Biomedical Engineering and Bioengineering Commons^™

Apply Dry Powder On Drug Loading And Enteric Coating Of Esomeprazole Magnesium Trihydrate Beads And Capsules, Xiaojing Ge

Electronic Thesis and Dissertation Repository

Esomeprazole magnesium tri-hydrate (EMT) is a proton pump inhibitor, used for the treatment of gastric and duodenum ulcers. It is currently the best choice for the treatment of acid-related diseases, but it is extremely unstable in gastric acid and sensitive to wet, heat, light. It also will react with the enteric coating material used in this study. So enteric coating and sub coating is needed.

This study offers a new approach, dry powder coating technology, to achieve drug loading and enteric coating of EMT beads and capsules. Dry powder coating, a new type of solvent-less coating technology, can address most …

Development Of Granulation Tissue Mimetic Scaffolds For Skin Healing, Adam Hopfgartner

Electronic Thesis and Dissertation Repository

Impaired skin healing is a significant and growing clinical concern, particularly in relation to diabetes, venous insufficiency and immobility. Previously, we developed electrospun scaffolds for the delivery of periostin (POSTN) and connective tissue growth factor 2 (CCN2), matricellular proteins involved in the proliferative phase of healing. This study aimed to design and validate a novel electrosprayed coaxial microsphere for the encapsulation of fibroblast growth factor 9 (FGF9), as a component of the POSTN/CCN2 scaffold, to promote angiogenic stability during wound healing. For the first time, we observed a pro-proliferative effect of FGF9 on human dermal fibroblasts (HDF) in vitro, indicating …

Electrospun Collagen Fibers For Tissue Regeneration Applications, Ying Li

Electronic Thesis and Dissertation Repository

Tissue engineering aims to regenerate damaged and deceased tissue by combining cells with scaffold made from an appropriate biomaterial and providing a conducive environment to guide cell growth and the formation or regeneration of new tissue or organ. While collagen, an important material of the extracellular matrix (ECM), is a natural choice as a scaffold biomaterial, the conducive environment can only be created by having the ability to control the geometry, organization, structural and mechanical properties of the scaffold. Moreover, degradability and degradation rate control of the scaffold has to be taken into consideration too. In this work, we aim …

Engineering Graphene Oxide-Based Nanostructures For Dna Sensors, Aditya Balaji

Electronic Thesis and Dissertation Repository

Various nanostructures have been explored in DNA biosensors to convert the hybridization of DNA sequences to easily measurable processes, including optical, mechanical, magnetic, or electrochemical process. In this thesis, graphene oxide, a two-dimensional nanostructure, is applied in quenching the fluorescence of a core-shell nanoparticles modified with targeted DNA sequences. The core-shell nanoparticles, iron oxide (Fe₃O₄) core, and fluorescent silica (SiO₂) shell, were produced through a wet chemical process which can directly link to a targeted DNA sequence (DNA-t), and the graphene oxide nanosheets were produced by the oxidation of graphite. In the meantime, …

Preparation And Characterization Of Electrospun Rgo-Poly(Ester Amide) Tissue Engineering Scaffolds, Hilary Stone

Electronic Thesis and Dissertation Repository

Tissue engineering scaffolds should support tissue maturation through exposure to biologically relevant stimuli and through successful cell infiltration. External electrical stimulation is particularly relevant for cardiac and neural applications, and requires conductive scaffolds to propagate electrical signals; cell infiltration is only possible with scaffolds that have sufficient porosity. The aim of this study was to impart conductivity and increased porosity of electrospun poly(ester amide) (PEA) scaffolds. Reduced graphene oxide (rGO) was incorporated into blend PEA and coaxial PEA-chitosan fibrous scaffolds, which increased scaffold conductivity and supported cardiac differentiation. The novel combination of ultrasonication and leaching of a sacrificial polymer was …

Covalently Crosslinked Organic/Inorganic Hybrid Biomaterials For Bone Tissue Engineering Applications, Dibakar Mondal

