Development of double network polyurethane-chitosan composite bioinks for soft neural tissue engineering

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Three-dimensional (3D) bioprinting is a key technology for creating engineered tissues.
• Biodegradable polymers are essential for creating biocompatible scaffolds.
• Developing novel bioinks with enhanced properties is crucial for advancing tissue engineering.

Purpose of the Study:

• To develop novel ternary soft segment-based biodegradable polyurethanes (tPUs) for 3D bioprinting.
• To evaluate the properties and cell compatibility of the developed tPUs and their composite hydrogels.
• To assess the potential of these materials for neural stem cell (NSC) applications in tissue engineering.

Main Methods:

• Synthesis of novel ternary soft segment-based biodegradable polyurethanes (tPUs) via waterborne processes.
• Characterization of tPU properties, including stiffness and tan delta.
• 3D bioprinting of tPU and composite hydrogels (tPU/gelatin, tPU/agarose, tPU/chitosan).
• Assessment of cell viability, proliferation, and neural differentiation of NSCs within the bioprinted constructs.

Main Results:

• tPU2, composed of poly(ε-caprolactone) (PCL), polylactide, and poly(3-hydroxybutyrate) (PHB) (0.7:0.2:0.1 molar ratio), exhibited low stiffness (~2.3 kPa) and high tan delta (~0.64).
• Bioprinted tPU2 constructs maintained high NSC vitality (91.3%) and promoted significant cell proliferation (~200% in 7 days) and neural differentiation.
• Polyurethane-chitosan (PUC) composite hydrogels demonstrated self-healing properties, excellent bioprintability, and superior promotion of NSC proliferation (~300% in 7 days) and differentiation compared to tPU2 alone.

Conclusions:

• Novel biodegradable tPUs and PUC composite hydrogels were successfully developed for 3D bioprinting.
• The developed bioinks support NSC viability, proliferation, and neural differentiation, indicating significant potential for neural tissue engineering.
• These materials offer promising new avenues for advanced 3D bioprinting applications in regenerative medicine.