3D cellular tracheal analogue fabrication using rotational printing system

Fabricating clinically relevant three-dimensional (3D) tissue/organ analogue is one of the main issues in tissue engineering. Recently, 3D printing technology has become a powerful tool, enabling precise control and distribution of various biomaterials. Despite its advantages, layer-by-layer process is time-consuming to create macroscale tissue/organ analogues. In this study, we present a rational 3D printing strategy to create a 3D cellular tracheal analogue consisting of framework, cartilage and epithelium. We divided printing process into framework fabrication and cell printing process. Firstly, we fabricated the framework in a bellows shape to mimic a mechanical behavior of native trachea. The bellows framework was fabricated by intermittent dispensing of polycaprolactone from printing nozzle. Before cell printing process, it was thermally incubated and treated with oxygen plasma to increase the structural integrity and hydrophilicity, respectively. And then, using rotational printing system, collagen hydrogel each encapsulating human nasal septal chondrocytes and human turbinate mesenchymal stromal cells were printed at the outer grooves and inner surface of bellows framework. Since the 3D cell pinting time is as short as within 5 minutes, it can enhance cell viability and further functions of celluar tracheal analogue. This strategy can significantly reduce the fabrication time of the clinically relevant tracheal analogue.2