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

Abstract 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 Food and Drug Administration approval process, clinical-grade manufacturing must be validated. Here, we present a manufacturing process and post-manufacturing 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 facility using Formlabs Biomed Elastic 50 A (E 50 A) and Biomed Flexible 80 A (F 80 A) 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 50 A macroporous implants resembled the modulus of soft tissue, while F 80 A 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 0.4- and 0.5- mm geometries, respectively. 3D printed implants supported the infusion of gelatin methacryloyl 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 toward regulatory approval and eventual clinical integration.