The repair of damaged or diseased bone tissue often requires the use of metallic implants which form an interface with the surrounding bone tissue. Understanding this interface is important for improving the outcomes of implant placement and overall health of patients. Bone is a composite material of organic collagen fibrils and inorganic mineral phases that have structural variations across multiple length scales. This heterogeneous and hierarchical nature poses characterization challenges for (i) understanding bone, (ii) creating biomaterial structures that mimic it, and (iii) approaches for evaluating biomaterials. These challenges formed the basis for the three papers presented in this thesis. In Chapter 3, leporine bone was examined using atom probe tomography (APT) to visualize in vivo mineralized collagen fibrils, their chemical composition, and spatial arrangement in 3D with sub-nanometer accuracy. This provided new insight into the location of biomineral with respect to collagen and demonstrated the power of APT for understanding collagen-mineral arrangement. In Chapter 4, commercially pure titanium was laser ablated to generate periodic surface structures inspired by the periodicity of collagen. Three different periodicities were generated with submicron-scale roughness and a high degree of reproducibility. All the surfaces were non-cytotoxic and encouraged cells to adhere perpendicular to the orientation of the surface structures. In Chapter 5, a simple five-minute room temperature ionic liquid treatment was developed to investigate the same laser-ablated titanium periodic structures with osteoblast-like cells adhered. The development of this technique fulfills an important niche in biological imaging by allowing for simultaneous and repeated visualization of submicron surface features and wet cells. Therefore, the combined impact of this thesis is novel imaging and biomaterials evaluation strategies to (i) improve understanding of bone structure; (ii) leading to bioinspired biomaterials design; and (iii) new methods for simultaneous biological and biomaterials evaluation. / Thesis / Doctor of Philosophy (PhD) / Bone implant devices are required to treat, augment, or replace bone tissue in dental and orthopaedic applications. These, often metallic, implanted devices have success when a structural and functional connection with natural bone tissue is created, a phenomenon known as osseointegration. Good osseointegration is required to ensure stability of the implant without compromising the quality of life of the patient. In order to improve osseointegration of biomaterials, both sides of the interface, i.e. the bone and implant surface, must be better understood. This thesis focuses on exploring methods to improve the evaluation and understanding of both bone structure at the nanoscale and structured metallic implant surfaces for the design of bone-interfacing biomaterials.
| Identifer | oai:union.ndltd.org:mcmaster.ca/oai:macsphere.mcmaster.ca:11375/25134 |
| Date | January 2019 |
| Creators | Lee, Bryan E.J. |
| Contributors | Grandfield, Kathryn, Biomedical Engineering |
| Source Sets | McMaster University |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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