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Full-Text Articles in Biomedical Engineering and Bioengineering

A Microfluidics-Based Cross-Flow Filtration Platform For Rapid Processing Of Amphiphilic Biomarkers From Blood, Kiersten D. Lenz Jul 2019

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 …


Acoustofluidics And Soft Materials Interfaces For Biomedical Applications, Frank A. Fencl Nov 2018

Acoustofluidics And Soft Materials Interfaces For Biomedical Applications, Frank A. Fencl

Biomedical Engineering ETDs

This dissertation describes fabrication of devices and other tools for biomedical applications through the integration of acoustofluidic systems with bio separation assays, instrumentation components, and soft materials interfaces. For example, we engineer a new class of transparent acoustic flow chambers ideal for optical interrogation. We demonstrate efficacy of these devices by enhancing the signal for high throughput acoustic flow cytometry, capable of robust particle focusing across multiple parallel flowing streams. We also investigate an automated sampling system to determine the parameters of transient particle stream focusing in between sample boluses and air bubbles to model a high throughput, multi-sampling acoustic …


Direct Quantification Of Deubiquitinating Enzyme Activity In Single Intact Cells, Nora Safabakhsh Aug 2018

Direct Quantification Of Deubiquitinating Enzyme Activity In Single Intact Cells, Nora Safabakhsh

LSU Doctoral Dissertations

Challenges in drug efficacy occur during the treatment of most types of cancer due to the heterogeneity of the tumor microenvironment. This has led to the development of personalized medicine. Due to the clinical success of the proteasome inhibitors Bortezomib and Carfilzomib in treatment of multiple myeloma, interest has shifted towards molecularly-targeted chemotherapeutics for ubiquitin-proteasome system (UPS). Deubiquitinating enzymes (DUBs) are an essential part of this pathway which have been found to promote Bortezomib resistance in multiple myeloma patients. Unfortunately, there is a lack of specific, high throughput biochemical assays to characterize DUB activity in patient samples before and after …


Developing Droplet Based 3d Cell Culture Methods To Enable Investigations Of The Chemical Tumor Microenvironment, Jacqueline A. De Lora Jul 2018

Developing Droplet Based 3d Cell Culture Methods To Enable Investigations Of The Chemical Tumor Microenvironment, Jacqueline A. 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 …


A Multi-Channel 3d-Printed Bioreactor For Evaluation Of Growth And Production In The Microalga Dunaliella Sp, Cristian A. Cox Dec 2016

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 …


Real-Time Analysis Of Brain Tumor Cell Dynamics: Novel Thermoelectric Detection Of L-Glutamate And Cell Metabolism Using Microfluidics, Siva Mahesh Tangutooru Oct 2012

Real-Time Analysis Of Brain Tumor Cell Dynamics: Novel Thermoelectric Detection Of L-Glutamate And Cell Metabolism Using Microfluidics, Siva Mahesh Tangutooru

Doctoral Dissertations

This study describes the design, fabrication and applications of a novel thermoelectric microfluidic bio-sensor. The bio-sensor is used for real time detection of the L-glutamate (L-glu) dynamics and metabolism for brain tumor cells immobilized in a microfluidic device. The microfluidic device is fabricated using a polymer/glass laminating technique (Xurography). An antimony-bismuth thin-film thermopile (primary sensing element) is integrated to the microfluidic device. The brain tumor cells are immobilized over the thermopile covering measuring and reference junctions of the thermopile using a poly-l-lysine coating layer. L-glutamate oxidase (L-GLOD) is immobilized over the measuring junctions of the thermopile prior to the immobilization …


Development Of A Microfluidic Device Coupled To Microdialysis Sampling For The Pre-Concentration Of Cytokines, Randy Francisco Espinal Cabrera May 2012

Development Of A Microfluidic Device Coupled To Microdialysis Sampling For The Pre-Concentration Of Cytokines, Randy Francisco Espinal Cabrera

Graduate Theses and Dissertations

A proof-of-concept microfluidic device combined with heparin-immobilized magnetic beads was created to concentrate cytokine proteins collected from microdialysis samples. Cytokines are known to be related to several diseases such as cancer, and Parkinson's diseases, so to be able to develop more effective diseases treatments their interactions have to be well understood. Amine-functionalized polystyrene and carboxyl-functionalized magnetic microspheres of ~6.0 ìm in diameter were used to immobilize heparin. The amount of heparin immobilized on polystyrene beads was 5.82 x 10-8 ± 0.36 x 10-8 M per 1.0 x 106 beads and for magnetic beads was 0.64 x 10-8 ± 0.01 x …