A rational fabrication strategy of 3D cell printed tracheal analogue for tracheal reconstruction and its implantation into tracheal defect model of rabbit

Abstract

Recently, 3D printing technology has become a powerful tool, enabling precise control and distribution of various biomaterials. However, in the case of cell printing, delayed printing time has significant effect on cell death and further in decreased functions of tissue analogue. 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 fabrication process into framework printing and cell printing. Firstly, we fabricated the framework in a porous bellows shape to mimic the mechanical behavior of native trachea. And then, using rotational printing system, collagen hydrogel each encapsulating human nasal septal chondrocytes or human turbinate mesenchymal stromal cells was printed at the outer grooves and inner surface of bellows framework to regenerate cartilage and epithelial part, respectively. The cell printing time was completed within 3 minutes for each surface. Upon fabrication, the 3D cell printed tracheal analogue was cultured for 3 days to stabilize the hydrogel-encapsulated cells. And then, it was implanted into tracheal defect model of rabbit. We harvested the tracheal samples at 1 month and 2 months after implantation We analyzed them histologically and conducted mechanical behavior using three-point bending. This rational fabrication strategy of 3D cell printed tracheal analogue might be a novel concept for tracheal reconstruction.