Development of Chlorhexidine-loaded Lipid Nanoparticles Incorporated in a Bioceramic Endodontic Sealer

Introduction: This study aimed to assess BioRoot RCS (BR) incorporating liposomal chlorhexidine digluconate (CHX) for its antibacterial activity, drug release capacity, and physicochemical properties. Methods: Drug release of CHX liposomal formulations in combination with BR was evaluated spectrophotometrically and through mathematical release models for 30 days. A selected combination was evaluated for antimicrobial properties against Enterococcus faecalis biofilm growth on human dentin. Cytotoxicity was assessed following the ISO 10993-5:2019 standard on days 1, 3, and 7. Physicochemical properties were evaluated through setting time, Fourier transform infrared spectroscopy, solubility, contact angle, and film thickness. Results: From BR, liposomal CHX released up to 7-fold higher CHX than CHX solution (P < .05), following a triphasic drug release pattern compared to the CHX solution, which followed a quasi-Fickian diffusion. BR combined with a selected liposomal CHX completely inhibited E. faecalis biofilm growth compared to the combination of BR with CHX solution and the control group (P < .05). Liposomal CHX decreased the contact angle (P < .05) and solubility but increased cytotoxicity (P < .05) of BR, staying above the ISO threshold. None of the other physicochemical characteristics tested differed from BR (P> .05). Conclusion: This liposomal formulation improved CHX release from BR, enhancing the antibacterial effectiveness. It presents a promising approach for local antibiofilm therapy in endodontics without substantially altering the physicochemical characteristics of BR.