Dissertation
Nanostructured hydroxyapatite and tricalcium phosphate based ceramics for bovine serum albumin protein delivery and bone implants using microwave sintering
Washington State University
Doctor of Philosophy (PhD), Washington State University
08/2008
DOI:
https://doi.org/10.7273/000005851
Abstract
The objective of this study was to investigate the potential of nanocrystalline hydroxyapatite [Ca10(PO4)6(OH)2, HA] and [beta]-tricalcium phosphate [[beta]-Ca3(PO4)2, [beta]-TCP] for controlled protein release and bone implant material. HA and [beta]-TCP nanopowders were synthesized using reverse micelle as template system. By varying synthesis parameters, [beta]-TCP nanopowders were synthesized with a particle size between 32 and 135 nm, different aspect ratios, and BET specific average surface area varying between 57 and 103 m2/g. Bovine serum albumin protein (BSA) release from [beta]-TCP and CDHA nanopowders was studied by ex situ adsorption of bovine serum albumin (BSA) onto nanoparticle surface. HA-BSA nanopowders were also synthesized by in situ co-precipitation technique. 2 mol% Zn2+ and Mg2+ were used as dopants to synthesize Zn2+ /Mg2+ doped HA-BSA nanopowders by in situ synthesis route. BSA release rate from ex situ synthesized [beta]-TCP-BSA nanopowders found to be faster compared to that from CDHA-BSA nanopowders. For in situ synthesized HA-BSA nanopowders, BSA release rate from Zn doped HA nanopowder found to be the highest, whereas much slower and sustained protein release was observed from in situ synthesized HA-BSA nanocarriers. Nanostructure HA compacts were processed using microwave sintering with ultrafine microstructures and improved mechanical properties for orthopedic implant applications. Nanostructured sintered HA compact showed superior compressive strength (395 36 MPa), indentation hardness (8.4 0.4 GPa) and indentation fracture toughness (2.0 0.1 MPa m1/2). HA compacts were assessed for cell material interaction using SEM, MTT assay and confocal microscopy after culturing human osteoblast cell line on HA disc surface for 1, 5 and 11 days. MTT assays showed higher number of living cell and faster proliferation on nano HA surface. Also osteoblast cells on nano HA surface expressed significantly higher amount of vinculin and alkaline phosphatase (ALP) protein markers for adhesion and differentiation respectively. This study showed that BSA release rate can be controlled by varying particle size, surface area, phase composition of HA and [beta]-TCP nanocarriers. Nanostructured HA exhibited superior mechanical strength and bioactivity com ared to micron grained HA compacts.
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Details
- Title
- Nanostructured hydroxyapatite and tricalcium phosphate based ceramics for bovine serum albumin protein delivery and bone implants using microwave sintering
- Creators
- Sudip Dasgupta
- Contributors
- Susmita Bose (Chair)
- Awarding Institution
- Washington State University
- Academic Unit
- Materials Science and Engineering Program
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 211
- Identifiers
- 99901055037801842
- Language
- English
- Resource Type
- Dissertation