Dual Physically Cross-Linked κ-Carrageenan-Based Double Network Hydrogels with Superior Self-Healing Performance for...

Area of Science:

• Materials Science
• Biomaterials Engineering
• Polymer Chemistry

Background:

• Chemically linked double network (DN) hydrogels possess excellent mechanical properties but lack self-healing and biocompatibility due to irreversible bonds and toxic cross-linkers.
• Existing DN hydrogels often utilize toxic chemical cross-linking agents, limiting their biomedical applications.
• There is a need for advanced hydrogel systems that combine robust mechanical performance with intrinsic self-healing and biocompatibility.

Purpose of the Study:

• To develop a novel κ-carrageenan/polyacrylamide (KC/PAM) double network (DN) hydrogel using a dual physical-cross-linking strategy.
• To overcome the limitations of traditional DN hydrogels, specifically poor self-healing and biocompatibility.
• To create a self-repairing DN hydrogel with enhanced mechanical properties and cytocompatibility for biomedical applications.

Main Methods:

• Fabrication of dual physically cross-linked DN (DPC-DN) hydrogels by combining ductile, hydrophobically associated polyacrylamide (PAM) as the first network and rigid potassium ion (K+) cross-linked κ-carrageenan (KC) as the second network.
• Optimization of KC concentration to achieve desired mechanical and self-healing properties.
• Evaluation of mechanical performance, including fracture tensile stress and toughness.
• Assessment of self-recovery, notch-insensitivity, self-healing capability, and cytocompatibility using stem cells.

Main Results:

• The optimized DPC-DN hydrogels exhibited excellent fracture tensile stress (1320 ± 46 kPa) and toughness (fracture energy: 6900 ± 280 kJ/m³), comparable to chemically linked DN hydrogels.
• The KC/PAM hydrogels demonstrated rapid self-recovery, remarkable notch-insensitivity, and effective self-healing capabilities.
• Excellent cytocompatibility was observed with stem cells, indicating suitability for biological applications.

Conclusions:

• A novel strategy for fabricating self-repairing dual physically cross-linked DN hydrogels with outstanding mechanical properties and biocompatibility was successfully developed.
• The developed KC/PAM hydrogels offer a promising alternative to traditional DN hydrogels for challenging biomedical applications.
• These advanced hydrogels show significant potential for use in artificial diaphragms, tendons, and cartilage replacements.