Super-Rapid In Situ Formation of a Silver Ion-Induced Supramolecular Hydrogel with Efficient Antibacterial Activity for Root Canal Disinfection

Abstract

Supramolecular hydrogels prepared using low-molecular-weight gelators have attracted considerable attention for biomedical applications. However, in situ supramolecular hydrogels are limited in terms of their prolonged gelation time and/or unstable nature at high temperatures. In this study, we constructed a stable supramolecular Ag-isoG hydrogel through super-rapid in situ formation, wherein hydrogelation process occurred instantaneously upon mixing isoG and Ag+ within 1 s under ambient conditions. Interestingly, unlike most nucleoside-based supramolecular hydrogels, this Ag-isoG hydrogel remains stable even at a high temperature (100 °C). Moreover, the as-designed hydrogel demonstrated significant antibacterial activity against Staphylococcus aureus and the oral bacterium Streptococcus mutans owing to the strong chelating ability of Ag ions, and the hydrogel exhibited relatively low cytotoxicity in root canal and an easy removal feature by saline. The hydrogel was then applied to a root canal infection model, which demonstrated strong antibacterial activity against Enterococcus faecalis, with performance even better than that of the regular calcium hydroxide paste. This feature makes the Ag-isoG hydrogel a prospective alternative material as intracanal medicaments for root canal treatment.

Recent Advances in Functional Hydrogels for Treating Dental Hard Tissue and Endodontic Diseases

“…(b) Ag-isoG hydrogel shows excellent antibacterial activity against S. aureus and S. mutans . (c) Application of Ag-isoG hydrogel to the root canal infection model of tooth extraction, showing good antibacterial activity against E. faecalis . Reprinted with permission under a Creative Commons CC BY license from ref .…”

“…(c) Application of Ag-isoG hydrogel to the root canal infection model of tooth extraction, showing good antibacterial activity against E. faecalis . Reprinted with permission under a Creative Commons CC BY license from ref . Copyright 2023 American Chemical Society.…”

Unraveling the New Perspectives on Antimicrobial Hydrogels: State-of-the-Art and Translational Applications

“…These hydrogels can release antimicrobial agents within the root canal system to eliminate or suppress bacterial colonization, preventing reinfection and promoting proper healing [ 156 , 157 ]. For example, in root canal disinfection, AMHs have been loaded with diclofenac, chlorhexidine, and metronidazole or silver ions [ 158 , 159 , 160 ]. In dental pulp regeneration, fibrin or chitosan hydrogels have been loaded with clindamycin-loaded poly (D,L)-lactic acid NPs or polyhexamethyleneguanidine hydrochloride (PHMB), respectively, with promising results in vitro [ 161 , 162 ].…”

Nucleobase-Functionalized 7-Deazaisoguanine and 7-Deazapurin-2,6-diamine Nucleosides: Halogenation, Cross-Coupling, and Cycloaddition

“…For their synthesis, purin-2,6-diamine nucleosides have been used as precursors. , The purin-2,6-diamine 2′-deoxyribonucleoside is a constituent of viral DNA where it replaces dA . Isoguanine nucleosides and oligonucleotides develop supramolecular assemblies and form hydrogels . Isoguanine and purin-2,6-diamine 2′-deoxyribonucleosides are used to expand the genetic code …”