Chemical Engineering Commons^™

Silver Nanoparticle Coated Bioactive Glasses - Composites With Dex/Cmc Hydrogels: Characterization, Solubility, And In Vitro Biological Studies, Anthony W. Wren, Pegah Hassanzadeh, Lana M. Placek, Timothy J. Keenan, Aisling Coughlan, Lydia R. Boutelle, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Silver (Ag) coated bioactive glass particles (Ag-BG) were formulated and compared to uncoated controls (BG) in relation to glass characterization, solubility and microbiology. X-ray diffraction (XRD) confirmed a crystalline AgNP surface coating while ion release studies determined low Ag release (/L). Cell culture studies presented increased cell viability (127 and 102%) with lower liquid extract (50 and 100 ml/ml) concentrations. Antibacterial testing of Ag-BG in E. coli, S. epidermidis and S. aureus significantly reduced bacterial cell viability by 60-90%. Composites of Ag-BG/CMC-Dex Hydrogels were formulated and characterized. Agar diffusion testing was conducted where Ag-BG/hydrogel composites produced the largest inhibition zones …

Bioactive Glass Reinforced Elastomer Composites For Skeletal Regeneration: A Review, Ehsan Zeimaran, Sara Pourshahrestani, Ivan Djordjevic, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Biodegradable elastomers have clinical applicability due to their biocompatibility, tunable degradation and elasticity. The addition of bioactive glasses to these elastomers can impart mechanical properties sufficient for hard tissue replacement. Hence, a composite with a biodegradable polymer matrix and a bio glass filler can offer a method of augmenting existing tissue. This article reviews the applications of such composites for skeletal augmentation.

Matrix Compliance And The Regulation Of Cytokinesis, Savitha Sambandamoorthy, Shomita Mathew-Steiner, Scott Varney, Jonathan M. Zuidema, Ryan J. Gilbert, Livingston De Van Water, Susan E. Laflamme

Chemical and Biochemical Engineering Faculty Research & Creative Works

Integrin-mediated cell adhesion to the ECM regulates many physiological processes in part by controlling cell proliferation. It is well established that many normal cells require integrin-mediated adhesion to enter S phase of the cell cycle. Recent evidence indicates that integrins also regulate cytokinesis. Mechanical properties of the ECM can dictate entry into S phase; however, it is not known whether they also can affect the successful completion of cell division. To address this issue, we modulated substrate compliance using fibronectin-coated acrylamide-based hydrogels. Soft and hard substrates were generated with approximate elastic moduli of 1600 and 34,000 Pascals (Pa) respectively. Our …

Gold Nanoparticle Enhancements In Electroporation Mediated Dna And Rna Therapeutics, Shuyan Huang

Doctoral Dissertations

Nonviral gene delivery methods have been explored as the replacement of viral systems for their low toxicity and immunogenicity. However, they have yet to reach levels competitive to their viral counterparts. Electroporation figured prominently as an effective nonviral gene delivery approach for its balance on the transfection efficiency and cell viability, no restrictions of probe or cell type, and operation simplicity. The commercial electroporation systems have been widely adopted in the past two decades but still carry drawbacks associated with the high applied electric voltage, unsatisfied delivery efficiency, and/or low cell viability. What we did was to improve electroporation performance …

Diamond Mems Biosensors: Development And Applications, Wenli Zhang

Doctoral Dissertations

This research focuses on the development a dielectrophoresis-enhanced microfluidic impedance biosensor (DEP-e-MIB) to enable fast response, real-time, label-free, and highly sensitive sensor for bacterial detection in clinical sample. The proposed design consists of application of dielectrophoresis (DEP) across a microfluidic channel to one of the impedance spectroscopy electrodes in order to improve the existent bacterial detection limits with impedance spectroscopy. In order to realize such a design, choice of electrode material with a wide electrochemical potential window for water is very important. Conventional electrode material, such as gold, are typically insulated for the application of DEP, and they fail when …

