“…According to the method, reagents and variables adopted, it is possible to obtain materials based on CaP with different phases, which results in materials with diverse characteristics and properties, such as crystalline defects, high surface area, organic material affinity found in physiological medium and so on [46]. HAp can be synthesized by a variety of techniques that can be broadly grouped into six sets of methods: i) dry methods: involve solid state and mechanochemical reactions [63][64][65][66][67]; ii) wet methods: based on low-temperature chemical precipitation [68], co-precipitation [66,69,70], sol-gel route [71][72][73][74][75][76] and hydrolysis [77,78]; iii) hydrothermal methods: use aqueous solutions of high temperature and high voltage, as hydrothermal [79][80][81], emulsion and microemulsion [82,83], and sonochemical [84]; iv) high temperature processes: include combustion [85,86] and pyrolysis [87,88]; v) synthesis based on biogenic sources: can be extracted from fish bones [89], shells [90], eggshells [91,92], bovine bones [93,94], in the presence of biomolecules [95][96][97] or biomembranes [98]; and vi) combination of the aforementioned methods. All methods used for synthesizing HAp particles have different processing characteristics and can result ...…”