(161e) Engineering Hybrid Colloidal Bioinks Based on Charge-Driven Self-Assembly between Spherical and 2D Nanoparticles

To achieve important milestones in bioprinting, formulating printable bioinks is crucial. As a prominent biomaterial for bioprinting, gelatin methacryloyl (Gel-MA) is widely used. However, because of the low viscosity of Gel-MA bioink, the shape fidelity entirely relies on layer-by-layer postprinting chemical crosslinking under UV exposure that slows down the printing process markedly. Also, the UV light might damage the encapsulated cells. Here we show that the controlled assembly between oppositely-charged gelatin spherical nanoparticles and 2-dimensional silicate bioactive nanomaterials results in an injectable hybrid colloidal gel that serves as an efficient bioink without any need for postprinting crosslinking. The designed hybrid colloidal gels exhibit pronounced shear-thinning and self-healing properties and can be efficiently processed by direct ink writing 3D bioprinting technique. This advantage renders these hybrid materials as promising and inexpensive bioactive bioinks with advanced capability for bone tissue engineering.