Astrocyte Response To Nanoscale Topography On Anodized Alumina Surfaces, D. Ganguly, C. D.L. Johnson, D. A. Borca-Tasciuc, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Astrocytes are one of the most important and abundant resident glial cells of the central nervous system (CNS). They play a critical role in the foreign body response, by participating in the formation of the glial scar sunouncling implants. As part of the effort to minimize the foreign body response, biomaterials strategies einployiug engineered surfaces topographies are being explored. In this context, we have investigated the response of astrocytes to surface topography of alumiua, a material used in CNS applications. Specifically, astrocytes were seeded oil alumina surfaces with nanopores 20 nm and 100 nm in diameter, respectively. Pore-free alumina …

Effects Of Strontium Substitution On Bioactivity Of Hydroxyapatite, Chokchai Yatongchai, Lana M. Placek, Mark R. Towler, Anthony W. Wren

Chemical and Biochemical Engineering Faculty Research & Creative Works

Effect of strontium (Sr) substitution on bioactivity of hydroxyapatite (HA) was investigated. The substitution of Sr²⁺ for Ca²⁺ in the HA lattice increases biodegradability of Sr-substituted HA (Sr-HA) and accelerates the formation of apatite crystals on the Sr-HA surface. Moreover, the dissolution products from HA and Sr-HA samples are not cyto-toxic.

Analysis Of Neurite Outgrowth On Electrospun Fiber Scaffolds In The Presence Of Blebbistatin And Paclitaxel, A. R. D'Amato, N. J. Schaub, C. D.L. Johnson, J. Cardenas, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

In an attempt to increase the rate of neurite extension from E9 chick embryo dorsal root ganglion (DRG) on electro spun fiber scaffolds we experimented with two drugs that have been used previously to affect neuronal growth. Blebbistatin and paclitaxel were added to DRG cultured on electro spun fibers in an attempt to increase the rate of neurite extension along fibrous scaffolds. Blebbistatin increased the length of neurites extending from the DRG explant in comparison to the drug-free control group. In contrast, paclitaxel completely eliminated all neurite extension from the DRG explant when compared to the control. A third treatment …

Initial Astrocyte Response To Electrospun Poly-L-Lactic Acid Fibers Of Varying Nanoscale Diameters, C. D.L. Johnson, J. M. Zuidema, G. P. Desmond, A. R. D'Amato, N. J. Schaub, R. J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

We hypothesized that fiber diameter within an electro spun fiber scaffold would affect astrocyte elongation and maturation. To examine the relationship, astrocytes were seeded on 400nm and 800nm diameter electro spun PLLA fibers. Immunohistochemistry was used to monitor cell morphology, and GLT-1 expression over the first 96 hours after seeding. The results indicate that astrocytes extended along the primary axis of the 800nm fibers more rapidly than astrocytes seeded on fibers of half the size. While GLT-1 was expressed diffusely throughout the surface of the astrocytes, elongated cell processes exhibited dense regions of GLT-1. These results show that 800nm fibers …

Evaluating The Viability Of Graphene Oxide For The Removal Of Ni(Ii) Ions From Waste Water, Cale M. White

Biomedical Engineering Undergraduate Honors Theses

When levels of heavy metal ions such as nickel (Ni), copper (Cu), lead (Pb), Zinc (Zn), and Cobalt (Co) exceed the tolerance values for industrial wastewater, it can devastate the environment as well as the health of the individuals consuming the water. Heavy metal ions are not biodegradable and will accumulate in organic matter.(1) This accumulation leads to toxic levels in the blood and hence damage to nerve tissue, kidneys, the liver, and other vital organs. (2) Effective removal processes of these heavy metals from water must be developed. This study explores a method to adsorb nickel from water with …

The Investigation Of Chitosan-Based Hydrogels For Intratumoral Delivery Of Immunotherapeutic Cytokines, Ethan Drew Lowry

