Biomedical Engineering and Bioengineering Commons^™

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 …

Microfabrication Of Bio-Analytical Devices: Microelectrode Array And Traveling-Wave Electrophoresis, Neil Draper

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The need for potable water is increasing with the ever-increasing world population. Further development of fast, portable, and cost effective analytical tools is necessary in order to create diagnostic techniques capable of supporting the water needs of the world’s population. Within the last decade microfluidics and Lab-on-a-Chip (LOC) technologies have increased the portability and speed of detection for aqueous samples. Photolithography techniques serve as a cost effective fabrication tool to create LOC electrodes on the micron scale.

An in-depth look at the fabrication process is undertaken in this paper in order to further the development of micro-scale detection techniques. An …

Microfabrication Of Electrochemical Analytical Devices For Detection Of Pathogen Species Dna And Toxic Metal Ions, Spencer Williams

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Water quality is a crucial factor in determining the health of an environment, and in turn the health of all those living in the given environment. Early detection of potential hazards in source water used for drinking would help to avoid outbreaks of sickness and even death. Contaminants, found in contact and drinking water, having negative effects on human health may include pathogenic microorganisms, and metal ion pollutants such as lead or cadmium. Lead and cadmium were selected due to well-known electrochemical properties providing easy references for developing new detection devices. Current methods for detection of these contaminants are extremely …

In Vitro, Non-Invasive Imaging And Detection Of Single Living Mammalian Cells Interacting With Bio-Nano-Interfaces, Qifei Li

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Study of bio-nano-interfaces of living mammalian cells will help the identification of cellular alterations (e.g. nucleic acids, amino acids, biomechanics, etc.) due to external stimuli, the design of biomaterials (e.g. nanoparticles, nanotubes) and the investigation on the interaction between cells and bio-nano-interfaces (e.g. cell differentiation on 3D nanostructured materials). The chemical, physical, and mechanical changes of mammalian cells interacting with biomaterials can be investigated by analytical techniques. In this dissertation, cellular responses and property changes are evaluated by non-invasive spectroscopic technique, Raman microscopy (RM), and atomic force microscopy (AFM) combined with traditional biological methods. This dissertation includes the biophysical, biochemical …

Bio-Inspired Materials And Micro/Nanostructures Enabled By Peptides And Proteins, Swathi Swaminathan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bio-nanotechnology refers to the field of science that intersects nanotechnology with biology. The study involves in the creation of bio-mimetic devices that emulate elements and systems of nature finding use in various applications. Nanotechnology involves the characterization of nanomaterials along with the study of molecular self-assembly and nanoelectronics. Controlled binding and assembly of proteins onto nanomaterials is at the core of biological materials science and engineering with wide-ranging applications. This hybrid technology opens up several avenues in the field of sensors, pharmaceuticals, artificial implants and so on.

In this work, different biomaterials and polymers were characterized for phage displayed peptide …

Non-Catalytic Co-Gasification Of Sub-Bituminous Coal And Biomass, Guevara Che Nyendu

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Utilization of coal as a low-cost domestic energy source is becoming a subject of utmost importance due to fluctuating crude oil prices. However, coal use emits pollutants such as nitrous oxides (NO_x), sulfur oxides (SO_x), carbon dioxide (CO₂), and particulates that have negative environmental impact and significant issues on health. To minimize the harmful effects of coal use, renewable and sustainable biological or green materials called biomass are processed with coal to produce synthetic gas (syngas) that can be processed into clean energy fuels and value-added products.

Currently, coal is converted using combustion technology; …

Modeling The Contributions Of Hand Loads To Cervical Spine Compressive Forces, Mohamed R.S. Amar

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

The purpose for this study is threefold. All involve single handed lifting tasks where the height of the lifted object, the distance of the lifted object from the body, and the angle of the lift relative to the body were varied. First, examine the activity of each of the shared musculature of selected shared muscles between the shoulder and cervical spine. Second, attempt to empirically model the activations of the shared muscles. Third, to understand the relationship between the active and antagonistic contraction. Finally, to establish a biomechanical model to estimate the compressive forces on the cervical spine.

