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Articles 1 - 22 of 22
Full-Text Articles in Engineering
Nanocellulose Based Foams For Low-Cost Disposable Medical Applications, Dominic Kugell
Nanocellulose Based Foams For Low-Cost Disposable Medical Applications, Dominic Kugell
Electronic Theses and Dissertations
Polyurethane foams have been a staple material for their use in medical positioners, such as post-surgery elevation pillows as well as specific tailored positioners for their use during surgery. Polyurethane foams are preferred because of their lower cost compared to other petroleum derived foams, their versatility, and suitable mechanical properties. However, the environmental impact, including both cost and perception, of these foams is immense. Therefore, alternatives are being explored with biopolymers emerging as a promising class of materials. Cellulose is one such polymer that has recently demonstrated desirable properties. In this study, cellulose nanofibrils (CNF), a household foaming agent, and …
An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez
An Experimental Study On The Mechanical Properties And Chemical Composition Of Lcd 3d Printed Specimens, Sebastian Gomez
Electronic Theses and Dissertations
Additive manufacturing technologies have been enhanced throughout the years yet have surprised the manufacturing industry due to their high-end surface finish and dimensional accuracy. Different experiments have been done to identify a specific phenomenon known in the vat-polymerization field. Distortion and dimensional inaccuracy tend to affect the overall properties of the process, either physical or chemical. This approach allows the understanding of how the physical properties have been affected and how to study the chemical properties to avoid this type of phenomenon. The chemical reaction between polymer and UV light has been studied and experimented with to the point that …
The Influence Of Processing And Additives On Cellulose Nanofiber Properties For Orthopedic Application, Mitchell P. Chesley
The Influence Of Processing And Additives On Cellulose Nanofiber Properties For Orthopedic Application, Mitchell P. Chesley
Electronic Theses and Dissertations
Current orthopedics are separated into three different classes of materials, metals, polymers, and ceramics. While these devices have had success throughout the years they are not without their faults. Metallic devices for example are usually extraordinarily stiff when compared with the surrounding bone. This difference in stiffness induces localized stress-shielding promoting cortical atrophy, which can lead to osteoporosis. Polymers while having the capacity of being biodegradable and bioabsorbable also have the potential to incite localized demineralization and weakness in surrounding bone. A result of breakdown byproducts not efficiently being evacuated from the area, which additionally acts as catalysts expediating the …
Developing And Characterizing A Novel Tempo Cnf Hydrogel Adjuvant And Delivery System For Aquatic Vaccines, Kora Kukk
Electronic Theses and Dissertations
Aquaculture is a large part of the food production sector which is greatly expanding. One of the largest losses in aquaculture is due to pathogens. Current solutions for protecting farmed finfish from pathogens can be very expensive with variable efficiency. Current disease prevention strategies include vaccination. Types of vaccines include immersion vaccines, feed vaccines, and injectable vaccines. The most popular solution is oil-based injectable vaccines due to its protection. However, the oil-based adjuvant used in most of these formulations causes adverse reactions in the fish including reduced growth. These vaccines require multiple administrations throughout the fish’s lifetime causing unwanted handling …
Continuous, Non-Destructive Detection Of Surface Bacterial Growth With Bioinspired Vascularized Polymers, Brandon Dixon
Continuous, Non-Destructive Detection Of Surface Bacterial Growth With Bioinspired Vascularized Polymers, Brandon Dixon
Electronic Theses and Dissertations
Reducing or eliminating bacteria on surfaces is vital for medical devices, drinking water quality, and industrial processes. Evaluating surface bacterial growth at buried interfaces can be problematic due to the time-consuming disassembly process required for obtaining standard surface samples. In this work, a continuous, non-destructive, and reusable method was developed to detect surface bacterial growth at buried interfaces. Inspired by vascular systems in nature that permit chemical communication between the surface and underlying tissues of an organism, bacterial-specific signals diffusing from cells on the surface were detected in channels filled with an inert carrier fluid embedded in a polymer matrix. …
Fabrication And Characterization Of Lactobacillus Crispatus Containing Bioprints For Bacterial Vaginosis Application., Anthony J. Kyser
Fabrication And Characterization Of Lactobacillus Crispatus Containing Bioprints For Bacterial Vaginosis Application., Anthony J. Kyser
Electronic Theses and Dissertations
