Research progress on laser surface microstructuring systems for drug storage and release from orthopedic implants

Postoperative infection and insufficient osseointegration of orthopedic implants are core challenges leading to surgical failure, and endowing implants with drug storage and release functions has become a key innovative direction to break through this bottleneck. As the core carrier of the drug storage and release system, the size, morphology, and porosity of micro/nano topological structures directly determine the drug-loading efficiency and release kinetics. With its unique advantages of precise controllability and the ability to achieve multi-level topological structure integration in a single step, laser processing technology has received much attention in the integrated application of multifunctional design and drug storage/release for orthopedic implants. This review systematically summarizes the research progress of laser technology in constructing drug storage and release microstructures on the surface of orthopedic implants: first, it introduces the development history of implant surface microstructure design and mainstream preparation methods; then it focuses on the use of ultrafast lasers to construct surface micro/nano topological structures to achieve antibacterial and sustained drug release; it emphasizes the discussion on the preparation of implant scaffolds with complex microstructures and graded porosity by laser additive manufacturing technology, and their application in improving drug-loading capacity and achieving on-demand drug release; finally, it analyzes the existing challenges in this field and looks forward to future development trends and research directions.