Hydroxyapatite (HA), a material proven to be biocompatible within the human body, has been produced to a high level of purity. This material has been applied as a coating on Ti-6Al-4V alloy by using the air plasma spraying technique. The coat was characterizted with SEM, XRD, FTIR and Raman spectroscopy methods to consist of a mixture of calcium phosphates including HA mainly and traces of tric...

An animal's hard tissue is mainly composed of crystalline calcium phosphate. In vitro, small changes in the reaction conditions affect the species of calcium phosphate formed, whereas, in vivo, distinct types of crystalline calcium phosphate are formed in a well-controlled spatiotemporal-dependent manner. A variety of proteins are involved in hard-tissue formation; however, the mechanisms by wh...

Phosphocitrate [PC] is a powerful inhibitor of biological crystallization and a potential disease modifying drug for crystal associated diseases such as crystals associated osteoarthritis [OA]. Recently, it has been reported that a new PC complex salt, calcium sodium PC [CaNaPC], is much more powerful than its precursor, sodium PC [NaPC], in reducing the size of chemically-induced calcified pla...

The present in vitro study created nanometer crystalline hydroxyapatite (HA) and amorphous calcium phosphate for novel orthopedic applications. Specifically, nano-crystalline HA and amorphous calcium phosphate nanoparticles were synthesized by a wet chemical process followed by hydrothermal treatment for 2 hours at 200 degrees C and 70 degrees C, respectively. Resulting particles were then pres...

A cogent understanding of the microstructure, and indeed nano-structure, of hydroxyapatite (HA) and the interface between Ti-6Al-4V and HA is crucial to its appropriateness as a biomaterials. This paper reports the analysis of plasma-sprayed HA/Ti-6Al-4V composites by transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) to elucidate the intricate nature of...

Recent experimental evidence suggests that octacalcium phosphate (OCP) is a necessary precursor to hydroxyapaptite in the amorphous-crystalline transformation that occurs after the spon..: taneous precipitation of calcium phosphate in the pH range 7.00-9.25. The transformation appears to occur by heterogeneous nucleation of OCP by the initially formed amorphous calcium phosphate (ACP) phase. AC...

The majority of human kidney stones are comprised of multiple calcium oxalate monohydrate (COM) crystals encasing a calcium phosphate nucleus. The physiochemical mechanism of nephrolithiasis has not been well determined on the molecular level; this is crucial to the control and prevention of renal stone formation. This work investigates the role of phosphate ions on the formation of calcium oxa...

The hybrid nanoparticles of amorphous calcium phosphate (ACP)-catalase (CAT) developed by in situ biomineralization can create a stable semi-aqueous nanoscale environment for entrapped proteins against thermal denaturation. This finding indicates the importance of an amorphous mineral phase in the preservation of organic macromolecules.

Aqueous micelles of the multi-protein calcium phosphate complex, casein, were treated at 60°C and pH 7 over several months. Although partial dissociation of the micelles into 12 nm sized amorphous calcium phosphate (ACP)/protein nanoparticles occurred within a period of 14 days, crystallization of the ACP nanoclusters into bundles of hydroxyapatite (HAP) nanofilaments was not observed until aft...