Biology and Biomimetic Materials Commons^™

Dielectrophoretic Biomarkers For Cancer Detection And Cell Analysis: Integrating Microfluidics And Ai, Raphael Olumide Oladokun

Graduate Theses, Dissertations, and Problem Reports (ETD)

Pancreatic ductal adenocarcinoma (PDAC) carries a five-year survival rate of 13%, driven largely by late-stage diagnosis and the absence of sensitive noninvasive screening tools. Current diagnostic methods lack the sensitivity to detect disease-associated systemic changes at early and precancerous stages, representing a critical clinical gap. This dissertation addresses the central hypothesis that PDAC and its pathological subtypes induce measurable, disease-associated electrophysiological changes in circulating PBMCs that can serve as correlative liquid-biopsy biomarkers. To test this hypothesis, this work asks: can dielectrophoresis (DEP), impedance and zeta potential analysis with AI-assisted classification distinguish benign pancreatic conditions (non-malignant control), precancerous lesions (primarily IPMNs), …

Fabricating Silver-Ceria Polymer Nanocomposite Scaffolds For Biomedical Therapeutic Applications, Shreya S. Pawar

Honors Undergraduate Theses

Improper healing of bone fractures and limited regeneration of bone following bone tumor resection remain a prevalent complication worldwide. Long-term effects of this include joint instability, limited movement, and arthritis. Bone infections (osteomyelitis), reactive oxygen species (ROS) generation via excessive inflammation, and underlying conditions such as osteoporosis can contribute to suboptimal bone tissue regeneration. ROS accumulation stimulates osteoblast apoptosis, while promoting osteoclast differentiation. These processes inhibit mineralization and osteogenesis. Conventional therapeutics involve the utilization of drugs and bone grafts. However, these approaches pose limitations and can result in subsequent complications. Microbial infections, ROS accumulation, and excessive inflammations are factors that …

The Bacteriostatic, Regenerative, And Immunomodulatory Properties Of Extracellular Matrix Particles For Lung Injury, Keera P. Rhoads

Theses and Dissertations

Acute respiratory distress syndrome (ARDS) is a prevalent, life-threatening lung condition, affecting nearly 200,000 Americans annually, with a 40% international mortality rate. There is no cure for ARDS, and current pharmacological treatments have limited effectiveness. Symptoms can be mitigated with mechanical ventilation, though this often leads to ventilator-induced lung injuries (VILI) and puts critically ill patients at risk of infections, including ventilator-associated pneumonia (VAP). A promising therapeutic is the extracellular matrix (ECM), a complex network of structural proteins and bioactive molecules that has been shown to have anti-inflammatory properties and prevent fibrosis. We aim to utilize the regenerative and immunomodulatory …

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 …

Low Impedance, Durable, Self-Adhesive Hydrogel Epidermal Electrodes For Electrophysiology Recording, Naiyan Wu

McKelvey School of Engineering Graduate Student Theses & Dissertations

Traditional electrodes used for electrophysiology recording, characterized by their hard, dry, and inanimate nature, are fundamentally mismatched with the soft, moist, and bioactive characteristics of biological tissues, leading to suboptimal skin-electrode interfaces. Hydrogel materials, mirroring the high water content and biocompatibility of biological tissues, emerge as promising candidates for epidermal electronic materials due to their adjustable physicochemical properties. However, challenges such as inadequate electrical conductivity, elevated skin impedance, unreliable adhesion in moist conditions, and performance decline from dehydration have significantly restricted the efficacy and applicability of hydrogel-based electrodes. In this thesis, we report a high-performance hydrogel epidermal electrode patch for …

Matrix Stiffness Sensing By Nascent Adhesions And The Role Of Riam In Adhesion Assembly, Nikhil Mittal

Dissertations, Master's Theses and Master's Reports

Mechanical stiffness of the extracellular matrix (ECM) impacts many cellular functions such as proliferation, migration, and differentiation. ECM stiffness is sensed by a cell via integrin-based focal adhesions (FAs) by changing conformation and biochemical activities of molecules within FAs by the exchange of the force between the ECM and filamentous actin (F-actin). Cells in turn respond to this stiffness by generating traction force that plays an important role in many biological events such as tissue morphogenesis, stem cell differentiation, wound healing, and cancer cell metastasis. The stiffness of the extracellular matrix induces differential tension within integrin-based adhesions. Understanding stiffness sensing …

Air-Jet Bioprinting Of Stem Cell-Encapsulated Alginate Micro-Droplets For Organoid Biomanufacturing, Mirabella B. Stump

