Release and Minimum-Inhibition-Concentration Studies of Microencapsulated Antimicrobial Agents

Objectives: The objective of this study was to demonstrate the effectivenes of antimicrobial agents released from microcapsules with permeable membranes against gram positive and gram negative bacteria.
Methods: A heterogeneous polymerization technique was utilized to prepare microcapsules containing aqueous solutions of benzalkonium chloride (BAK) and cetyl pyridinium chloride (CPC). Antimicrobial agent release profiles were studied as a function of initial antimicrobial agent concentration within the microcapsule, antimicrobial agent type, and chemical structure of the microcapsule. Antimicrobial agent detection was measured using uv/vis spectroscopy. Standard MIC experiments were performed using wellplates and uv/vis spectroscopy. Bacillus Subtilis and Escherichia Coli colonies were exposed to microencapsulated aqueous solutions of BAK and CPC.
Results: Antimicrobial agent release profiles were studied and reported as a function of time, initial concentration in the microcapsule and chemical structure. The antimicrobial agent releasing microcapsules were then plated with B. Sub. and E coli. The MIC was measured as a function of microcapsule loading in the well plate.
Conclusions: Release profiles were generated for microencapsulated aqueous solutions that contained antimicrobial agents useful in fighting recurrent decay. Antimicrobial agents released from microcapsules were effective at inhibiting the growth of gram positive and gram negative bacteria.