Proanthocyanidins-Loaded Nanoparticles Enhance Dentin Degradation Resistance

Area of Science:

• Biomaterials Science
• Dental Materials Science
• Polymer Nanotechnology

Background:

• Demineralized dentin is susceptible to biodegradation, compromising dental restorations.
• Grapeseed extract (GSE), rich in proanthocyanidins (PAs), shows promise in improving dentin's resistance to degradation.
• Novel delivery systems are needed to effectively utilize GSE's properties in dentin treatment.

Purpose of the Study:

• To investigate the efficacy of poly-[lactic-co-glycolic acid] (PLGA) nanoparticles loaded with GSE for enhancing the biodegradation resistance of demineralized dentin.
• To evaluate the impact of this delivery strategy on dentin's structural stability, mechanical properties, and biochemical integrity over time.
• To assess the infiltration and distribution of nanoparticles within dentinal tubules and their effect on the resin-dentin interface.

Main Methods:

• Synthesized PLGA nanoparticles loaded with GSE at varying ratios (100:75, 100:50, 100:25 w/w) via nanoprecipitation.
• Characterized nanoparticles for morphology, physicochemical properties, drug loading, entrapment, and release kinetics.
• Applied nanoparticle suspensions to demineralized dentin specimens simulating pulpal pressure and assessed biodegradation resistance using SEM, TEM, nanoindentation, and hydroxyproline release assays.
• Evaluated the resin-dentin interface morphology after adhesive application.

Main Results:

• GSE-loaded PLGA nanoparticles effectively infiltrated dentinal tubules and their lateral branches.
• Treatment significantly enhanced collagen fibril structural resistance and improved biomechanical and biochemical stability of demineralized dentin.
• Nanoparticles with a PLGA/GSE ratio of 100:75 exhibited the highest GSE release and provided the greatest improvement in biodegradation resistance.
• SEM analysis revealed a uniform hybrid layer and well-formed resin tags with nanoparticles integrated into the dentin structure.

Conclusions:

• Biodegradable PLGA nanoparticles offer a promising strategy for delivering GSE into demineralized dentin.
• This approach effectively enhances dentin's resistance to biodegradation by reinforcing collagen structure and improving mechanical and biochemical properties.
• The findings highlight the potential of nanoparticle-mediated delivery of crosslinkers for long-term stability of dental restorations.