Electronic Theses and Dissertations

Biomanufactured 3D-organoids show promise for modeling and treating various conditions, particularly insulin-dependent diabetes mellitus (type-1 diabetes). Pancreatic islet organoids serve as sustainable sources of insulin-producing β-cells, potentially restoring insulin regulation in patients and providing a long-term solution for diabetes. Hydrogel droplet printing is an emerging technique in regenerative medicine due to its advantageous tunability and biocompatibility; however, challenges of consistency, quality control, and scalability persist. To address these issues, we developed a novel air-jetting based droplet bioprinting system for the generation of monodispersed alginate micro-droplets. The objective of this project was to incorporate human induced pluripotent stem cells (hiPSCs) into …

Diffusive Dynamics Of Biological Macromolecules In The Cytoplasm Of Live Bacteria, Asmaa Sadoon

Graduate Theses and Dissertations

Bacteria are small organisms that play important roles in our bodies and in maintaining our surrounding environment. However, bacterial infections are considered as one of the health diseases that threatens the lives of humans. Resistance of bacteria to antibiotics has made treating bacterial infections more challenging. With the emergence of many developed optical techniques, it has become possible to study various biological mechanisms of molecules inside these small organisms with high resolution and precise localization. In this research, single particle tracking photoactivation localization microscopy (sptPALM) technique was used to investigate the dynamics of fluorescent histonelike nucleoid-structuring proteins (H-NS) in live …

The Tin Man Needs A Heart: A Proposed Framework For The Regulation Of Bioprinted Organs, Linda Foit

Fordham Law Review

Each day, seventeen people die in the United States while waiting for an organ transplant. At least part of this need could be met by bioprinting, a technology that allows the on-demand production of custom-sized organs from a patient’s own cells. The field of bioprinting is progressing rapidly: the first bioprinted organs have already entered the clinic. Yet, developers of bioprinted organs face significant uncertainty as to how their potentially lifesaving products will be regulated—and by which government agency. Such regulatory uncertainty has the potential to decrease investment and stifle innovation in this promising technological field. This Note examines how …

Development Of An Injectable Methylcellulose Hydrogel System For Nucleus Pulposus Repair And Regeneration, Nada A. Haq-Siddiqi

Dissertations and Theses

Low back pain is the most common cause of disability in the world and is often caused by degeneration or injury of the intervertebral disc (IVD). The IVD is a complex, fibrocartilaginous tissue that allows for the wide range of spinal mobility. Disc degeneration is a progressive condition believed to begin in the central, gelatinous nucleus pulposus (NP) region of the tissue, for which there are few preventative therapies. Current therapeutic strategies include pain management and exercise, or surgical intervention such as spinal fusion, none of which address the underlying cause of degeneration. With an increasingly aging population, the socioeconomic …

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

Artificial Synthetic Scaffolds For Tissue Engineering Application Emphasizing The Role Of Biophysical Cues, Samerender Nagam Hanumantharao

Dissertations, Master's Theses and Master's Reports

The mechanotransduction of cells is the intrinsic ability of cells to convert the mechanical signals provided by the surrounding matrix and other cells into biochemical signals that affect several distinct processes such as tumorigenesis, wound healing, and organ formation. The use of biomaterials as an artificial scaffold for cell attachment, differentiation and proliferation provides a tool to modulate and understand the mechanotransduction pathways, develop better in vitro models and clinical remedies. The effect of topographical cues and stiffness was investigated in fibroblasts using polycaprolactone (PCL)- Polyaniline (PANI) based scaffolds that were fabricated using a self-assembly method and electrospinning. Through this …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi S. Patel

University Scholar Projects

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi Patel

Honors Scholar Theses

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

Soft-Microrobotics: The Manipulation Of Alginate Artificial Cells, Samuel Sheckman

Mechanical Engineering Research Theses and Dissertations

In this work, the approach to the manipulation of alginate artificial cell soft-microrobots, both individually and in swarms is shown. Fabrication of these artificial cells were completed through centrifugation, producing large volumes of artificial cells, encapsulated with superparamagnetic iron oxide nanoparticles; these artificial cells can be then externally stimulated by an applied magnetic field. The construction of a Permeant Magnet Stage (PMS) was produced to manipulate the artificial cells individually and in swarms. The stage functionalizes the permanent magnet in the 2D xy-plane. Once the PMS was completed, Parallel self-assembly (Object Particle Computation) using swarms of artificial cells in complex …

A 3d Biomimetic Scaffold Using Electrospinning For Tissue Engineering Applications, Samerender Nagam Hanumantharao

