Enzyme-degradable self-assembled hydrogels from polyalanine-modified poly(ethylene glycol) star polymers

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Chronic wounds present challenges for effective protein-based therapies due to the need for sustained and targeted delivery.
• Biocompatible hydrogels offer potential as matrices for protein encapsulation and controlled release.

Purpose of the Study:

• To synthesize and characterize novel star-shaped block copolymers for hydrogel formation.
• To evaluate the potential of these hydrogels for sustained protein (albumin) encapsulation and triggered release.
• To assess the feasibility of using elastase-mediated degradation for targeted protein release in a wound environment.

Main Methods:

• Synthesis of star-shaped block copolymers with a poly(ethylene glycol) (PEG) core and a polyalanine (PAla) shell.
• Characterization of copolymer self-assembly into hydrogels in aqueous solutions.
• In vitro studies on albumin encapsulation, retention, and release kinetics.
• Investigation of hydrogel degradation by the proteolytic enzyme elastase and subsequent protein release.

Main Results:

• Successfully generated star-shaped block copolymers that self-assemble into hydrogels in water.
• The resulting hydrogels provide a hydrophilic environment suitable for protein handling.
• Albumin was effectively withheld for extended periods, with triggered release observed upon elastase-induced material degradation.

Conclusions:

• The developed PEG-PAla star-shaped block copolymers form promising hydrogel systems for protein delivery.
• The triggered release mechanism, responsive to elastase, is particularly relevant for applications in chronic wounds where this enzyme is overexpressed.
• These materials hold significant potential for localized delivery of therapeutic proteins and inhibitors in wound healing.