2023-11-20 ワシントン州立大学(WSU)
◆従来の手術インプラントが感染症の原因となることが多い中、この新しいインプラントは、3Dプリンティング技術を用い、チタン合金に耐食性金属のタンタルムと抗菌効果のある銅を組み合わせて開発されました。インプラントの表面に触れた細菌はほぼ全てが破壊され、同時に周囲の骨や組織との健康な細胞成長が促進されます。この研究は、感染症対策と骨組織統合の両方に対応する多機能デバイスとしての可能性を示唆しています。
<関連情報>
- https://news.wsu.edu/press-release/2023/11/20/infection-resistant-3d-printed-metals-developed-for-implants/
- https://iopscience.iop.org/article/10.1088/2631-7990/ad07e7/meta
次世代耐荷重インプラント用添加製造Ti-Ta-Cu合金 Additively manufactured Ti–Ta–Cu alloys for the next-generation load-bearing implants
Amit Bandyopadhyay, Indranath Mitra, Sushant Ciliveri, Jose D Avila, William Dernell, Stuart B Goodman and Susmita Bose
International Journal of Extreme Manufacturing Published 17 November 2023
DOI:10.1088/2631-7990/ad07e7
Highlights
- Ti3Al2V demonstrated comparable mechanical performance to Ti6Al4V.
- Adding 3 wt.% Cu in Ti3Al2V reduced planktonic bacteria colonies by 78%–86% compared to commercially pure Ti.
- Ti3Al2V–10Ta displayed the best in vivo biocompatibility with 3.5-fold higher bone formation than Ti6Al4V.
- Ti3Al2V–10Ta–3Cu multifaceted alloy has the potential to replace Ti6Al4V in orthopedic and dental applications with superior early-stage osseointegration and inherent antibacterial performance.
Abstract
Bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. In this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum (Ta)–Copper (Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological, mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta (10Ta) and 3 wt.% Cu (3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e. 78%–86% with respect to CpTi. Mechanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. In vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with 10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse inflammatory response in vivo. Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.
