The heterogeneity of pancreatic cancer renders many available general therapies ineffective holding the five-year survival rate close to 10% for decades. Surgical resection eligibility, resistance to chemotherapy and limited efficacy of immunotherapy emphasize the dire need for diverse and innovative treatments to combat this challenging disease. This study evaluates co-therapy strategies that combine non-thermal, minimally invasive ablation technology and targeted drug delivery to enhance treatment efficacy. Our research begins by uncovering the multifaceted potential of Irreversible Electroporation (IRE), a cutting-edge non-thermal tumor ablation technique. This study demonstrates IRE-mediated ability to trigger programmed necrotic cell death, induce cell cycle arrest, and modulate immune cell populations within the tumor microenvironment. This transformation from a pro-tumor state to a proinflammatory milieu, enriched with cytotoxic T lymphocytes and neutrophils. IRE-induced proinflammation in the tumor site renders immunologically "cold" tumor into immunologically "hot" tumor and holds significant promise of improving treatment efficacy. Notably, IRE-treated mice exhibited an extended period of progression-free survival, implying clinical potential. The transient nature of these effects suggests potential mechanisms of tumor recurrence highlighting the need for further studies to maximize the efficacy of IRE. Our mechanistic studies evaluated the IFN-STAT1-PD-L1 feedback loop as a possible reason for pancreatic tumor recurrence. Our data also suggest a stronger IFN-PD-L1 feedback loop compared to mammary, osteosarcoma and glioblastoma tumors rendering pancreatic cancer immunologically "cold". This study also investigates the use of histotripsy (a non-thermal, noninvasive, nonionizing ultrasound-guided ablation modality) to treat pancreatic cancer utilizing a novel immunocompromised swine model. We successfully generated human orthotopic pancreatic tumors in the immune deficient pigs, which allowed for consequent investigation of clinical challenges presented by histotripsy. While rigorous clinical studies are indispensable for validation, the promise of histotripsy offers new hope for patients. In parallel, we used our immunocompromised swine model of orthotopic pancreatic cancer to investigate the SonoTran® system, which employs ultrasound-activated oscillating particles to enhance drug delivery within hard-to-reach tumors. Our study demonstrates that SonoTran® significantly enhances the intratumoral penetrance of therapeutic agents, including commonly used chemotherapy drugs like paclitaxel and gemcitabine. Additionally, SonoTran® improved delivery of the anti-epidermal growth factor (EGFR) monoclonal antibody, cetuximab- which is frequently used in cancer immunotherapy. Together, our findings address challenges in the delivery of a range of therapeutics while simultaneously exposing challenges like off-target damage. In conclusion, this study presents a multifaceted approach to confront the complex characteristics of pancreatic cancer. Given the variations in patient response and the complexity of the disease, it is clear that a singular solution is unlikely. Our research, which combines IRE, histotripsy, and SonoTran®, to interrogate a promising array of tools to tackle different challenges to provide tailored treatments. In the ever-evolving landscape of pancreatic cancer therapy, this research opens new avenues to investigate deeper into molecular mechanisms, co-therapy treatment options, future preclinical and clinical studies which eventually encourage the potential for improved patient outcomes. / Doctor of Philosophy / Pancreatic cancer is a formidable disease, known for its late-stage diagnosis and limited treatment options with a poor 5-year survival rate of ~10%. However, a promising frontier in the battle against this lethal disease has emerged through combining mechanical, cell based and immunotherapies to attack the cancer from multiple angles at once. In my PhD research, I explored novel approaches to transform the landscape of pancreatic cancer treatment. We began by investigating Irreversible Electroporation (IRE), a non-thermal method to ablate tumors. Beyond its known function of reducing tumor size, IRE initiated programmed necrotic cell death, halted tumor cell division, and triggered changes in the immune landscape within the tumor. In response to IRE treatment, the immune environment shifted from pro-tumor to proinflammatory state, showing potential for clinical use. Mice treated with IRE experienced extended cancer progression-free survival temporarily, followed by eventual relapse. During relapse, we found that immune cells reverted back to their original, pre- IRE treated state. This observation logically implies combining IRE and immune checkpoint inhibitors aimed towards maintaining the IRE-altered immunological environment. Next, we developed and used novel pig models that closely resemble human pancreatic cancer patients to test histotripsy, a first phase toward making histotripsy as a non-invasive treatment approach for pancreatic cancer. Use of orthotopic tumor in a large animal model and clinical device allowed us to expose some challenges of ultrasound guidance of histotripsy. Notably, the treatment results in partial ablation and a reduction in stroma materials, which play a role in the tumor's resistance to commonly used treatments. While rigorous clinical studies are needed for validation, this approach offers hope in the quest for innovative pancreatic cancer treatment. Another promising approach we investigated involves SonoTran® particles, ultrasound-activated oscillating particles that can increase drug absorption in a targeted fashion. Our study demonstrated increased concentrations of commonly used therapeutic agents within tumors through SonoTran®-facilitated delivery, providing an effective means to overcome drug delivery issues within pancreatic tumors. There is no one size fits all treatment to address the complexity of pancreatic cancer. The future of treatment lies in the integration of IRE, histotripsy and SonoTran® into clinical practice. In summary, this PhD research identified promising novel technologies and combinations of treatments for pancreatic cancer, reaffirming the importance of exploring innovative solutions to combat pancreatic cancer. The dynamic nature of the pancreatic tumor microenvironment underscores the importance of further research to extend the positive impacts of these treatments and improve tumor debulking.

