Abstract
Two novel chitosan derivatives were prepared by incorporating salicylhydrazide into chitosan Schiff base (SCsSB) and chitosan (SCs). Two nanocomposites, SCs/TiO2-1% and SCs/TiO2-3%, were also prepared. Their structures were confirmed using elemental analyses, FTIR, XRD, SEM, EDX and TEM. Their antimicrobial and anti-biofilm activities were arranged as: SCs/TiO2-3% > SCs/TiO2-1% > SCs > SCsSB > chitosan. SCs showed minimum inhibitory concentration (MIC) value of 1.95 μg/mL against A. niger which was comparable with that of Amphotericin B. SCs/TiO2-3% showed higher inhibition against S. epidermidis, S. aureus, S. pyogenes, P. aeruginosa and E. coli than Vancomycin. While, it showed comparable inhibition activity to that of Vancomycin against B. subtilis and P. mirabilis. SCs/TiO2-3% showed MIC values equal 0.48 and 0.98 μg/mL corresponded to 0.98 and 1.95 μg/mL of Amphotericin B against C. albicans, A. fumigatus and A. niger, respectively. SCs/TiO2-3% showed much lower minimum biofilm inhibitory concentration (MBIC) values, ranged between 1.95 and 7.81 μg/mL, than those of SCs, ranged from 62.5 to 125 μg/mL. SCs/TiO2-3% was safe on normal human cells. The modifiers and TiO2 nanoparticles incorporated into chitosan in one structure developed its performance. It is approach for attaining appropriate structures which are good competitors for antimicrobial agents.
•Novel two chitosan-based salicylhydrazido derivatives were synthesized.•Two TiO2 salicylhydrazido chitosan nanocomposites were also prepared.•Confirmation of their structures was done using various analytical techniques.•They are more efficient against biofilm and microbial growth than chitosan.•Some of them have higher efficiency than Vancomycin and Amphotericin B.