Morphological, physical and chemical characteristic of biocompatible nano-sized carbonate-substituted hydroxyapatite

Morphological, Physical and Chemical Characteristics of Biocompatible

Nano-Sized Carbonate-Substituted Hydroxyapatite

Trubitsyn M.A.1,а, Doan Van Dat2,b, Le Van Thuan3,с, Gabruk N.G.4,d

,

Oleynikova I.I5,e, Shuteeva T.A.6,f

1

Belgorod State National Research University, 85 Pobeda Str., Belgorod, Russia

[email protected], b

[email protected], c

[email protected], d

[email protected],

e

[email protected], f

[email protected]

Keywords: nano-sized hydroxyapatite, modified hydroxyapatite, degree of substitution,

morphology, specific surface area, biocompatibility, electron microscopy.

Abstract. Hydroxyapatite and compounds based on it are important and promising inorganic

biomaterials that can be used in dentistry and bone surgery due to its biocompatibility with the bone

tissue of a living organism. The paper presents the synthesis of carbonate-substituted

hydroxyapatite powders and studies their morphology, physical and chemical characteristics and

biocompatibility in vivo. The synthetic carbonate-substituted hydroxyapatite are biocompatible, and

they do not cause degenerative changes in the surrounding tissues. The result of this research

suggests that the carbonate-substituted hydroxyapatite is promising biomaterial for orthopedic and

dental prosthetics.

Introduction

In recent years, the increased interest in the calcium phosphate materials, and more

particularly to a calcium can be explained by their unique properties and a wide range of possible

applications and implementations as in the instrumentation, and in human medicine. Among the

biomaterials used in bone surgery and deltal a hydroxyapatite Ca10(PO4)6(OH)2 (HA) takes a special

place, it can be regarded, with some limitations, as a crystallochemical analogue of the main

mineral constituent of human and animal skeletal, he successfully serves as the base component of

synthetic materials for orthopedics and dentistry [1]. However, the hydroxyapatite has a low rate of

resorption in contact with interstitial fluid in the body. Regenerative approach requires modern

biomaterials primarily accelerate the process of accretion, implant replacement with new bone and

the implant material osteostimulation action [2]. So now as osteoplastic material when filling bone

defects a synthetic carbonate-substituted hydroxyapatite (CHA) is often used, for it reproduces the

structure of the bone compared to unmodified HA and has increased biosorption due

microdistortions encountered when entering the carbonate ion in apatite structure [3].

Materials and Methods

In this work unmodified [4] and modified [5] HA were synthesized by precipitation from

aqueous solution. The starting materials include: the saturated solution of calcium hydroxide, the

solution of phosphoric acid and ammonium carbonate.

These reactions are illustrated by the following equations:

(10-d)Са(OH)2 + (6-х)H3PO4 + x(NН4)2CO3 = Са10-d(РО4)6-x,(CO3)x(ОН)2+x-2d↓ + 2xNH3↑ + (18-

x)Н2О

where х=0.25; 0.5; 0.75; 1; 1.5; 2 - degree of carbonate substitution in the crystal structure

of HA.

Microscopic morphological examination of the samples in hydrogel form was performed on

a JEM 2100 transmission electron microscope (JEOL Ltd., Japan) with a resolution - 0.2 nm. The

accelerating tension of an electron gun was 200 kV, the cathode material is a single crystal of

lanthanum boride (LaB6), leakage current at the switched on cathode - 101.5 mA. To conduct a

research in the transmission mode the samples were applied onto a copper grid with circular

Advanced Materials Research Vol. 1040 (2014) pp 97-102 Submitted: 13.05.2014

© (2014) Trans Tech Publications, Switzerland Revised: 09.06.2014

doi:10.4028/www.scientific.net/AMR.1040.97 Accepted: 02.07.2014

All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of TTP,

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