Biological Engineering Commons^™

Development Of Translational Microscale Systems To Interrogate How Biophysical And Biochemical Cues Alter The Phenotype Of Hormone Positive Breast Cancer, Braulio Ortega Quesada

All Dissertations

Cancer is a complicated disease and one in every three diagnoses are women with breast cancer. Recent research shows that the progression of cancer depends strongly on interactions with other non-cancerous cells and non-cellular components. Metastasis, the spread of cancer to other parts of the body, is a key step in cancer progression and makes treatment harder, leading to poor response to treatments culminating in death in ~90% of patients. This dissertation focused on creating a series of microdevices as novel pre-clinical models of breast cancer. Two different devices were fabricated to (1) study how exposing cancer cells to the …

Shape Memory Alloy Capsule Micropump For Drug Delivery Applications, Youssef Mohamed Kotb

Theses and Dissertations

Implantable drug delivery devices have many benefits over traditional drug administration techniques and have attracted a lot of attention in recent years. By delivering the medication directly to the tissue, they enable the use of larger localized concentrations, enhancing the efficacy of the treatment. Passive-release drug delivery systems, one of the various ways to provide medication, are great inventions. However, they cannot dispense the medication on demand since they are nonprogrammable. Therefore, active actuators are more advantageous in delivery applications. Smart material actuators, however, have greatly increased in popularity for manufacturing wearable and implantable micropumps due to their high energy …

Investigating The Role Of Fluid Shear Stress During Metastasis On Enhanced Breast Cancer Extravasation, Alejandra M. Ham

LSU Master's Theses

In 2022, ~288,000 American women were diagnosed with metastatic breast cancer which was the leading cause of patient mortality with ~43,000 American women succumbing to the disease. Women can be diagnosed with four different molecular subtypes of breast cancer: luminal A, luminal B, human epithelial growth receptor type 2 enriched (HER2+), and triple-negative breast cancer (TNBC). TNBC accounts for ~12% of all breast cancers, yet it has the worst outcomes. TNBC is highly invasive, with ~46% of TNBC patients developing metastatic disease. A further understanding of metastatic TNBC is needed to provide a greater understanding of how to treat this …

Two-Dimensional & Three-Dimensional Microarray Cell Culture Using Elastomeric Assembly Substrates, Angel Olivera-Torres

Honors Program: Senior Projects (Public)

Tissue engineering and regenerative medicine represent the collection of all engineering disciplines brought together for the common goal of developing novel ways of growing tissues and organs in the laboratory. Efforts have made it possible to replicate or induce growth of 2D structures in the human body like skin, but the clinical need for on-demand solid organs has yet to be met due to lack of understanding of the variables responsible for organogenesis. Cell-colony heterogeneity, 3D-cellular architecture, bioactive molecules, and crosstalk communication between parenchymal cell populations need to be further investigated, and high-throughput technologies can rapidly increase the rate at …

A Microfluidics-Based Cross-Flow Filtration Platform For Rapid Processing Of Amphiphilic Biomarkers From Blood, Kiersten D. Lenz

Biomedical Engineering ETDs

Early and accurate detection of bacterial infections can help save lives, prevent the spread of disease, and decrease the overuse of antibiotics. Our team at the Los Alamos National Laboratory has developed novel assays to detect bacterial biomarkers from patient blood at the point-of-care in order to facilitate a universal diagnostic platform. However, these biomarkers are amphiphilic in nature, and this biochemical property causes them to be sequestered by high-density and low-density lipoproteins (HDL and LDL) in the host’s blood. Extraction of the bacterial biomarkers from the lipoprotein complexes is thereby required for the development and deployment of a diagnostic …

Use Of Surface-Enhanced Raman Scattering (Sers) Probes To Detect Fatty Acid Receptor Activity In A Microfluidic Device, Han Zhang, Wei Zhang, Lifu Xiao, Yan Liu, Timothy A. Gilbertson, Anhong Zhou

Biological Engineering Faculty Publications

In this study, 4-mercaptobenzoic acid (MBA)-Au nanorods conjugated with a GPR120 antibody were developed as a highly sensitive surface-enhanced Raman spectroscopy (SERS) probe, and were applied to detect the interaction of fatty acids (FA) and their cognate receptor, GPR120, on the surface of human embryonic kidney cells (HEK293-GPRR120) cultured in a polydimethylsiloxane (PDMS) microfluidic device. Importantly, the two dominant characteristic SERS peaks of the Raman reporter molecule MBA, 1078 cm⁻¹ and 1581 cm⁻¹, do not overlap with the main Raman peaks from the PDMS substrate when the appropriate spectral scanning range is selected, which effectively avoided the …

Fluid Delivery System For A Cell Culture On A Microfluidic Chip, Austin J. Roeder, Colleen A. Richards, Emily A. Matteson

Biomedical Engineering

This project report provides a description of the progress made in the development of a fluid delivery system for a microfluidic cell culture on a chip. The system is intended to be used in a humidified incubator in a university laboratory and the fluid delivery system is required to exist and operate within that incubator for extended periods of time. Therefore, the system will be gravity-driven and contain no electronic components. The key specification of the system is to provide fluid flow at a constant velocity.

