Open Access. Powered by Scholars. Published by Universities.®

Biomedical Engineering and Bioengineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 10 of 10

Full-Text Articles in Biomedical Engineering and Bioengineering

Biological Scaffolds For Peripheral Vascular Surgery, George Fercana Dec 2013

Biological Scaffolds For Peripheral Vascular Surgery, George Fercana

All Dissertations

The gold standards for small diameter peripheral vascular graft replacement are autologous arteries or veins; however, one-third of patients lack such vessels due to previous vessel harvesting or advanced vascular disease. A promising approach for patients in this category is tissue engineering with off-the-shelf biological vascular grafts. Three small diameter acellular scaffolds were developed and evaluated as vascular grafts. Porcine renal arteries (2-3 mm diameter, 20 mm length) were decellularized by immersion and stabilized with penta-galloyl glucose (PGG) with and without subsequent heparinization via carbodiimide chemistry. Bovine mammary (4-6 mm ID, 250 mm length) and femoral arteries (6-8 mm ID ...


Electrospinning Of Core-Shell Collagen Nanofibers, Ying Li Aug 2013

Electrospinning Of Core-Shell Collagen Nanofibers, Ying Li

Electronic Thesis and Dissertation Repository

In tissue engineering, the scaffold plays a critical role in guiding and supporting cells to function and grow optimally. The electrospun nanofibrous scaffold can serve as a near ideal substrate for tissue engineering because it has high surface area and the three-dimensional interconnected porous network can enhance cell attachment and proliferation. Core-shell nanofibrous scaffolds produced with coaxial electrospinning allow bioactive molecule encapsulation to improve cell adhesion, mediate and promote the proper signaling among the cells for their functioning and growth. In the current study, core-shell collagen nanofibers were fabricated via coaxial electrospinning with horizontal and vertical configurations. Core-shell nanofibers with ...


Spatial Control Of Magnetic Nanoparticles Integrated With Cellular Spheroids As Tissue Engineered Building Blocks, Brandon Mattix Aug 2013

Spatial Control Of Magnetic Nanoparticles Integrated With Cellular Spheroids As Tissue Engineered Building Blocks, Brandon Mattix

All Dissertations

Magnetic nanoparticles (MNPs) have been investigated in tissue engineering applications to provide in situ imaging, drug delivery, and tissue patterning, but direct and prolonged interaction between cells and MNPs can have adverse effects on cell function. Therefore, methods which reduce or limit the interaction of MNPs with cells, or utilize more biocompatible MNP-based strategies will improve upon the commonly used iron oxide MNPs. We investigated a variety of methods to improve upon the use of MNPS in tissue engineering.
Cell aggregates, or spheroids, have been used as tissue engineered building blocks that can closely mimic the native three-dimensional in vivo ...


A Novel Hybrid Hydrogel For Scaffold-Mediated Gene Delivery, Jeremy Zhang Aug 2013

A Novel Hybrid Hydrogel For Scaffold-Mediated Gene Delivery, Jeremy Zhang

All Dissertations

Scaffold-mediated nonviral gene delivery avoids several drawbacks of systemic injection such as clearance by the reticulo-endothelial system and serum aggregation. Existing synthetic and natural polymers used in gene delivery scaffolds are primarily derived from other tissue engineering applications with design parameters focused on the physicochemical properties of the scaffold and its biocompatibility. Common synthetic materials used in polymeric scaffolds such as PEG are practically bio-inert with minimal cell and protein interaction. Therefore, an opportunity exists for the rational design novel gene delivery scaffolds with components capable of increasing the expression of incorporated transgene by including scaffold components that interact with ...


Shelf Life Study Of Electrospun Plga Copolymers, Sean Youra, Nick Hudson Jun 2013

Shelf Life Study Of Electrospun Plga Copolymers, Sean Youra, Nick Hudson

Biomedical Engineering

Poly(lactic-co-glycolic acid) (PLGA) is one of the most commonly used copolymers for electrospinning in tissue engineering applications. However, most research has not focused on the copolymer itself in regards to how long it can be used effectively and if varying the concentrations of polylactic acid (PLA) and polyglycolic acid (PGA) affect the resulting properties. Electrospinning is the method we use to create the three-dimensional constructs, or “scaffolds”, for the blood vessel mimic (BVM) in the tissue engineering lab. The aim of our project was to investigate if the morphology and mechanical properties of the scaffolds changed over time when ...


