Growing Macroscopic Functional Human Tissues on 3D Printed Peptide Hydrogels

Support-bath-assisted 3D-printed peptide hydrogels enable centimeter-scale growth of functional human pluripotent stem cell-derived cardiac, neural, and hippocampal tissues with directionally biased connectivity.

• Why it matters: Tissue-scale function depends on coordinated substructures, but controlling architecture beyond cellular length scales has been difficult while preserving self-organization in vitro.
• What they did: The authors 3D-print peptide hydrogel frameworks, use high-aspect-ratio scaffolds for centimeter-scale neural organoid beds, and print hydrogel connectoids to guide axonal projections between pre-patterned dentate gyrus (DG)- and CA3-enriched spheroids.
• The result: Printed connectoids support functional communication directionally biased toward the canonical feedforward DG-to-CA3 pathway, demonstrating macroscopic architecture specification while maintaining intrinsic self-organizing capacity in vitro.