Antimicrobial Properties of the Polyaniline Composites against Pseudomonas aeruginosa and Klebsiella pneumoniae

Abstract

CuO, TiO2, or SiO2 was decorated on polyaniline (PANI) by a sonochemical method, and their antimicrobial properties were investigated for two common Gram-negative pathogens: Pseudomonas aeruginosa (PA) and Klebsiella pneumoniae (KP). Without PANI, CuO, TiO2, or SiO2 with a concentration of 220 µg/mL exhibited no antimicrobial activities. In contrast, PANI-CuO and PANI-TiO2 (1 mg/mL, each) completely suppressed the PA growth after 6 h of exposure, compared to 12 h for the PANI-SiO2 at the same concentration. The damage caused by PANI-SiO2 to KP was less effective, compared to that of PANI-TiO2 with the eradication time of 12 h versus 6 h, respectively. This bacterium was not affected by PANI-CuO. All the composites bind tightly to the negative groups of bacteria cell walls to compromise their regular activities, leading to the damage of the cell wall envelope and eventual cell lysis.

Photocatalytic Degradation of Organic Dyes and Antimicrobial Activities by Polyaniline–Nitrogen-Doped Carbon Dot Nanocomposite

“…The unpaired or free electrons in PANI-N@CDs can react with the dissolved oxygen in the solution to produce additional ROS. The free radical properties of PANI are shown in our previous publications [ 33 , 34 , 35 , 36 ]. The synthesized PANI-N@CDs have a negative charge on their surface due to the presence of various functional groups, as confirmed by XPS spectra ( Figure 2 ).…”

“…The inclusion of CDs has improved the physical and chemical activity of the polymer. The release of ROS (reactive oxygen species) causes effective oxidative damage to cellular components and leads to cell lysis [ 33 , 34 , 35 , 36 ].…”

Advances in Polyaniline for Biomedical Applications

“…PANI/Zn@CuO composites exhibit synergistic effect between PANI and the inorganic part, thanks to the movement of free electrons along the polymer that could be combined with the O2 in the suspension to enhance the production of radicals. Remarkable antimicrobial activity was also observed for PANI/TiO2 and PANI/SiO2 nanocomposites against both gram-positive and gram-negative bacteria [170,171]. More recently, innovative nanoAu/PANI/Penicillin G nanoconjugates were easily prepared by photopolymerization of aniline in the presence of AuCl3, leading to Au/PANI composites, then grafted to the C3 carboxyl group of the  lactam ring of penicillin in the presence of EDAC (N-(3dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride) able to activate the COOH group of penicillin [172].…”

Emerging Applications of Versatile Polyaniline-Based Polymers in the Food Industry

“…In addition, PANI has been proven to be active against various fungi and bacteria, such as Aspergillus niger, Escherichia coli , Pseudomonas aeruginosa , Bacillus cereus , Salmonella typhimurium, and Staphylococcus aureus [ 50 , 98 , 99 , 100 ]. Its quaternary ammonium structure renders it strong antibacterial and antifungal properties ( Figure 8 ).…”