Dissertation
EFFECTS OF DOPANTS ON PHYSICAL, MECHANICAL, IN VITRO AND IN VIVO OSTEOBLASTOGENIC AND OSTEOCLASTOGENIC PROPERTIES OF CALCIUM PHOSPHATE CERAMICS FOR BONE TISSUE ENGINEERING AND VITAMIN C DELIVERY
Doctor of Philosophy (PhD), Washington State University
01/2016
Handle:
https://hdl.handle.net/2376/111413
Abstract
The objective of this research is to understand the effects of different dopants such as lithium (Li), iron (Fe), silicon (Si), strontium (Sr), and magnesium (Mg) in calcium phosphate based ceramics (CaP) on their physical and mechanical properties, as well as in vitro and in vivo bone formation. The release behavior of vitamin C as a natural biomolecule from tricalcium phosphate (TCP) samples was also investigated. The hypothesis of this research is that the presence of different trace elements in CaPs influences their phase stability, microstructure, mechanical strength, and both in vitro and in vivo bioactivity. We also hypothesize that the gradual release of vitamin C from TCP can be controlled by polycaprolactone (PCL) coating and alters the interaction between TCP and bone forming cells.
Presence of Li and Fe stabilized the β-TCP structure and increased its compressive strength. While addition of 0.15 wt. % Li increased the osteoblast cell proliferation, Fe addition enhanced the proliferation and differentiation of osteoblast cells in dose dependent manner. Addition of Si to brushite cement (BrC) activated the osteoclastogenesis and induced osteogenesis and vasculogenesis in vivo.
Initial burst release of vitamin C from TCP samples was found at both pH of 5.0 and 7.4 and applying PCL coating decreased the cumulative release of vitamin C. Gradual release of vitamin C increased the proliferation of osteoblast cells in vitamin C and/or PCL loaded samples regardless of vitamin C concentration. However, the differentiation of cells was only induced in samples loaded with 2 µg of vitamin C.
Addition of Sr and Mg to TCP and hydroxyapatite (HA) activated the signaling pathways related to enhanced osteoblastogenesis. In addition, the bone remodeling was induced in presence of Sr and Mg in osteoblast-osteoclast co-culture system. In dense TCP structures, addition of Sr enhanced the proliferation and differentiation of mesenchymal stem cells at early time points while Mg addition increased the cellular activity gradually over the course of 21 days. Our results show that presence of dopants has significant effect on the physical, mechanical, in vitro and in vivo osteogenesis CaPs for bone tissue engineering applications.
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Details
- Title
- EFFECTS OF DOPANTS ON PHYSICAL, MECHANICAL, IN VITRO AND IN VIVO OSTEOBLASTOGENIC AND OSTEOCLASTOGENIC PROPERTIES OF CALCIUM PHOSPHATE CERAMICS FOR BONE TISSUE ENGINEERING AND VITAMIN C DELIVERY
- Creators
- Sahar Vahabzadeh Vahabzadeh
- Contributors
- Susmita Bose (Advisor)Amit Bandyopadhyay (Committee Member)Anita Vasavada (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Mechanical and Materials Engineering, School of
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Number of pages
- 244
- Identifiers
- 99900581634801842
- Language
- English
- Resource Type
- Dissertation