Poly(vinyl alcohol) physical hydrogels: noncryogenic stabilization allows nano- and microscale materials design

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanobiomedicine

Background:

• Poly(vinyl alcohol) (PVA) hydrogels are widely used in biomedicine due to their safety.
• Limitations include poor control over internal structure and limited bioconjugation.
• These factors hinder precise material design at the micro- and nanoscale.

Purpose of the Study:

• To develop a method for creating PVA physical hydrogels with controlled dimensions.
• To enable micro- and nanoscale precision in PVA hydrogel fabrication.
• To functionalize PVA hydrogels for advanced biomedical applications like drug delivery.

Main Methods:

• Assembly of PVA hydrogels using a noncryogenic "salting-out" method.
• Microtransfer molding to create structured hydrogels for analysis.
• Characterization of hydrogel properties (stability, swelling, modulus) based on PVA characteristics and processing parameters.
• Synthesis of functionalized PVA via RAFT polymerization and conjugation with RITC cargo.

Main Results:

• Achieved control over hydrogel dimensions from ~100 nm to centimeter scale.
• Demonstrated the influence of PVA molecular weight, concentration, and salting-out time on hydrogel properties.
• Successfully incorporated functionalized PVA-RITC, varying cargo concentration over three orders of magnitude.

Conclusions:

• The developed "salting-out" method enables precise fabrication of PVA physical hydrogels.
• Functionalized PVA hydrogels can be produced for diverse applications.
• This approach is particularly promising for surface-mediated drug delivery systems.