Antibacterial Countermeasures via Metal-Organic Framework-Supported Sustained Therapeutic Release

Area of Science:

• Biomaterials Science
• Nanotechnology
• Infectious Diseases

Background:

• Long-term antimicrobial therapies are crucial for intracellular pathogens and biothreat agents.
• Current treatments involve frequent injections over extended periods (up to 8 weeks).
• There is a need for improved drug delivery systems for sustained antimicrobial release.

Purpose of the Study:

• To develop a novel drug delivery system using zeolitic imidazolate framework-8 (ZIF-8) for sustained release of ceftazidime.
• To evaluate the antibacterial efficacy and cellular compatibility of ceftazidime-loaded ZIF-8 particles.
• To demonstrate direct intracellular uptake of ZIF-8 particles without staining.

Main Methods:

• Metal-organic framework (MOF) synthesis and characterization of ZIF-8.
• Encapsulation of ceftazidime within the ZIF-8 matrix.
• In vitro drug release studies.
• Antibacterial assays against Escherichia coli.
• Cellular compatibility studies with macrophage and lung epithelial cells.
• Confocal microscopy with 3D reconstruction to visualize MOF particle internalization.

Main Results:

• Successful encapsulation of ceftazidime within ZIF-8, demonstrating sustained release for up to one week.
• Confirmed antibacterial activity of ceftazidime@ZIF-8 against Escherichia coli.
• ZIF-8 particles showed compatibility with macrophage and lung epithelial cell lines.
• Unambiguous demonstration of direct MOF particle internalization using intrinsic ZIF-8 fluorescence and confocal microscopy.

Conclusions:

• ZIF-8 serves as a robust platform for sustained ceftazidime delivery, offering a promising alternative to conventional antimicrobial therapies.
• The ability to track MOF internalization directly simplifies methodology and avoids artifacts from carrier breakdown.
• This approach enhances the potential for effective intracellular delivery of antibiotics to combat challenging infections.