After manufacturing and testing the device, all specifications were met except for the fluid …

Neuron-Glial (Ng) Interactions: A Microfluidic Examination Of Ng Emergent Responses For Repair, Tanya Singh

Dissertations and Theses

Neuron-glia communication is crucial to the development, plasticity, and repair of the nervous system (NS). While neurons are well known to conduct electrical impulses that transfer biological information and stimuli throughout the NS, our understanding of the roles of glia continues to evolve from when the cells were largely believed to act solely for neuronal support. Recent decades of research has shown that glia can alter metabolism, conduct impulses and change phenotype for NS repair. NG interactions have, thereby, become heavily researched in varied areas of biomedical engineering, including embryogenesis, neural regeneration, growth, and intracellular synaptic activity. However, while NG …

Controlled Migration Of Retinal Progenitor Cells Within Electro-Chemotactic Fields, Shawn Mishra

Dissertations and Theses

Vision loss in retinal degenerative diseases is overwhelmingly attributed to damage and death of retinal photoreceptor cells. Studies in mouse retina have suggested that transplantation of isolated post-natal or stem cell-derived retinal progenitor cells (RPCs) to replace apoptotic or damaged photoreceptors may be a novel approach to restore vision. Thus far, outcomes project that the amount of restored visual response depends upon the migration of transplanted cells from insertion in the sub-retinal space to the outer nuclear layer (ONL). However, transplantation efficiency is exceedingly low – ~5% cells transplanted enter the retina – directly limiting the efficacy of the treatments. …

Microfluidic Electrical Impedance Spectroscopy, John J. Foley

Master's Theses

The goal of this study is to design and manufacture a microfluidic device capable of measuring changes in impedance valuesof microfluidic cell cultures. Tocharacterize this, an interdigitated array of electrodes was patterned over glass, where it was then bonded to a series of fluidic networks created in PDMS via soft lithography. The device measured ethanol impedance initially to show that values remain consistent over time. Impedance values of water and 1% wt. saltwater were compared to show that the device is able to detect changes in impedance, with up to a 60% reduction in electrical impedance in saltwater. Cells were …

Developing Droplet Based 3d Cell Culture Methods To Enable Investigations Of The Chemical Tumor Microenvironment, Jacqueline Alexandria De Lora

Biomedical Sciences ETDs

Adaptation of cancer cells to changes in the biochemical microenvironment in an expanding tumor mass is a crucial aspect of malignant progression, tumor metabolism, and drug efficacy. In vitro, it is challenging to mimic the evolution of biochemical gradients and the cellular heterogeneity that characterizes cancer tissues found in vivo. It is well accepted that more realistic and controllable in vitro 3D model systems are required to improve the overall cancer research paradigm and thus improve on the translation of results, but multidisciplinary approaches are needed for these advances. This work develops such approaches and demonstrates that new droplet-based cell-encapsulation …

Tumor-Targeted Double Emulsions For Ultrasound-Triggered Delivery Of Molecular Therapeutics., Connor S Centner

Electronic Theses and Dissertations

Cancer is the second leading cause of death in the United States, with 1.74 million new cancer cases diagnosed and 610,000 cancer deaths expected in 2018 alone. Current treatments often result in negative systemic effects and ineffective treatment of the tumor. Drug delivery vehicles have been developed for more effective local delivery methods, but many drug delivery vehicles lack spatial and temporal control. Targeted double emulsions are a new class of drug delivery vehicles which present a promising option for a high payload and controlled delivery. The purpose of our project was to develop and characterize an aptamer-chelated double emulsion …

The Use Of Microfluidics And Dielectrophoresis For Separation, Concentration, And Identification Of Bacteria, Cynthia Hanson, Michael Sieverts, Karen Tew, Annelise Dykes, Michaela Salisbury, Elizabeth Vargis

Biological Engineering Faculty Publications

Traditional bacterial identification methods take one to two days to complete, relying on large bacteria colonies for visual identification. In order to decrease this analysis time in a cost-effective manner, a method to sort and concentrate bacteria based on the bacteria's characteristics itself is needed. One example of such a method is dielectrophoresis, which has been used by researchers to separate bacteria from sample debris and sort bacteria according to species. This work presents variations in which dielectrophoresis can be performed and their associated drawbacks and benefits specifically to bacterial identification. In addition, a potential microfluidic design will be discussed.