Biomedical Engineering and Bioengineering Commons^™

Development Of Brain-Derived Bioscaffolds For Neural Progenitor Cell Culture And Delivery, Julia Terek

Electronic Thesis and Dissertation Repository

The use of brain extracellular matrix (ECM) as a biomaterial has the potential to promote neural tissue regeneration by providing cell-instructive cues that direct survival, proliferation, and differentiation. This study developed a novel detergent-free decellularization protocol that effectively reduced cellular content while preserving key ECM components in porcine and rat brains. The resulting decellularized brain tissue (DBT) was incorporated into microcarriers to assess its effects on the growth, phenotype and neurotrophic factor gene expression of rat brain-derived progenitor cells cultured within spinner flask bioreactors, using purified collagen microcarriers as a control. Both types of microcarriers supported cell expansion and survival, …

Development Of Multifunctional Drug Delivery Systems For Locoregional Therapy, Xinyi Li

Electronic Thesis and Dissertation Repository

Locoregional treatment is the specific delivery of therapeutics to their desired sites of action with minimized systemic adverse effects. In this approach, drug is administered through topical instillation, inhalation, intra-lesional or intra-arterial injection. Decades of experience in locoregional treatment have delivered meaningful benefits to patients with localized diseases (e.g., osteoarthritis, ocular disorders and liver cancers). However, improvements are required for this type of treatment to be more effective. For transarterial chemoembolization (TACE) therapy of hepatocellular carcinoma (HCC), the most current approaches do not allow repeat treatment as the drug delivery vehicle is not degradable. In addition, image contrast agents for …

The Co-Delivery Of Syngeneic Adipose-Derived Stromal Cells And Macrophages On Decellularized Adipose Tissue Bioscaffolds For In Vivo Soft Tissue Regeneration, Hisham A. Kamoun

Electronic Thesis and Dissertation Repository

Decellularized adipose tissue (DAT) bioscaffolds are a promising platform for the delivery of pro-regenerative cell populations with the goal of promoting adipose tissue regeneration. The current study investigated the effects of seeding DAT bioscaffolds with syngeneic bone marrow-derived macrophages and/or adipose-derived stromal cells (ASCs) on in vivo soft tissue regeneration. Methods were established to derive the macrophages from MacGreen mice, which were dynamically seeded onto the DAT scaffolds alone or in combination with ASCs. Seeded and unseeded scaffolds were implanted subcutaneously into C57Bl/6 mice. At 2 and 4 weeks, cell infiltration, angiogenesis, and adipogenesis were analyzed through histology and immunohistochemistry. …

The Efficacy Of Bionate As An Articulating Surface For Joint Hemiarthroplasty, Sarah Dedecker

Electronic Thesis and Dissertation Repository

Hemiarthroplasty procedures replace the diseased side of the joint with an implant to maximize bone preservation while maintaining more native anatomy than a total joint replacement. Even though hemiarthroplasty procedures have been clinically successful, they cause progressive cartilage damage over time due to the use of relatively stiff metallic implant materials. This work investigates the role of low moduli implant material on implant-cartilage contact mechanics and early in vitro cartilage wear. A finite element simulation was developed to assess the effect of low moduli implants in the range of 0.015-0.288 GPa on contact mechanics. Higher contact area and lower peak …

Effect Of Hemiarthroplasty Implant Contact Geometry And Material On Early Cartilage Wear, Alana Khayat

Electronic Thesis and Dissertation Repository

Hemiarthroplasty is a minimally invasive, cost-effective alternative to total arthroplasty in joints of the upper limb. Though these procedures reduce patient morbidity while restoring joint kinematics, their longevity is limited by wear of the adjacent cartilage. This work investigates the roles of contact geometry and implant stiffness on cartilage wear with the aim of elucidating the mechanics that contribute to cartilage damage. An in vitro study examined the influence of implant geometry on cartilage wear using a pin-on-plate wear simulator. A significant decrease in volumetric wear was observed as contact area increased, which suggests that maximizing contact area should be …

Functional Co-Substituted Poly[(Amino Acid Ester)Phosphazene] Biomaterials, Amanda L. Baillargeon

Electronic Thesis and Dissertation Repository

The development of new and improved biomaterials is essential for tissue engineering and regenerative medicine applications. Amino acid-based polyphosphazenes are being explored as scaffold materials for tissue engineering applications due to their non-toxic degradation products and tunable material properties. This work focuses on the synthesis of non-functional and novel functional poly[(amino acid ester)phosphazene]s using a facile method of thermal ring opening polymerization followed by one-pot room temperature substitution. The family of polyphosphazenes developed in this work is based on L-alanine (PNEAs), L-phenylalanine (PNEFs), and L-methionine (PNEMs) with L-glutamic acid imparting the functionality. Characterization of these materials demonstrated that the one-pot …

Calcium Phosphate-Based Resorbable Biomaterials For Bone Regeneration, Daniel O. Costa

Electronic Thesis and Dissertation Repository

Bone defects are a prevalent problem in orthopedics and dentistry. Calcium phosphate-based coatings and nanocomposites offer unique solutions towards producing scaffolds with suitable physical, mechanical and biological properties for bone regeneration.

We developed a novel method to synthesize hydroxyapatite (HA) particles with high aspect ratio using sol-gel chemistry and hydrothermal treatment. We obtained tunable pure-phase carbonated-HA in the form of micro/nanorods and nanowires (diameters 25-800 nm). To mimic the structure of bone, HA nanowires were homogenously mixed within poly(ε-caprolactone) (PCL) to produce nanocomposites with improved mechanical properties as determined by uniaxial tensile testing.

Surface chemistry and topography of biomaterials play …