Expeditious Synthesis of C-Glycosyl Barbiturate Ligands of Bacterial Lectins: From Monomer Design to Glycoclusters and Glycopolymers

Microwave-Assisted Synthesis of β-N-Aryl Glycoamphiphiles with Diverse Supramolecular Assemblies and Lectin Accessibility

Glycoamphiphiles have attracted considerable interest in a broad range of application fields owing to their solution and bulk-state self-assembly abilities. Despite their importance, the straightforward synthesis of glycoamphiphiles consisting of a hydrophilic carbohydrate linked to a hydrophobic aglycone remains one of the major challenges in glycosciences. Here, a rapid, simple, and efficient synthetic access to chemically stable glycoamphiphiles at physiological pH, namely, N-(β-d-glycosyl)-2-alkylbenzamide, is reported. It leverages the nonreductive amination of unprotected carbohydrates with ortho-substituted aniline derivatives which could be readily obtained by reacting commercially available primary alkylamines with isatoic anhydride. This strategy avoids protection and deprotection of sugar hydroxyl groups and the use of reductive agents, which makes it advantageous in terms of atom and step economy. Moreover, in order to circumvent the cons of classical N-aryl glycosylation, we investigate the use of microwave as a heat source that provides fast, clean, and high-yield β-N-arylation of unprotected carbohydrates. Their self-assembly into water led to multiple morphologies of dynamic supramolecular glycoamphiphiles that were characterized to assess their ability to bind to lectins from pathogenic bacteria. Biophysical interactions probed by isothermal titration microcalorimetry revealed micromolar affinities for most of the synthesized glycoamphiphiles.

Exploring the Toxicity, Lung Distribution, and Cellular Uptake of Rifampicin and Ascorbic Acid-Loaded Alginate Nanoparticles as Therapeutic Treatment of Lung Intracellular Infections

Nanotechnology is a very promising technological tool to combat health problems associated with the loss of effectiveness of currently used antibiotics. Previously, we developed a formulation consisting of a chitosan and tween 80-decorated alginate nanocarrier that encapsulates rifampicin and the antioxidant ascorbic acid (RIF/ASC), intended for the treatment of respiratory intracellular infections. Here, we investigated the effects of RIF/ASC-loaded NPs on the respiratory mucus and the pulmonary surfactant. In addition, we evaluated their cytotoxicity for lung cells in vitro, and their biodistribution on rat lungs in vivo after their intratracheal administration. Findings herein demonstrated that RIF/ASC-loaded NPs display a favorable lung biocompatibility profile and a uniform distribution throughout lung lobules. RIF/ASC-loaded NPs were mainly uptaken by lung macrophages, their primary target. In summary, findings show that our novel designed RIF/ASC NPs could be a suitable system for antibiotic lung administration with promising perspectives for the treatment of pulmonary intracellular infections.