Scheme 1

The schematic synthesis of HA-based nanoparticles and the biomineralization process according to which it is possible to synthesize HA-based nanoparticles on chitosan chains. Specifically, in (A), the wet acid-base neutralization of acidic chitosan solution containing phosphate ions in a basic suspension containing calcium ions – and additional doping ions, i.e. Mg²⁺, Fe²⁺, and Fe³⁺ – is reported, leading to the biomineralization of chitosan (B). In (C) the magnification of the schematic formation of hydroxyapatite nanoparticles doped with ions on the chitosan template is reported. Created with Biorender.com