4D‐Printed Photothermal‐Responsive Shape‐Memory Scaffold with ε‐Polylysine Coating for Dual Antibacterial–Osteogenic Therapy

Common bone implant materials lack dynamic shape adaptability and antibacterial functionality, which can easily lead to mismatches between the scaffold and the irregular defect site, as well as postoperative infections and other complications. To address these challenges, this study develops a 4D‐printed near‐infrared (NIR)‐triggered photothermal‐responsive shape‐memory multifunctional composite bone scaffold. By incorporating lysine‐modified graphene oxide (L‐GO), polylactic acid (PLA) is endowed with photothermal functionality and enhanced mechanical properties. Using fused deposition modeling (FDM) 3D printing technology and PLA/L‐GO shape memory composites, 4D‐printed composite porous scaffolds with a triply periodic minimal surface (TPMS) structure are fabricated, followed by surface loading of an ε‐polylysine (EPL) antibacterial–osteogenic dual‐function coating. Experimental results demonstrate that the incorporation of L‐GO endows the scaffold with a significant photothermal effect under NIR irradiation, achieving a photothermal‐responsive shape recovery rate of 85%. Antibacterial tests show that the ε‐EPL coating scaffold exhibits an antibacterial efficacy of over 80% against Escherichia coli . Meanwhile, cell experiments verify that the composite scaffold can effectively facilitate the proliferation and osteogenic differentiation of osteoblast cells. The multifunctional scaffold, integrating NIR‐responsive shape memory, antibacterial therapy, and cell‐promoting capabilities, provides a potential solution for the repair of complex bone defects.