Biomaterials Commons^™

Crevice Corrosion Mechanisms Of Cocrmo Alloys In Orthopedic Implants: Retrieval Analysis, Nano-Tribocorrosion And Cellular Responses, Hwaran Lee

All Dissertations

Mechanically assisted corrosion and non-mechanically (chemically) driven corrosion in modular junctions of orthopedic implants using cobalt-chromium-molybdenum (CoCrMo) alloys remain clinical concerns and may contribute to implant failure. The underlying corrosion mechanisms are not yet fully understood, leaving a critical research gap. We hypothesized that corrosion in modular junctions may be driven by aggressive local environments, including fretting, metal ion release (cobalt ion, Co²⁺), low pH and reactive oxygen species (ROS). This dissertation aims to (1) analyze corrosion modes and potential causes in modular junctions; (2) identify chemically driven corrosion modes on CoCrMo alloys using simulated inflammatory modular taper …

Comparison Of Milling Cutting Forces In Synthetic And Biological Cancellous Bone, Matthew Christopher Hartwell

Masters Theses

In many orthopedic and dental interventions, the cutting and removal of bone is necessary. Therefore, it is of the utmost importance that the tools used during these procedures are designed and tested with biological bone or a bone surrogate material that machines the same way as biological bone. To avoid the cost, hazard, and inconsistency of biological cadaveric bone or animal models, many biological engineering firms use bone surrogate material made of glass fiber filled epoxy and polyurethane foam. Although these materials may mimic the elongation of cortical and cancellous bone, respectively, the match of machinability of the bone is …

Investigating The Effects Of Collagen Alignment And Tricalcium Phosphate Incorporation On Osteoblast Cell Response, Kathryn Elizabeth Bock

Theses and Dissertations

Every year, over 20 million people globally are affected by bone tissue loss due to disease or trauma. Bone tissue engineering (BTE) is touted as a promising approach to promote bone tissue repair and regeneration. In this realm, development of collagen-based scaffolds incorporated with a bioceramic is often attempted to generate tissue scaffolds that resemble the organic and inorganic composition of native bone. In addition, a variety of different collagen processing techniques have been employed to produce anisotropically aligned scaffolds that can provide the essential biochemical and structural cues to guide cell response. While there have been numerous studies on …

Recent Advances In Bone Research 2022 Edition, Jean-Philippe Berteau, Laurent Pujo-Menjouet

Publications and Research

More and more scientific and engineering applications in bone research make pivotal advances in treating patients with orthopedics issues. Hence, bone research in the 21st century combines, inter alia, biology, chemistry, mathematics, and mechanics with complementary characteristics that help a holistic approach to bone-related pathologies. Nowadays, it is hard to connect new evidence when jargoning and money remain two significant obstacles to sharing knowledge. “Recent Advances In Bone Research” is a free book – no money involved at any stage - that combines the most recent efforts in bone research from several experts with different backgrounds, every expert seeks to …

Computational Bone Mechanics Modeling With Frequency Dependent Rheological Properties And Crosslinking, Timothy G. Moreno

Master's Theses

Bone is a largely bipartite viscoelastic composite. Its mechanical behavior is determined by strain rate and the relative proportions of its principal constituent elements, hydroxyapatite and collagen, but is also largely dictated by their geometry and topology. Collagen fibrils include many segments of tropocollagen in staggered, parallel sequences. The physical staggering of this tropocollagen allows for gaps known as hole-zones, which serve as nucleation points for apatite mineral. The distance between adjacent repeat units of tropocollagen is known as D-Spacing and can be measured by Atomic Force Microscopy (AFM). This D-Spacing can vary in length slightly within a bundle, but …

Optimal Parameter Values For Accurate And Repeatable Nanoindentation Of Human Trabecular Bone, Stephen Matthew Kmak

Master's Theses

Nanoindentation techniques have not been standardized for use on bone tissues, making comparison of bone material properties obtained via nanoindentation across studies difficult and unreliable. This study determined a set of optimal parameter values for thermal drift correction time, dwell time, and loading rate that can be used to obtain accurate and repeatable material properties from human femoral trabecular bone through experimentation and statistical analysis. All testing was conducted using a single nanoindenter on a single trabeculae, with the assumption that material properties within the individual trabeculae were internally consistent. Parameters not of interest during this study, such as ambient …