Ten subjects …

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 …

Impact Of Collagen-Incorporation Within Electrospun Vascular Conduits On The Inflammatory Response And Conduit Mechanics, Karamveer Birthare

Theses and Dissertations

Current surgical alternatives for treating coronary artery diseases are limited in patients with systemic vascular diseases due to unavailability of suitable autologous vessels. The overall goal of this research project is to develop an appropriate tissue engineered vascular grafts (TEVGs) for small-diameter (<6 mm) arteries. Current grafts fail from intimal hyperplasia, caused by hyperproliferation of the smooth muscle cells (SMCs), and graft thrombosis, caused by lack of functional endothelium. Formation of the endothelium, and production of pro-inflammatory species that limits the long term patency, are partially due to the accumulation of oxidized lipid species. In this study, the scaffold composition was systematically varied to assess the inflammatory response and lipid oxidation levels in a rat peritoneal model. Specifically, we determined the collagen to PCL ratio required to limit the production of pro-inflammatory species, while maintaining the required mechanical strength for vascular grafts. Electrospun conduits were prepared from 0%, 10%, and 25% blends of collagen/ PCL (w/w) and implanted in the rat peritoneal cavity for 4 weeks. The results of the study showed that scaffold composition can be varied while keeping the fiber diameter similar. Results from 10% blend conduits showed significantly higher expression for contractile markers compared to the 25% and 0% blend conditions. In general, adding collagen to the PCL conduits reduced the accumulation of oxidized species within the implanted conduits. All conduits exhibited sufficient tensile strength post- implantation. In conclusion, these results demonstrate that introducing 10% collagen into electrospun scaffolds limits the pro-inflammatory characteristics of the recruited peritoneal cells that can potentially improve patency of the TEVGs.

Design And Development Of Two Component Hydrogel Ejector For Three-Dimensional Cell Growth, Thomas Dunkle, Jessica Deschamps, Connie Dam

Honors Scholar Theses

Hydrogels are useful in wound healing, drug delivery, and tissue engineering applications, but the available methods of injecting them quickly and noninvasively are limited. The medical industry does not yet have access to an all-purpose device that can quickly synthesize hydrogels of different shapes and sizes. Many synthesis procedures that have been developed result in the formation of amorphous hydrogels. While generally useful, amorphous hydrogels exhibit limited capability in tissue engineering applications, especially due to their viscous properties. This endeavor aims to modulate the appropriate gelation parameters, optimize the injection process, and create a prototype that allows for the extrusion …

Finite Element Analysis Of The Application Of Ultrasound-Generated Acoustic Radiation Force To Biomaterials, Nicole J. Piscopo

Honors Scholar Theses

While most bone fractures can heal simply by being stabilized, others can take a longer time to rejoin or they could fail to merge back together completely. Numerous studies have shown the positive effects that ultrasonic therapy have had on delayed-union and non-union bone fracture repair but little is known as to what specific biological mechanisms are at play. Ultrasound may be a valuable tool for bone tissue regeneration at these fracture sites using a tissue engineering approach, however, more must be understood about its impact on stimulating tissues to heal before this can be a reality. For that reason, …

Effect Of Crimping, Multilayering, And Twisting On Polymer Fibers For Acl Replacement, Mariana Ocampo

Theses and Dissertations - UTB/UTPA

The Anterior Cruciate Ligament (ACL) is the most common knee injury in the United States; roughly 150,000 ACL surgeries are performed annually. The ACL lacks self-healing properties due to its location inside the knee’s intra – articular environment (IA). Treatments for ACL ruptures involve the use of autogenous grafts or allografts. More suitable treatments can be found in new bio engineered tissue scaffolds, composed of natural and synthetic polymers. The polymers provide stronger mechanical properties and the ability to promote cell adhesion. It is believed that mimicking the crimping pattern of human ligaments will enhance polymer properties. Four polymers were …

Assessment Of Bore-Cone Taper Junctions In Explanted Modular Total Hip Replacements, Christine Margaret Stamer

All Theses

For people with chronic hip pain due to arthritis or other conditions, a total hip replacement (THR) is a common procedure used to eliminate the pain. Due to the natural variation in patient anatomy, THR prostheses are becoming increasingly more modular to allow for a more customized initial replacement and for an easier revision if needed in the future. Currently, THR prostheses routinely have modular femoral heads to provide surgeons with intraoperative flexibility. This modularity allows the surgeons to maintain the proper leg length and restore hip biomechanics for the patient and insert the components more easily and precisely. Modular …

Evaluating The Effectiveness Of Cranial Molding For Treatment Of Positional Plagiocephaly Using Finite Element Analysis, Maziyar Keshtgar

Master's Theses

Since the advent of recommendations for placing infants in the supine position during sleep to reduce the incidence of sudden infant death syndrome, clinicians have noted an increase in the frequency of cranial asymmetry due to deformation of suture sections of the infants’ skulls as a result of constant concentrated stress in one area at the back of their head. This specific form of cranial deformation is known as positional plagiocephaly and its rate of occurrence has increased from 0.3% in 8.2% within the past 30 years.

Current treatments and methodologies for preventing and correcting positional plagiocephaly such as stretching …