Microemulsion-based formulation of enterocin CC2: a novel antimicrobial solution targeting Streptococcus mutans

Dental caries, driven predominantly by Streptococcus mutans, remains a significant global challenge. Conventional treatments often fall short due to antimicrobial resistance and limited efficacy. Enterocin CC2, a potent bacteriocin, offers a promising alternative but is hindered by stability and delivery challenges. This study pioneers the development of a cutting-edge microemulsion designed to enhance the stability, bioavailability, and antimicrobial potency of enterocin CC2 against S. mutans. A comprehensive screening of 124 formulations was conducted, evaluating thermodynamic stability, cytotoxicity, and antioxidant potential. The optimized formulation underwent rigorous analysis for physicochemical properties, antimicrobial activity, and long-term stability under varied storage conditions. The innovative microemulsion formulation, incorporating 0.5 mg/mL enterocin CC2, 0.5% surfactant blend (Tween 80 + PEG 400, 1:1), and 0.5% oil, demonstrated micro-sized droplets (88.50-92.10 nm), exceptional thermodynamic stability, and robust antimicrobial efficacy. Remarkably, it reduced the time to eradicate S. mutans UKMCC 1019 from 8 h (unformulated) to 5 h, outperforming 0.2% w/v chlorhexidine and 0.5 mg/mL nisin. Stability tests confirmed consistent performance in pH, viscosity, and antimicrobial activity for up to six weeks across various temperatures, with no detectable cytotoxicity. This study introduces a groundbreaking microemulsion formulation that redefines antimicrobial therapy for S. mutans. By leveraging the enhanced stability and rapid action of enterocin CC2, this innovation offers a transformative approach to oral health management, paving the way for next-generation antimicrobial solutions.