Biomedical Engineering Undergraduate Honors Theses

Controlled and localized delivery of Interleukin 12 (IL-12) is critical to effective and non-toxic cancer immunotherapy. Current delivery protocols for pre-clinical anti-tumor trials utilize solutions of chitosan, a mucoadhesive and bioeliminable biopolymer, to slow the release of IL- 12 into the tumor microenvironment. In order to further increase IL-12 retention, we have developed and characterized two chitosan-based in situ gelling hydrogels for IL-12 immunotherapy. One hydrogel, composed of heparin and chitosan, is herein described from initial conception through multiple stages of characterization including isolation of a range of suitable hydrogel formulations and observational physical and chemical properties. A second hydrogel …

Fluorescent Imaging On A Microfluidics Chip For Quantification Of Leukocyte Count, Aneeka Majid

Biomedical Engineering Undergraduate Honors Theses

We have demonstrated a method for conducting a leukocyte count in whole blood using a microfluidics chip and epi-fluorescence setup. Leukocyte counts provide physicians with a wealth of information about a patient’s medical condition and as such are routinely completed for many hospital visits. Miniaturization of this diagnostic tool may enable physicians to provide healthcare in resource-limited settings, where patients would otherwise not receive this test. The microfluidics chip was fabricated in polydimethylsiloxane (PDMS) using soft-film lithography. Following further processing and cleaning, the PDMS mold is exposed to UV-ozone for surface activation, and then sealed with a glass coverslip to …

Development Of An In Vitro Myogenesis Assay, Anna Arnaud

Biomedical Engineering Undergraduate Honors Theses

The objective of this study was to explore the interaction between mouse C2C12 cells and the extracellular matrix, particularly the process of myoblasts converting to myocytes. This study aimed to create a myogenesis assay that presents a process to effectively monitor the development of mouse C2C12 myoblasts into differentiated skeletal myotubes through detection of the protein MyoD. Myogenesis, the development of muscle tissue, occurs when muscle progenitor cells, myoblasts, fuse to form multinucleated myotubes, followed by cell fusion and resulting in a myofiber capable of contraction. An in vitro myogenesis assay would enable further research to efficiently test the effect …

Multiplexed Microfluidic Loop-Mediated Isothermal Amplification Of The 16s Rrna Gene For The Diagnosis Of Neonatal Sepsis In Resource-Limited Environments, Griffin Thomas Sonaty

Biomedical Engineering Undergraduate Honors Theses

Bacterial infection, or sepsis, places a disproportionately high burden on newborns in developing countries. This is due in part to a lack of diagnostic tools suitable for sustainable use in resource-limited nurseries. One potential vehicle for a new diagnostic assay is loop-mediated isothermal amplification (LAMP), a high-yield DNA amplification method. LAMP has been used to detect single genes from bacteria in blood serum samples to aid in sepsis diagnosis. While specific, this approach can only provide detection for one species at a time. LAMP could be adapted to detect a broader set of bacteria, while retaining a degree of specificity …

Intracellular Uptake Of Chitosan Nanoparticle-Based Vaccines, Katherine E. Wilson

Biomedical Engineering Undergraduate Honors Theses

Particle-based delivery systems are a promising approach to enhance antigen-specific immunity for use in vaccines. Chitosan, a natural polysaccharide derived from the exoskeletons of crustaceans, shows great potential as a vaccine carrier due to its favorable properties as a biomaterial, including biocompatibility and biodegradability. In this study, the intracellular uptake of chitosan nanoparticles is explored and compared to that of other commonly used particle-based delivery vehicles, such as poly (lactic-co-glycolic acid) (PLGA). Fluorescein isothiocyanate-labeled bovine serum albumin (FITC-BSA) was used as a model protein antigen and encapsulated in both chitosan particles via precipitation-coacervation and PLGA particles via double emulsion solvent …

Characterization Of Novel Chitosan/Polyelectrolyte Nanoparticles, Michaela Wynne Mertz

