Novel nano-cubosomal chlorhexidine for endodontic irrigation: Development, characterization, and performance evaluation against E. faecalis and streptococcal biofilms in human extracted teeth

Disinfection of the root canal system is one of the most complicated procedures and involves the use of a variety of equipment and techniques, irrigation regimens, and intracanal medications. “Cubosomes” (CUs) are among the few nanocarriers that are currently being explored for active drug delivery systems. A novel cubosomal chlorhexidine (CHX) for root canal irrigation was developed, and its release profile and antimicrobial efficacy against Enterococcus faecalis and streptococcal biofilms were evaluated. CUs were characterized for shape, particle size, polydispersity index, zeta potential, and drug entrapment. Drug release was determined using the dialysis method. Microbial analysis of live and dead bacteria was performed via confocal laser scanning microscopy (CLSM). The average particle size, polydispersity index, and zeta potential of the CHX CUs were 157 nm, 0.4, and 19 mV, respectively. The drug entrapment efficiency was approximately 47%. Drug release studies revealed that the cubosomal formulation released approximately 77% of the drug at the end of 6 hours, and complete release was detected at 24 hours. Confirmation of biofilm formation by CLSM and the percentage (%) survival of biofilm cells revealed that the Cubosomal formulation more effectively inhibited biofilm formation even after 48 hours. Both colony-forming unit and CLSM tests revealed that cubosomal CHX showed improved antimicrobial efficacy. The novel cubosomal CHX delivery system for endodontic irrigation was proven to be successful, as it improved the release of CHX, in turn improving its antimicrobial efficacy compared to that of regular CHX solution.