Quaternized chitosans bind onto preexisting biofilms and eradicate pre-attached microorganisms

Area of Science:

• Biochemistry
• Materials Science
• Microbiology

Background:

• Chitosan derivatives are explored for antimicrobial applications.
• Biofilm formation poses challenges in various settings.
• Developing effective biofilm eradication strategies is crucial.

Purpose of the Study:

• To synthesize and characterize N,N,N-trimethylchitosans (TMC) with varying quaternization degrees.
• To evaluate the antimicrobial efficacy of TMC against planktonic bacteria and fungi.
• To investigate the ability of TMC to bind to and eradicate pre-formed biofilms.

Main Methods:

• Synthesis of TMC via methylation of chitosan.
• Characterization using FT-IR and 1H-NMR.
• Antimicrobial assays against Staphylococcus epidermidis, Escherichia coli, and Candida albicans.
• Biofilm formation on PMMA films and subsequent TMC treatment.
• Zeta potential, UV studies, CFU determination, SEM, CLSM, and fluorescence microscopy for biofilm analysis.
• MTT assay for biocompatibility assessment.

Main Results:

• TMC synthesis was confirmed by spectroscopic methods.
• TMC demonstrated potent biocidal effects against planktonic Gram-positive bacteria, Gram-negative bacteria, and yeast.
• TMC rapidly bonded to pre-existing bacterial and fungal biofilms on PMMA.
• TMC effectively eradicated cells within pre-formed biofilms.
• TMC samples showed good biocompatibility with rat skin fibroblast cells.

Conclusions:

• Quaternized chitosans (TMC) are effective antimicrobial agents.
• TMC exhibits strong potential for eradicating established biofilms.
• The synthesized TMC possesses favorable biocompatibility, suggesting potential for biomedical applications.