Micronized curcumin fabricated by supercritical CO2 to improve antibacterial activity against Pseudomonas aeruginosa.

Curcumin (CM) is a natural polyphenolic compound with multiple biomedical functions. However, clinical applications face more challenges due to its low dissolution rate and poor bioavailability. Micronization is an effective strategy to overcome these drawbacks. Herein, CM nanoparticles (CM NPs, ∼300 nm) were fabricated using solution enhanced dispersion by supercritical CO2 (SEDS). The solubility of CM NPs was remarkably enhanced. Aim to study the effects of micronization on the biological functions of CM, we investigated the antibacterial activity of original CM and CM NPs upon Pseudomonas aeruginosa. In vitro, the minimal inhibitory concentrations (MIC) assay, solid-medium spot assay, growth kinetics assay and morphologic observation using atomic force microscopy (AFM) confirmed that the anti-P. aeruginosa activity of CM NPs was enhanced compared to original CM. Moreover, CM NPs also showed stronger inhibition for adhesion and biofilm formation of P. aeruginosa compared to original CM. Experiments on mice infected with P. aeruginosa showed that CM NPs have a better therapeutic effect than the original CM in vivo. In summary, CM NPs may be a novel and promising therapeutic candidate for bacterial infection.

Preparation, Characterization, and Antimicrobial Properties of Chitosan-Silver Nanocomposites Films Against Fish Pathogenic Bacteria and Fungi.

ABSTRACT: Development of nanostructured films using natural polymers and metals has become a considerable interest in various biomedical applications. Objective of the present study was to develop silver nano particles (AgNPs) embedded chitosan films with antimicrobial properties. Based on the Ag content, two types of chitosan silver nano films, named as CAgNfs-12 (12 mM) and CAgNfs-52 (52 mM) were prepared and characterized. Field emission scanning electron microscope (FE-SEM) images of two CAgNfs showed the circular AgNPs, which were uniformly embedded and distributed in the matrix of chitosan films. Antimicrobial experiment results clearly indicated that CAgNfs can inhibit the growth of fish pathogenic bacteria Vibrio (Allivibrio) salmonicida, V. tapetis, Edwardsiella tarda and fungi Fusarium oxysporum. Moreover, CAgNfs significantly reduced the experimentally exposed V. salmonicida levels in artificial seawater, suggesting that these CAgNfs could be used to develop antimicrobial filters/membranes for water purifying units to eliminate the pathogenic microbes.