Biomimetic Surface Nanoengineering of Biodegradable Zn‐Based Orthopedic Implants for Enhanced Biocompatibility and Immunomodulation

Abstract

AbstractZinc (Zn) is gaining increased recognition as a biodegradable metal in biomedical applications but clinical translation is limited due to its poor biocompatibility. This study addresses these issues through an innovative biomimetic strategy, introducing an efficient surface nanoengineering approach that creates nano‐geometric features and chemical compositions by modulating the exposure time to a biological medium – Dulbecco's Modified Eagle Medium(DMEM). These nanoengineered Zn implants exhibited tunable degradation rates. The nanostructures enhanced human osteoblast attachment, proliferation, and differentiation following direct contact, and improved macrophage function by promoting pseudopod formation and transitioning from a pro‐inflammatory M1 to a pro‐reparative M2 phenotype. In vivo studies show that the surface‐engineered implants effectively promoted tissue integration via M2 macrophage polarization, resulting in a favorable immunomodulatory environment, and increased collagen deposition. Proteomic analyses show that the tissues in the vicinity of the surface‐engineered Zn implants are enriched with proteins related to key wound healing biological mechanisms such as cell adhesion, cytoskeletal structural arrangement, and immune response. This study highlights the improved biocompatibility and anti‐inflammatory effects of surface‐engineered Zn, with important implications for the clinical translation of biodegradable Zn‐based orthopedic implants.