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Chemical Engineering

Retrospective Theses and Dissertations

Articles 1 - 9 of 9

Full-Text Articles in Biomedical Engineering and Bioengineering

Engineering Polyanhydride Microspheres For The Stabilization And Controlled Release Of Proteins , Amy Sywassink Determan Jan 2006

Engineering Polyanhydride Microspheres For The Stabilization And Controlled Release Of Proteins , Amy Sywassink Determan

Retrospective Theses and Dissertations

This work investigates the use of polyanhydride microspheres as drug delivery carriers for therapeutic proteins. The polymers investigated are poly(sebacic anhydride) and opolymers of poly[1,6-bis(p-carboxyphenoxy)hexane] (poly(CPH)) and poly(SA), 20:80 (CPH:SA), 50:50 (CPH:SA), and 80:20 (CPH:SA). The model protein bovine serum albumin (BSA) was encapsulated in poly(SA), 20:80 (CPH:SA), 50:50 (CPH:SA), and 80:20 (CPH:SA) microspheres to determine the feasibility of using polyanhydrides as protein carriers. Poly(SA) and 20:80 (CPH:SA) were found to stabilize the encapsulated BSA and were ...


Recovery And Purification Of Recombinant Protein From Transgenic Corn By Aqueous Two-Phase Partitioning , Zhengrong Gu Jan 2006

Recovery And Purification Of Recombinant Protein From Transgenic Corn By Aqueous Two-Phase Partitioning , Zhengrong Gu

Retrospective Theses and Dissertations

Aqueous two-phase (ATP) partitioning was paired in a variety of ways to use of transgenic corn for protein expression. Systems were developed to selectively partition corn proteins from classes of potential recombinant proteins as well as the specific case of dog gastric lipase. More fundamentally, ATP partitioning was used to expand 2D gel electrophoretic characterization of protein size and pI to the third dimension of hydrophobicity with the usefulness of the method illustrated for corn extracts;ATP partitioning in polyethylene glycol (PEG)-salt systems separates proteins primarily according to their surface hydrophobicity differences. The average hydrophobicity of pH 7 extracts ...


Directed Growth And Selective Differentiation Of Neural Progenitor Cells Using A Synergistic Combination Of Topographical And Soluble Cues , Jennifer Behr Recknor Jan 2006

Directed Growth And Selective Differentiation Of Neural Progenitor Cells Using A Synergistic Combination Of Topographical And Soluble Cues , Jennifer Behr Recknor

Retrospective Theses and Dissertations

The purpose of this study is to develop strategies to facilitate nerve regeneration using a synergistic combination of guidance cues. We are investigating the cellular mechanisms of development using adult rat hippocampal progenitor cells (AHPCs) and have demonstrated that manipulating a combination of physical, chemical and biological cues can lead to oriented astrocyte and neural progenitor cell outgrowth and can influence progenitor cell differentiation. To provide physical guidance, micropatterned polystyrene (PS) substrates were fabricated and chemically modified with laminin. Astrocytes or AHPCs cultured on these substrates align along the grooves of the patterned surface extending highly elongated processes. To further ...


Engineering Bioerodible Polymers With Tailored Micro/Nanostructure For Vaccine Delivery , Matthew J. Kipper Jan 2004

Engineering Bioerodible Polymers With Tailored Micro/Nanostructure For Vaccine Delivery , Matthew J. Kipper

Retrospective Theses and Dissertations

This work describes the investigation of bioerodible polyanhydrides as controlled drug delivery vehicles. The polymers studied are based on the 1,6-bis(p-carboxyphenoxy)hexane (CPH) and sebacic acid (SA) monomers. These two materials erode at vastly different rates and can be combined in random copolymers or blends to achieve tailored erosion kinetics. The hydrophobic nature of these materials offers the potential to stabilize proteins, and their mutual incompatibility and semicrystallinity provide an interesting phase behavior, which can be exploited to aid in tailoring the release kinetics. Theoretical and experimental description of the microstructure of polyanhydride copolymers reveals the details of ...