Electronic Thesis and Dissertation Repository

Scaffolds are key components for bone tissue engineering and regeneration. They guide new bone formation by mimicking bone extracellular matrix for cell recruitment and proliferation. Ideally, scaffolds for bone tissue engineering need to be osteoconductive, osteoinductive, porous, degradable and mechanically competent. As a single material can not provide all these requirements, composites of several biomaterials are viable solutions to combine various properties. However, conventional composites fail to fulfil these requirements due to their distinct phases at the microscopic level. Organic/inorganic (O/I) class II hybrid biomaterials, where the organic and inorganic phases are chemically crosslinked on a molecular scale, hence the …

Fabrication And Modification Of Titania Nanotube Arrays For Harvesting Solar Energy And Drug Delivery Applications, Ahmed El Ruby Abdel Rahman Mohamed

Electronic Thesis and Dissertation Repository

The fast diminishing of fossil fuels in the near future, as well as the global warming caused by increasing greenhouse gases have motivated the urgent quest to develop advanced materials as cost-effective photoanodes for solar light harvesting and many other photocatalytic applications. Recently, titania nanotube arrays (TNTAs) fabricated by anodization process has attracted great interest due to their excellent properties such as: high surface area, vertically oriented, highly organized, one-dimensional, nanotubular structure, photoactivity, chemical stability and biocompatibility. This unique combination of excellent properties makes TNTAs an excellent photoanode for solar light harvesting. However, the relatively wide band gap energy of …

Design And Validation Of Delivery Systems For Galectin-3 For Skin Healing Applications, Karrington A. Mcleod

Electronic Thesis and Dissertation Repository

Chronic wounds present a significant burden to patients, causing pain, impairing limb function, and often resulting in the need for amputation. Treatment of chronic dermal wounds is challenging, with current therapies showing limited efficacy in clinical trials. As galectin-3 has been implicated in several wound healing processes, its efficacy as a therapeutic in skin healing was investigated in this study. An electrospun gelatin scaffold loaded with galectin-3 was developed as a delivery system. The influence of human recombinant galectin-3 in skin healing, when delivered topically and using an electrospun scaffold, was then investigated in wild type and diabetic mice. Electrospun …

Assessment Of The Non-Linear Stress-Strain Characteristics Of Poly (Vinyl Alcohol) Cryogel, Mojdeh Zakeri

Electronic Thesis and Dissertation Repository

Creation of tissue-mimicking constructs is of great importance in the field of biomedical engineering. Poly (vinyl Alcohol) (PVA) is a biomaterial capable of simulating a wide range of geometries and mechanical properties of biological tissues. It is nontoxic, biocompatible, and easy to produce. PVA can be physically crosslinked by repeated cycles of freezing and thawing. The final product of this process is called PVA cryogel (PVA-C). The mechanical properties of PVA-C can be accurately controlled by changing PVA molecular weight, PVA concentration, and number and duration of freeze/thaw cycles (FTC). In this study, the stress-strain behavior of PVA cryogel was …

Investigation Of Chitosan-Based Hydrogels As A Cell Delivery Platform For Adipose-Derived Stem/Stromal Cell Transplantation To Promote Angiogenesis In Ischemic Tissues, Jobanpreet Singh Dhillon

Electronic Thesis and Dissertation Repository

Stem cell transplantation is under investigation to stimulate angiogenesis in patients with peripheral artery disease. To develop a cell-delivery platform that enhances cell retention and function post-transplantation, the response of human adipose-derived stem/stromal cells (ASCs) encapsulated within N-methacrylate glycol chitosan (MGC) hydrogels with or without integrin-binding RGD or IKVAV motifs was explored. ASC viability was enhanced in the MGC and MGC-RGD hydrogels relative to the MGC-IKVAV group under hypoxic (2% O­₂) culture conditions, with cell spreading and higher metabolic activity noted in MGC-RGD at 14 days. Analysis of angiogenic gene expression revealed similar patterns between all hydrogel …

Effect Of L-Ascorbic Acid And All-Trans Retinoic Acid On Smooth Muscle Cells Cultured On Pcl Scaffolds, Brandon Chaffay

Electronic Thesis and Dissertation Repository

The aim of vascular tissue engineering (VTE) is to fabricate tissues that are both mechanically and biologically competent similar to the native vessel they are intended to replace. To this end, the incorporation of sufficient extracellular matrix elastin and collagen is important. The objective of this thesis work was to evaluate the effect of two biochemical factors, l-ascorbic acid (AA) and all-trans retinoic acid (atRA), on elastin synthesis when coronary artery smooth muscle cells were cultured on 3D polycaprolactone (PCL) scaffolds. First, porous PCL scaffolds were fabricated using a solvent casting and particulate leaching approach. The effect of different …

