Discussion on the biocompatibility of medical nitinol spring tubing: consideration of allergic reaction and rejection reaction

Basics of biocompatibility of Nitinol
Nitinol, with its excellent mechanical properties, shape memory effect and superelasticity, occupies an important position in the manufacture of medical devices. Its biocompatibility, that is, the degree of interaction when in contact with biological tissues or cells, is a key indicator for measuring the safety of medical materials. Nitinol can coexist harmoniously with human tissues and is not easy to cause significant rejection or allergic reactions, mainly due to the titanium dioxide layer on its surface. This layer can form a barrier to effectively inhibit the release of nickel elements, thereby reducing the risk of adverse reactions caused by nickel allergies.

Analysis of the possibility of allergic reactions and rejection reactions
Although Nitinols have excellent performance in biocompatibility, in practical applications, it is still necessary to be vigilant about the possibility of allergic reactions and rejection reactions. Allergic reactions are usually caused by an individual's sensitivity to specific substances (such as nickel), manifested as symptoms such as skin itching, redness, swelling, and rash. Although the nickel element in Nitinol is suppressed by the titanium dioxide layer, it is still possible to release a small amount during long-term implantation or contact, thereby triggering an allergic reaction.

Rejection is an immune response of the organism to foreign matter (such as implants). As a foreign substance, Nitinol theoretically has the risk of being recognized by the immune system, thereby triggering a mild local inflammatory reaction. However, due to its good biocompatibility, this rejection reaction is usually mild and can be effectively controlled through appropriate medical intervention.

Factors affecting biocompatibility
The biocompatibility of medical nitinol spring tubings is affected by many factors, including but not limited to material purity, surface treatment, implantation site, individual immune response, etc. Improving the purity of the material and reducing the content of impurities and harmful elements are the key to improving biocompatibility. In addition, appropriate surface treatment of Nitinol, such as polishing and coating, can further improve its biocompatibility and reduce the risk of allergic reactions and rejection reactions.

The choice of implant site is also crucial. Tissues in different parts have different tolerances to materials. Therefore, when selecting the implant site, the biocompatibility of the material and the compatibility of the tissue should be fully considered.

Individual immune response is another important factor affecting biocompatibility. Each person's immune system reacts differently to foreign matter. Therefore, before using the medical nitinol spring tubing, conducting an allergy test on the patient to understand his or her sensitivity is an effective means of preventing allergic reactions and rejection reactions.