Bacterial vaginosis (BV) is a condition in which healthy lactobacilli are replaced by an overabundance of pathogenic bacteria in the female reproductive tract. Current antibiotic treatments often fail to “cure” infection, resulting in recurrence in more than 50% of women, 6 months post-treatment. Recently, probiotics have demonstrated promise to restore vaginal health; however, as with other active agents, delivery requires once-to-twice daily administration. Recently, three-dimensional (3D)-bioprinting has enabled the fabrication of well-defined cell-laden architectures with tunable agent release, thereby presenting a novel approach with which to deliver probiotics. One promising bioink, gelatin alginate, was selected for study, due to its …
Release Kinetics Of Metronidazole From 3d Printed Silicone Scaffolds., Sydney E. Herold
Release Kinetics Of Metronidazole From 3d Printed Silicone Scaffolds., Sydney E. Herold
Electronic Theses and Dissertations
Sustained local administration of active agents has been proposed to cure bacterial vaginosis in the female reproductive tract and restore the resident bacterial fauna. Bioprinting has shown promise for the development of systems for local agent delivery. In contrast to oral ingestion, agent release kinetics can be fine-tuned by bioprinting specialized scaffold designs tailored for particular treatments while enhancing dosage effectiveness via localized sustained release. It has been challenging to establish scaffold properties for sustained release as a function of fabrication parameters. Towards this goal, we evaluate 3D printed scaffold formulation and feasibility to sustain release of metronidazole, a representative …
Machine Learning Applied To Colloidal Properties Of Perfluorocarbon Nanoemulsions For Imaging In Ards/Ali, Marco Hosfeld
Machine Learning Applied To Colloidal Properties Of Perfluorocarbon Nanoemulsions For Imaging In Ards/Ali, Marco Hosfeld
Electronic Theses and Dissertations
Acute Respiratory distress Syndrome (ARDS) and Acute Lung Injury (ALI) are inflammatory lung pathologies consisting of non-hydrostatic pulmonary edema leading to hypoxia and impaired gas exchange in the lungs. ARDS/ALI is both difficult to study and treat as it is not in itself a specific pathology but rather a syndrome consisting of many pathologies that vary case by case. It is, however, consistently characterized by an explosive acute inflammatory response in the lung parenchyma leading to hypoxia. Although time has seen to an increase in the understanding of ARDS/ALI, the mortality rate remains in the range of 30-50%. For these …
Nanocellulose Conduits For Enhanced Regeneration Of Peripheral Nerve Injuries, Nicklaus R. Carter
Nanocellulose Conduits For Enhanced Regeneration Of Peripheral Nerve Injuries, Nicklaus R. Carter
Electronic Theses and Dissertations
Peripheral neuropathy is estimated to afflict 20 million people in the United States. Most cases of neuropathy result from physical injuries and trauma arising from automobile accidents and war. Peripheral nerves have the intrinsic ability to regenerate over time, bridging the injury gap. However native regeneration is limited to a distance of only a few millimeters. Current methods utilized to assist in the regeneration of peripheral nerves over distances exceeding those amenable to native repair include nerve autografts and allografts, and implantation of conduits. Nerve autografts are regarded as the most effective method but require a second surgical site to …
Handling And Manipulation Of Water- And Air- Borne Biological Samples Using Liquid-Infused Surfaces, Daniel P. Regan
Handling And Manipulation Of Water- And Air- Borne Biological Samples Using Liquid-Infused Surfaces, Daniel P. Regan
Electronic Theses and Dissertations
Research on novel materials to handling water- and airborne samples for biological threats analysis is in great demand due to the COVID-19 pandemic. Work conducted on a new field of material science, called liquid-infused surfaces, demonstrate strong potential for the handling and manipulation of biological samples. As a result of the field’s infancy, only a limited number of studies have explored how liquid-infused surfaces can apply droplet manipulation strategies to address real-world problems. Presented in this dissertation are two platforms that leverage liquid-infused surfaces to address the challenges associated with handling water- and airborne biological samples. When dealing with waterborne …
Bio-Inspired Materials For Electrochemical Sensors, Matthew Joseph Hummel
Bio-Inspired Materials For Electrochemical Sensors, Matthew Joseph Hummel
Electronic Theses and Dissertations
Electrochemical biosensors are a rapidly growing research area that has greatly improved its specificity, accuracy, and precision in the detection of biomolecules in contemporary literature and industry alike. Typically, these systems exist in a three-electrode conformation with a working electrode functioning as the anode, a counter electrode functioning as the cathode, and a reference electrode allowing for the control of potential in the system. The method by which these sensors work is through the sharing of electrons via redox reactions with the target molecule and the working electrode or modifications on its surface. By exploiting the function of biomaterials that …
