To research the cytotoxicity of Fe-Ni soft magnetic alloy in order to provide a biological basis for the clinical application.

Five groups of materials (Pure Ti, Fe-Ni alloy, Fe-Ni plated Cr⁶⁺, Co-Cr alloy, and PVC) were cut into 2 cm × 2 cm × 0.2 cm blocks and prepared for the extract after sterilization. L-929 cells were incubated in five 96-well culture plates at a concentration of 6 × 10³ per well for 24 h to allow the attachment. The culture medium was replaced with 100 μl exaction per well. After 1, 2, 3, 4 and 5 d culturing, the cells of each groups were observed under microscope. 10 μl CCK-8 solution was added to each well and cultured for 1.5 h, the absorbance values were obtained with a spectrophotometer. The cytotoxicity of the materials was evaluated by calculating the relative growth rate (RGR) .

The shape of L-929 cells of each group was normal besides the PVC group under the microscope. The cytotoxicity of PVC was grade 3, and all the other materials were grade 0~1 based on the RGR. All of the experimental materials were safe for clinical application except PVC.

Both Fe-Ni alloy and Fe-Ni plated Cr⁶⁺ have good biocompatibility.