Nitinol Biocompatibility

Nitinol Biocompatibility

Metal implants containing a combination of biocompatible metals or used in conjunction with other biomaterials are often considered the standard for many implant types. When materials are introduced to the body it is important not only that the material does not damage the body, but also that the environment of the body does not damage the implant. One method that prevents the negative effects resulting from this interaction is called passivation. Passivation is a process that removes corrosive implant elements from the implant-body interface and creates an oxide layer on the surface of the implant. The process is very important for making biomaterials more biocompatible. The following investigation will examine passivation as it relates to NiTi, nitinol, a commonly used biomaterial especially in the development of stent technology.

Nitinol, which is formed by alloying nickel and titanium (~ 50% Ni), is a shape memory alloy with superelastic properties much similar to that of bone in comparison to that of stainless steel (another commonly used biomaterial). This property makes nitinol an especially advantageous material for biomedical applications. Some of the biomedical applications that utilize nitinol, include stents, heart valve tools, bone anchors, staples, septal defect devices and implants.