Effects of sterilization processes on NiTi alloy: surface characterization

Area of Science:

• Biomaterials Science
• Surface Chemistry
• Medical Device Sterilization

Background:

• Sterilization is essential for medical devices contacting the human body.
• Surface modifications after sterilization can impact device biocompatibility.
• Limited data exists on sterilization effects on novel biomaterials like nickel-titanium (NiTi).

Purpose of the Study:

• To investigate the impact of various sterilization techniques on the surface properties of NiTi.
• To analyze surface modifications induced by dry heat, steam autoclaving, ethylene oxide, peracetic acid, and plasma sterilization.
• To provide foundational data for selecting appropriate sterilization methods for NiTi.

Main Methods:

• Electropolished NiTi disks were subjected to five different sterilization methods.
• Surface analysis was conducted using Auger electron spectroscopy (AES), atomic force microscopy (AFM), and contact angle measurements.
• Quantification of surface elemental composition, topography, and surface energy was performed.

Main Results:

• Dry heat and ethylene oxide sterilization increased nickel concentration and oxide layer thickness.
• Dry heat sterilization led to a threefold increase in surface roughness.
• Plasma sterilization resulted in a significant increase (up to 100%) in surface energy.

Conclusions:

• Sterilization procedures induce notable surface modifications on NiTi.
• Different sterilization methods result in distinct surface property changes.
• Further research is needed to correlate these surface modifications with NiTi biocompatibility and determine optimal sterilization protocols.