Engineering Photo-Cross-Linkable MXene-Based Hydrogels: Durable Conductive Biomaterials for Electroactive Tissues and...

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Nanotechnology

Background:

• Light-cured conductive hydrogels are crucial for electroactive tissue regeneration and bioelectronic interfaces.
• MXene (MX) incorporation offers unique properties but its light-blocking effect complicates photocurable hydrogel synthesis.
• Efficient cross-linking of MX-containing photocurable hydrogels requires careful selection of photoinitiators and concentrations.

Purpose of the Study:

• To investigate the photo-cross-linking of MX-gelatin methacrylate (GelMa) composites using different photoinitiators and MX concentrations.
• To prepare biocompatible, injectable, conductive, and photocurable composite hydrogels.
• To analyze the impact of MX light-blocking on hydrogel properties and optimize curing strategies.

Main Methods:

• Synthesized MX-GelMa composite hydrogels using Eosin Y (Type I), Irgacure 2959 (Type I), and lithium phenyl-2,4,6-trimethylbenzoyl phosphinate (Type II) photoinitiators.
• Varied MX concentrations to assess effects on hydrogel thickness, pore structure, swelling, degradation, mechanical properties, and conductivity.
• Performed in vitro cytocompatibility assays with C2C12 myoblasts.

Main Results:

• MX light-blocking significantly influenced hydrogel thickness, pore structure, swelling, degradation, and mechanical properties.
• Type II photoinitiators enabled rapid curing (<60s) of centimeter-sized thick films with superior mechanical properties (up to 300% increase) and higher swelling ratios (648-1274%).
• Type I photoinitiators produced thin films (0.5 mm) with conductivity up to 1 mS/cm at 0.1 mg/mL MX, and both types demonstrated excellent C2C12 cell viability and proliferation.

Conclusions:

• Optimized photo-cross-linking strategies using Type I and Type II photoinitiators allow tunable fabrication of MX-GelMa hydrogels.
• The developed hydrogels exhibit excellent biocompatibility, conductivity, and mechanical strength, suitable for tissue engineering scaffolds.
• These photocurable GelMa-MX hydrogels show potential for modulating cellular functions and interfacing with biological tissues and devices.