Biomedical Engineering Undergraduate Honors Theses

Chitosan-based nanoparticles are under investigation as delivery vehicles for drugs, genes, and proteins. Due to the biocompatibility, mucoadhesive nature, and biodegradable nature of chitosan and binding qualities, anionic nature, and biocompatible qualities of heparin, chitosan/heparin nanoparticles (CHNPs) are a promising platform for the delivery of labile proteins. However, the literature lacks a definitive process to control the size, efficiency, and yield of CHNPs at higher concentrations of reagents. Additionally there is a need to improve loading efficiency of CHNPs. In this study CHNPs have been synthesized and characterized for size, yield, protein loading efficiency, and release. The CHNPs were prepared …

Fractionation Of Chitosan Using A Novel Precipitation Method, Davis J. Ward

Biomedical Engineering Undergraduate Honors Theses

Chitosan is a derivative of chitin, a biopolymer found in the exoskeletons of crustaceans. Chitosan is under heavy investigation in the field of drug delivery due to its wide versatility. One such delivery mechanism is the use of hydrogels in cancer immunotherapy delivery. The viscosity of chitosan in its use as a hydrogel depends on the length of chitosan’s N-acetyl D-glucosamine chains, which in turn determines the molecular weight of chitosan. Because there is such a wide range of viscosity in a typical sample of chitosan, there is a need for a simple technique to fractionate the chitosan based on …

Monitoring The Effects Of Mmp Inhibitors On Extracellular Matrix Degradation For Use In Implant Protection, Jake D. Jones

Biomedical Engineering Undergraduate Honors Theses

In order to lengthen the functional time of implantable ECM, the mechanism of degradation must be inhibited. The matrix metalloproteases are the primary method by which ECM is broken down, and the TIMP family of proteins exists as proof that inhibition of these proteases is possible naturally. In particular, the glycoprotein TIMP-1 plays an inhibitory role with most of the MMPs including the collagenases. Furthermore, there exist synthetic or chemical molecules that likewise inhibit the catalytic actions of MMPs. One such molecule is Batimastat (BB-94) which has been proven to be a dose dependent inhibitor of MMPs during the inflammatory …

Nebulized Solvent Ablation Of Aligned Plla Fibers For The Study Of Neurite Response To Anisotropic-To-Isotropic Fiber/Film Transition (Afft) Boundaries In Astrocyte-Neuron Co-Cultures, Jonathan M. Zuidema, Gregory P. Desmond, Christopher J. Rivet, Kathryn R. Kearns, Deanna M. Thompson, Ryan J. Gilbert

Chemical and Biochemical Engineering Faculty Research & Creative Works

Developing robust invitro models of in vivo environments has the potential to reduce costs and bring new therapies from the bench top to the clinic more efficiently. This study aimed to develop a biomaterial platform capable of modeling isotropic-to-anisotropic cellular transitions observed in vivo, specifically focusing on changes in cellular organization following spinal cord injury. In order to accomplish this goal, nebulized solvent patterning of aligned, electro spun poly-. l-lactic acid (PLLA) fiber substrates were developed. This method produced a clear topographic transitional boundary between aligned PLLA fibers and an isotropic PLLA film region. Astrocytes were then seeded on these …

Fabrication And Characterization Of Poly(Octanediol Citrate)/Gallium-Containing Bioglass Microcomposite Scaffolds, Ehsan Zeimaran, Sara Pourshahrestani, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Hussin A. Rothan, Rohana Yusof, Mark R. Towler, Ivan Djordjevic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bone can be affected by osteosarcomae requiring surgical excision of the tumor as part of the treatment regime. Complete removal of cancerous cells is difficult and conventionally requires the removal of a margin of safety around the tumor to offer improved patient prognosis. This work considers a novel series of composite scaffolds based on poly (octanediol citrate) (POC) impregnated with gallium-based bioglass microparticles for possible incorporation into bone following tumor removal. The objective of this research was to fabricate and characterize these scaffolds and subsequently report on their mechanical and biological properties. The porous micro composite scaffolds with various concentrations …

