Surface modifications of Nitinol for biomedical applications.

Area of Science:

• Materials Science
• Biomaterials Engineering
• Surface Chemistry

Background:

• Nitinol (Nickel-Titanium shape memory alloy) requires surface modification for biomedical applications.
• Chitosan is a versatile biopolymer for fabricating functional films.
• Electrophoretic deposition (EPD) offers a controllable method for film fabrication.

Purpose of the Study:

• To fabricate composite films using cathodic electrophoretic deposition (EPD) for Nitinol surface modification.
• To incorporate functional materials like heparin, hydroxyapatite, and bioglass into a chitosan matrix.
• To evaluate the properties and potential applications of the fabricated composite films.

Main Methods:

• Cathodic EPD was used to deposit chitosan (CH) based composite films.
• Chitosan-heparin, chitosan-hydroxyapatite, and chitosan-bioglass composites were prepared.
• Film thickness, antithrombin binding, nanoparticle orientation, and corrosion protection were analyzed.

Main Results:

• Chitosan-heparin films exhibited significantly increased deposition rates and enhanced antithrombin binding compared to pure chitosan.
• Chitosan-hydroxyapatite films (1-30 microm) showed preferred nanoparticle orientation and provided corrosion protection to Nitinol substrates.
• Room-temperature processing was achieved for all fabricated composite films.

Conclusions:

• Cathodic EPD is effective for fabricating functional chitosan-based composite films on Nitinol.
• The composite films demonstrate improved properties, including enhanced biocompatibility and corrosion resistance.
• The developed method offers a versatile, room-temperature approach for creating advanced biomaterials for medical devices.