This study focuses on developing a new bone‑repair implant material for patients with fragile bone, such as those suffering from osteoporosis. Ti‑6Al‑4V titanium alloy is widely used in orthopedic and dental implants because of its high strength and biocompatibility, yet its direct bonding to bone (osteoconductivity) is limited, leading to loosening—especially in osteoporotic bone. Furthermore, as populations age, clinical cases increasingly require the long‑term local delivery of anti‑resorptive drugs (bisphosphonates) in parallel with implant placement.
Dual‑Layer Hybrid Surface
Inorganic base layer – The Ti alloy surface was converted, via a Ca‑heat chemical treatment, into a three‑dimensional nanonetwork of calcium titanate (cd‑CT).
Organic top layer – A gelatin coating containing the bisphosphonate minodronic acid was applied over the cd‑CT. Thermal cross‑linking of gelatin allows it to dissolve gradually, yielding sustained drug release.
Key Findings
Mechanical integrity – The hybrid coating showed excellent scratch resistance and adhesion.
Bioactivity – In simulated body fluid (SBF), the surface rapidly formed a widespread hydroxyapatite layer, indicating strong bone affinity.
Drug release – Therapeutically effective concentrations of minodronic acid were released for more than one week.
Structural synergy – The tight physical and chemical bonding between the inorganic cd‑CT layer and the organic gelatin layer improves fixation and guards against early implant failure.
By simultaneously enhancing bone integration and providing controlled drug therapy through a single surface modification, this technology offers a promising route toward next‑generation implants tailored for osteoporotic patients.
Article information & citation
Yamaguchi S., Akeda K., Shintani S.A., Sudo A., Matsushita T.
Drug-Releasing Gelatin Coating Reinforced with Calcium Titanate Formed on Ti–6Al–4V Alloy Designed for Osteoporosis Bone Repair. Coatings, 12(2):139 (2022).
https://doi.org/10.3390/coatings12020139