Engineering synthetic poly(ethylene) glycol-based hydrogels compatible with injection molding biofabrication

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Biofabrication

Background:

• Hydrogel injection molding is a promising biofabrication technique for creating complex, cell-laden hydrogel structures.
• This method requires hydrogels with delayed crosslinking to allow for injection and molding before gelation.
• Synthetic polymers, such as poly(ethylene) glycol (PEG), offer tunable properties for hydrogel development.

Purpose of the Study:

• To investigate the feasibility of using synthetic PEG-based hydrogels for injection molding.
• To functionalize PEG hydrogels with strain promoted azide-alkyne cycloaddition (SPAAC) click chemistry for controlled gelation.
• To evaluate the mechanical properties, cell viability, and adhesive ligand retention of these injectable hydrogels.

Main Methods:

• Developed a library of PEG-based hydrogels functionalized with SPAAC click chemistry.
• Assessed hydrogel mechanical properties, including time to gelation and injectability.
• Evaluated the binding and retention of adhesive ligand RGD and characterized encapsulated cell viability and function.

Main Results:

• Successfully demonstrated the injection molding of synthetic PEG-based hydrogels with tunable mechanical properties.
• Confirmed successful generation of complex hydrogel geometries using the injection molding technique.
• Showcased good binding and retention of RGD ligands and maintained viability and function of encapsulated cells.

Conclusions:

• Synthetic PEG-based hydrogels functionalized with SPAAC click chemistry are feasible for injection molding.
• This approach supports the creation of complex, cell-laden constructs for tissue engineering.
• The findings highlight potential clinical and biomanufacturing applications for this advanced biofabrication method.