Bioprinted vascularized soft-tissue flaps with an integrated arterial-venous loop.

This study contributes to ongoing efforts in tissue engineering and regenerative medicine to fabricate soft-tissue flaps and addresses the key limitations of current reconstructive strategies for extensive tissue loss. By applying a multimodal printing approach and employing a tailored bioink together with diverse human-derived cell populations, we enabled the fabrication of vascularized soft-tissue flaps. The flaps comprised muscle and adipose compartments within a single construct, interconnected by a continuous vascular network and lymphatic vasculature. A printed arteriovenous loop was integrated centrally within the flap, serving as a feeding axis that enabled direct microsurgical anastomosis to the host circulatory system. Immediate and sustained perfusion following implantation provided rapid nutrient delivery and efficient waste removal throughout the thick, multi-tissue flap, thereby supporting adipose and muscle differentiation alongside vascular and lymphatic integration. Collectively, by addressing these critical challenges, this work advances bioprinting toward clinically relevant applications in soft-tissue flap reconstruction.