Thermally stable, photocrosslinkable and biocompatible copolymers for melt electrowriting

Introduces coumarin-functionalized trimethylene carbonate (MUM) copolymers with caprolactone that are thermally stable during multi-week MEW processing and rapidly photocrosslinkable under long‑wave UV (~180 mW/cm^2 for ~2 min per layer), yielding low-sol (<5%) networks. The materials show tunable thermal and mechanical properties (Tg, crystallinity, modulus), stable molecular weight/composition during extended heating, good MEW processability (defined CTS, fiber diameters, crimped fiber printing), and cytocompatibility with NIH‑3T3 fibroblasts and rabbit Achilles tendon tenocytes.