Osteon Mimetic Scaffolding, Janay Clytus

Senior Theses

The purpose of this research is to provide an alternative to naturally derived bone grafts. There is a gap in the supply of donors and the demand of bone tissue. Artificial scaffold creation can work as an implant and decrease the shortage of bone grafts and increase the range of injuries that can be repaired. Current research focuses on optimizing mechanical properties such as porosity, improving vascularization using cells, and generating osteoconductivity. For osteodifferentiation, mesenchymal stem cells (MSCs) can differentiate into mesodermal lineages such as chondrocytes, osteoblasts, adipocytes, and tenocytes by supplementing cultures with lineage-specific soluble factors (Marchetti). Co-culturing ECFCs …

An Injectable Stem Cell Delivery System For Treatment Of Musculoskeletal Defects, Shirae Leslie

Theses and Dissertations

The goal of this research was to develop a system of injectable hydrogels to deliver stem cells to musculoskeletal defects, thereby allowing cells to remain at the treatment site and secrete soluble factors that will facilitate tissue regeneration. First, production parameters for encapsulating cells in microbeads were determined. This involved investigating the effects of osmolytes on alginate microbead properties, and the effects of alginate microbead cell density, alginate microbead density, and effects of osteogenic media on microencapsulated cells. Although cells remained viable in the microbeads, alginate does not readily degrade in vivo for six months. Therefore, a method to incorporate …

Finite Element Analysis Of The Application Of Ultrasound-Generated Acoustic Radiation Force To Biomaterials, Nicole J. Piscopo

Honors Scholar Theses

While most bone fractures can heal simply by being stabilized, others can take a longer time to rejoin or they could fail to merge back together completely. Numerous studies have shown the positive effects that ultrasonic therapy have had on delayed-union and non-union bone fracture repair but little is known as to what specific biological mechanisms are at play. Ultrasound may be a valuable tool for bone tissue regeneration at these fracture sites using a tissue engineering approach, however, more must be understood about its impact on stimulating tissues to heal before this can be a reality. For that reason, …

A Local, Sustained Delivery System For Zoledronic Acid And Rankl-Inhibitory Antibody As A Potential Treatment For Metastatic Bone Disease, Rohith Jayaram

Theses and Dissertations--Biomedical Engineering

Cancerous solid tumors can migrate and lead to metastatic bone disease. Drugs prescribed to reduce bone resorption from metastasis, such as zoledronic acid and the RANKL-inhibitory antibody Denosumab, cause side effects such as osteonecrosis of the jaw when delivered systemically. This project used two biocompatible materials, acrylic bone cement (PMMA) and poly(lactic-co-glycolic acid) (PLGA), to incorporate and sustain release of anti-resorptive agents. Results showed similar mechanical properties for acrylic bone cements loaded up to 6.6% drug by weight. Results showed sustained zoledronic acid release for 8 weeks from both systems, with PMMA releasing up to 22% of loaded drug and …

Modeling The Zimmer Fitmore And Ml Taper Implantation, Tyler Kazuo Franklin

Master's Theses

With more young adults requiring total hip

arthroplasties the need for bone saving implants becomes

more important. The Zimmer Fitmore is a new bone saving

implant that utilizes an implantation technique that

reduces the damage to the muscle tissue allowing for

patients to have a short recovery time as well as a new

design that allows it to rest on the medial cortex. There

has been anecdotal evidence that this device leads to early

revision within six months of implantation due to failures

occurring in the medial cortex. The main goal of this

study was to computationally model the Zimmer …

Current Concepts Review - Corrosion Of Metal Orthopaedic Implants, Joshua J. Jacobs, Jeremy L. Gilbert, Robert M. Urban

Biomedical and Chemical Engineering - All Scholarship

No abstract provided.

Projection Effect Errors In Biomaterials And Bone Research, K. N. Bachus, R. D. Bloebaum

Cells and Materials

Micoradiography and backscattered electron (BSE) imaging are techniques used to investigate the morphologic, histometric, and mineral content changes at the bone/biomaterials interface. Investigators have shown that the superimposition of multiple tissue layers can cause errors with both the morphologic observations and the histometric measurements of bone. The objective of this study was to document errors in the bone mineral content measurements associated with overlapping tissues.

Using a digital image analysis system, microradiographic and BSE images from canine cortical and cancellous bone were captured and analyzed. The results of this study showed that microradiography had more projection effect errors associated with …