Seamless vessel-microenvironment bioprinting reveals contact-dependent vascular communications

Vessel-microenvironment interactions are pivotal in tissue development and disease. Existing experimental platforms fail to recapitulate the seamless extracellular matrix (ECM) continuity required for physiological vessel-stromal communications, often creating disruptive material boundaries. In this study, we developed a consubstantial bioink-supporting bath system using collagen modified with nanoscale PEGylated polyhedral oligomeric silsesquioxane, enabling interface-free vessel-microenvironment modeling. This suspension matrix approach maintains uninterrupted, biomimetic ECM to preserve spatial complexity and multicellular crosstalk. We validated this platform through complementary models: a regenerative vessel-stromal model demonstrating the dominance of contact-dependent signaling over paracrine effects and a pathological vessel-tumor model. Single-cell RNA sequencing and cell-cell communication analysis revealed cancer-associated fibroblast-mediated networks driving pathological angiogenesis. This study advances vessel-microenvironment biology and provides a platform to investigate vascular mechanisms and therapies.