The Use Of Nanoparticles And Electrospun Fibers For Intravaginal Delivery To Treat Viral And Bacterial Infections And Electrophysiological Measurements Of Synthetic Chloride Channels., Farnaz Minooei
Electronic Theses and Dissertations
Female reproductive viral and bacterial infections affect millions of women worldwide. Given the diversity and magnitude of these unmet reproductive health challenges, topical administration of antiretrovirals (ARVs) and antibiotics have emerged as promising approaches to maintain and restore reproductive health. However, currently available intravaginal dosage forms often suffer from low user adherence and the need for frequent, daily administration to achieve therapeutic effect. To address these challenges, the broad goal of this research was to focus on the development of new localized nanoparticle (NP) and electrospun fiber dosage forms to prolong the delivery and enhance the efficacy of active agents …
Pilot Study Exploring The Effect Of Targeted Cox-2 Inhibition In Macrophages Responding To Neuronal Injury; Promoting Enhanced Axonal Regeneration, Alyssa Brauckmann
Pilot Study Exploring The Effect Of Targeted Cox-2 Inhibition In Macrophages Responding To Neuronal Injury; Promoting Enhanced Axonal Regeneration, Alyssa Brauckmann
Electronic Theses and Dissertations
Celecoxib nanoemulsion (CXB-NE) has been developed as a macrophage targeted analgesics by Dr. Janjic and her team at Duquesne University, (Janjic et al, 2018; Liu et al, 2020; Saleem et al, 2019b; Vasudeva et al, 2014). The CXB-NE nanoemulsion carrying a Nonsteroidal Anti-inflammatory (NSAID) inhibitor of COX-2 activity result in a reduction in PGE2 expression in macrophages. Using CXB-NE in rats that have peripheral nerve injury constricting the sciatic nerve relieves hypersensitivity, a pain-like behavior. The treatment also decreases inflammation associated with this chronic constriction injury (Janjic et al, 2018; Saleem et al, 2019b; Stevens et al, 2019). In this …
Characterization Of Nano-Cellulose Based Composites For Biomedical Applications, Mitchell P. Chesley
Characterization Of Nano-Cellulose Based Composites For Biomedical Applications, Mitchell P. Chesley
Electronic Theses and Dissertations
The number of orthopedic surgeries performed globally has steadily increased over the past decade due to the standardization of procedures as well as technological advancements. During this time orthopedic devices have been composed predominantly of metals, such as Titanium, Vanadium, Molybdenum, and Stainless steel, as well as their alloys, due to the high strength and durability of these materials. However, metals may, in fact, be suboptimal for orthopedic devices. For example, metals exhibit Young’s modulus much greater than the surrounding bone, inducing localized stress-shielding promoting cortical atrophy, which can lead to osteoporosis. In recent years polymers have been successfully explored …
Design, Construction And Application Of A Home-Built, Two-Photon Microscope, William P. Breeding
Design, Construction And Application Of A Home-Built, Two-Photon Microscope, William P. Breeding
Electronic Theses and Dissertations
Two-photon microscopy (TPM) is a powerful, versatile imaging modality for the study of biological systems. This thesis overviews the relevant physics involved in TPM, design considerations and process of constructing a home-built, two-photon microscope, and provides a set of procedures to operate the system. Furthermore, this work explores several applications of TPM through the study of single-cell metabolism and imaging the cellular-material interface. Explored in particular depth was the imaging of cellulose nanofiber (CNF) materials, with the goal of understanding the three-dimensional nature of fibroblast cell growth when embedded within the materials. This work uncovered several optical properties of CNF, …
Suture-Less Trocar Site Closure Clip, Hares A. Patel
Suture-Less Trocar Site Closure Clip, Hares A. Patel
Electronic Theses and Dissertations
Introduction: Following laparoscopic surgery, there is a need, in many cases, to close trocar sites to prevent hernias. Currently, devices that exist on the market are suture based, but the lack of standardization in the suturing techniques together with the time-consuming nature of the procedure leads to the need for improvement in trocar site closure products. Trocar closure sites do not need to be fully closed on the fascial layer; rather, sufficiently blocking the hole at the abdominal wall can significantly reduce post-operative herniation. A retrospective study on trocar site herniation (TSH) after laparoscopic surgery indicates a TSH incidence …
Plga-Modified Nanoparticles For The Treatment Of Hypo-Vascularized Hpv-Related Cervical Cancers., Lee B. Sims
Plga-Modified Nanoparticles For The Treatment Of Hypo-Vascularized Hpv-Related Cervical Cancers., Lee B. Sims
Electronic Theses and Dissertations
