Enzyme-responsive hydrogel microparticles for pulmonary drug delivery

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Pulmonary Medicine

Background:

• Hydrogels are suitable for pulmonary drug delivery due to tunable size for bronchial targeting and swelling to evade macrophage clearance.
• Matrix metalloproteinases (MMPs) are often overexpressed in pulmonary diseases, presenting a therapeutic target.
• Enzyme-responsive drug delivery systems can enhance therapeutic outcomes by targeting disease-specific conditions.

Purpose of the Study:

• To develop novel enzyme-responsive hydrogel microparticles for pulmonary drug delivery.
• To synthesize poly(ethylene glycol) (PEG)-based microparticles that degrade in response to MMPs.
• To engineer microparticles with sizes appropriate for inhalation and targeted lung delivery.

Main Methods:

• Solution polymerization of poly(ethylene glycol) diacrylate (PEGDA) precursors incorporating peptides.
• Synthesis of spherical PEG hydrogel microparticles via high-concentration aqueous dissolution of PEGDA.
• Characterization of microparticle size (2.8–4 μm) and correlation with precursor properties and enzymatic degradation rates.

Main Results:

• Spherical PEG hydrogel microparticles (2.8–4 μm) were successfully synthesized using a novel solution polymerization method.
• Microparticles incorporated peptides and demonstrated degradation in response to matrix metalloproteinases (MMPs).
• Particle mesh size directly correlated with degradation rate, with larger mesh sizes leading to faster degradation.

Conclusions:

• Developed enzyme-responsive PEG hydrogel microparticles are promising for pulmonary drug delivery.
• The synthesis method allows for size control suitable for inhalation and targeted lung delivery.
• Degradation in response to MMPs offers a mechanism for controlled drug release in diseased lung environments.