TYRAY-Functionalized Alginate Bioinks for 3D Bioprinting Support Stem Cell Culture and Endothelial Network Formation.

3D bioprinting is transforming tissue engineering by enabling spatial arrangement of cells and cell aggregates within supportive hydrogels. Among available materials, alginate remains widely used for its biocompatibility, printability, and cost-effectiveness. However, its bioinert nature and lack of adhesive moieties restrict its capacity to support essential processes like cell adhesion, migration, and proliferation. In this study, we propose a comprehensive approach to enhance alginate hydrogels focusing on stem, stromal, and endothelial cell types to support extended growth and vascular network formation. Key innovations include the incorporation of the TYRAY peptide in 3D alginate hydrogels─its first application in this context─to promote cell adhesion and migration, accompanied by Ca(OH)2-modified surfaces for stable hydrogel anchoring and an ultrasonic mist cross-linking to preserve 3D structure fidelity. Functionalization with the TYRAY peptide significantly enhanced cell proliferation, promoted multicellular spheroid fusion, and supported endothelial network development in comparative culture setting. Together, these findings establish this defined, xeno-free alginate system as a versatile bioink material suitable for 3D culture and bioprinting applications.