To address the three key requirements for orthopedic and dental implants—mechanical strength, osteoconductivity, and long‑term antibacterial activity—we newly designed and fabricated titanium scaffolds whose pore diameters decrease gradually from the exterior to the interior (900 µm → 600 µm → 300 µm). A simple surface treatment simultaneously loaded the scaffold with both calcium and iodide ions.
Mechanical performance
Exhibited a low elastic modulus close to that of human cancellous bone and high compressive strength.
Withstood 1 million cycles at 10 kN without failure, demonstrating fatigue strength sufficient for load‑bearing clinical use.
Bioactivity
In simulated body fluid, hydroxyapatite—the principal component of bone—formed on all internal surfaces within three days, indicating rapid bone‑bonding capability.
Antibacterial function
Iodide ions were released in a two‑step manner—initial burst followed by diffusion‑controlled release—maintaining > 99 % bactericidal efficacy against MRSA for more than three months.
The gradient‑pore architecture allows large outer pores to promote bone ingrowth and fixation, while smaller inner pores help retain antibacterial ions over time—achieving a high‑level balance between osteoconduction and antimicrobial activity. Cell studies confirmed excellent biocompatibility and enhanced osteoblast differentiation, positioning this material as a promising next‑generation implant capable of simultaneously preventing infection and aseptic loosening.
Article information & citation
Mahmoud Gallab, Phuc Thi Minh Le, Seine A. Shintani, Hiroaki Takadama, Morihiro Ito, Hisashi Kitagaki, Tomiharu Matsushita, Shintaro Honda, Yaichiro Okuzu, Shunsuke Fujibayashi, Seiji Yamaguchi. Mechanical, bioactive, and long-lasting antibacterial properties of a Ti scaffold with gradient pores releasing iodine ions. Biomaterials Advances, 158, 213781, 2024.