# Multifunctional Fe3O4@ZIF-8 Nanoparticles with Antibiosis and Osteogenesis for Treatment of Jaw Osteomyelitis

## TL;DR

A new nanoparticle platform combines antibacterial and bone-regenerating properties to treat jaw osteomyelitis, a challenging bone infection.

## Contribution

Fe3O4@ZIF-8 core–shell nanoparticles offer a dual-function therapy for jaw osteomyelitis by combining antibiosis and osteogenesis.

## Key findings

- Fe3O4@ZIF-8 nanoparticles degrade in acidic environments, releasing Zn²⁺ to disrupt bacterial cell membranes and inhibit bacterial survival.
- The released Fe3O4 nanoparticles, under a static magnetic field, promote bone regeneration in infected jaw lesions.
- The platform effectively addresses both persistent infection and bone defect repair in jaw osteomyelitis.

## Abstract

Background/Objectives: Jaw osteomyelitis (OM) is a refractory purulent inflammation caused by bacterial infection, characterized by persistent infection, excessive bone resorption, and resultant bone defects. Currently, mainstream therapies for jaw OM struggle to eradicate persistent infections, avoid antibiotic resistance, and repair infected bone defects, posing a critical challenge in clinical practice. Methods: Herein, the Fe3O4@ZIF-8 core–shell nanoparticles (NPs) platform designed for jaw OM treatment consisted of Fe3O4 as the core and zeolitic imidazolate framework-8 (ZIF-8) as the shell. Results: The core–shell platform not only integrated the pH-responsive degradation capability of ZIF-8 but also retained the superparamagnetism of Fe3O4 NPs. In the acidic, infectious microenvironment, Fe3O4@ZIF-8 NPs underwent continuous degradation, releasing Zn2+, thereby conferring potent antibacterial activity. The specific antibacterial mechanism of the nanoparticles lies in the fact that high concentrations of Zn2+ directly disrupted bacterial cell membranes and inhibited the bacterial heat shock response. This dysregulates bacterial proteostasis, rendering the bacteria more sensitive to external adverse stresses, ultimately leading to bacterial death. With ZIF-8 framework degradation, the encapsulated Fe3O4 NPs were released. Under static magnetic field (SMF) synergy, Fe3O4 NPs collaborated with Zn2+ to promote bone regeneration and repair infected bone defects in jaw OM lesions. Conclusions: As a multifunctional core–shell platform, Fe3O4@ZIF-8 NPs meet the dual clinical needs of antibiosis and osteogenesis, offering a promising translational strategy for jaw OM therapy.