Curcumin Liposomal Photodynamic Gel for Plaque Control: Physicochemistry, Singlet-oxygen Yield, and Biofilm Kill Curves - An In vitro Study.
BACKGROUND Effective plaque control is essential for preventing caries and periodontal diseases. While curcumin-mediated photodynamic therapy has demonstrated antimicrobial efficacy, its clinical use is limited by poor solubility and bioavailability. This study evaluates a curcumin-loaded liposomal photodynamic gel for enhanced in vitro plaque control. MATERIALS AND METHODS Curcumin was encapsulated in phosphatidylcholine-based liposomes and incorporated into a bioadhesive gel. Physicochemical properties, including particle size, zeta potential, and encapsulation efficiency, were characterized. Singlet oxygen (1O2) generation was measured under blue light (450 nm) using the 1,3-diphenylisobenzofuran assay. A multispecies oral biofilm model was established with Streptococcus mutans, Lactobacillus casei, Actinomyces viscosus, and Fusobacterium nucleatum. Biofilms were treated with curcumin gel ± light, and bacterial viability was quantified. RESULTS The liposomal gel exhibited a mean particle size of ~ 250 nm, encapsulation efficiency of ~ 85%, and pH of ~ 6.8. Curcumin liposomal gel generated a higher 1O2 yield than free curcumin. Photodynamic treatment reduced viable biofilm bacteria by > 4 log10 CFU/ml, significantly more than control treatments. CONCLUSION Curcumin liposomal gel shows enhanced 1O2 production and potent photodynamic biofilm inactivation. This formulation may offer a novel adjunct for nonantibiotic plaque control.