Injectable gelatin-PEG hydrogels obtained via cytochrome C-mediated polymerization

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Biomedical Engineering

Background:

• Injectable hydrogels are crucial for minimally invasive surgery and drug delivery.
• Current methods often rely on transition metals, which can have limitations.
• Developing novel crosslinking strategies is essential for advanced hydrogel applications.

Purpose of the Study:

• To develop novel injectable hydrogels using cytochrome C (CyC) as a redox mediator.
• To investigate the properties and performance of these CyC-mediated hydrogels.
• To establish a transition metal-free crosslinking system for injectable hydrogels.

Main Methods:

• Synthesized hydrogels from gelatin methacrylate (GelMA) and poly(ethyleneglycol) dimethacrylate (PEGDA).
• Utilized a Fenton-like radical polymerization mediated by Cytochrome C (CyC) with H2O2 and L-ascorbic acid.
• Characterized hydrogel properties including gelation time, mechanical properties, injectability, cytotoxicity, and drug release.

Main Results:

• Achieved rapid sol-gel transition within 1.0-2.0 minutes.
• Demonstrated tunable mechanical properties and linear viscoelastic region (LVR) by adjusting precursor concentrations.
• Confirmed biocompatibility with no detectable cytotoxicity and sustained release of a model drug (rhodamine 101) up to ~70% over 7 days.
• Showed that enzymatic degradation is dependent on the degree of crosslinking.

Conclusions:

• Cytochrome C (CyC) effectively mediates radical polymerization for injectable hydrogels, replacing traditional transition metals.
• The developed hydrogels are biocompatible, injectable, and possess tunable properties suitable for biomedical applications.
• This novel CyC-mediated system offers a promising alternative for creating advanced injectable hydrogels for drug delivery and regenerative medicine.