FRESH-bioprinted vascular constructs: a quantitatively characterized workflow for reproducible device-oriented...

The lack of standardized and reproducible in vitro vascular models remains a major obstacle to the quantitative evaluation of endovascular devices and vessel-device interactions. While recent bioprinted vascular constructs have increased biological complexity, reproducibility, shape fidelity, and mechanical consistency remain insufficiently characterized. Here, we establish a quantitatively characterized FRESH-bioprinted workflow that enables reproducible fabrication and standardized characterization of vessel-like constructs for device-oriented testing. Bioink formulation, printing parameters, and post-processing conditions were systematically optimized. At the same time, construct geometry and mechanical reproducibility were quantitatively evaluated using micro-computed tomography (micro-CT), confined compression, and ring tensile testing. Sterile fabrication, preliminary cellularization, controlled perfusion, and intraluminal stent-like ring deployment were further explored to assess procedural compatibility within a device-oriented vascular testing framework. The optimized workflow enabled reproducible fabrication of vessel-like constructs across multiple geometrical scales, with close agreement between designed and measured dimensions and limited batch-to-batch variability. Micro-CT analysis revealed controlled post-processing-induced geometrical changes, including mild shrinkage and lumen reduction, while mechanical testing demonstrated reproducible axial and circumferential responses across independent fabrication batches. Intraluminal deployment of a radiopaque polycaprolactone ring induced local vessel expansion of approximately 8% while preserving lumen patency and structural integrity under low-pressure perfusion conditions. Preliminary biological assays confirmed high cell viability for up to 14 days and initial endothelial adhesion, supporting compatibility with sterile cell culture procedures and providing a robust foundation for future biologically advanced vascular models. By integrating biofabrication, quantitative imaging, mechanical characterization, and preliminary biological validation into a single workflow, this work establishes a quantitatively characterized and reproducible FRESH-bioprinted vascular platform that bridges the gap between rigid vascular phantoms and biologically advanced tissue-engineered systems. The proposed platform provides a robust experimental foundation for future process standardization, device-oriented vascular testing, and the progressive development of standardized experimental models for endovascular research.