Molecular, Cellular, and Tissue Engineering Commons^™

Phagolysosomes Break Down The Membrane Of A Non-Apoptotic Corpse Independent Of Macroautophagy, Shruti Kolli, Cassidy J. Kline, Kimya M. Rad, Ann M. Wehman

Biological Sciences: Faculty Scholarship

Cell corpses must be cleared in an efficient manner to maintain tissue homeostasis and regulate immune responses. Ubiquitin-like Atg8/LC3 family proteins promote the degradation of membranes and internal cargo during both macroautophagy and corpse clearance, raising the question how macroautophagy contributes to corpse clearance. Studying the clearance of non-apoptotic dying polar bodies in Caenorhabditis elegans embryos, we show that the LC3 ortholog LGG-2 is enriched inside the polar body phagolysosome independent of autophagosome formation. We demonstrate that ATG-16.1 and ATG-16.2, which promote membrane association of lipidated Atg8/LC3 proteins, redundantly promote polar body membrane breakdown in phagolysosomes independent of their role …

Use Of Electrical Bone Growth Stimulators In High-Risk Patients Following Spinal Fusion, Soumya Malhotra, Khavir Sharieff

HCA-NSU MD Research Day

Title: Use of Electrical Bone Growth Stimulators in High-Risk Patients Following Spinal Fusion Authors: Soumya Malhotra, BA., MS1 & Khavir Sharieff, DO, MBA2 1Class of 2027, Nova Southeastern University Dr. Kiran C. Patel College of Osteopathic Medicine, Fort Lauderdale, FL 2Assistant Professor of Surgery, Nova Southeastern University Dr. Kiran C. Patel College of Osteopathic Medicine, Tampa Bay, FLNova Southeastern University Dr. Kiran C. Patel College of Osteopathic Medicine Objective: This study aimed to elucidate the advantages of EBGSs following high-risk spinal fusions. Background: Pseudarthrosis is a condition where bones fail to fuse after an injury or surgery. It causes significant …

Hypoxic Incubator: Improving Robustness/Reliability And Demonstrating Physiological Efficacy, Damon Dennis Tan

Master's Theses

The Microphysiological Systems Laboratory aims to develop colorectal cancer tumor models under a hypoxic environment to assess model response to pharmaceutical compounds in vitro. To perform relevant studies, researchers have attempted to use different hypoxic inducing strategies such as a nitrogen pod and hypoxic incubator to recreate in vivo physiological responses to hypoxia. However, studies would be interrupted due to incubator functionality failure. To ensure successful and physiologically relevant studies, I improved and verified the robustness and reliability of a hypoxic incubator previously designed and manufactured in the lab. Through the testing and iterating design processes, I engineered and implemented …

The Development Of A Novel Cartilage Analog Scaffold For Chondral Regeneration, Vishal Thomas

All Dissertations

Focal Chondral Defects (FCDs) are cartilage injuries that affect about 900,000 Americans every year. Left untreated, these may lead to osteoarthritis and eventually necessitate painful knee replacements. Current treatment options are limited in terms of durability, cost, and availability of grafts. Tissue engineering, using natural scaffolds, are a highly attractive alternative promising cost efficiency, abundance, and long-term benefits. However, their low mechanical strength and dense matrices are impediments that could lead to sub-optimal repair.

In this work, a natural biomaterial, the bovine nucleus pulposus (bNP), derived from intervertebral disc tissue, was identified as a candidate scaffold for cartilage regeneration. Mechanical …

Bioaffinity Analysis Of Aptamer-Target Interactions, Pooja Karunanithi

Honors Theses

This study explores the bioaffinity of aptamer-target interactions through a comprehensive analysis. Aptamers, oligonucleotides that can bind to target molecules, have emerged as powerful tools in various fields, including diagnostics and therapeutics. The primary objective of this research was to assess the binding affinity and specificity of selected aptamers to their respective targets using a combination of experimental techniques and computational models. The binding affinity of 10 different complexes were measured through surface plasmon resonance (SPR) followed by molecular simulations. The results showed that the 6th complex had the best binding affinity. The data suggest that these aptamers could be …

Tissue Engineered Models Of Environmental And Metabolism-Driven Cancer-Nerve Crosstalk, Emory Gregory

Graduate Theses and Dissertations

Purpose: Within the last 30 years, cancer-nerve interactions have garnered attention for causing patient pain, increasing the risk of recurrence, and decreasing patient prognosis. There are 2 key forms cancer-nerve crosstalk takes: perineural invasion (PNI), in which cancer cells infiltrate nerves as a route for metastasis, and tumor innervation (TI), in which neurites penetrate solid tumors to promote tumor progression. Present in vitro models of cancer-nerve crosstalk primarily include Matrigel® mouse matrix and collagen I hydrogels; whereas collagen I hydrogels neglect tumor extracellular matrix (ECM) complexity, Matrigel® is controversial for its batch-to-batch inconsistencies and inclusion of experiment-altering growth factors. Decellularized …

Engineered Nucleic-Acid Binding Intrinsically Disordered Proteins For Biomedical Applications, Telmo Diez Perez

