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Santa Clara University

Bioengineering Master's Theses

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Towards Targeted Delivery To Cns Neurons By Conquering The Bbb, David G.A. Bengford Jun 2022

Towards Targeted Delivery To Cns Neurons By Conquering The Bbb, David G.A. Bengford

Bioengineering Master's Theses

Brain cancer treatments have long been restricted by the blood-brain barrier (BBB). Semi-permeable in the most selective way, this barrier may be crossed by one of three methods: membrane integrity disruption, passive transport, or active transport. The third option offers the opportunity for many medically relevant cargoes, such as proteins and nucleic acids, to be shuttled into the brain. The concept of a therapeutic “Trojan horse” builds on this capability by employing engineered nanovesicles—in this work, engineered exosomes—whose surfaces are studded with ligands functioning as the keys to crossing the BBB. Exosomes are a powerful methodology for this approach because …


Staphylococcus Aureus Sortase A Protein Applications And Methods: (1) Drug Discovery In Anti-Infectious Agents; (2) A Biotechnique Analysis For Indication Sortase A Protein Purification Methods; (3) In Vivo Protein Ligation For Discovery Of Novel Protein Engineering Methods:, Melina Huang Xia Jun 2022

Staphylococcus Aureus Sortase A Protein Applications And Methods: (1) Drug Discovery In Anti-Infectious Agents; (2) A Biotechnique Analysis For Indication Sortase A Protein Purification Methods; (3) In Vivo Protein Ligation For Discovery Of Novel Protein Engineering Methods:, Melina Huang Xia

Bioengineering Master's Theses

It has been understood that during Gram-positive bacterial infection, the bacterial cells interact with host mammalian cells via the virulence factors whose anchorage onto the bacterial surface are mainly catalysed by Sortase A[2]. Emergence of antibiotic-resistant bacterial strains, especially the Gram-positive bacteria, has rendered the rise of many antibiotic resistant bacteria, resulting in rise of infection cases that bypass traditional first-line antibiotics treatments. It is crucial for the public health that scientists and researchers discover an alternative treatment for the bacterial infection that targets the underlying pathogenic mechanism that are responsible for the increased virulence of such bacteria without contributing …


Identification Of Messenger Molecule For Immuno-Antibacterial Infection Drug Discovery With The Usage Of Bio-Ai, Minqiao (Lisa) Jin Apr 2022

Identification Of Messenger Molecule For Immuno-Antibacterial Infection Drug Discovery With The Usage Of Bio-Ai, Minqiao (Lisa) Jin

Bioengineering Master's Theses

Facing the danger of Gram-positive bacterial infection, mammalian cells have their defense line. A functional proteomics study aided with Deep Learning indicates the direct interaction between collagen V from mammalian cell membrane and Sortase A which catalyzes the display of virulence factors on the gram positive bacteria. And CHO cell proteomes conducted with the use artificial intelligence via Tensorflow and found that the identified anti collagen V binds to Sortase A of S. aureus and regulates its monomer-homodimer equilibrium, which is responsible for the bacterial cell wall sorting activity. Our results suggest that the collagen V plays an instrumental role …


Development Of Novel Deep Learning Models In The Detection Of Breast Cancer And Brain Aneurysm, Pradnya Patel Jun 2021

Development Of Novel Deep Learning Models In The Detection Of Breast Cancer And Brain Aneurysm, Pradnya Patel

Bioengineering Master's Theses

Three deep learning models using convolutional neural network (CNN) were developed for the early detection of breast cancer and brain aneurysm. Model 1 was built for the detection of breast mass; it consists of 20 total layers including 5 convolutional layers, 5 maxpool layers with Rectifier Linear Unit as the activation function for feature extraction, one flatten layer, 4 batch normalization with fully connected layers, and one output layer. This CNN model was trained and validated on an open-source breast ultrasound dataset that contains a total of 830 images categorized into three classes: normal (133 images), benign (487 images), and …


Characterizing A Gaucher’S Disease Model For The Evaluation Of Novel Exosome-Based Enzyme Replacement Therapy, Annie Brown Jun 2020

Characterizing A Gaucher’S Disease Model For The Evaluation Of Novel Exosome-Based Enzyme Replacement Therapy, Annie Brown

Bioengineering Master's Theses

Gaucher’s disease is a rare genetic lysosomal storage disorder. People suffering from Gaucher’s disease do not have functional beta-glucocerebrosidase (GBA), which results in toxic build-up of undegraded substrates within the cell. Currently, patients living with this disease rely on biologics to reduce their symptoms, however, they require frequent transfusions and are incapable of crossing the blood brain barrier (BBB) to address neurologic symptoms of the disease. To evaluate the efficacy of novel biologic therapeutics, a human Gaucher’s disease model is required. Here, we have utilized near-haploid human cells (Hap1) modified via CRISPR-Cas9 to model Gaucher’s disease in vitro. These cells …


In Vivo Non-Ribosomal Protein Synthesis In Mammalian Cells, Akhil Choppa Apr 2020

