Assembly mechanism of high-crystallized selenium-doped hydroxyapatite nanorods via particle attachment and their effect on stem cells fate

Hydroxyapatite is the main inorganic component of human bone. Synthetic hydroxyapatite and its different modified forms, which has shown to be biocompatible and osteoconductive, have been widely used in bone tissue engineering. Until now, it is still challenging to controllably synthesize hydroxyapatite with targeted morphology. In this work, we synthesized a highly crystalline selenium-doped hydroxyapatites nanorods (SeHAN) via a two-step alcohol thermal method and provided a completed explanation of the synthesis mechanism. Tracing the crystals made from solvated phase to crystal phase with high-resolution microscopy, the nanorods formation route can be briefly described as follow: as a basic unit, ~30 nm amorphous apatite (ACP) initially formed in the first step and partly crystallized in early part of the second step; After a period of alcohol thermal reaction, immature nanorods appeared, which assembled by nanocrystal; finally, immature nanorods transform to the single crystal nanorods through crysta...