Polyethylene Glycol Nanofiller for Robust Lyophilization of Graphically Encoded Hydrogel Microparticles

Area of Science:

• Biomaterials Science
• Biosensing Technology
• Nanotechnology

Background:

• Hydrogel microparticle-based biosensing offers multiplexing and sensitivity but lacks stable storage.
• Lyophilization-induced structural deformation hinders practical application of hydrogel microparticle sensors.

Purpose of the Study:

• To develop a long-term, stable storage protocol for hydrogel microparticles using a novel lyophilization strategy.
• To enhance the preservation of hydrogel microparticle structure and function after freeze-drying.

Main Methods:

• Utilized polyethylene glycol (PEG) as a nanofiller within hydrogel microparticles to prevent structural collapse during lyophilization.
• Investigated the effect of PEG nanofillers on particle geometry preservation and reconstitution.
• Assessed immunoassay performance and long-term storage stability (over 6 months) via thermal aging.

Main Results:

• PEG nanofiller-mediated lyophilization successfully inhibited particle deformation, preserving microparticle geometries.
• Achieved high decoding accuracy (>95%) for reconstituted, lyophilized microparticles.
• Lyophilized antibody-functionalized microparticles demonstrated immunoassay performance comparable to non-lyophilized controls.

Conclusions:

• The PEG nanofiller strategy provides an effective method for stabilizing hydrogel microparticles through lyophilization.
• This innovative storage protocol enables long-term stability, paving the way for practical field deployment of hydrogel microparticle biosensors.