Core-shell microneedles with MMP/pH-triggered release for periodontitis bone repair.

Area of Science:

• Biomaterials Science
• Regenerative Medicine
• Periodontology

Background:

• Periodontitis involves inflammation and alveolar bone loss, complicating treatment due to the inflammatory environment and need for bone regeneration.
• Pathological characteristics of periodontal lesions include high matrix metalloproteinase (MMP) expression and an acidic microenvironment.

Purpose of the Study:

• To develop a core-shell microneedle drug delivery system responsive to MMP and pH for periodontitis treatment.
• To achieve precise spatiotemporal release of therapeutics and multimodal synergistic treatment for periodontitis-associated bone defects.

Main Methods:

• A core-shell microneedle system was designed, with the shell containing glycyrrhizic-acid-functionalized MIL-101 and the core containing mesenchymal stem cell-derived exosomes.
• The system utilizes dual MMP hydrolysis and pH triggering for drug release, targeting inflammatory cytokines and oxidative stress initially, followed by sustained exosome release.

Main Results:

• The microneedle system demonstrated rapid release of drug-loaded nanoparticles under elevated MMP and low pH conditions, inhibiting inflammation and oxidative stress.
• Sustained release of exosomes from the microneedle core rebalanced the immune microenvironment and induced new bone formation in periodontal defects.

Conclusions:

• This novel microneedle system offers precise drug delivery, immune regulation, and tissue regeneration for periodontitis.
• The system overcomes challenges in graded drug release within the oral environment, presenting an innovative therapeutic paradigm for periodontitis treatment.