Evaluation of the effectiveness of N-Acetylcysteine (NAC) and N-acetylcysteine-cyclodextrins Multi-Composite in Pseudomonas aeruginosa biofilm formation

Pseudomonas aeruginosa is a gram-negative bacillus involved in biofilm production in several lung diseases. In this study, the in vitro anti-biofilm effect of both N-acetylcysteine (NAC)-a well-known antioxidant compound and GSH prodrug-and NACESOLTM-a new multicomposite based on NAC, resveratrol, and cyclodextrins-was investigated by evaluation of reduction of bacterial colonies growth. Physico-chemical analysis of NACESOL™ was performed by differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR) spectroscopy, and X-ray powder diffraction (XRPD) techniques. The anti-biofilm activity of NAC and NACESOL™, expressed as percentage of biofilm reduction, revealed an increased biological activity of multicomposite at low concentrations. Furthermore, the NAC activity against P. aeruginosa biofilm was also studied using scanning electron microscopy (SEM) joined to the energy dispersive spectrometry (EDS) technique, which is able to evaluate the reduction of sulfur element on biofilm surface. The use of SEM-EDS highlights the biofilm amount decrease with increasing NAC concentration. This work permitted us to highlight the minimum concentration of NAC able to interact in the P. aeruginosa biofilm formation process and the promising use of a new composite based on NAC and cyclodextrins.