A Glass Polyalkenoate Cement Carrier For Bone Morphogenetic Proteins, Adel M.F. Alhalawani, Omar Rodriguez, Declan J. Curran, Russell Co, Sean Kieran, Saad Arshad, Timothy J. Keenan, Anthony W. Wren, Gazelle Crasto, Sean A.F. Peel, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This work considers a glass polyalkenoate cement (GPC)-based carrier for the effective delivery of bone morphogenetic proteins (BMPs) at an implantation site. A 0.12 CaO–0.04 SrO–0.36 ZnO–0.48 SiO₂ based glass and poly(acrylic acid) (PAA, Mw 213,000) were employed for the fabrication of the GPC. The media used for the water source in the GPC reaction was altered to produce a series of GPCs. The GPC liquid media was either 100 % distilled water with additions of albumin at 0, 2, 5 and 8 wt% of the glass content, 100 % formulation buffer (IFB), and 100 % BMP (150 µg …

Investigating The Solubility And Cytocompatibility Of Cao-Na2o-Sio2/Tio2 Bioactive Glasses, Anthony W. Wren, Aisling Coughlan, Courtney M. Smith, Sarah P. Hudson, Fathima R. Laffir, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

This study aims to investigate the solubility of a series of titanium (TiO₂)-containing bioactive glasses and their subsequent effect on cell viability. Five glasses were synthesized in the composition range SiO₂-Na₂O-CaO with 5 mol % of increments TiO₂ substituted for SiO₂. Glass solubility was investigated with respect to (1) exposed surface area, (2) particle size, (3) incubation time, and (4) compositional effects. Ion release profiles showed that sodium (Na⁺) presented high release rates after 1 day and were unchanged between 7 and 14 days. Calcium (Ca²⁺) release …

Technoeconomics And Sustainability Of Renewable Methanol And Ammonia Productions Using Wind Power-Based Hydrogen, Michael J. Matzen, Mahdi H. Alhajji, Yaşar Demirel

Yaşar Demirel Publications

This study analyzes and compares the economics and sustainability aspects of two hydrogenation processes for producing renewable methanol and ammonia by using wind-power based electrolytic hydrogen. Carbon dioxide from an ethanol plant is used for producing methanol, while the nitrogen is supplied by an Air Separation Unit (ASU) for producing ammonia. The capacities are 99.96 mt/day methanol and 1202.55 mt/day anhydrous ammonia. The methanol plant requires 138.37 mt CO₂/day and 19.08 mt H₂/day. The ammonia is synthesized by using 217.72 mt H₂/day and 1009.15 mt N₂/day. The production costs and the carbon …

Biomimetic Oral Mucin From Polymer Micelle Networks, Sundar Prasanth Authimoolam

Theses and Dissertations--Chemical and Materials Engineering

Mucin networks are formed by the complexation of bottlebrush-like mucin glycoprotein with other small molecule glycoproteins. These glycoproteins create nanoscale strands that then arrange into a nanoporous mesh. These networks play an important role in ensuring surface hydration, lubricity and barrier protection. In order to understand the functional behavior in mucin networks, it is important to decouple their chemical and physical effects responsible for generating the fundamental property-function relationship. To achieve this goal, we propose to develop a synthetic biomimetic mucin using a layer-by-layer (LBL) deposition approach. In this work, a hierarchical 3-dimensional structures resembling natural mucin networks was generated …

Long Term Blood Oxygenation Membranes, Joseph V. Alexander

Theses and Dissertations--Biomedical Engineering

Hollow fiber membranes are widely used in blood oxygenators to remove carbon dioxide and add oxygen during cardiopulmonary bypass operations. These devices are now widely used off-label by physicians to perform extracorporeal blood oxygenation for patients with lung failure. Unfortunately, the hollow fiber membranes used in these devices fail prematurely due to blood plasma leakage and gas emboli formation.

This project formed ultrathin (~100nm) polymer coatings on polymer hollow fiber membranes. The coatings were intended to “block” existing pores on the exterior surfaces while permitting high gas fluxes. This coating is synthesized using surface imitated control radical polymerization.

