The field of implantology is centred around interfacial interactions with the
surrounding bone tissue. Assessing the suitability of novel engineering materials as
implants for clinical application follows a preliminary workflow that can be
simplified into three main stages: (i) implant design, (ii) in vitro compatibility, and
(iii) in vivo compatibility. This thesis is subdivided to mirror each of these three
themes, with a specific focus on the multiscale features of the implant itself as well
as appositional bone tissue. In Chapter 3, a biomimetic approach to generate porous
metallic implants is presented, using preferential seeding in a 3D Voronoi
tessellation to create struts within a porous scaffold that mirror the trabecular
orientation in human bone tissue. In Chapter 4, cytocompatible succinate-alginate
films are generated to promote the in vitro activity of osteoblast-like cells and
endothelial cells using a methodology that could be replicated to coat the interior
and exterior of porous metals. In Chapter 5, two types of porous implants with
graded and uniform pore size are implanted into rabbit tibiae to characterize the
biological process of osseointegration into porous scaffolds. In Chapter 6, these
same scaffolds are probed with high-resolution 2D and 3D methods using scanning
transmission electron microscopy (STEM) and the first-ever application of plasma
focused ion beam (PFIB) serial sectioning to observe structural motifs in
biomineralization at the implant interface in 3D. This thesis provides new
knowledge, synthesis techniques, and development of characterization tools for
bone-interfacing implants, specifically including a means to: (i) provide novel
biomaterial design strategies for additive manufacturing; (ii) synthesize coatings
that are compatible with additively manufactured surfaces; (iii) improve our
understanding of mineralization process in newly formed bone, with the ultimate
goal of improving the osseointegration of implants. / Thesis / Doctor of Philosophy (PhD) / Metallic implants are widely used in dental and orthopedic applications but can be
prone to failure or incomplete integration with bone tissue due to a breakdown at
the bone-implant interface as defined by clinical standards. In order to improve the
ability of the implant to anchor itself into the surrounding bone tissue, it is possible
to use novel three-dimensional (3D) printing approaches to produce porous metals
with an increased area for direct bone-implant contact. This thesis examines
strategies to design porous implants that better mimic the structure of human bone,
possible coating materials to accelerate early bone growth at the implant interface,
and the microscale-to-nanoscale origins of bone formation within the interior of
porous materials.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/27720 |
| Date | January 2022 |
| Creators | Deering, Joseph |
| Contributors | Grandfield, Kathryn, Materials Science and Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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