Surface Modification of NiTi Shape MemoryAlloys with Chitosan-Based Coatings: A Brief Literature Review.

Metallic biomaterials stand out for their mechanical strength, good electrical conductivity, corrosion resistance, and thermal stability at high temperatures, which enables effective sterilization. However, some of these materials, such as Nitinol, cause undesirable effects in the physiological environment due to the release of Ni2+ ions that are known to be toxic. One way to solve this problem is to functionalize the surface of these alloys through the application of biocompatible coatings based on composite materials or polymer matrices. Thus, the objective of this work was to evaluate the information available in the literature of scientific articles on the use of chitosan-based coatings applied in the functionalization of the surface of the shape memory alloy of NiTi (Nitinol), in view of the extensive application of titanium-based alloys for the production of biomaterials and the recent search for bioactive materials of natural origin for the manufacture of advanced systems applied in the biomedical sector. Therefore, the information presented here may serve as a basis for guiding future research aimed at the development of intelligent biomaterials (biomimetics), using chitosan as a polymeric matrix for modifying the surface of the NiTi alloy applied in the production of orthopedic and orthodontic implants and in cardiovascular surgeries.