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 …

Controlled Delivery Of Angiogenic And Arteriogenic Growth Factors From Biodegradable Poly(Ester Amide) Electrospun Fibers For Therapeutic Angiogenesis, Somiraa S. Said

Electronic Thesis and Dissertation Repository

Therapeutic angiogenesis relies on the delivery of exogenous growth factors to stimulate neovessel formation. However, systemic administration of angiogenic factors results in rapid clearance from the site of interest due to their short biological half-life. In this work, we are reporting controlled delivery of a ‘cocktail’ of growth factors, an angiogenic factor −fibroblast growth factor-2 (FGF2), and an arteriogenic factor −fibroblast growth factor-9 (FGF9), from biodegradable poly(ester amide) (PEA) electrospun fibers towards targeting neovascular formation and maturation. FGF2 and FGF9 were dual loaded into PEA fibers using a mixed blend and emulsion electrospinning technique. Matrigel tube formation and Boyden chamber …

The Role Of Bone Sialoprotein In Periodontal Tissue Development And Bone Repair, Yohannes Soenjaya

Electronic Thesis and Dissertation Repository

Bone development and repair involve complex processes that include interaction between cells and their surrounding matrix. In the body, bone sialoprotein (BSP) expression is up-regulated at the onset of mineralization. BSP is a multifunctional acidic phosphoprotein with collagen-binding, hydroxyapatite nucleating, and integrin recognition (RGD sequence, which is important for cell-attachment and signaling) regions. Mice lacking BSP expression (Bsp^-/-), exhibit a bone phenotype with reductions in bone mineral density, bone length, osteoclast activation, and impaired bone healing. This thesis examined the role of BSP in tooth development and also its potential use as a therapeutic reagent for bone …

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 …

Passive Acoustic Emissions Monitoring Of Fluidized Bed Pellet Coating, Taylor Sheahan

Electronic Thesis and Dissertation Repository

Passive acoustic emissions were assessed for their potential as a non-invasive monitoring tool for the coating of pellets in a fluidized bed. Pharmaceutical pellets are small spherical particles that contain an active ingredient. They are film coated for the purpose of modified drug release and packed into capsules as a multiple unit dosage form. A more reliable monitoring and control method is desired to ensure the appropriate drug release profile is achieved by minimizing variations within and between coated pellets.

Microphones attached to the exterior of a conical top spray fluidized bed measured acoustic emissions produced from the coating process. …

Bioactive Glass-Ceramic Coating Of Titanium Substrates By Alkaline Hydrothermal Process, Mohamed Gebril

Electronic Thesis and Dissertation Repository

Surface modification is a well-known approach to enhance the osseointegration of titanium dental implants. In this study, a novel hydrothermal method for coating titanium surfaces with bioactive glass was developed. Our method included sol-gel synthesis of bioactive glass, followed by hydrothermal coating of titanium under different NaOH concentrations. The surface properties of coated substrates were evaluated by scanning electron microscopy, X-ray diffraction, energy dispersive X-ray spectroscopy, and surface profilometry. By varying the alkalinity of the hydrothermal process, different surface topographies, crystalline phases and chemistries could be obtained. Soaking the hydrothermally coated titanium substrates in simulated body fluid resulted in hydroxyapatite …

Synthesis And Evaluation Of A Novel Polymer Microfiber Drug Delivery System, Julie La

Electronic Thesis and Dissertation Repository

Skin cancer is the most prevalent cancer diagnosis worldwide. Squamous cell carcinoma (SCC) is one of the most common diagnoses. Fortunately, these cancers are rarely fatal if detected and treated early on. However, current treatment options can be painful, disfiguring and can require long-term treatment courses, resulting in poor patient compliance and cancer progression. Since SCC begins as precancerous lesions, an opportunity exists for early preventative interventions which this work aims to address. We produced stabilized microfibers via centrifugal spinning and UV photocrosslinking composed of poly(ethylene oxide) functionalized with cinnamoyl chloride. Curcumin, a molecule known for its anti-cancer properties was …

