Calcium phosphates with apatitic structure (or apatites) constitute the mineral
part of hard tissues in vertebrates. The structure and properties of apatites open several
possibilities in medical sciences and also play an important role in living organisms for
biomineralization processes. One of the most interesting characteristics of apatitic
calcium phosphate is its surface reactivity and capability to exchange mineral ions and
small molecules upon interaction with surrounding fluids. Such surface properties can
be exploited and tailored in materials science to obtain nanostructured and bioactive
biomaterials, in particular in view of drug delivery and tissue engineering.
In this chapter, biogenic calcium phosphates will be first presented, giving details about
the principal characteristics of bone, tooth and pathological calcifications where calcium
phosphates are present. We will then expose a general presentation of calcium
phosphates used as biomaterials, especially in terms of ceramics, cements and coatings.
Then the surface chemistry of synthetic and biogenic calcium phosphates will be
examined in detail, summarizing the principal surface characteristics of biomimetic
nanocrystalline apatites and of some other calcium phosphates of biological interest. In
a subsequent part of the chapter, we will discuss surface interaction processes between
calcium phosphate and molecules of biological interest: on one hand in the case of
biomolecules (including peptides and proteins) for biomaterials development and
biomineralization aspects, and on the other hand in the case of bioactive molecules for
specific applications in drug delivery. Finally, we will conclude this chapter by
presenting some in vitro and in vivo results obtained on functionalized calcium
phosphates with the aim to develop innovative drug delivery devices.
Keywords: Calcium phosphates, biomineralization, nanocrystalline apatites, bone
tissue engineering, drug delivery.
