Synergistic advances in additive manufacturing and surface engineering for polymeric biomedical devices

Additive manufacturing (AM) of polymeric materials is rapidly transforming the biomedical field by enabling the fabrication of patient-specific, anatomically complex structures with precise control over internal architecture. Polymers are especially attractive for AM of biomedical devices due to their cost-effectiveness, abundance, low density, and tunable mechanical and degradation properties, supporting diverse applications in soft and hard tissue engineering, microfluidics, and drug delivery. However, many medical-grade polymers interact poorly with mammalian cells and tissues due to the lack of bioactive surface functional groups, which can hinder their performance in biomedical applications that rely on cell-material interactions such as tissue regeneration. This review systematically surveys physical, chemical, and biomimetic surface modification techniques for AM-compatible medical polymers to improve biomedical applications and targeted functionalities. While much attention has been paid in the literature to surface modification in bone tissue engineering, functional coatings incorporating bioactive molecules and nanoparticles further provide antibacterial, anti-inflammatory, and pro-regenerative functions. A major emphasis of this review is the synergy between AM and surface engineering, enabling simultaneous optimization of internal architecture and surface bioactivity-capabilities fundamentally unattainable by conventional manufacturing techniques. Finally, challenges such as sterilization compatibility and long-term stability of surface modifications are discussed as key to clinical translation.