Biomedical Engineering and Bioengineering Commons^™

Optimized 3d-Printing Of Carbon Fiber-Reinforced Polyether-Ether-Ketone (Cfr-Peek) For Use In Overmolded Lattice Composite, Ryan C. Ogle

Masters Theses

Current orthopedic implants are overwhelmingly composed from metallic materials. These implants show superior mechanical properties, but this can additionally result in stress shielding due to a modulus mismatch between the bone tissue and implanted device. Polymeric implants reduce this stress shielding effect but have much lower mechanical properties, limiting their use. Polylactic acid (PLA) is a widely used biodegradable thermoplastic polymer, however, its use has been limited by the polymer’s mechanical properties and rapid loss of strength during degradation in vivo. Polyether-ether-ketone (PEEK) is another common biocompatible polymer , with chemical and mechanical properties which make it a popular alternative …

The Influence Of Processing And Additives On Cellulose Nanofiber Properties For Orthopedic Application, Mitchell P. Chesley

Electronic Theses and Dissertations

Current orthopedics are separated into three different classes of materials, metals, polymers, and ceramics. While these devices have had success throughout the years they are not without their faults. Metallic devices for example are usually extraordinarily stiff when compared with the surrounding bone. This difference in stiffness induces localized stress-shielding promoting cortical atrophy, which can lead to osteoporosis. Polymers while having the capacity of being biodegradable and bioabsorbable also have the potential to incite localized demineralization and weakness in surrounding bone. A result of breakdown byproducts not efficiently being evacuated from the area, which additionally acts as catalysts expediating the …

Porous Scaffold And Soft Hydrogel Composite For Biomedical Applications, Matthew Dicerbo

Theses and Dissertations

Biophysical signals including stiffness and dimensionality influence a myriad of stem cell behaviors including morphology, mechanosensing, and differentiation. 2D stiff environments cause increased cellular spreading and induce osteogenic differentiation whereas 3D soft environments favor rounder cell morphologies attributed to a chondrogenic phenotype. The goal of this study is to create a composite that integrates these divergent biophysical signals within one system. This composite consists of a stiff and porous polycaprolactone (PCL) backbone that provides mechanical stiffness and a 2D environment. The PCL backbone is then perfused with mesenchymal stem cells (MSCs) and a soft methacrylated gelatin (GelMe) hydrogel to provide …

Electroactive Polymeric Composites To Mimic The Electromechanical Properties Of Myocardium In Cardiac Tissue Repair, Kaylee Meyers, Bruce Lee, Rupak Rajachar

Michigan Tech Publications

Due to the limited regenerative capabilities of cardiomyocytes, incidents of myocardial infarction can cause permanent damage to native myocardium through the formation of acellular, non-conductive scar tissue during wound repair. The generation of scar tissue in the myocardium compromises the biomechanical and electrical properties of the heart which can lead to further cardiac problems including heart failure. Currently, patients suffering from cardiac failure due to scarring undergo transplantation but limited donor availability and complications (i.e., rejection or infectious pathogens) exclude many individuals from successful transplant. Polymeric tissue engineering scaffolds provide an alternative approach to restore normal myocardium structure and function …

Engineering Bacterial Cellulose Scaffold And Its Biomimetic Composites For Bone And Cartilage Tissue Regeneration, Pelagie Marlene Favi

Doctoral Dissertations

A very promising approach to quickly and safely restore normal function to extensively damages and diseases bone and cartilage tissues is the regeneration of these injured tissues using an engineered support scaffold. This dissertation research focuses on the development and evaluation of native bacterial cellulose (BC) and chemically modified BCs as potential biomaterials for bone and cartilage regeneration using equine-derived bone marrow mesenchymal stem cells (EqMSCs).

The ability of native BC scaffold to maintain cell proliferation, viability, and in vitro differentiation of the seeded EqMSCs for application in bone and cartilage tissue engineering was studied. BC morphology was characterized using …

Development Of A Moldable Composite Bone Graft Substitute Releasing Antibacterial And Osteogenic Drugs, Matthew E. Brown

Theses and Dissertations--Biomedical Engineering

Large infected bone defects (IBD) are very complicated to treat due to their high variability; they often require multiple procedures. Bone autografts are the gold standard for treatment but have several drawbacks, such as a need for a second surgery site, limited grafting material, and donor site morbidity. The objective of this research was to develop a moldable synthetic bone grafting material capable of releasing both antimicrobial and osteogenic drugs over a clinically relevant time course for the treatment of IBDs. Current treatment methods for large IBDs require two separate procedures to treat the bone defect and the infection.

This …