Evaluation of antibacterial and antibiofilm potentials of polyphenol-grafted lignin nanoparticles against periodontal pathogens

Periodontal disease affects nearly half of the global population, posing a significant public health challenge. While antimicrobial agents remain the standard treatment, the growing concern of antimicrobial resistance among periodontal pathogens necessitates the exploration of alternative therapeutic strategies. This study presents ellagic acid-functionalized lignin nanoparticles (LeLNPs) as a novel and sustainable approach for periodontal therapy. Lignin was functionalized with ellagic acid using laccase-mediated oxidation, followed by high-shear homogenization to generate LeLNPs with a slightly uniform nanoscale size (average diameter <58 nm) and enhanced phenolic content. The nanoparticles exhibited strong antimicrobial activity against periodontal pathogens, with a minimum inhibitory concentration (MIC) of 0.625 mg/L. Mechanistic evaluations revealed that LeLNPs disrupt bacterial membrane integrity, elevate reactive oxygen species (ROS) levels, and reduce metabolic activity, impairing microbial survival. Given their potent antimicrobial efficacy, natural biocompatibility, and eco-friendly properties, LeLNPs hold promise as an innovative therapeutic agent for periodontal disease. Their potential application in oral healthcare products, such as toothpaste and mouthwash, underscores their relevance as a sustainable solution for dental health.