*3.11. Cell Culture*

MC3T3E1 and L929 cells were obtained from a cell bank (Procell Life Science & Technology Co., Ltd., Wuhan, China) and HUVEC were received from an institute of zoology (Chinese academy of

sciences, Beijing, China). MC3T3E1 was grown as monolayer at 37 ◦C in a 5% CO2 incubator and cultured in Dulbecco's modified eagle medium (DMEM) containing 10% (*v*/*v*) fetal bovine serum (FBS) and 1% (*w*/*v*) penicillin-streptomycin. L929 and HUVEC cells were cultured in MEM and DMEM/F12 (1:1), respectively.