Biomedical Engineering ETDs

This dissertation explores the use of intrinsically disorder proteins (IDPs) in biomedical applications related to the detection and biosensing of nucleic-acid species. We engineer several low critical solution temperature (LCST) nucleic-acid binding elastin-like polypeptides (ELPs) as model IDPs and study their potential in biomedical application via interactions with short single-stranded (ss) DNA, tRNA and viral RNAs. First, we engineer a simple polycationic ELP capable of recruiting DNA on demand in a DNA-protein-rich condensate via LLPS. Moreover, we develop a modified Flory-Huggins theory to quantify the partitioning of DNA and protein upon coacervate formation with and without salts. We then design …

Innovative 4d Printing Of Biomimetic Collagen-Tcp Scaffolds For Bone Regeneration, Karly Morgan Liebendorfer

Theses and Dissertations

Bone tissue engineering (BTE) is a promising alternative approach to autografts and allografts when treating various bone diseases and disorders. BTE enables the fabrication of biocompatible, biomimetic, and osteo-stimulating constructs for the repair and regeneration of damaged bone tissue. The native bone environment primarily consists of anisotropic type 1 collagen (organic) and hydroxyapatite nanocrystals (inorganic). Composite biomimetic scaffolds fabricated by combining collagen with bioceramics have shown immense promise for BTE applications. Prior work has reported on different biofabrication methods to synthesize collagen-based composite scaffolds for use in BTE applications. However, to date, a customizable 3D composite scaffold that resembles the …

Deep Learning Framework For Graph-Based Molecular Drug Discovery, Daniel Manu

Electrical and Computer Engineering ETDs

This dissertation proposes the GraphGANFed framework, which combines Graph Convolutional Networks (GCN), Generative Adversarial Networks (GAN), and Federated Learning (FL) to generate novel molecules while preserving data privacy. FL allows learning from distributed clients without sharing local datasets, GCN extracts molecular structural properties, and GAN generates new molecules retaining the learned properties. Extensive simulations on three benchmark datasets show GraphGANFed's effectiveness, producing molecules with high novelty (≈ 100) and diversity (> 0.9). Results indicate a trade-off among evaluation metrics, and the right dropout ratio avoids mode collapse. Additionally, Conditional GraphGANFed (cGraphGANFed) incorporates a critic network from Reinforcement Learning (RL) to …

Engineering An Injectable Hydrogel With Self-Assembling 3d Vasculature, Kendyl Cohn

Master's Theses

This research developed methods for culturing self-assembling capillaries in an injectable gel as a potential method for vascularizing tissue-on-a-chip models to mimic physiological drug delivery. Additionally, a mathematical model was developed as a tool for understanding nutrient delivery and comparison of potential delivery systems. Organs-on-a-chip provide novel platforms for studying biology and physiology in 3D, allow exploration of tissue engineering on a manageable scale, and serve as models for drug screening and drug-delivery testing.

Methods were first developed for co-culture of endothelial cells and fibroblasts (3T3s or HDFs) in 2D, evaluating culture time, seeding density and ratio of HUVECs and …

Scaffold-Free Development Of Multicellular Tumor Spheroids With Spatial Characterization Of Structure And Metabolic Radial Profiles, Shelby N. Bess, Gaven K. Smart, Matthew J. Igoe, Timothy J. Muldoon

Biomedical Engineering Faculty Publications and Presentations

Purpose

In vitro assays are essential for studying cellular biology, but traditional monolayer cultures fail to replicate the complex three-dimensional (3D) interactions of cells in living organisms. 3D culture systems offer a more accurate reflection of the cellular microenvironment. However, 3D cultures require robust and unique methods of characterization.

Methods

The goal of this study was to create a 3D spheroid model using cancer cells and macrophages, and to demonstrate a custom image analysis program to assess structural and metabolic changes across spheroid microregions.

Results

Structural characterization shows that cells at the necrotic core show high normalized fluorescence intensities of …

Modeling Synergistic Effects Of Integrin And Tgf-Beta Signaling In Epithelial Mesenchymal Transition, Prerak Thakkar

Biology and Medicine Through Mathematics Conference

No abstract provided.

Calcium Analysis Of Intercellular Communications Between Alpha Cells And Delta Cells Across The Pancreatic Islet, Shichao Gao

McKelvey School of Engineering Graduate Student Theses & Dissertations

The intricate communication between different cell types within pancreatic islets plays a crucial role in regulating glucose homeostasis. Among these cellular interactions, the interplay between α cells (responsible for glucagon secretion) and δ cells (secreting somatostatin) is particularly intriguing due to the inhibitory effects of somatostatin on glucagon release. Understanding the intercellular interactions between α and δ cells may provide insights into the mechanisms underlying the coordinated regulation of blood glucose levels. In this study, we employed a multi-modal approach combining confocal imaging, image analysis, and correlation network analysis to investigate the spatial relationships and potential functional connections between α …

Design And Application Of Phase-Separating Peptides In Cytosolic Drug Delivery, Huihao Wang

McKelvey School of Engineering Graduate Student Theses & Dissertations

This research investigates the design and application of phase-separating peptides for direct cytosolic drug delivery. Novel peptides (GHGXY)4, with variable amino acids, were synthesized using microwave-assisted chemistry to enhance phase separation and membrane fusion. In vitro experiments utilizing advanced imaging techniques demonstrated the peptides' capability to form coacervates and facilitate direct cargo, DNA, mRNA, and protein, delivery into the cytosol, bypassing traditional cellular barriers. The study also explores the role of inhibitor Bafilomycin and NH4Cl in phase-separating peptides functionality, offering significant insights into their delivery mechanisms. This research underscores the potential of phase-separating peptides in improving therapeutic delivery strategies.

