Antimicrobial Effect of a Novel Chitosan Derivative and Its Synergistic Effect with Antibiotics.

Cationic polymers are promising antibacterial agents because bacteria have a low propensity to develop resistance against them, but they usually have low biocompatibility because of their hydrophobic moieties. Herein, we report a new biodegradable and biocompatible chitosan-derived cationic antibacterial polymer, 2,6-diamino chitosan (2,6-DAC). 2,6-DAC shows excellent broad-spectrum antimicrobial activity with minimum inhibitory concentrations (MICs) of 8-32 μg/mL against clinically relevant and multidrug-resistant (MDR) bacteria including , , , , , and .

Hydrogel Effects Rapid Biofilm Debridement with ex situ Contact-Kill to Eliminate Multidrug Resistant Bacteria in vivo.

Multidrug resistance and the refractory character of bacterial biofilms are among the most difficult challenges in infection treatment. Current antimicrobial strategies typically are much more effective for prevention of biofilm formation than for eradication of established biofilms; these strategies also leave dead bacteria and endotoxin in the infection site, which impairs healing. We report a novel hydrogel that eradicates biofilm bacteria by non-leaching-based debridement followed by ex situ contact-killing (DESCK) away from the infection site.

Stereochemistry and mechanistic study of intramolecular Pd(II)-catalyzed oxypalladation and 1,3-chirality-transfer reactions.

Pd(II)-catalyzed cyclizations of chiral epsilon-, zeta-, and eta-hydroxy-alpha,beta-unsaturated alcohols are described. The reactions took place stereospecifically to give chiral 2,5-disubstituted tetrahydrofurans, 2,6-disubstituted tetrahydropyrans, and 2,7-disubstituted oxepanes, respectively. The chirality of the carbon center of the chiral allylic alcohol is transferred stereospecifically to the carbon center of the newly generated oxacyclic ring.