Topology-optimized melt-electrowritten PCL patch for abdominal wall reconstruction.

Abdominal wall patches are clinically essential for treating abdominal defects or hernias, with mechanical strength representing a critical requirement. Therefore, rational scaffold design and fabrication methods are crucial for achieving optimal performance. This study introduces an innovative approach to the design of scaffolds for abdominal wall repair, using topology optimization and melt electrowriting (MEW). Through topology optimization, we provided a systematic, data-driven basis for scaffold design. We further refined the scaffold structure to enhance print efficiency and continuity, and successfully implemented MEW as fabrication technology, marking its first application in abdominal repair. Mechanical testing revealed that the topology-optimized scaffold achieved abdominal tensile strength of 1.85 ± 0.02 N/cm, 39 % superior to conventional designs. Subsequent biological assessments - including fibroblast proliferation and alignment analyses - showed that collagen coating significantly enhanced cell attachment and proliferation, especially in multi-layer (300 layers) scaffolds, maintaining diameters of 11.34 ± 0.67 μm throughout the depth. Finally,