In Vivo Non-Ribosomal Protein Synthesis In Mammalian Cells, Akhil Choppa

Bioengineering Master's Theses

The mechanism of Sortase A substrate specificity has been widely studied and applied to many approaches to bioconjugation. Current research includes transpeptidation between peptide nucleotide acids, polypeptides, viruses, or antibodies. These applications help improve drug targeting and delivery. Scientists have performed Sortase A-mediated protein ligation in vitro. This project proposes an in vivo protein ligation method with Sortase A. In this design, Sortase A acts as a catalyst to initiate bioconjugation between the LPETG motif and pentaglycine (Gly5) chain to express GFP. This technique bypasses the ribosome and offers an alternative way to synthesize protein in mammalian cells. Three recombinant …


Scale Optimization Of Milkguard Biosensor For Detecting E. Coli In Human Breast Milk, Jerard Roniel Del Rosario Madamba Jun 2019

Scale Optimization Of Milkguard Biosensor For Detecting E. Coli In Human Breast Milk, Jerard Roniel Del Rosario Madamba

Bioengineering Master's Theses

Milkguard is an alginate-based biosensor developed to detect E. coli in human breast milk via the metabolism of X-gal (5-Bromo-4-Chloro-3-Indolyl β-D-Galactopyranoside) by β-galactosidase. In order to deconvolute metabolic reproducibility from scaling laws, the commercial enzyme β-galactosidase was used to mimic the biological function of the bacterial lac operon. Downscaling was explored as an optimization of the biosensor design based on numerical solutions to Fickian-based diffusion models. The characterization of large capsules (d ≅ 3 mm) and atomized microcapsules (d ≅ 300 ± 60 μm) yielded size-specific Michaelis-Menten constants. Small capsules (Km = 3.6 x 10-4 M; Vmax ’’ …


Automated Atrial Fibrillation Detection From Electrocardiogram, Senbao Lu Apr 2019

Automated Atrial Fibrillation Detection From Electrocardiogram, Senbao Lu

Bioengineering Master's Theses

In this study, a novel Atrial Fibrillation (AFib) detection algorithm is presented based on Electrocardiography (ECG) signals. In particular, the spectrogram of ECG signal is used as an input to a Convolutional Neural Network (CNN) to classify normal and AFib ECG signals. This model is shown to perform well with an accuracy of 92.91% and a value of 0.9789 for the area under the ROC curve (AUC). This study demonstrated the potential of using image classification methods and CNN model to detect abnormal biosignals with noise.


Engineering Nanoscale Exosomes For Lysosomal Delivery Of Bioactive Enzymes, Mai Anh Do Jun 2018

Engineering Nanoscale Exosomes For Lysosomal Delivery Of Bioactive Enzymes, Mai Anh Do

Bioengineering Master's Theses

There are at least 50 lysosomal storage diseases that are caused by accumulation of a substrate due to a defective enzyme. Although some treatment options are available, low efficacy, high cost, and immunogenicity are main challenges of current treatments. To overcome those limitations, we use cell-derived nanoparticles to deliver biologically active cargos into lysosomes. Naturally produced exosomes can deliver proteins without triggering an immune response. Additionally, exosome have an intrinsic ability to cross blood brain barrier benefiting patients at a late disease stage that affects the brain. After fusing either Gaussia luciferase (gLuc) or puromycin resistant protein (puro) onto a …


Lysosomal Delivery Of Bioactive Proteins To Living Human Cells Via Engineered Exosomes, Daniel Levy Jun 2018

Lysosomal Delivery Of Bioactive Proteins To Living Human Cells Via Engineered Exosomes, Daniel Levy

Bioengineering Master's Theses

Exosomes are naturally secreted nanovesicles derived from mammalian cells that are used for intercellular communication in vivo. As a result, they can potentially be used for intracellular delivery of therapeutics for disease treatment. We have developed an exosome pseudotyping approach using vesicular stomatitis virus glycoprotein (VSVG) to produce protein chimeras that optimize production of modified exosomes containing protein therapeutics and facilitate effective delivery to their target cells. To the VSVG transmembrane scaffold, we have fused both fluorescent and luminescent reporters for exosome tracking/visualization and quantification of activity respectively. Through our design, we have shown the biogenesis of VSVG modified exosomes …


Exploration Of Sortase A-Inhibitor Binding Mechanisms Through Isothermal Titration Calorimetry, Eddy Liu Jun 2017

Exploration Of Sortase A-Inhibitor Binding Mechanisms Through Isothermal Titration Calorimetry, Eddy Liu

Bioengineering Master's Theses

The enzyme Sortase A plays a critical role in the virulence of gram-positive bacteria, facilitating their ability to attach to and infect host tissues. Because of its accessible location on the surface of bacteria and in light of the emergence of antibiotic-resistant bacterial strains, Sortase A has become an important target for novel drugs and their associated research. Here we investigate the thermodynamic characteristics and binding mechanism of Sortase A and inhibitors using isothermal titration calorimetry. The results support a two-step, sequential binding mechanism involving induced fit and conformational change. We recommend that further studies involving other small molecule inhibitors …