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 ( 1 O 2 ) 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 1 O 2 yield than free curcumin. Photodynamic treatment reduced viable biofilm bacteria by > 4 log 10 CFU/ml, significantly more than control treatments.

CONCLUSION

Curcumin liposomal gel shows enhanced 1 O 2 production and potent photodynamic biofilm inactivation. This formulation may offer a novel adjunct for nonantibiotic plaque control.