Dissertations, Master's Theses and Master's Reports

Electrospinning holds great promise for designing functional 3D biomimetic scaffolds for tissue engineering applications. The technique allows for the reproducible fabrication of 3D scaffolds with control over the porosity and thickness. In this work, a novel method for the synthesis of a 3D electroactive scaffold using electrospinning from polycaprolactone (PCL), Polyvinylidene Fluoride (PVDF) and Polyaniline (PANI) is reported. Additional scaffolds involving different morphologies of PCL, PCL-PVDF and PCL-PANI-PVDF were also fabricated and evaluated. The scaffolds were characterized using electron microscopy to visualize the morphologies. Infrared spectroscopy was used to confirm the presence of polymers and their respective phases in the …

Alginate Hydrogels As Three-Dimensional Scaffolds For In Vitro Culture Models Of Growth Plate Cartilage Development And Porcine Embryo Elongation, Taylor D. Laughlin

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

The establishment of in vitro culture models utilizes tissue engineering principles to design functional mimics of in vivo environments in vitro. Advantages for the use of in vitro culture models include ethical alleviation of animal models for therapeutic testing, cost efficiency, and a greater ability to study specific mechanisms via a systematic, ground-up approach to development. In this thesis, alginate hydrogels are utilized in the development of in vitro culture models of porcine embryo elongation and growth plate cartilage development. First, the effect of scaffold and modifications to the scaffold were explored in both projects. In order to modulate …

Incorporation Of Fibrin Into A Collagen–Glycosaminoglycan Matrix Results In A Scaffold With Improved Mechanical Properties And Enhanced Capacity To Resist Cell-Mediated Contraction, Claire Brougham, Tanya J. Levingstone, Stefan Jockenhoevel, Thomas C. Flanagan, Fergal J. O'Brien

Articles

Fibrin has many uses as a tissue engineering scaffold, however many in vivo studies have shown a reduction in function resulting from the susceptibility of fibrin to cell-mediated contraction. The overall aim of the present study was to develop and characterise a reinforced natural scaffold using fibrin, collagen and glycosaminoglycan (FCG), and to examine the cell-mediated contraction of this scaffold in comparison to fibrin gels. Through the use of an injection loading technique, a homogenous FCG scaffold was developed. Mechanical testing showed a sixfold increase in compressive modulus and a thirtyfold increase in tensile modulus of fibrin when reinforced with …

Biological Implications Of Satellite Cells For Scaffold-Based Muscle Regenerative Engineering, Maggie R. Del Ponte, Charter Chain, Meng Deng Dr., Feng Yue Dr., Shihuan Kuang Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Satellite cells are anatomically localized along the surface of muscle fibers and have been regarded as a population of muscle-specific progenitors that are responsible for muscle regeneration. In response to muscle injuries, satellite cells are activated to enter the cell cycle, then proliferate and differentiate into mature muscle cells to regenerate damaged myofibers. Unfortunately, this natural repair mechanism is interrupted in conditions such as muscle degenerative diseases or volumetric muscle loss. The function of stem cells is regulated by signals from their local microenvironment which is called the stem cell niche. Current satellite cell-based strategies such as direct cell transplantation …

Characterization Of Swelling Ratio And Water Content Of Hydrogels For Cartilage Engineering Applications, Emily E. Gill, Renay S.-C. Su, Julie C. Liu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Due to the high prevalence of arthritis and cartilage-related injuries, tissue engineers are studying ways to grow cartilage tissue replacements. Resilin, an elastomeric protein found in insect cuticles, is known for its extraordinary resilience and elasticity. In previous studies, recombinant resilin-based hydrogels, or cross-linked protein networks, exhibited potential for use in cartilage tissue scaffolds. Our lab successfully developed resilin-based proteins with a sequence based on the mosquito gene and showed that resilin-based hydrogels possess mechanical properties of the same order of magnitude as native articular cartilage. In addition, these mechanical properties can be controlled by changing the protein concentration. To …

Determining A Method For Rendering Low Cost Cdse(Zns) Core(Shell) Quantum Dots Aqueous Soluble Via Amphiphilic Polymer Wrapping, Patrick Mcbride

Materials Engineering

Herein is described the procedure of two amphiphilic polymer wrapping techniques that may be employed for obtaining aqueous soluble quantum dots (QDs) for use in biological fluorescent imaging applications. The advent of QDs has led to new nanoscale fluorescent materials that exhibit unparalleled quantum yields (QYs), high resistance to photobleaching, tunable emissions, and
absorption over a large optical range. However, the QD synthesis employed here at Cal Poly to obtain bright, photostable CdSe(ZnS) core(shell) QDs involves the use of organic solvents and surfactants, leading to hydrophobic QDs. Since all of biology relies on aqueous solubility, this hydrophobicity creates a major …

