Clickable PEG hydrogel microspheres as building blocks for 3D bioprinting

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• 3D bioprinting is crucial for creating complex tissues.
• Bioinks require a balance of high viscosity and low shear force for successful printing and cell survival.
• Existing bioinks face challenges in achieving both printability and cytocompatibility.

Purpose of the Study:

• To introduce a novel bioink based on poly(ethylene glycol) (PEG) microgels.
• To demonstrate the bioink's suitability for 3D bioprinting applications.
• To highlight the bioink's tunable properties and potential for regenerative manufacturing.

Main Methods:

• Preparation of PEG microgels using off-stoichiometry thiol-ene click chemistry.
• Characterization of microgel bioink properties, including viscosity and printability.
• Assessment of post-printing stability via photochemical annealing with a secondary thiol-ene reaction.
• Evaluation of cell viability, proliferation, and spreading within printed constructs.

Main Results:

• The novel PEG microgel bioink demonstrated easy extrusion and excellent post-printing stability.
• Photochemical annealing enhanced the long-term stability of printed constructs.
• The bioink supported high cell viability during printing, with cells spreading and proliferating post-annealing.
• Tunable physicochemical properties of the PEG microgels were confirmed.

Conclusions:

• The developed microgel bioink is a versatile platform for 3D bioprinting.
• It addresses key challenges in bioink formulation, balancing printability and cytocompatibility.
• This technology holds significant promise for regenerative manufacturing and the development of engineered tissues.