Preliminary tests on PEG-based thermoresponsive polymers for the production of 3D bioprinted constructs

In the last years, the growing demand for tissues and organs led to the development of novel techniques, such as 3D bioprinting. This technique proved to be promising for both patient-specific and custom-made applications when using autologous cells, and for the creation of standardized models that in the future could be used for instance for high-throughput drug screening. Within this context, the formulation of bioinks that could provide reliable, reproducible, and replicable structures with good mechanical properties and high biocompatibility is a crucial challenge. In this work, the use of a thermoresponsive PEG-based formulation was investigated as a bioink, allowing its use for 4D bioprinting applications triggered by thermal changes. First, the polymer was synthesized by reversible addition-fragmentation chain transfer polymerization (RAFT), which allows for optimal control over the final properties of the polymer. Then, the printability for extrusion-based bioprinting of this formulation was assessed through in-situ imaging. Finally, the use of this polymer as bioink was tested by encapsulation of endothelial cells and evaluating cell distribution within the construct.