The remarkable properties of bone derive from a highly organized arrangement of coaligned nanometer-scale apatite platelets within a fibrillar collagen matrix. The origin of this arrangement is poorly understood and the crystal structures of hydroxyapatite (HAP) and the nonmineralized collagen fibrils alone do not provide an explanation. Moreover, little is known about collagen-apatite interact...

Thermally processed hydroxyapatite coatings used on dental implants and hip prostheses for enhanced fixation may typically consist of a number of chemical and structural phases. These phases affect coating performance and tissue attachment. Hydroxyapatite was plasma sprayed to examine the phase evolution during processing. Coatings were examined with X-ray diffraction and elemental analysis. Re...

AIMS The study evaluated the relationship between cardiovascular risk factors (CRF), gene polymorphism, calcification and fibrosis of stenotic aortic valves. METHODS AND RESULTS The calcium content of 187 excised stenotic aortic valves was determined using atomic absorption spectroscopy. Hydroxyproline content was quantified. Left-heart catheterization was performed. CRF and genotypes of the ...

nanocrystalline hydroxyapatite was precipitated from calcium hydroxide and phosphoric acid. effects of precipitation temperature and different calcium to phosphate ratios (ca/p) on the obtained powders were investigated. characteriza-tion of the powders was performed using xrd and ftir spectra, scanning electron microscopy, and transmission electron microscopy. increase in precipitation tempera...

Hydroxyapatite Ca10(PO4)6(OH)2 (HAp) and calcium phosphate ceramic materials and coatings are widely used in medicine and dentistry because of their ability to enhance the tissue response to implant surfaces and promote bone ingrowth and osseoconduction processes. The deposition conditions have a great influence on the structure and biofunctionality of calcium phosphate coatings. Corrosion proc...

Titanium has an osseointegrative property, while hydroxyapatite has an osteoconductive property. It remains a matter of controversy among researchers whether hydroxyapatite has higher osteoblast compatibility than titanium. Here, we compared the activities between osteoblasts cultured on titanium and those cultured on hydroxyapatite. An osteoblast-like cell line, MC3T3-E1, was cultured on machi...

Objective: The aim of this paper was to assess the relationships among chemical, phase and structural composition and etiopathogenic factors of non-infectious phosphate calculi formed in patients with low and high urinary phosphate concentrations, and to characterize the mechanism of their formation related on biochemical results. Material and Methods: Twelve samples of phosphate renal calculi ...

Porous blocks of calcium hydroxyapatite ceramic were evaluated as delivery systems for the sustained release of antibiotics. We tested gentamicin sulphate, cefoperazone sodium, and fiomoxef sodium in powder form placed in a cylindrical cavity in calcium hydroxyapatite blocks, using in vitro studies of elution and in vivo studies in rats. Gentamicin sulphate gave a maximum concentration within t...

objective(s):  although several chemical and physical methods for gene delivery have been introduced, their cytotoxicity, non-specific immune responses and the lack of biodegradability remain the main issues. in this study, hydroxyapatite nanoparticles (nps) and 1,2-dioleoyl-sn-glycero-3-phosphoethanol​amine (dope)-modified hydroxyapatite nps was coated with antisense oligonucleotide of e6 mrna...

Hydroxyapatite (HAp) ceramics based on calcium phosphates, chemical compounds being natural constructive element of bones is now regarded to be one of better implantation materials in osseous surgery and stomatology. HAp is poorly soluble and slowly resorbing in tissues material. Easiness of connecting of hydroxyapatite ceramics with other materials creates possibilities to produce new composit...