UNIINK · Universal 3D printer bioink for Type 1 diabetes cell therapy

Type 1 Diabetes (T1DM) results from autoimmune destruction of pancreatic insulin-producing -cells. Nowadays, insulin injections remain the leading therapeutic option. However, injection treatment fails to emulate the highly dynamic insulin release that -cells provide. During the last years, 3D cell-laden microspheres have been proposed as a major platform for bioengineering insulin-secreting constructs for tissue graft implantation and a model for in vitro drug screening platforms. Current microsphere fabrication technologies have several drawbacks: the need for an oil phase containing surfactants, diameter inconsistency of the microspheres, and high time-consuming processes, among others. These technologies have widely used alginate for its rapid gelation, high processability, and low cost. However, its low biocompatible properties do not provide effective cell attachment. To overcome these limitations, Uniink proposes a high-throughput 3D bioprinting methodology that employs an ECM-like microenvironment for effective cell-laden microsphere production. Crosslinking the resulting microspheres with tannic acid (TA) prevents collagenase degradation and enhances spherical structural consistency while allowing the diffusion of nutrients and oxygen. In addition, the approach allows customization of microsphere diameter with extremely low variability. In conclusion, we will develop in Uniink a novel bio-printing procedure to fabricate large amounts of reproducible microspheres capable of secreting insulin in response to extracellular glucose stimuli. We expect that Uniink will represent a valid alternative to islet transplantation in T1DM patients, thus bringing cell therapy closer to the application in humans.