Dissertation
DESIGNING MULTI-SCALE FUNCTIONALITIES IN 3D PRINTED TITANIUM AND TANTALUM METAL IMPLANTS TOWARD EARLY-STAGE OSSEOINTEGRATION
Washington State University
Doctor of Philosophy (PhD), Washington State University
01/2021
DOI:
https://doi.org/10.7273/000001849
Handle:
https://hdl.handle.net/2376/119940
Abstract
In recent years, advanced materials research in implantable metallic devices for bone tissue engineering has significantly influenced orthopedic and dental applications. However, these devices' practical usage still has several challenges concomitant to acquiring and retaining biological fixation at the implant site. An important goal of current biomaterials research is to induce and accelerate bone tissue growth around the implants. In addition to rapid wound healing at the surgery site, these implants must have adequate biomechanical characteristics. This dissertation elaborates on investigating the effect of developing surface charge on Titania (TiO2) nanotubes and assessed it’s in vitro and in vivo early-stage osseointegration. Growing TiO2 nanotubes on commercially pure titanium led to the introduction of bioactivity in an otherwise bioinert material via physical anchoring surface for the bone tissue to bond. Surface charge enhances makes the surfaces more hydrophilic and better suited for cellular interactions. We have further explored the effect of compositional modifications through alloying titanium (Ti) with tantalum (Ta) to induce bioactivity. Comparisons among porous and dense Ti-Ta with and without surface modification through TiO2 nanotubes were drawn to assess the variation in cellular interactions and in vivo early-stage bone regeneration.
Our results indicate a stored charge of 37.15 ± 14 mC/cm2 for TNT surfaces. Histomorphometric analyses show ~40% increase in mineralized bone formation around the TNT-P implants than the TNTs at 5 weeks, indicative of accelerated bone remodeling cycle. We have shown comparable performance of porous Ta and surface-modified porous Ti64 implants towards early-stage osseointegration at 5 weeks post-implantation through seamless bone-material interlocking. However, a continued and extended efficacy of porous Ta is found in terms of higher osteoid formation at 12 weeks post-surgery. Alloying Ta with Ti during additive fabrication resulted in an overall decrease in elastic modulus of Ti (Ti: 110GPa, 25Ta: 63± 5.5 GPa), helping circumvent any mechanical instability that can arise from a very high mismatch in modulus. Consequently, porous Ti-Ta alloys exhibited increased osseous tissue formation at the implant-bone interface (70% trabecular bone formation in rabbit femur), providing evidence of the superior biological performance of the material towards early-stage bone healing.
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Details
- Title
- DESIGNING MULTI-SCALE FUNCTIONALITIES IN 3D PRINTED TITANIUM AND TANTALUM METAL IMPLANTS TOWARD EARLY-STAGE OSSEOINTEGRATION
- Creators
- Indranath Mitra
- Contributors
- Amit Bandyopadhyay (Advisor)Susmita Bose (Committee Member)William S. Dernell (Committee Member)
- Awarding Institution
- Washington State University
- Academic Unit
- Graduate School
- Theses and Dissertations
- Doctor of Philosophy (PhD), Washington State University
- Publisher
- Washington State University
- Number of pages
- 182
- Identifiers
- 99900606549401842
- Language
- English
- Resource Type
- Dissertation