It has been reported that 26-1 ferrite stainless steel has excellent biological characteristics, but the report of its biocompatibility is rare, especially the evaluation of biocompatibility by apoptosis mechanism.OBJECTIVE:
To study the pattern of cell death induced by magnetic-attached 26-1 ferrite stainless steel and to evaluate whether 26-1 ferrite stainless steel meets the biocompatibility in clinical application.DESIGN, TIME AND SETTING:
A contrast observational study at the level of molecular biology was performed at Central Laboratory of China Medical University from June 2004 to June 2005.MATERIALS:
26-1 ferrite stainless steel (Fe - 26% Cr - 1% Mo), Tilite [70% Ni - 16% Cr - (4%-6%) Ti - other alloy elements] and Co-Cr alloy (Co - 30% Cr - 5% Mo) were used in this study. Embed and cast metal materials then were cut into roll discs whose diameters were 12 mm.METHODS:
① The fibroblast L929 cells were co-cultured with the three materials, while cells in the negative control group were cultured in RPMI1640 media. At 18 and 24 hours after culture, types of cell death were quantitatively detected using fluorescein isothiocyanate and propidium iodide (PI) staining. ② Apoptosis rate and cycle distribution of L929 cells were detected using flow cytometry and PI staining at 24 hours after respectively culturing in 25%, 50%, and 100% leaching liquor.MAIN OUTCOME MEASURES:
Ratio between apoptosis and necrosis of L929 cells induced by different materials; apoptotic rate and cycle distribution of L929 cells.RESULTS:
All the three materials could decrease the survival rate of L929 cells; in particular, there was no significant difference in necrosis rate between different concentration material groups and negative control group, suggesting that cell apoptosis was the major factor to induce cytopathic effect, but there was no significant difference between the three material groups. Apoptosis of L929 cells indicated a great fashion of time- and concentration-dependence. There was no significant difference in apoptosis rate of L929 cells between the three material groups.CONCLUSION:
Cell apoptosis is a major pattern induced by 26-1 ferrite stainless steel which meets the biocompatibility as a clinical material and can be safely applied in clinic.