Facile Bioprinting Process for Fabricating Size-Controllable Functional Microtissues Using Light-Activated Decellularized Extracellular Matrix-Based Bioinks

The concept of microtissues has evolved to adapt to the generation of human tissue analogs that mimic physiologically relevant morphological and functional features. These microtissues can provide an in vitro testing platform for the development of advanced therapeutic options. Optimizing the manufacturing process of biomaterials brings several great benefits to achieve the desired mechanical, chemical, and biological properties for tissue modeling. Hence, 3D bioprinting technology has been utilized to fabricate functional microtissues. However, current microtissue bioprinting systems still require a cumbersome and time-consuming task, such as washing, which renders it difficult to maintain the shape of intact constructs, thereby resulting in inappropriate tissue morphogenesis. To overcome this limitation, a single-step bioprinting method is developed easier and more versatile for microtissue production based on a dual-crosslinkable decellularized extracellular matrix with ruthenium/sodium persulfate (dERS). The developed method enables the fabrication of spheroidal and tubular microstructures into a medium chamber, followed by the immediate culturing of printed structures without multiple postprocesses. The structural characteristics can be controlled by adjusting the printing parameters. Each dERS-based microtissue promotes tissue maturation and exhibits biofunctional attributes. These results suggest that the developed method may enable the simultaneous achievement of adequate print fidelity and tissue functionality.