Special Poster Session Biofabrication
As a promising biofabrication technology, extrusion-based bioprinting has gained significant attention in the last decade. However, materials that offer an "ideal" combination of printability, shape fidelity, suitable crosslinking mechanism and cytocompatibility are rare. Poly(2-oxazoline)s based biomaterials have been discussed as a potential alternative to the more established polyethylene glycol biomaterial system, due to their facile synthesis, physicochemical versatility and good cyto-/biocompatibility. Although a few different POx-based block copolymers that undergo thermogelation were described recently, it's not possible to print the real 3D constructs at this point. Herein, we describe a hybrid system of nanoclay and a thermoresponsive hydrogel as a novel bioink, and discuss its critical properties relevant for extrusion-based bioprinting, including viscoelastic properties, printability and cytocompatibility. The hybrid hydrogel retains its thermogelling properties but is strengthened by the added clay (G’= 5 kPa). Importantly, the shear-thinning character is further enhanced, which, in combination with very rapid structure recovery (~2 s) is highly beneficial for 3D printing. Accordingly, various 3D patterns are printed with high-resolution and greatly enhanced shape fidelity compared to the bioink without added clay. Results from in vitro cytocompatibility and cell-laden printing suggests its feasibility for cell printing. Overall, a novel ideal bioink is proposed in this study which will expand the options available to researchers in 3D bioprinting biofabrication, and lead to more complex and biomimetic structures in the future. In addition, it may provide a new promising material platform for controlled delivery and release, sacrificial material templates in fabrication of microfluidic devices and thermoresponsive self-protection.