Polydopamine Modified CuFeSe2 Reinforcing PLA/PEG Bone Scaffolds: Interfacial Regulation, Mineralization Enhancement and Photothermal Functionalization

To repair irregular bone defects after tumor resection, this study employed FDM 3D printing technology to incorporate PDA modified CuFeSe 2 ceramic nanoparticles into a PLA/PEG matrix, thereby constructing a multifunctional composite scaffold that integrates shape memory and photothermal capabilities. The composite scaffolds possessed compression strength matching that of cancellous bone. With the plasticizing effect of PEG, the glass transition temperature (T g ) of the scaffold containing PDA@CuFeSe 2 was modulated to 39.7°C, achieving a shape recovery ratio exceeding 89%. Further proof of concept experiments revealed that the scaffold could undergo spiral adaptive deployment in a warm water bath and enable remotely controlled recovery of a petaloid structure via NIR light stimulation. This confirms its potential for minimally invasive implantation and noncontact regulation in complex defect environments. The scaffold with PDA@CuFeSe 2 could steadily generate mild heat at around 45°C to induce tumor cell apoptosis. Additionally, PDA conferred enhanced hydrophilicity to the scaffold, which accelerated PLA degradation while buffering local pH fluctuations. Moreover, the in-situ surface deposition at the solid-liquid interface inhibited the early burst release of metal ions, ensuring a long-term and safe release profile. In vitro mineralization and cellular experiments demonstrated that the composite scaffold effectively induced calcium phosphate minerals deposition, exhibited good cell compatibility, and promoted osteogenic differentiation.