Microparticles as BDMDAC (Quaternary Ammonium Compound) Carriers for Water Disinfection: A Layer-by-Layer Approach...

Area of Science:

• Materials Science
• Microbiology
• Biotechnology

Background:

• Antimicrobial resistance necessitates novel strategies.
• Microparticle-based delivery systems offer targeted antimicrobial action.
• Benzyldimethyldodecyl ammonium chloride (BDMDAC) is a quaternary ammonium compound with known antimicrobial properties.

Purpose of the Study:

• To investigate the antimicrobial efficacy of BDMDAC-coated microparticles with varying morphologies.
• To explore the mechanism of bacterial inactivation by these functionalized microparticles.
• To assess the stability and potential biocide leaching from the coated microparticles.

Main Methods:

• Layer-by-layer (LbL) self-assembly was used to coat hydroxyapatite (Hap), calcium carbonate (CaCO3), and glass beads (GB) with BDMDAC.
• Characterization included Fourier-Transform Infrared Spectroscopy (FTIR), Brunner-Emmett-Teller (BET), and Scanning Electron Microscopy (SEM).
• Antimicrobial activity was evaluated against planktonic *Pseudomonas fluorescens* at different concentrations (100, 200, 400 mg/L) over 240 minutes.

Main Results:

• BDMDAC-coated Hap microparticles demonstrated complete reduction of *Pseudomonas fluorescens* at 200 mg/L after 240 minutes.
• SEM analysis revealed distinct morphological structures of the coated microparticles.
• High-Performance Liquid Chromatography (HPLC) analysis detected no biocide release over two weeks.

Conclusions:

• BDMDAC-coated Hap microparticles exhibit significant antimicrobial activity against *Pseudomonas fluorescens*.
• The observed bacterial inactivation is likely mediated by a contact-killing mechanism.
• The absence of biocide release indicates a stable and safe functionalization approach for antimicrobial applications.