Design And Fabrication Of A Multifunctional Nano-On-Micro Delivery System, Alexandra D. Bannerman

Electronic Thesis and Dissertation Repository

The treatment of tumours using microbeads for embolization and drug delivery is a widely used, but often ineffective, technique. In this work, we aim to produce microbeads for this application with four main improvements: visibility, target-ability, degradability, and an alternative route for drug loading. We accomplish this through the fabrication of ~100μm diameter microbeads composed of poly(vinyl alcohol) (PVA), iron oxide nanoparticles, and cellulose nanocrystals (CNC) using a custom-designed microchannel system. Characterization demonstrated that microbeads were magnetic, as well as visible under clinical CT. Separately, the dissolution of PVA iron oxide hydrogels exposed to different environmental conditions was studied. Iron …

Engineering Periodontal Tissue Regeneration With The Use Of A Novel Periostin Electrospun Scaffold, Kendal I. Creber

Electronic Thesis and Dissertation Repository

Clinical therapies for the treatment of periodontitis are unable to reproducibly stimulate regeneration of the periodontium. We assessed the use of a novel electrospun type I collagen scaffold containing recombinant periostin to stimulate regeneration of the periodontal ligament (PDL) and bone. Human PDL cells demonstrated the ability to form a mineralized matrix in vitro and reduced osteogenic potential with increased donor age. In vitro analysis indicated scaffolds were biocompatible, however, periostin did not significantly influence adhesion or growth. In the healing of fenestration defects in rats, type I collagen scaffolds (with and without periostin) initially delayed cell infiltration and increased …

A New Generation Of Polymer/Ceramic Composite Biomaterials For Bone Regeneration, Mehrnaz Salarian

Electronic Thesis and Dissertation Repository

There is a substantial emerging interest for fundamental and applied research on the reinforcement of polymeric materials using nanotechnology. In the biomedical industry, development of novel bone cement composite materials with enhanced mechanical properties is of tremendous potential importance. The most universally used injectable bone cement is made of poly(methyl methacrylate) (PMMA); however, the major disadvantage of PMMA is its non-biodegradability. Polymers such as poly(propylene fumarate) (PPF) and polycaprolactone (PCL) are biodegradable, but suffer from a lack of mechanical properties. The aim of this research was to test the efficacy of these biodegradable polymers integrating nanotechnology for the development of …

Poly(Ester Amide) And Poly(Ethyl Glyoxylate) Nanoparticles For Controlled Drug Release, Amira Mohamed Moustafa

Electronic Thesis and Dissertation Repository

The objective of this research was to develop polymeric nanoparticles (NPs) having improved drug release properties for drug delivery. Poly(ester amide)s (PEAs) are promising biodegradable polymers. PEA NPs were prepared via emulsification-evaporation and salting-out methods and optimized through by varying different processing parameters. Polymer-model drug conjugates based on PEAs containing L-aspartic acid and rhodamine B were synthesized and used for NP preparation. Release behavior was studied and compared to a control system with physically encapsulated rhodamine B. It was shown that the release of rhodamine B from the covalent system did not show the burst effect and exhibited a slower …

Laser-Assisted Surface Modification Of Hybrid Hydrogels To Prevent Bacterial Contamination And Protein Fouling, Guobang Huang

Electronic Thesis and Dissertation Repository

Silicone hydrogels have been extensively studied in the fields of contact lenses, tissue engineering, and drug delivery due to their good biocompatibility, high oxygen permeability, and proper light transmission. However, their applications in biomedical devices are limited by protein adsorption and bacterial contamination because of the hydrophobic surface of silicone, which will cause more irreversible protein adsorption. Several physical methods can be applied to create a hydrophilic surface on hydrogels, such as spin coating, physical vapor deposition, dip coating, drop casting, etc. Compared to the conventional methods, the matrix assisted pulsed laser evaporation (MAPLE) is suitable to produce biopolymer/polymer film …

Curcumin-Loaded Magnetic Nanoaggregates Conjugated With Folic Acid For Targeted Cancer Treatment, Melessa Salem

