Biochemical and Biomolecular Engineering Commons^™

3d Differentiation Of Neural Stem Cells In Macroporous Photopolymerizable Hydrogel Scaffolds, Nic Leipzig

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Neural stem/progenitor cells (NSPCs) are the stem cell of the adult central nervous system (CNS). These cells are able to differentiate into the major cell types found in the CNS (neurons, oligodendrocytes, astrocytes), thus NSPCs are the mechanism by which the adult CNS could potentially regenerate after injury or disorder. Microenviromental factors are critical for guiding NSPC differentiation and are thus important for neural tissue engineering. In this study, D-mannitol crystals were mixed with photocrosslinkable methacrylamide chitosan (MAC) as a porogen to enhance pore size during hydrogel formation. D-mannitol was admixed to MAC at 5, 10 and 20 wt% D-mannitol …

Fabrication And Degradation Of Electrospun Scaffolds From L-Tyrosine Based Polyurethane Blends For Tissue Engineering Applications, Lingyun Liu

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

It is important to control the degradation rate of a tissue-engineered scaffold so that the scaffold will degrade in an appropriate matching rate as the tissue cells grow in. A set of potential tissue engineering scaffolds with controllable rates of degradation were fabricated from blends of two biocompatible, biodegradable L-tyrosine-based polyurethanes (PEG1000-HDI-DTH and PCL1250-HDI-DTH) using the electrospinning process. The scaffolds were characterized by mat morphology, fiber diameter, diameter distribution, pore size, and hydrolytic degradation behavior. The majority of the scaffolds, despite having radically different chemical compositions, possessed no statistical difference with pore sizes and fiber diameters. The degradation pattern observed …

Increasing Pt Oxygen Reduction Reaction Activity And Durability With A Carbon-Doped Tio 2 Nanocoating Catalyst Support, Kan Huang, Kotaro Sasaki, Radoslav R. Adzic, Yangchuan Xing

Chemical and Biochemical Engineering Faculty Research & Creative Works

We report a conductive TiO2 nanocoating on carbon nanotubes (CNTs) as a Pt electrocatalyst support that shows a significant enhancement in Pt catalyst activity and durability for the oxygen reduction reaction. by using CNTs as the substrate for TiO2 nanocoating, the nanoscale morphology of the oxide was retained during heat treatment. after carbon doping of the TiO2 nanocoating, X-ray photoelectron spectroscopy suggests a shift in the binding energy of Ti 2p, implying a suboxide formation. the X-ray absorption near-edge structure showed the mid-edge and post-edge up to 5010 eV, which are attributed to a 1s → 4p transition and promotion …

The Study Of Bone Diffusion In Canine Tibia, Mariela Gonzalez-Nieves

Undergraduate Research Posters 2012

The provision of nutrients is imperative in order to maintain healthy bone structure. Bones are composed of dense connective tissues that are consistently reforming making it difficult for simple diffusion of large signaling molecules to occur. Fully understanding the rate at which nutrients, minerals, and waste travel throughout bone could lead to solutions to problems such as bone illnesses, breaks, and integration of prosthetics in the human body. Enhanced targeted medication delivery can be established as well.

Developing Novel Prognostic Biomarkers For Multivariate Fracture Risk Prediction Algorithms, Ernest K. Poku, Mark R. Towler, Niamh M. Cummins, Jeff D. Newman

Chemical and Biochemical Engineering Faculty Research & Creative Works

Multivariate prediction algorithms such as FRAX® and QFracture Scores provide an opportunity for new prognostic biomarkers to be developed and incorporated, potentially leading to better fracture prediction. As more research is conducted into these novel biomarkers, a number of factors need to be considered for their successful development for inclusion in these algorithms. In this review, we describe two well-known multivariate prediction algorithms for osteoporosis fracture risk applicable to the UK population, FRAX and QFracture Scores, and comment on the current prognostic tools available for fracture risk; dual X-ray assessment, quantitative ultrasonography, and genomic/biochemical markers. We also highlight the factors …

Phase Transitions Of Nanoemulsions Using Ultrasound: Experimental Observations, Ram Singh, Ghaleb A. Husseini, William G. Pitt

Faculty Publications

The ultrasound-induced transformation of perfluorocarbon liquids to gases is of interest in the area of drug and gene delivery. In this study, three independent parameters (temperature, size, and perfluorocarbon species) were selected to investigate the effects of 476-kHz and 20-kHz ultrasound on nanoemulsion phase transition. Two levels of each factor (low and high) were considered at each frequency. The acoustic intensities at gas bubble formation and at the onset of inertial cavitation were recorded and subsequently correlated with the acoustic parameters. Experimental data showed that low frequencies are more effective in forming and collapsing a bubble. Additionally, as the size …

Gallium Containing Glass Polyalkenoate Anti-Cancerous Bone Cements: Glass Characterization And Physical Properties, A. W. Wren, A. Coughlan, L. Placek, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

