Arginine-loaded silica nanoparticles inhibit E. faecalis in root canals

Area of Science:

• Biomaterials Science
• Nanotechnology
• Endodontics

Background:

• Enterococcus faecalis (E. faecalis) infection is a major cause of root canal treatment failure.
• Intracanal medication is crucial for controlling root canal infections.
• Mesoporous silica nanoparticles (MSNs) offer potential for effective intracanal drug delivery due to their structure and biocompatibility.

Purpose of the Study:

• To evaluate the antibacterial efficacy of an arginine-loaded MSN system (MSN@Arg) against E. faecalis.
• To assess MSN@Arg's effects on osteogenic differentiation in MC3T3-E1 cells.
• To compare MSN@Arg's efficacy in controlling root canal infection against chlorhexidine (CHX) and calcium hydroxide.

Main Methods:

• Synthesized MSNs (<100 nm) with sustained arginine release.
• Evaluated antibacterial activity against planktonic and biofilm E. faecalis.
• Assessed osteogenic differentiation using alkaline phosphatase and Alizarin Red staining.
• Compared MSN@Arg efficacy in an infected root canal model with CHX and calcium hydroxide.

Main Results:

• MSN@Arg demonstrated sustained arginine release and inhibited E. faecalis in both planktonic and biofilm states.
• MSN@Arg promoted osteogenic differentiation in MC3T3-E1 cells with high biocompatibility.
• MSN@Arg showed superior antibacterial efficacy to calcium hydroxide early on and comparable/superior efficacy to CHX over time.

Conclusions:

• MSN@Arg exhibits significant antibacterial efficacy against E. faecalis in root canals.
• The nanoparticle system promotes osteogenic differentiation, indicating good biocompatibility.
• MSN@Arg's deep penetration and sustained release make it a promising agent for root canal disinfection.