Multifunctional Nano-Delivery System Based on DNase I and Photodynamic Therapy for Combatting Enterococcus faecalis Biofilm Infections

To address Enterococcus faecalis biofilm infections in periapical treatment, we developed a multifunctional nano-delivery system (DNase I-Lip@Ce6) integrating enzymatic and photodynamic therapies. DNase I and liposome-encapsulated Ce6 were assembled into DNase I-Lip@Ce6 nanoparticles and characterized via DLS and TEM. Antibacterial efficacy was assessed by CFU counting and SEM imaging, biofilm removal by crystal violet staining and confocal microscopy, and biocompatibility by hemolysis and CCK-8 assays. DNase I-Lip@Ce6 demonstrated superior anti-Enterococcus faecalis activity under 660 nm illumination, causing severe bacterial damage, and reducing biofilm biomass by 99.99% (p < 0.001). Biocompatibility tests confirmed high L929 cell viability. This study integrates enzymatic biofilm disruption with photodynamic therapy, offering a promising strategy for periapical infection treatment.