A gallium (Ga) glass series (0.48SiO₂-0.40ZnO-0.12CaO, with 0.08 mol% substitution for ZnO) was developed to formulate a Ga-containing Glass Polyalkenoate Cement (GPC) series. Network connectivity (NC) and X-ray Photoelectron Spectroscopy (XPS) was employed to investigate the role of Ga³⁺ in the glass, where it is assumed to act as a network modifier. Ga-GPC series was formulated with E9 and E11 polyacrylic acid (PAA) at 50, 55 and 60 wt% additions. E11 working times (T_w) ranged from 68 to 96 s (Lcon.) and 106 s for the Ga-GPCs (LGa-1 and LGa-2). Setting times (T_s) …

Experimental Composite Guidance Conduits For Peripheral Nerve Repair: An Evaluation Of Ion Release, X. F. Zhang, A. Coughlan, H. O'Shea, Mark R. Towler, S. Kehoe, D. Boyd

Chemical and Biochemical Engineering Faculty Research & Creative Works

Poly (lactide-co-glycolide) (PLGA) - Pluronic F127 - glass composites have demonstrated excellent potential, from the perspective of controlled mechanical properties and cytocompatibility, for peripheral nerve regeneration. In addition to controlling the mechanical properties and cytotoxicity for such composite devices, the glass component may mediate specific responses upon implantation via degradation in the physiological environment and release of constituent elements. However, research focused on quantifying the release levels of such therapeutic ions from these experimental medical devices has been limited. To redress the balance, this paper explores the ion release profiles for Si⁴⁺, Ca²⁺, Na⁺, …

Characterization And Quantification Of Monomers, Oligomers, And By-Products From Xylan During Biomass Pretreatment, Ching-Shuan Lau

Graduate Theses and Dissertations

Biomass pretreatment generates inhibitory products, which reduce the overall yield of xylose for ethanol production. Understanding of hemicellulose depolymerization into xylose is essential to identify the pretreatment conditions that maximize xylose formation, but minimize the generation of these inhibitory products, such as formic acid and furfural. Thus, the goal of this project is to understand how dilute acid pretreatment parameters affect hemicellulose depolymerization, maximize xylose concentrations, and minimize by-products formation.

To progress towards this goal, rates and mechanisms of hemicellulose release must be determined. Birchwood xylan was used as the starting material to produce xylose oligomers. The hydrolyzed birchwood xylan …

Peptoid Based Slide Coatings For Disease Detection Via Elisa Microarray Analysis, Melissa Lea Hebert

Graduate Theses and Dissertations

Poly-N-substituted glycines (peptoids) are a very versatile family of synthetic molecules that can be customized for any number of applications. In this study, we chose to use peptoids as a foundation for sandwich ELISA microarray analysis with a long term goal of creating an early detection device for complex diseases such as cancer. The peptoids were designed to self-assemble into microspheres to be used in coatings on the surface of the microarray substrates to increase the surface area available for antibody attachment. This increased antibody density would lead to an increase in the microarray analysis sensitivity and dynamic range. Studies …

Optimization Of A Dynamic Hot Water Pretreatment Of Switchgrass Using Catalysis By Carbonation To Maximize Carbochemical Yields, Rohit Tanaji Dhamdere

Graduate Theses and Dissertations

A bio-refinery is a facility that converts renewable bio-resources into value-added chemicals and products. In this context of a bio-refinery, the production of the carbochemicals such as HMF, furfural and organic acids illustrate that multiple products can be produced from a renewable source such as lignocellulosic biomass (switchgrass). Traditionally, carbochemicals such as furfural and HMF are produced using inorganic acids such as H2SO4, HCL, and H3PO4. The use of such acids requires the application of high cost materials of construction such as Hastelloy-C, titanium etc.

The objective of this study is to develop a semi-continuous process for the conversion of …

Processes For The Production Of Buprenorphine With Reduced Impurity Formation, Brenda E. Allen, Esa T. Jarvi, Dennis J. Kaluta, James R. Meyer, Keith Tomazi, Anthony Mannino, Brian Orr

Chemical and Biochemical Engineering Faculty Research & Creative Works

The present invention provides process for the production of opiate alkaloids. In particular, the present invention provides processes for the production of buprenorphine or a derivative of buprenorphine that minimizes the formation of impurities.

An Oxidase-Based Electrochemical Fluidic Sensor With High-Sensitivity And Low-Interference By On-Chip Oxygen Manipulation, Nitin Radhakrishnan, Jongwon Park, Chang Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

Utilizing a simple fluidic structure, we demonstrate the improved performance of oxidase-Based enzymatic biosensors. Electrolysis of water is utilized to generate bubbles to manipulate the oxygen microenvironment close to the biosensor in a fluidic channel. for the proper enzyme reactions to occur, a simple mechanical procedure of manipulating bubbles was developed to maximize the oxygen level while minimizing the pH change after electrolysis. the sensors show improved sensitivities based on the oxygen dependency of enzyme reaction. in addition, this oxygen-rich operation minimizes the ratio of electrochemical interference signal by ascorbic acid during sensor operation (i.e., amperometric detection of hydrogen peroxide). …

The Structural Characterization Of Ga 2o 3-Na 2o-Cao-Zno-Sio 2 Bioactive Glasses, T. J. Keenan, A. W. Wren, A. Coughlan, M. M. Hall, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

The characterization of bioactive glasses in which zinc (Zn) has been incrementally replaced by gallium (Ga). © 2012 IEEE.

