Abstract: [Objective] Investigate the toxic effect of metal ion C02+,Cr3+ on osteoblast under the static magnetic field,and search a method for preventation and treatment of aseptic loosening.[Methods] CoCl2 powder and CrCl3 powder were dissolved in the asepsis injecting water. Mouse calvarial osteoblasts(MC3T3-E1) were cultured with C02+,Cr3+ ions in different magnetic field of 10Gs，100Gs，1000Gs for 12，24 and 48 h．Observe morphological features of cell growth under inverted microscope . Scanning electron microscopy detect ultrastructure of osteoblasts. Cell apoptosis rate was assured by flow cytometry. ELISA method was appied to detect ALP content in serum supernatant.[Results] Under the static magnetic field,osteoblast showed more mature morphological features; the group 10Gs，100Gs，1000Gs has obviously lower apoptosis rate compared with the expriment group; the A value tested by ALP ELISA method in expriment group up-regulated obviously. [Conclusion] The static magnetic field could reduced the toxic effect of metal ion C02+,Cr3+ on osteoblast, offered the experimental evidence for preventation and treatment of aseptic loosening with magnetic field therapy.

Key words: static magnetic field, osteoblast, metal ion, aseptic loosening