Construction of a Rough Surface with Submicron Ti2Cu Particle on Ti-Cu Alloy and Its Effect on the Antibacterial Properties and Cell Biocompatibility

A novel titanium alloy for load-bearing biomedical implants: Evaluating the antibacterial and biocompatibility of Ti536 produced via electron beam powder bed fusion additive manufacturing process

Additive manufacturing (AM) of Ti-based biomedical implants is a pivotal research topic because of its ability to produce implants with complicated geometries. Despite desirable mechanical properties and biocompatibility of Ti alloys, one major drawback is their lack of inherent antibacterial properties, increasing the risk of postoperative infections. Hence, this research focuses on the Ti536 (Ti5Al3V6Cu) alloy, developed through Electron Beam Powder Bed Fusion (EB-PBF), exploring bio-corrosion, antibacterial features, and cell biocompatibility. The microstructural characterization revealed grain refinement and the formation of Ti2Cu precipitates with different morphologies and sizes in the Ti matrix. Electrochemical tests showed that Cu content minimally influenced the corrosion current density, while it slightly affected the stability, defect density, and chemical composition of the passive film. According to the findings, the Ti536 alloy demonstrated enhanced antibacterial properties without compromising its cell biocompatibility and corrosion behavior, thanks to Ti2Cu precipitates. This can be attributed to both the release of Cu ions and the Ti2Cu precipitates. The current study suggests that the EB-PBF fabricated Ti536 sample is well-suited for use in load-bearing applications within the medical industry. This research also offers an alloy design roadmap for novel biomedical Ti-based alloys with superior biological performance using AM methods.

Antibacterial Ti-Cu implants: A critical review on mechanisms of action

Titanium (Ti) has been widely used for manufacturing of bone implants because of its mechanical properties, biological compatibility, and favorable corrosion resistance in biological environments. However, Ti implants are prone to infection (peri-implantitis) by bacteria which in extreme cases necessitate painful and costly revision surgeries. An emerging, viable solution for this problem is to use copper (Cu) as an antibacterial agent in the alloying system of Ti. The addition of copper provides excellent antibacterial activities, but the underpinning mechanisms are still obscure. This review sheds light on such mechanisms and reviews how incorporation of Cu can render Ti-Cu implants with antibacterial activity. The review first discusses the fundamentals of interactions between bacteria and implanted surfaces followed by an overview of the most common engineering strategies utilized to endow an implant with antibacterial activity. The underlying mechanisms for antibacterial activity of Ti-Cu implants are then discussed in detail. Special attention is paid to contact killing mechanisms because the misinterpretation of this mechanism is the root of discrepancies in the literature.