“…HA is an essential mineral for human bones, which consist of 70% low-crystalline or amorphous apatite, 30% collagen, and bone marrow cells [ 8 , 9 , 10 , 11 , 12 ]. At present, apatite preparation methods mainly include wet [ 13 , 14 , 15 ], dry [ 16 , 17 , 18 ], sol–gel [ 19 , 20 , 21 ], biological tissue synthesis [ 22 , 23 , 24 ], hydrothermal [ 25 , 26 , 27 ], and freeze-drying methods [ 28 , 29 , 30 ]. HA has good biological activity, biocompatibility, and non-toxicity.…”