Deciphering Nano-Bio Interactions of Hyaluronic Acid-Clove Carbon Dots for Multifunctional Endodontic Nanotherapy

Background:Streptococcus mutans (S. mutans) plays a major role in dental biofilm-related infections and contributes to antimicrobial resistance. Therefore, the development of biocompatible nanomaterials with antibacterial, antibiofilm, and regenerative properties is important for dental applications. Methods: In this study, hyaluronic acid and clove extract were used as natural precursors to synthesize hyaluronic acid-clove carbon dots (HCCDs) through a hydrothermal method. The synthesized HCCDs were characterized by XRD, FTIR, TEM, SEM, SAED and EDAX analysis. The antibacterial and antibiofilm activities against S. mutans were tested. Cell viability tests, AO/PI staining, morphological observation and wound-healing assays were used to evaluate cytocompatibility in MG-63 cells. Results: A broad peak (23.449) observed from XRD coincided with an amorphous graphitic carbon structure. TEM images showed the presence of a spherical nanostructure with an average size of 4 ± 2 nm. The FTIR result verified the presence of hydroxyl, carbonyl and oxygen-containing functional groups on the HCCD surface. Their synthesized HCCDs exhibited noteworthy antibacterial and antibiofilm activity with an MIC of 62.5 µg/mL against the S. mutans. Low toxicity toward MG-63 cells was observed, with 86% cell viability at 200 µg/mL in the cytocompatibility study. Additional good cellular compatibility was confirmed using AO/PI staining and morphological analysis. Furthermore, normal cell migration was observed, as wound healing assays showed no significant difference in closure between the treated and control groups. Conclusion: HCCDs exhibited antibacterial, antibiofilm, biocompatible, and wound-healing properties, highlighting their potential for dental nanomedicine and the treatment of oral biofilm-associated infections.