Increasing The Quantity Of Silver In Zinc-Based Glass Polyalkenoate Cement: Is There An Improvement In Antibacterial Efficacy?, A. Coughlan, S. M. Breed, C. Ashraf, J. A. Cardinale, M. M. Hall, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bone cements should have the ability to chemically bond to both bone and surgical metals, exhibit no chemical or thermal necrosis, and have no significant shrinkage or exotherm upon setting. Taking these properties into consideration, glass polyalkenoate cements (GPCs) have potential as bone cements. GPCs are formed by the reaction between an ion-leachable glass and an aqueous solution of polyacrylic acid (PAA) [1] and have proven antibacterial and cariostatic properties [2], which are related to their ability to release beneficial amounts of ions over time [3, 4]. The GPCs can be formulated to release ions that can have a therapeutic …

Silver Coated Bioactive Glass Particles For Wound Healing Applications, P. Hassanzadeh, A. W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hench and colleagues discovered that bone could bond chemically to certain glass compositions in 1969 [1]. This group of glasses is known as bioactive glasses [1]. Some special compositions of bioactive glasses will bond to soft tissues as well as bone [1]. One of the important characteristics of bioactive glasses is their ability to release beneficial ions such as Ca²⁺, Na⁺, Zn²⁺, Sr²⁺, and PO 43- in the body, which promote self-healing [2]. Bioactive glasses generally contain much less glass former (e.g., SiO₂, B₂O₃ etc.) than conventional …

Gallium Containing Glass Polyalkenoate Bone Cements: Glass Characterization And Physical Properties, L. Placek, A. W. Wren, A. Coughlan, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Gallium (Ga) glasses were developed to formulate a Glass Polyalkenoate Cement (GPC) series with both E9 and E11 polyacrylic acid (PAA) at 50, 55 and 60wt% additions. Working times (T w), setting times (T s), compression (σ c), and biaxial flexural (σ f) strength testing were evaluated to determine the GPCs potential use in orthopedics. © 2012 IEEE.

Scalable Synthesis Of Palladium Nanoparticle Catalysts By Atomic Layer Deposition, Xinhua Liang, Lauren B. Lyon, Ying Bing Jiang, Alan W. Weimer

Chemical and Biochemical Engineering Faculty Research & Creative Works

Atomic layer deposition (ALD) was used to produce Pd/Al2O 3 catalysts using sequential exposures of Pd (II) hexafluoro acetylacetonate and formalin at 200 °C in a fluidized bed reactor. the ALD-prepared Pd/alumina catalysts were characterized by various methods including hydrogen chemisorption, XPS, and TEM, and compared with a commercially available 1 wt.% Pd/alumina catalyst, which was also characterized. the content of Pd on alumina support and the size of Pd nanoparticles can be controlled by the number of ALD-coating cycles and the dose time of the Pd precursor. One layer of organic component from the Pd precursor remained on the …

Silver Coated Bioactive Glass Particles For Wound Healing Applications, A. W. Wren, A. Coughlan, P. Hassanzadeh, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioactive glass particles (0.42SiO₂-0.15CaO-0.23Na ₂O-0.20ZnO) of varying size (<90 >μm and 425-850 μm) were synthesized and coated with silver (Ag) to produce Ag coated particles (PAg). These were compared against the uncoated analogous particles (Pcon.). Surface area analysis determined that Ag coating of the glass particles resulted in increased the surface area from 2.90 to 9.12 m²/g (90 μm) and 1.09-7.71 m²/g (425-850 μm). Scanning electron microscopy determined that the Ag coating remained at the surface and there was little diffusion through the bulk. Antibacterial (Escherichia coli - 13 mm and Staphylococcus epidermidis …

On The Measurement Of Gas Holdup Distribution Near The Region Of Impeller In A Gas-Liquid Stirred Rushton Tank By Means Of Γ-Ct, Li Na Kong, Wei Li, Lu Chang Han, Yue Jin Liu, He An Luo, Muthanna H. Al Dahhan, Milorad P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Three Flow Patterns of Flooding, Loading and Complete Recirculation in a Gas-Liquid Stirred Rushton Tank Were Identified based on Experimental Observation. the Gas-Liquid System Was Composed of Air and Water. under Different Operating Conditions of Gas Flow Rate and Impeller Rotating Speed, the Distribution of Gas Holdup Near the Region of Impeller Was Measured using a Γ-CT Scan Method. Both Quantitative Digital Distribution Curves of Gas Holdup and their Qualitative Color CT Images Were Obtained. at the Region of Impeller, There Was a Convex Characteristic Peak of Gas Holdup Distribution Both in Radial and in Axial Directions, and with the …