Light-Triggered Programmable Hydrogels Based on Natto Poly(γ-Glutamic Acid) with Tunable Adhesion and Integrated...

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Protein-based hydrogels often exhibit limited mechanical strength and responsiveness.
• Developing advanced hydrogels is crucial for applications like targeted drug delivery and food science.

Purpose of the Study:

• To develop a light-triggered, disulfide-cross-linked poly(γ-glutamic acid) (γ-PGA) hydrogel with enhanced mechanical properties and responsiveness.
• To investigate the hydrogel's antioxidant and anti-inflammatory activities for potential food-related oral delivery applications.

Main Methods:

• Synthesized γ-PGA hydrogels by integrating thiolated γ-PGA and α-lipoic acid (LA)-grafted γ-PGA under 405 nm irradiation.
• Characterized gelation kinetics, mechanical properties (storage modulus), substrate adhesion, and redox-triggered disassembly (using β-mercaptoethanol).
• Assessed antioxidant capacity (DPPH and hydroxyl radical scavenging) and in vitro anti-inflammatory effects in LPS-stimulated macrophages (ROS, NO, mitochondrial potential, gene expression).

Main Results:

• Achieved rapid gelation (below 60 s) with tunable mechanics (storage modulus ~100 Pa) via dynamic disulfide chemistry.
• Demonstrated substrate adhesion, rapid redox-triggered disassembly, and stability in simulated gastric fluid (pH 2).
• Exhibited broad-spectrum antioxidant activity and significant reduction of inflammatory markers (ROS, NO) in macrophages, alongside cytocompatibility up to 640 μg/mL.

Conclusions:

• The developed γ-PGA hydrogel platform, utilizing dynamic disulfide chemistry, offers programmable gelation and reversible adhesion.
• The hydrogel possesses gastric stability and coupled antioxidant/anti-inflammatory properties, making it suitable for food-related oral delivery systems.