Electronic Thesis and Dissertation Repository

Cancer has been, and still remains, one of the most complicated diseases to treat. As a result of the side effects experienced from current cancer treatment methods, there has been a growing interest in the development of targeted drug delivery systems that can destroy cancer cells, but render healthy tissue unharmed. To address this challenge, magnetite nanoaggregates were synthesized through the precipitation of iron oxide in the presence of polymers, conjugated with folic acid for folate targeting, and loaded with curcumin for cancer treatment. The resulting magnetite nanoparticles were 10 – 20 nm in size and the aggregates formed varied …

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 …

Oriented Collagen And Applications Of Waveguide Evanescent Field Scattering (Wefs) Microscopy, Qamrun Nahar

Electronic Thesis and Dissertation Repository

In this thesis, Waveguide Evanescent Field Scattering (WEFS) microscopy is developed as a non-invasive, label-free live cell imaging technique. This new high-contrast imaging can be employed to study the first hundred nanometers from the surface as it utilizes the evanescent field of a waveguide as the illumination source. Previously, waveguide evanescent field fluorescence (WEFF) microscopy was developed as a fluorescence imaging technique comparable to the total internal reflection fluorescent (TIRF) microscopy. Both the WEFF and WEFS technique utilizes the same fundamental concepts except in WEFS microscopy imaging is accomplished without the application of any fluorescent labeling. In this work, bacterial …

Humidity Effect On The Structure Of Electrospun Core-Shell Pcl-Peg Fibers For Tissue Regeneration Applications, Adam P. Golin

Electronic Thesis and Dissertation Repository

With the aim of creating a biodegradable scaffold for tympanic membrane (TM) tissue regeneration, core-shell nanofibers composed of a poly(caprolactone) shell and a poly(ethylene glycol) core were created using a coaxial electrospinning technique. In order to create fibers with an optimal core-shell morphology, the effect of relative humidity (RH) on the core-shell nanofibers was systematically studied, with a FITC-BSA complex encapsulated in the core to act as a model protein. The core-shell nanofibers were electrospun at relative humidity values of 20, 25, 30, and 40% RH within a glove box outfitted for humidity control. The core-shell morphology of the fibers …

Drug Delivery To The Respiratory Tract Using Dry Powder Inhalers, Doaa M.R. Mossaad

Electronic Thesis and Dissertation Repository

Aerosols are an effective method to deliver therapeutic agents to the respiratory tract. Among aerosol generation systems, dry powder inhales have been attractive area of research for both local and systemic delivery of drugs. The challenge of any inhalation delivery system is to generate particles with an adequate range of particle sizes. In order to advance powder aerosol technologies, researchers have recognized the importance of investigating determinants affecting powder dispersion. The effect of particles’ surface characteristics, inhalation airflow rate, inhalation device, and development of an effective drug-carrier system are some of the fundamental areas that have been under investigation.

The …

Surface Functionalization And Bioconjugation Of Nanoparticles For Biomedical Applications, Longyan Chen

Electronic Thesis and Dissertation Repository

Colloidal inorganic nanoparticles (NPs) have been attracting considerable interest in biomedicine, from drug and gene delivery to imaging, sensing and diagnostics. It is essential to modify the surface of nanoparticles to have enhanced biocompatibility and functionality for the in vitro and in vivo applications, especially in delivering locally and recognizing biomolecules. Herein, the goal of this research work is to develop advanced NPs with well-tailored surface functionalities and/or bio-functionality for the applications in cell tracking and analytes detection.

In the first project, quantum dots incorporating with gelatin nanoparticles (QDs-GNPs) have been developed for bioimaging applications. Two different approaches have been …

Production Of Lignin-Based Phenolic Resins Using De-Polymerized Kraft Lignin And Process Optimization, Homaira Siddiqui

Electronic Thesis and Dissertation Repository

Commercialization of Lignin-based phenol formaldehyde resins (LPF) has been limited due to the increase in curing temperatures and decrease in adhesive strength of LPF compared to conventional phenolic resins. Lignin depolymerization can increase the reactivity of lignin; however, the effect of lignin molecular weight on curing performance of LPF resins has yet to be investigated. This research work examined the optimization of synthesis parameters including percent substitution of phenol with lignin, formaldehyde- to-phenol ratio (F/P), and Mw of lignin to reduce the curing temperature and increase the adhesive strength of LPF. DSC analysis indicated that lignin with Mw ~1200g/mol resulted …