Fast stereolithographic printing of large-scale vascularized tissue

Statement of Purpose: Large size engineered soft tissues hold great promise for tissue repair and organ transplantation, but their fabrication is faced with challenges in vascularization and achieving clinically-relevant size and shape. 3D bioprinting is an emerging technology for tissue fabrication; however, its application in large tissue fabrication is limited due to the difficulty to fabricate at multiple length scales and the slow printing speed¹. Recently, the development of stereolithography (SLA)-based continuous liquid interface production (CLIP) technology enabled rapid printing of centimeter-thick parts in UV-curable resin². However, the high viscosity of the resin along with the large suction force at the printing interface limited the printing capacity of the CLIP to only thin-walled parts. The fabrication of large-sized solid tissue is currently not achievable using CLIP. In this work, we present a Fast hydrogeL prOjection stereolithogrAphy Technology (FLOAT) that allows high speed fabrication of human scale solid hydrogel tissues containing perfusable vascular networks through a single, rapid printing process. We demonstrate the compatibility of the process with multiple photocurable hydrogel materials and the approaches to optimize the printing material for improved tissue regeneration, such as the endothelialization of pre-fabricated vascular channels while maintaining high encapsulated cell viability.