3D-printed CoSi/PCL composite scaffold with NIR-II photothermal ability and enhanced adipogenic activity for breast reconstruction after mastectomy

Breast reconstruction after mastectomy aims to restore breast appearance and function. Current scaffolds often fail to meet the complex clinical demands of post-mastectomy breast reconstruction, which include personalized shaping, prevention of tumor recurrence and metastasis, and promotion of adipose tissue regeneration. This study aims to address these challenges by combining a readily processable biopolymer, polycaprolactone (PCL), with a multifunctional bioactive ceramic, cobalt orthosilicate (Co 2 SiO 4 , CoSi) to form a multi-functional CoSi/PCL composite scaffold through 3D printing technology. The scaffold exhibits a controllable shape with designed macroporous architecture. Its photothermal performances are well presented in both near-infrared (NIR) I and NIR-II regions, enabling effective tumor ablation with minimal side effects. Additionally, the release of bioactive silicate and cobalt ions promotes adipogenesis and angiogenesis, thereby enhancing the integration of the scaffold with surrounding tissues. This approach offers a promising strategy for combining tumor therapy with breast reconstruction, providing a clinically relevant solution for post-mastectomy patients.