Development Of Novel Polymeric Materials For Gene Therapy And Ph-Sensitive Drug Delivery: Modeling, Synthesis, Characterization, And Analysis , Brian Curtis Anderson Jan 2002

Development Of Novel Polymeric Materials For Gene Therapy And Ph-Sensitive Drug Delivery: Modeling, Synthesis, Characterization, And Analysis , Brian Curtis Anderson

Retrospective Theses and Dissertations

The aim of this work was to obtain a fundamental understanding of drug release mechanisms from polymers that undergo thermoreversible gelation and to synthesize new polymers based on these that exhibit both pH and temperature sensitivity. Novel block and random copolymers with cationic character have been developed for drug delivery and gene therapy applications. The development of these materials began with a study of the mechanism of drug release from poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) block copolymers. This study revealed the release rates of drugs from water-soluble hydrogels composed of the PEO-PPO-PEO block copolymer PluronicRTM F127 ...


Design Of A Bioartificial Nerve Graft , Gregory Edward Rutkowski Jan 1999

Design Of A Bioartificial Nerve Graft , Gregory Edward Rutkowski

Retrospective Theses and Dissertations

Nerve injuries complicate successful rehabilitation more than any other form of trauma because of loss of protective sensibility and tactile discrimination, denervation atrophy of muscles, and pain syndromes. While achieving full function and organ reinnervation after peripheral nerve injury is a challenge, a promising method of improving the rate and success of regeneration is the bioartificial nerve graft (BNG). The BNG developed in the laboratory consists of a porous bioresorbable tube containing cultured Schwann cells that help to direct and support nerve regeneration when used to bridge the gap between the ends of the severed nerve;To aid in the ...


Development Of A Coupled Model Of The Cardiorespiratory And Thermoregulatory Systems , Dawn Denise Downey Jan 1998

Development Of A Coupled Model Of The Cardiorespiratory And Thermoregulatory Systems , Dawn Denise Downey

Retrospective Theses and Dissertations

A model of the human body which integrates the variables involved in temperature regulation and blood gas transport within the cardiovascular and respiratory systems is presented in this dissertation. It expands upon previous work developed by the author to model the competition between skin and muscles when both require increased blood flows during exercise and/or heat stress. First, a detailed study of the control relations used to predict skin blood flow was undertaken. Four other control relations employed in the model were also examined and modified as indicated by empirical results found in literature;Several important cases were then ...


The Effects Of Physiological Levels Of Intermittent Pressure On The Development Of Articular Cartilage In Vitro , Scott Edward Carver Jan 1998

The Effects Of Physiological Levels Of Intermittent Pressure On The Development Of Articular Cartilage In Vitro , Scott Edward Carver

Retrospective Theses and Dissertations

A semi-continuous perfusion system has been designed and constructed to deliver physiological levels of hydrostatic pressure to regenerating cell/polymer constructs of articular cartilage over the long term (weeks to months). Prior to being transferred to the pressurized system, equine articular chondrocytes were dynamically seeded onto nonwoven meshes of polyglycolic acid which provide the cells with a three-dimensional growth environment similar to that found in vivo. When applied in an intermittent manner, physiological pressurization at 500 psi was found to stimulate articular chondrocytes to produce regenerated constructs with greater concentrations of sulfated glycosaminoglycan compared to control (unpressurized) constructs, while the ...


Water And Electrolyte Regulation During Space Flight And Exercise , Susan Elizabeth Doty Jan 1994

Water And Electrolyte Regulation During Space Flight And Exercise , Susan Elizabeth Doty

Retrospective Theses and Dissertations

When one is exposed to microgravity, fluid which is normally pooled in the lower extremities is redistributed headward and weight bearing bones begin to demineralize due to reduced mechanical stresses. The kidney, which is the primary regulator of body fluid volume and composition, responds to the fluid shift and bone demineralization by increasing the urinary output of water, sodium, and calcium. This research involves developing a mathematical description of how water and electrolytes are internally redistributed and exchanged with the environment during space flight. Various levels of activity are also considered, since it is believed that exercise can prevent some ...