Confined bioprinting and culture in inflatable bioreactor for the sterile bioproduction of tissues and organs.

The future of organ and tissue biofabrication strongly relies on 3D bioprinting technologies. However, maintaining sterility remains a critical issue regardless of the technology used. This challenge becomes even more pronounced when the volume of bioprinted objects approaches organ dimensions. Here, we introduce a novel device called the Flexible Unique Generator Unit (FUGU), which is a unique combination of flexible silicone membranes and solid components made of stainless steel. Alternatively, the solid components can also be made of 3D printed medical-grade polycarbonate. The FUGU is designed to support micro-extrusion needle insertion and removal, internal volume adjustment, and fluid management. The FUGU was assessed in various environments, ranging from custom-built basic cartesian to sophisticated 6-axis robotic arm bioprinters, demonstrating its compatibility, flexibility, and universality across different bioprinting platforms. Sterility assays conducted under various infection scenarios highlight the FUGU's ability to physically protect the internal volume against contaminations, thereby ensuring the integrity of the bioprinted constructs. The FUGU also enabled bioprinting and cultivation of a 14.5 cm3 human colorectal cancer tissue model within a completely confined and sterile environment, while allowing for the exchange of gases with the external environment. This FUGU system represents a significant advancement in 3D bioprinting and biofabrication, paving the path toward the sterile production of implantable tissues and organs.