvents (DES). Choline chloride and diverse hydrogen bond donors were used as plasticizers, we also explored the active properties of DES integrated into the chitosan (Ch) matrix. The Ch-based films with chlorine chloride: citric acid can prevent the mold spotting up to 29 days longer in comparison to bread wrapped in polyethylene films (PE). The obtained Ch/DES films exhibited mechanical properties comparable to conventional PE (e.g., up to tensile strength of 26 MPa and up to 210% in case of elongation at break). This synthesis approach represents a significant stride towards environmentally friendly packaging materials, aligning with the principles of green chemistry.

Fluorosurfactants for medical nanoemulsions, their surface-active and biological properties.

Nano- and microemulsions have found various applications in pharmaceutical and medical areas both in research field as well as in applied solutions for drug delivery or diagnostic agents. However, production of stable and bio- / hemocompatible nanoemulsions are still challenging. New group of ionic surfactants have been synthesized with perfluorohexyl- or perfluorooctyl-groups as hydrophobic tail. The CMC and the parametres of the O/W emulsion (the particle size distribution and the zeta-potential) were determined. The influence of the surfactants on in vitro proliferation of human endothelial cell lines HMEC-1, murine fibroblasts L929 and hemolysis were investigated as characteristic for biocompatibility. Three candidates of surfactants were selected for pre-clinical tests on a small animal model (adult Sprague Dawley rats) on the basis of preliminary studies. This allowed to obtain nanoemulsions with narrow droplets size (average droplet diameter 141-147 nm with PDI index 0.059 - 0.065) and showed better stability over time in comparison to the commercially available surfactants. Neither cytotoxic nor hemolytic potential were observed during incubation of obtained fluorosurfactans with model cell lines L929 and HMEC-1 (average cell viability above 85 % after incubation with 1% solutions) and erythrocytes (hemolysis rate below 3.1 % for all 0.5 % solutions). During acute toxicity test on rat model, it was found that all three tested surfactant solutions showed no significant differences in controlled parameters and survival rate with control group (p > 0.05). Presented surfactants are dedicated but not limited to emulsification of organic fluorocompounds.

"Choose-a-size" control in the synthesis of sucrose based urea and thiourea macrocycles.

Highly efficient synthesis of monomeric and dimeric thiourea macrocycles with a per-O-benzylated sucrose scaffold is reported. Application of flow synthesis results in exclusive formation of a monomer in 79% yield. Batch synthesis provides two isomeric dimers in 85% yield. Dimers are capable of anion binding via two thiourea groups acting cooperatively.

Chloride-Templated Macrocyclization and Anion-Binding Properties of C2-Symmetric Macrocyclic Ureas from Sucrose.

A high-yielding, one-pot simultaneous synthesis and full characterization of two regioisomeric C2-symmetrical macrocycles 3a and 3b from triphosgene and readily available hexa-O-benzyl-6,6'-diaminosucrose 1 is reported. The efficient macrocyclization (90% overall yield, ∼1:1 ratio of 3a vs 3b) is attributed to favorable steric constraints and to a templation by a chloride anion. 1H NMR titration studies and theoretical predictions revealed that both receptors show similar affinity for acetate and benzoate anions and enhanced preference for chloride over H2PO4-.