Assessment Of Electrospinning As An In-House Fabrication Technique For Blood Vessel Mimic Cellular Scaffolding, Colby M. James

Master's Theses

Intravascular devices, such as stents, must be rigorously tested before they can be approved by the FDA. This includes bench top in vitro testing to determine biocompatibility, and animal model testing to ensure safety and efficacy. As an intermediate step, a blood vessel mimic (BVM) testing method has been developed that mimics the three dimensional structure of blood vessels using a perfusion bioreactor system, human derived endothelial cells, and a biocompatible polymer scaffold used to support growth of the blood vessel cells. The focus of this thesis was to find an in-house fabrication method capable of making cellular scaffolding for …

Desulfovibrio Desulfuricans G20 Tetraheme Cytochrome Structure At 1.5 A˚ And Cytochrome Interaction With Metal Complexes, Mrunalini Pattarkine, J J. Tanner, C A. Bottoms, Y H. Lee, Judy D. Wall

Faculty Works

The structure of the type I tetraheme cytochrome c3 from Desulfovibrio desulfuricans G20 was determined to 1.5 A˚ by X-ray crystallography. In addition to the oxidized form, the structure of the molybdate-bound form of the protein was determined from oxidized crystals soaked in sodium molybdate. Only small structural shifts were obtained with metal binding, consistent with the remarkable structural stability of this protein. In vitro experiments with pure cytochrome showed that molybdate could oxidize the reduced cytochrome, although not as rapidly as U(VI) present as uranyl acetate. Alterations in the overall conformation and thermostability of the metal-oxidized protein were investigated …

Studies On The Formation Of Dna-Cationic Lipid Composite Films And Dna Hybridization In The Composites, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Krishna N. Ganesh

Faculty Works

The formation of composite films of double-stranded DNA and cationic lipid molecules (octadecylamine, ODA) and the hybridization of complementary single-stranded DNA molecules in such composite films are demonstrated. The immobilization of DNA is accomplished by simple immersion of a thermally evaporated ODA film in the DNA solution at close to physiological pH. The entrapment of the DNA molecules in the cationic lipid film is dominated by attractive electrostatic interaction between the negatively charged phosphate backbone of the DNA molecules and the protonated amine molecules in the thermally evaporated film and has been quantified using quartz crystal microgravimetry (QCM). Fluorescence studies …

Cationic Surfactant Mediated Hybridization And Hydrophobization Of Dna Molecules At The Liquid/Liquid Interface And Their Phase Transfer, Murali Sastry, Ashavani Kumar, Mrunalini Pattarkine, Vidya Ramakrishnan, Krishna N. Ganesh

Faculty Works

Hybridization of complementary oligonucleotides mediated by a cationic surfactant at the water/hexane interface leads to hydrophobic, double-helical DNA which may be readily phase transferred to the organic phase and cast into thin films on solid substrates.

Hybridization Of Dna By Sequential Immobilization Of Oligonucleotides At The Air-Water Interface, Murali Sastry, Vidya Ramakrishnan, Mrunalini Pattarkine, Anand Gole, K. N. Ganesh

Faculty Works

The hybridization of DNA by sequential electrostatic and hydrogen-bonding immobilization of single-stranded complementary oligonucleotides at the air-water interface with cationic Langmuir monolayers is demonstrated. The complexation of the single-stranded DNA molecules with octadecylamine (ODA) Langmuir monolayers was followed in time by monitoring the pressure-area isotherms. A large (and slow) expansion of the ODA monolayer was observed during each stage of complexation in the following sequence: primary single-stranded DNA followed by complementary single-stranded DNA followed by the intercalator, ethidium bromide. Langmuir-Blodgett (LB) films of the ODA-DNA complex were formed on different substrates and characterized using quartz-crystal microgravimetry (QCM), Fourier transform infrared …

Anion Induced Blue To Purple Transition In Bacteriorhodopsin, Mrunalini Pattarkine, Anil K. Singh

Faculty Works

Purple membrane (PM, λ" role="presentation">λmax" role="presentation">max 570 nm) of H. halobium on treatment with sulphuric acid changes its colour to blue (λ" role="presentation">λmax" role="presentation">max 608 nm). The purple chromophore can be regenerated from the blue chromophore by exogeneous addition of anions such as CI−" role="presentation">− and HPO42−" role="presentation">2−4. Chloride ion is found to be more effective than the dibasic phosphate ion in regenerating the purple chromophore. Nevertheless, one thing common to the anion regeneration is that both CI−" role="presentation">− and HPO42−" role="presentation">2−4 show marked pH effect. At pH 1.0 the efficiency of …