3D Printed Polyether Ester Biodegradable Hydrogels
3D printed biodegradable hydrogels have great potential in the clinic since they synergistically combine the unique advantages derived from the personalization of the medical device imparted by 3D printing, and the recognized clinical benefits of hydrogels. Developing 3D printable polyether esters, named “inks” here, enabling the optimal printing of custom‐made biodegradable hydrogels constitutes the keystone of this study. These inks comprise polyethylene oxide (PEO) chains that impart the needed hydrophilicity, and caprolactone or lactoyl units that confer to them their required biodegradability. Additionally, the inks are end‐capped with C═C double bonds to enable their UV photo‐polymerization during the printing process. They absorb large amounts of water, display enhanced mechanical properties, and degrade over a broad time range, spanning from less than two months to more than a year. The excellent printability of the inks is demonstrated by printing various mono‐ and bi‐ink complex architectures. Aiming at shedding light on the effect of crosslinking on the degradation behavior of the 3D printed hydrogels, their thermoplastic counterparts, having the same composition but chain extended instead of being C = C end‐capped, are synthesized and their degradability studied. Fundamentally degrading by a bulk degradation mechanism, the crosslinked hydrogels also display features characteristic of surface erosion.