Large-scale manufacturing of precisely patterned flexible soft tissue implants with high porosity

As improvements in material compatibility are achieved, stereolithography (SLA) 3D printing allows for the prototyping of soft tissue constructs with high reproducibility and precision. To streamline the Federal Drug Administration (FDA) approval process, clinical-grade manufacturing must be validated. Here, we present a manufacturing process and postmanufacturing analysis for soft-tissue implants used to reconstruct the nipple-areolar complex (NAC). The NAC is a specialized soft tissue structure that influences aesthetic outcomes in breast reconstruction. Physiologically-sized NAC implants were designed and printed in a good manufacturing practice (GMP) facility using Formlabs Biomed Elastic 50A (E 50A) and Biomed Flexible 80A (F 80A) resins. Documentation and procedures were established to standardize and control macroporous soft-tissue implant manufacturing. Post-manufacturing classification based on architectural and mechanical features defined the minimum acceptable criteria for future production. E 50A macroporous implants resembled the stiffness of soft tissue, while F 80A geometries showed higher reproducibility and preservation of fine architectural features.SLA printing enabled the patterning of implants with porosities of 74.65% and 72.74% for 0.4and 0.5-mm geometries, respectively. 3D printed implants supported the infusion of gelatin methacrylate for the delivery of biological cues, with a filling efficiency greater than 97%. This manufacturing platform achieves reproducible fabrication of soft-tissue implants that meet both structural and mechanical requirements. Further, the presented methodology can be adapted for a wide range of complex soft tissues to advance regenerative medicine solutions towards regulatory approval and eventual clinical integration.