Standalone methacrylated extracellular matrix for digital light processing bioprinting: a practical workflow

Decellularized extracellular matrix (dECM) materials are widely reported to present tissue-specific biochemical cues that influence cell behavior; here, we use porcine uterine dECM as a representative soft-tissue model to operationalize a practical digital light printing workflow. Digital light processing (DLP) offers high-fidelity, photopolymer-based fabrication that avoids shear stresses associated with extrusion and enables precise layer definition, yet its application to soft-tissue dECM remains limited. We produce and evaluate a standalone methacrylated dECM (dECM-MA) formulation and a stepwise, reproducible recipe using lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) and tartrazine. Histological and biochemical analyses confirm successful decellularization, substantial collagen retention, partial sGAG retention, and controlled methacrylation of accessible primary amine groups. The formulation prints via DLP to yield reproducibly defined acellular constructs at a 50-µm layer height and millimeter-scale geometries, demonstrating high dimensional fidelity and controlled swelling behavior. High resolution scanning electron microscopy (HR-SEM) imaging of printed ECM-MA and solid decellularized uterine tissue demonstrated no significant differences in porosity, pore size distribution profiles, and connectivity, as quantified by image analysis, suggesting similar capacity to support diffusion and cell penetration. In vitro studies with human uterine stromal fibroblasts-parenchymal cells of the endometrium-show surface attachment and early cell-matrix interaction on printed constructs. Together, these results establish a practical 405-nm digital light printing workflow for standalone methacrylated dECM, exemplified using uterine ECM, enabling acellular construct stereolithographic fabrication with preserved ECM features and compatibility with early cell attachment and histological processing.