Biomaterial Processing Techniques

**3**

**Chapter 1**

**Abstract**

are discussed.

**1. Introduction**

*and Anna Tampieri*

Synthesis of Nanostructured

Hydrothermal Route

*Andrea Ruffini, Simone Sprio, Lorenzo Preti* 

**Keywords:** hydrothermal synthesis, nanostructured hydroxyapatite,

Calcium phosphates (CaP) are the main mineral constituent of human bones and teeth. For this reason, synthetically CaP-based materials nowadays are the most ubiquitous family of biomaterials for their use in biological applications and tissue engineering. These attractive biomedical materials possess excellent biocompatibility, osteoconductive properties, nontoxicity, and chemical similarity to the

The realization of CaP biomaterials reproducing the calcified tissue (dense and porous block, granules, and powders) is clinically needed as an alternative to

crystal growth, morphology control, regenerative medicine

inorganic component of the natural bone [1].

Hydroxyapatite via Controlled

Hydroxyapatite represents the natural inorganic component of the bone and may be considered an essential element required for the development of bone substitutes in the field of regenerative medicine. Hydroxyapatite bone substitutes own biomimetic, osteoconductive, and osteoinductive properties thanks to their chemical-physical properties and nanostructure that play a critical role for the reconstruction of calcified tissues. Controlling the structure of hydroxyapatite nanocrystals is vital for obtaining a sustained product, and it should be an advantage on the final materials suitable for bone replacement, in terms of adsorptive activity, drug delivery system, etc. Compared to other synthesis techniques, hydrothermal processing (refers to a synthesis in aqueous solution at elevated pressure and temperature, in a closed system) has the ability to precipitate the hydroxyapatite from overheated solution, regulating the rate and uniformity of nucleation, growth, and maturation, which affect size, morphology, and aggregation of the crystals. This chapter wants to provide an overview of realization of nanosized hydroxyapatite-based bioceramics (e.g., powder and 3D structures) with desired morphology of crystallites, by hydrothermal processing. In this way, some critical hydrothermal parameters fundamental on the control of the crystal shape and dimension (pH, temperature, starting precursors, etc.)