Manufacturing Silicone In-House For The Creation Of Customized Neurovascular Blood Vessel Mimics, Jacob Wilbert Perisho

Master's Theses

The Tissue Engineering Lab at California Polytechnic State University San Luis Obispo focuses on creating tissue-engineered Blood Vessel Mimics (BVMs) designed for the preclinical testing of neurovascular devices. These BVMs are composed of silicone models, representing anatomically accurate neurovasculatures, that are sodded with vascular cell types and then cultivated in bioreactors (which maintain physiologic conditions). These silicone models are currently sourced externally from industry partners, so the primary goal of this thesis was to develop the means and methods for the Tissue Engineering Lab to manufacture silicone models in-house.

The first aim of this thesis was to develop and explore …

Evaluating Tissue Morphology In The Context Of Varied Initial Fabrication Conditions, Cassidy Caffin

Biomedical Engineering Undergraduate Honors Theses

Cardiovascular diseases have been the leading cause of death for years. This includes myocardial infarctions (MI) where blood flow to the myocardium is restricted. This causes damage to cardiac muscle due to insufficient oxygen. There are multiple ways to treat patients following an MI with the most common involving assorted medication. However, there are limited medications that can be used for treating patients following MIs, and the FDA’s decreasing approval rate for new cardiac drugs will not dramatically improve the range of options. The lead-up to drug candidate rejection by the FDA can involve drugs exhibiting promising preliminary research that …

Utilizing Spatial Transcriptomics To Compare Gene Expression In Volumetric Muscle Loss Injury Recovery, Colton Gattis

Biomedical Engineering Undergraduate Honors Theses

Volumetric Muscle Loss (VML) injuries are known to disrupt the normal regenerative process via fibrosis leading to an extensive permanent loss of muscle function. The specific causation of this disruption remains to be defined; however, with new developments in transcriptomics, genetic trends can be identified across regions of tissue over time. This study follows VML injuries within the tibialis anterior of a mouse model for fifteen days after initial injury to attempt to identify expected transitions in healing. Genetic presence began to become more diversified as recovery progressed from four to fifteen days post injury with spatial clusters becoming globalized …

Investigating The Presence Of Patented In Vitro Models For Cancer-Nerve Crosstalk Methods, Christoff Hauptmann

Biomedical Engineering Undergraduate Honors Theses

The purpose of this research project is to investigate the presence of patented in vitro models for perineural invasion (PNI) and tumor innervation, the two most prominent modes of cancer-nerve crosstalk that play an active role in cancer initiation and progression. PNI occurs through a positive feedback loop in which cancer cells invade passive nerves to metastasize. Tumor innervation is the process where tumor cells attract nearby nerves to the tumor microenvironment (TME) for tumor growth and metastasis. These crosstalk paths have been established for many types of cancer and result in poor patient prognosis. Recently, in vitro models have …

Evaluation Of The Efficiency Of Muscle-Specific Promoters To Express Non-Endogenous Proteins In Skeletal Muscle, Gabrielle Bulliard, Made Harumi Padmaswari, Christopher E. Nelson

Biomedical Engineering Undergraduate Honors Theses

Gene therapies are emerging as powerful tools for treating genetic diseases and cancers, offering the potential for a permanent cure. Hemophilia B, affecting approximately 6,000 men in the U.S., results from a deficiency in coagulation factor IX protein (FIX), which is crucial for blood clotting. A substantial portion of patients, over 40%, suffer from severe hemophilia B, experiencing spontaneous, prolonged bleeding. Current prophylactic treatments involve frequent coagulation factor infusions, yet a curative approach would alleviate this burden. Gene editing technologies like CRISPR-Cas systems show promise for correcting genetic mutations, but the diverse nature of factor IX gene (F9) …

Environment And Response Of 3d-Encapsulated Mesenchymal Stem Cells To Mechanical Loading, Augustus Greenwood

McKelvey School of Engineering Graduate Student Theses & Dissertations

This thesis explores the micromechanical environment induced when cyclically compressing hydrogels via finite element modeling and experimentally on the impact of loading on mesenchymal stem cells (MSCs) when encapsulated withing 3D hydrogel matrices. Degenerative joint diseases, characterized by cartilage degradation, present significant challenges due to cartilage's limited self-repair capacity. Innovative approaches, including stem cell-based therapies and engineered biomaterials, have emerged as promising strategies for cartilage repair and regeneration. This work specifically investigates the calibration of a bioreactor, the uniformity of load response across the hydrogel constructs via finite element modeling (FEM), and the stress response of MSCs subjected to various …