Construction of artificial lung tissue structure with 3D-inkjet bioprinting core for pulmonary disease evaluation.

By integrating 3D-inkjet bioprinting technology, differentiated human cells can be assembled into artificial lung tissue structure to achieve a rapid, efficient, and reproducible disease model construction process. Here, we developed a novel 3D-inkjet bioprinting-based method to construct artificial lung tissue structure (ALTs) for acute lung injury (ALI) disease modeling, research and application. It can also be used to study the role of relevant cells in the disease by adjusting the cell type and adapted to study the bio-functions of immune cells during the cell-cell interactions. Firstly, a series of process optimizations were done to mass-produce the alginate hydrogel microspheres (Alg) with a particle size of 262.63 ± 5 μm using a 3D bioprinter, then the type I collagen and polydopamine were deposited in turns to construct a cell adhesion layer on the surfaces of Alg (P-Alg) and the particle size was increased to 328.41 ± 3.81 μm. This platform exhibites good stability, timescale-dependent behavior, and long-term cell adhesion. Subsequently, several human cells including endothelial, epithelial, fibroblast, and even immune cells such as macrophages were adhered to P-Alg through rotational culture, leading to cell contractions and aggregation, subsequently formed ALTs or ALTs with macrophages (ALTs@M) with human alveolar-like structure. Finally, we successfully constructed an ALI model with lung barrier damage on ALTs using lipopolysaccharide stimulation in vitro, and comparison of secreted inflammatory factors between ALTs and ALTs@M. Results demonstrated that ALTs@M was more effective than ALTs in stimulating the inflammatory microenvironment of the lungs, providing a novel in vitro model for cellular interactions and human macrophage research. Altogether, this artificial lung tissue structure construction strategy using 3D-inkjet bioprinting technology allowed the flexible development of artificial lung tissue structures as potential disease models for preclinical studies.