A major challenge associated with delivery of active agents in the female reproductive tract (FRT) is the ability of agents to efficiently diffuse through the cervicovaginal mucosa (CVM) and reach the underlying sub-epithelial immune cell layer and vasculature. A variety of drug delivery vehicles have been employed to improve the delivery of agents across the CVM and offer the capability to increase the longevity and retention of active agents to treat infections of the female reproductive tract. Nanoparticles (NPs) have been shown to improve retention, diffusion, and cell-specific targeting via specific surface modifications, relative to other delivery platforms. In particular, …
Materials Design With Polylactic Acid-Polyethylene Glycol Blends Using 3d Printing And For Medical Applications., Jeremiah R. Bauer
Materials Design With Polylactic Acid-Polyethylene Glycol Blends Using 3d Printing And For Medical Applications., Jeremiah R. Bauer
Electronic Theses and Dissertations
This thesis is an examination of two material systems derived from polylactic acid (PLA) and polyethylene glycol (PEG). PLA is a polymer commonly sourced from renewable sources such as starches and sugars. It is a relatively strong, biodegradable polymer, making it ideal for use in the body. Even though it has a relative high strength, PLA is also brittle leading to the use of plasticizers to increase flexibility. One such plasticizer is PEG, which is a material that can exist at room temperature as either a thin liquid, or a hard waxy solid depending on the molecular weight. The first …
Nanocellulose Fibers As A Potential Material For Orthopedic Implantation Application, David Gregg Holomakoff
Nanocellulose Fibers As A Potential Material For Orthopedic Implantation Application, David Gregg Holomakoff
Electronic Theses and Dissertations
The field of biomaterials is of immense importance and will continue to grow and develop in the coming years. Novel materials, as well as new approaches for use of existing materials, are sought after now more than ever. Current metal orthopedic implants have an over engineered stiffness and Young’s modulus, causing a phenomenon called stress shielding. Metal implants absorb the majority of force typically exerted on bone and the osteocytes within. When osteocytes fail to sense mechanical forces bones become less dense and weaken, causing possible fracture and other complications. A new orthopedic material is needed matching Young’s modulus of …
A Multi-Channel 3d-Printed Bioreactor For Evaluation Of Growth And Production In The Microalga Dunaliella Sp, Cristian A. Cox
A Multi-Channel 3d-Printed Bioreactor For Evaluation Of Growth And Production In The Microalga Dunaliella Sp, Cristian A. Cox
Electronic Theses and Dissertations
We explored the capabilities of additive manufacturing using a photo-cured jetted material 3D printer to manufacture a milli-microfluidic device with direct application in microalgae Dunaliella sp growth and intracellular compounds biosynthesis tests. A continuous microbioreactor for microalgae culture was CAD designed and successfully built in 1 hour and 49 minutes using black photopolymer cured by UV and a support material. The microreactor was made up of 2 parts including the bioreactor itself and a microchannel network for culture media fluids and microalgae. Both parts were assembled to form a single unit. Additional optical and auxiliar components were added. An external …
Techno-Economic And Fluid Dynamics Analysis For Growing Microalgae With The Intent Of Producing Biofuel Using A System Model, Leah R. Raffaeli
Techno-Economic And Fluid Dynamics Analysis For Growing Microalgae With The Intent Of Producing Biofuel Using A System Model, Leah R. Raffaeli
Electronic Theses and Dissertations
Techno-economic and systems studies on microalgal growth scenarios to date are abbreviated and missing a number of important variables. By including these variables in a detailed model integrating biology, chemistry, engineering, and financial aspects, a more defined systems analysis is possible. Through optimizing the model productivity based on the resulting net profit, the system analysis results in a more accurate assessment of environmental and economic sustainability of specific algal growth scenarios. Photobioreactor algal growth scenario optimization in the system model has resulted in realistic engineering design requirements based on algal growth requirements and fluid dynamics analysis. Results show feasibility for …
Influence Of Compressible Aerogel Electrodes On The Properties Of An Electrochemical Cell, Chris Sponheimer
Influence Of Compressible Aerogel Electrodes On The Properties Of An Electrochemical Cell, Chris Sponheimer
Electronic Theses and Dissertations
In the biomedical field the need for intra organ pressure measurement can only be facilitated by adapting existing pressure sensing technology to the specific tissues under test. The customization of these sensors has only driven up cost and the need to explore new technologies has become increasingly more important. For this dissertation, we explore the use of a new technology, particularly electrochemical pressure sensing to provide a low-cost pressure sensor to fill this need. Preliminary testing showed that electrically conductive polymers exhibited a change in voltage when pressurized if bubbles were first electrolyzed in the gel creating an aerogel, and …