Femtosecond Laser Patterned Templates And Imprinted Polymer Structures, Deepak Rajput May 2013

Femtosecond Laser Patterned Templates And Imprinted Polymer Structures, Deepak Rajput

Doctoral Dissertations

Femtosecond laser machining is a direct-write lithography technique by which user-defined patterns are efficiently and rapidly generated at the surface or within the bulk of transparent materials. When femtosecond laser machining is performed with tightly focused amplified pulses in single-pulse mode, transparent substrates like fused silica can be surface patterned with high aspect ratio (>10:1) and deep (>10 μm) nanoholes. The main objective behind this dissertation is to develop single-pulse amplified femtosecond laser machining into a novel technique for the production of fused silica templates with user-defined patterns made of high aspect ratio nanoholes. The size of the nanoholes ...


Sol-Gel Derived Biodegradable And Bioactive Organic-Inorganic Hybrid Biomaterials For Bone Tissue Engineering, Bedilu A. Allo Apr 2013

Sol-Gel Derived Biodegradable And Bioactive Organic-Inorganic Hybrid Biomaterials For Bone Tissue Engineering, Bedilu A. Allo

Electronic Thesis and Dissertation Repository

Treatments of bone injuries and defects have been largely centered on replacing the lost bone with tissues of allogeneic or xenogeneic sources as well as synthetic bone substitutes, which in all lead to limited degree of structural and functional recovery. As a result, tissue engineering has emerged as a viable technology to regenerate the structures and therefore recover the functions of bone tissue rather than replacement alone. Hence, the current strategies of bone tissue engineering and regeneration rely on bioactive scaffolds to mimic the natural extracellular matrix (ECM) as templates onto which cells attach, multiply, migrate and function.

In this ...


Controlled Formation Of Beta-Cell Aggregates And Their Characterization, Abigail Banaszek Bernard Jan 2013

Controlled Formation Of Beta-Cell Aggregates And Their Characterization, Abigail Banaszek Bernard

Chemical & Biological Engineering Graduate Theses & Dissertations

Islets of Langerhans are multi-cellular aggregates within the pancreas containing β-cells that sense changes in blood glucose levels and respond by secreting insulin. Transplantation of these functional cell clusters represents a promising avenue for the treatment of severe cases of type 1 diabetes mellitus but much remains unknown about key aspects of cell-cell and cell-matrix communication that influence cell survival post-transplantation. Cell-cell contact between islet cells is crucial for cell survival and maintenance of glucose-dependent insulin release but large islets exhibit necrosis of central cells under transplant conditions. To facilitate cell-cell contact but limit aggregate size, several methods have been ...


The Effects Of Matrix Elasticity, Composition, And Exogenous Growth Factors On The Vascular Differentiation Of Mesenchymal Stem Cells, Kathryn Anne Wingate Jan 2013

The Effects Of Matrix Elasticity, Composition, And Exogenous Growth Factors On The Vascular Differentiation Of Mesenchymal Stem Cells, Kathryn Anne Wingate

Mechanical Engineering Graduate Theses & Dissertations

Cardiovascular diseases are the leading cause of death in the western world. Regeneration of functional vascular tissue remains a critical barrier to successful treatment of these diseases. Attempts to produce functional vascular tissue with autogenous vascular cells have limited success due to the need for invasive surgery. Mesenchymal stem cells (MSCs) are a powerful cellular alternative for vascular regeneration as they are easily obtainable, multipotent, and thrombo-resistant. Currently, the mechanisms that drive MSC differentiation to healthy or diseased vascular phenotypes are not well understood. There is a critical need to define the factors in the cellular microenvironment that guide MSC ...


Development And Characterization Of A 3d Multicell Microtissue Culture Model Of Airway Smooth Muscle., Glenn Gaudette, Adrian West, Nishat Zaman, Darren Cole, Matthew Walker, Wesley Legant, Thomas Boudou, Christopher Chen, John Favreau, Elizabeth Cowley, Geoffrey Maksym Dec 2012

Development And Characterization Of A 3d Multicell Microtissue Culture Model Of Airway Smooth Muscle., Glenn Gaudette, Adrian West, Nishat Zaman, Darren Cole, Matthew Walker, Wesley Legant, Thomas Boudou, Christopher Chen, John Favreau, Elizabeth Cowley, Geoffrey Maksym

Glenn R. Gaudette

Airway smooth muscle (ASM) cellular and molecular biology is typically studied with single-cell cultures grown on flat 2D substrates. However, cells in vivo exist as part of complex 3D structures, and it is well established in other cell types that altering substrate geometry exerts potent effects on phenotype and function. These factors may be especially relevant to asthma, a disease characterized by structural remodeling of the airway wall, and highlights a need for more physiologically relevant models of ASM function. We utilized a tissue engineering platform known as microfabricated tissue gauges to develop a 3D culture model of ASM featuring ...