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Preparation and Property of Calcium Phosphate Bone Cement Containing Carboxymethyl Chitosan

Author: HanZuoZuo
Tutor: ZhouChangRen
School: Jinan University
Course: Materials Science
Keywords: carboxymethyl chitosan calcium phosphate cement phosphate buffered solution pH value
CLC: TQ172
Type: Master's thesis
Year: 2007
Downloads: 257
Quote: 1
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Abstract

Many reports on calcium phosphate cement showed that chitosan as an additive could improve the clinical applicability. However, chitosan can just be dissolved in acidic solution, which affected the property of the cements to composite with cells. In order to solve this proplem, we used in this paper a kind of water-soluble chitosan derivatives—carboxymethyl chitosan as an additive, and the phosphate buffered solution as the liquid solvent. On the basis of controlling the early pH value when setting, we made up a new type of calcium phosphate cement with non-acidic liquid.First, tetra-calcium phosphate (TTCP), anhydrous calcium hydrogen phosphate(DCPA), and carboxymethyl chitosan(CMC) needed in this research were prepared according to mature technologies. By XRD, FTIR and the determination of molecular weight, the degree of deacetylation(DD) and the degree of substitution(DS), the results showed that TTCP and DCPA had high purity, and TTCP did not contain CaO and HAP; N,O-carboxymethyl chitosan was prepared with the molecular weight of 4.61×10~5, and the degree of deacetylation and that of substitution was 94% and 0.94 respectively.By the research of chemical and physical properties of calcium phosphate cement with CMC as additive, we knew that addition of CMC in a limitied concentration scope(＜4%) could decrease the setting time effectively and raise the compressive strength; The pH value studies showed that the major factor which controlled the change of pH value was the phosphate buffered solution, and CMC gave little impact to slurry pH changes.The cement was immersed in the simulated body fluid(SBF) to test bioactivity. By the means of ICP, FTIR, SEM and XRD, the results showed that calcium phosphate cement contained CMC could induce deposition of Ca, P ions in the solution on the surface of materials, which demonstrated excellent bioactivity. HAP which was generated on the surface of materials contained a part of bone-like carbonated hydroxyapatite. We also knew from this study that the phase composition after CPC setting was not affected whether CMC was added or not. By the preliminary evaluation of biocompatibility, we got that calcium phosphate cement with CMC as additive had no cytotoxicity and meet the requirements of hemolytic standards well, which was a kind of bone tissue repairing materials with good biocompatibility.

Preparation and Property of Calcium Phosphate Bone Cement Containing Carboxymethyl Chitosan

Abstract

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