Development of strontium doped hydroxyapatite porous bodies for bone implantation /
Development of bioactive porous scaffolds that exhibits good interconnected porous structures and possesses mechanical properties compatible to host bone is a challenging task in the field of biomedical engineering. Hydroxyapatite (HA) is normally used for this purpose due to its bioactive character...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
Kuala Lumpur:
Kulliyyah of Engineering, International Islamic University Malaysia,
2011
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| Subjects: | |
| Online Access: | Click here to view 1st 24 pages of the thesis. Members can view fulltext at the specified PCs in the library. |
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| Summary: | Development of bioactive porous scaffolds that exhibits good interconnected porous structures and possesses mechanical properties compatible to host bone is a challenging task in the field of biomedical engineering. Hydroxyapatite (HA) is normally used for this purpose due to its bioactive characteristics and its compatibility to the human body. Interfacial hydroxyapatite porous bone however, posses lower mechanical strength, thus it needs to be doped or coated. In this study, strontium doped hydroxyapatite (SrHA) nanopowder was synthesized through a sol-gel method, where strontium concentrations were varied at 0, 2, 5, 10 and 15 mol%. The obtained gel was then dried and subsequently subjected to 900 ºC calcination. Morphological evaluation by FESEM measurement shows that the particles of the SrHA agglomerates are globular in shape with an average size of 1-2 μm in diameter while the primary particles have a diameter of 30-50 nm in average. The calcined powders contained hydroxyapatite phase only for all doping concentration except for the smallest doping concentration, 2 mol%, where β-TCP appeared as the secondary phase. This indicates that the substitution of Sr atoms for Ca atoms have stabilized the HA phase, leading to the inhibition of the appearance of β-TCP phase upon high temperature calcination. SrHA porous bodies were fabricated by using polymeric sponge method with various Sr concentrations. To prepare the porous samples, the synthesized SrHA powders was mixed with distilled water and appropriate amount of dispersing agent followed by drying in the ambient air and specific sintering process. The morphology and distribution of the macropores could be related to the starting powder crystallinity and morphology as well as to the rheological properties of the suspensions. The compressive strength of the materials was strongly influenced by the porosity, while there was almost no dependence on the crystallinity of the powder since XRD patterns showed high crystallinity of HA phase for all porous samples. Morphological evaluation by FESEM measurement revealed that the SrHA scaffolds were characterized by macro-micro interconnected porosity, which replicates the morphology of the cancellous bone. Compression test on the porous scaffolds revealed that doping 10 mol% of strontium in HA has increased the compressive strength by a factor of two compared to the undoped HA with 1.81±0.26 MPa at 41% porosity. |
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| Item Description: | Abstract in English and Arabic. "A thesis submitted in fulfilment of the requirements for the degree of Master of Science (Materials Engineering)."--On t.p. |
| Physical Description: | xvi, 120 leaves : ill. ; 30cm. |
| Bibliography: | Includes bibliographical references (leaves 110-120). |