Electrical properties of hydroxyapatite

Abstract

Despite being one of the mostly studied biomaterials for orthopedic, dental, protein purification and stem cell applications, electrical properties of hydroxyapatite has received only limited attention. Since the prediction in 2005 of the possibility of piezo and pyroelectricity in hydroxyapatite several theoretical and experimental works in this field may lead to new understandings of electrical behaviors of calcified tissues in vertebrates. Also, the ability of creating discrete electrostatic domains on nanocrystalline films of hydroxyapatite will open the possibility of understanding how surface charge influences biological interactions. The outlook for future endeavours in this field will be discussed.

Calcium orthophosphates (CaPO 4 ): Occurrence and properties

“…A shell model was developed to study the lattice dynamics of HA (Calderin et al 2005), while a cluster growth model was created to illustrate its growth (Onuma and Ito 1998). Polarization characteristics (Tanaka et al 2010a, b), pyroelectric (Tofail et al 2009(Tofail et al , 2015 and piezoelectric (Tofail et al 2015;Bystrov 2015) properties of HA as well as diffusion of protons inside the HA crystal lattice (Yashima et al 2014) were investigated. The thermodynamic properties of HA and other types of orthophosphate-based apatites were summarized (Drouet 2015).…”

Ferroelectric polarization of hydroxyapatite from density functional theory

“…16 Although being one of the prevalently studied biomaterials for orthopedic, dental, protein purication and stem cell applications, there is less research done on the electrical properties of hydroxyapatite. 19 Since the prediction of the possibility of piezo-and pyro-electricity in hydroxyapatite, several experimental and theoretical reports have led to the new level of understanding the electrical behaviors of calcied tissues in vertebrates. 19 Both bone and dentine show interesting electrical properties foremost of which is piezoelectricity, i.e.…”

“…19 Since the prediction of the possibility of piezo-and pyro-electricity in hydroxyapatite, several experimental and theoretical reports have led to the new level of understanding the electrical behaviors of calcied tissues in vertebrates. 19 Both bone and dentine show interesting electrical properties foremost of which is piezoelectricity, i.e. the possibility of generating electrical charge at the surface when it is subjected to a stress.…”

Calcium orthophosphate bioceramics

“…Occasionally, an interest to both electric/dielectric [304,[377][378][379][380][381][382][383][384][385][386][387][388][389][390] and piezoelectric [391,392] properties of CaPO 4 bioceramics is expressed. For example, a surface ionic conductivity of both porous and dense HA bioceramics was examined for humidity sensor applications, since the room temperature conductivity was influenced by relative humidity [378].…”

“…There is an interesting study on the interaction of a blood coagulation factor on electrically polarized HA surfaces [423]. Further details on the electric properties of CaPO 4 -based bioceramics are available in literature [304,389,390,[424][425][426][427][428]. [498].…”