The coating …

Inhalable Nanocomposites And Anticancer Agents For Cancer Therapy, Nathanael A. Stocke

Theses and Dissertations--Chemical and Materials Engineering

Cancer is designated as the leading cause of mortality worldwide and lung cancer is responsible for nearly 30% of all cancer related deaths. Over the last few decades mortality rates have only marginally increased and rates of recurrence remain high. These factors, among others, suggest the need for more innovative treatment modalities in lung cancer therapy. Targeted pulmonary delivery is well established for treating pulmonary diseases such as asthma and provides a promising platform for lung cancer therapy. Increasing local deposition of anticancer agents (ACAs) and reducing systemic exposure of these toxic moieties could lead to better therapeutic outcomes and …

Formulation Of Benzoxaborole Drugs In Plla: From Materials Preparation To In Vitro Release Kinetics And Cellular Assays, Saad Sene, Joshua Mclane, Nicholas Schaub, Sylvie Bégu, P. Hubert Mutin, Lee Ligon, Ryan J. Gilbert, Danielle Laurencin

Chemical and Biochemical Engineering Faculty Research & Creative Works

Benzoxaboroles are a family of organoboron molecules, which have been finding over the past few years an increasing number of biological applications, notably for the design of new drugs. Given that these molecules are still relatively new in the biomedical context, very few investigations regarding their formulation have been reported to date. Here, a complete study on the formulation of benzoxaboroles in a biopolymer, poly-l-lactic acid (PLLA), is reported. The incorporation of two small benzoxaboroles, namely the simplest benzoxaborole molecule (BBzx) and the antifungal drug tavaborole (AN2690), inside PLLA films was investigated. Different variations in the film composition and texture …

Astrocytes Increase Atp Exocytosis Mediated Calcium Signaling In Response To Microgroove Structures, Ajay V. Singh, Michael Raymond, Fabiano Pace, Anthony Certo, Jonathan M. Zuidema, Christopher A. Mckay, Ryan J. Gilbert, X. Lucas Lu, Leo Q. Wan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Following central nervous system (CNS) injury, activated astrocytes form glial scars, which inhibit axonal regeneration, leading to long-term functional deficits. Engineered nanoscale scaffolds guide cell growth and enhance regeneration within models of spinal cord injury. However, the effects of micro-/nano size scaffolds on astrocyte function are not well characterized. In this study, a high throughput (HTP) microscale platform was developed to study astrocyte cell behavior on micropatterned surfaces containing 11/4m spacing grooves with a depth of 250 or 500â €...nm. Significant changes in cell and nuclear elongation and alignment on patterned surfaces were observed, compared to on flat surfaces. The …

Evaluation Of The Signature Molecular Descriptor With Blosum62 And An All-Atom Description For Use In Sequence Alignment Of Proteins, Lindsay M. Aichinger

Williams Honors College, Honors Research Projects

This Honors Project focused on a few aspects of this topic. The second is comparing the molecular signature kernels to three of the BLOSUM matrices (30, 62, and 90) to test the accuracy of the mathematical model. The kernel matrix was manipulated in order to improve the relationship by focusing on side groups and also by changing how the structure was represented in the matrix by increasing the initial height distance from the central atom (Height 1 and Height 2 included).

There were multiple design constraints for this project. The first was the comparison with the BLOSUM matrices (30, 62, …

Effect Of Nitrogen On Properties Of Na2o-Cao-Sro-Zno-Sio2 Glasses, Ahmed Bachar, Cyrille Mercier, Arnaud Tricoteaux, Jean Christophe Hornez, Anne Leriche, Claudine Follet, Bertrand Revel, Stuart Hampshire, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glasses in the Na₂O-CaO-SrO-ZnO-SiO₂ system have previously been investigated for suitability as a reagent in Al-free glass polyalkenoate cements (GPCs). These materials have many properties that offer potential in orthopedics. However, their applicability has been limited, to date, because of their poor strength. This study was undertaken with the aim of increasing the mechanical properties of a series of these Zn-based GPC glasses by doping with nitrogen to give overall compositions of: 10Na₂O-10CaO-20SrO-20ZnO-(40-3x)SiO₂-xSi₃N₄ (x is the no. of moles of Si₃N₄). The density, glass-transition temperature, hardness, …