Programmable higher-order biofabrication of self-locking microencapsulation

Three-dimensional (3D) hydrogel microcapsules offer great potential in a wide variety of biomedical and tissue engineering applications for their promising biodegradability and customizable geometry. Although recent advances in microfluidics and electrospray techniques have achieved high-throughput production of droplet microcapsules, they are still faced with the intractable challenge of obtaining programmable shape-engineered microcapsules with complex spatial architecture. Herein, a programmable light-induced biofabrication strategy is proposed to construct higher-order microcapsule architectures by developing a microencapsulation microchip. Such a method not only enables one to prepare various 2D Ca-alginate hydrogel sheets with well-tailored shapes and sizes, but also forms 3D perfectly matched microcapsule components by taking advantage of shrinkage and swelling phenomena. The proposed biofabrication method overcomes the drawback of conventional monotonous microencapsulation and allows us to fabricate sophisticated microcapsules with higher-order and biomimicking joints, such as a self-locking architecture. It can provide wide applications in biomedicine and would offer many unprecedented possibilities of artificial tissue engineering.