Brain tumors are among the most devastating types of solid tumors to treat. Standard of care for glioblastoma (GBMs), the most aggressive form of primary brain tumors, has failed to improve the current survival rates in the past decades. Despite many other solid tumors, recent advances in cancer immunotherapies have also shown disappointing outcomes in GBMs. The heterogenous nature of GBMs, the immunosuppressive tumor microenvironment and the restrictive role of blood brain barrier (BBB) are some of the main challenges faced for treating GBMs. Electroporation-based treatments have demonstrated promising results, treating preclinical models of GBMs. It has been shown that low and high frequency irreversible electroporation treatments shift the immunosuppressive tumor microenvironment and reversibly open large areas of blood brain barrier (BBB). In this dissertation, in vitro cell culture models are utilized to study electroporation-based treatments for achieving a more optimized treatment for glioblastoma. We are proposing to utilize the immunomodulatory effects of electroporation treatments to improve the outcomes of immunotherapies in the brain. / Doctor of Philosophy / Despite the current advancements in treating solid tumors, brain tumors remain among the most difficult cancers to treat. The special structure of the brain as an organ as well as tumor complexity can lead to treatment failure. It is also known that infiltration of the immune cells within the tumor mass is limited due to the tumor's immunosuppressive nature. Hence, the use of newly advancing immunotherapy techniques is limited in the brain. Local treatments have become one of the most promising tools against brain tumors. Such treatments include methods that use excessive heating of the tissue to kill the tumors. Relying on heat for tissue destruction could damage the critical structures near the tumor and will reduce the favorable immune response after the treatment. A new treatment modality known as electroporation has been introduced for non-thermal treatment of brain tumors. Due to its non-thermal nature, electroporation treatments will allow for sparing of critical structures and can lead to a more robust immune response comparing to thermal treatment modalities. In this dissertation, we utilize electroporation-based treatments to try to overcome some of the challenges associated with treating brain tumors such as tumor heterogeneity and immune suppression.

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Yes / The removal of the ubiquitous phenol and phenolic compounds in industrial wastes is a critical environmental issue due to their harmful threats to wildlife and potential adverse human health effects. The removal of such compounds is therefore of significant importance in water treatment and reuse. In recent years, reverse osmosis (RO) has been successfully utilised in several industrial processes and wastewater treatment including phenol removal. In this paper, a new model based on a spiral-wound RO process is developed for the removal of phenol from wastewater. A simplified mathematical algorithm using an irreversible thermodynamic approach is developed. This results in a set of non-linear Differential and Algebraic Equations (DAEs), which are solved based on a number of optimised model parameters using a combined methodology of parameter estimation and experimental phenol-water data derived from the literature. The effects of several operational parameters on the performance (in terms of removal of phenol) of the process are explored using the model.

The most common and aggressive malignant brain tumor, glioblastoma (GBM), demonstrates on average a 5-year survival rate of only 6.8%. Difficulties arising in the treatment of GBM include the inability of large molecular agents to permeate through the blood-brain barrier (BBB); migration of highly invasive GBM cells beyond the solid tumor margin; and gross, macroscopic intratumor heterogeneity. These characteristics complicate treatment of GBM with standard of care, resulting in abysmal prognosis. Electroporation-based therapies have emerged as attractive alternates to standard of care, demonstrating favorable outcomes in a variety of tumors. Notably, irreversible electroporation (IRE) has been used for BBB disruption and nonthermal ablation of intracranial tumor tissues. Despite promising results, IRE can cause unintended muscle contractions and is susceptible to electrical heterogeneities. Second generation High-frequency IRE (H-FIRE) utilizes bursts of bipolar pulsed electric fields on the order of the cell charging time constant (~1 μs) to ablate tissue while reducing nerve excitation, muscle contraction, and is far less prone to differences in electrical heterogeneities. Throughout my dissertation, I discuss investigations of H-FIRE for the treatment of malignant gliomas and other intracranial disorders. To advance the versatility, usability, and understanding of H-FIRE for intracranial applications, my PhD thesis focuses on: (1) characterizing H-FIRE-mediated BBB disruption effects in an in vivo healthy rodent model; (2) the creation of a novel, real-time impedance spectroscopy technique (Fourier Analysis SpecTroscopy, FAST) using waveforms compatible with existing H-FIRE pulse generators; (3) development of FAST as an in situ technique to monitor ablation growth and to determine patient-specific ablation endpoints; (4) conducting a preliminary efficacy study of H-FIRE ablation in an orthotopic F98 rodent glioma model; and (5) establishing the feasibility of MRI-guided H-FIRE for the ablation malignant gliomas in a spontaneous canine glioma model. The culmination of this thesis advances our understanding of H-FIRE in intracranial tissues, as well as develops a novel, intraoperative impedance spectroscopy technique towards determining patient-specific ablation endpoints for intracranial H-FIRE procedures. / Doctor of Philosophy / The most aggressive malignant brain tumor, glioblastoma (GBM), demonstrates on average a 5-year survival rate of only 6.8%. Difficulties arising in the treatment of GBM include the inability of chemotherapy agents to diffuse into brain tumor tissue as these molecular are unable to pass the so-called blood-brain barrier (BBB). This tumor tissue also presents with cells with the propensity to invade healthy tissue, to the point where diagnostic scans are unable to capture this migration. These characteristics complicate treatment of GBM with standard of care, resulting in abysmal prognosis. Electroporation-based therapies have emerged as attractive alternates to standard of care, demonstrating favorable outcomes in a variety of tumors. For instance, irreversible electroporation (IRE) has been used to successfully treat tumors in the prostate, liver, kidney, and pancreas. Second generation High-frequency IRE (H-FIRE) may possess even greater antitumor qualities and this is the focus of my dissertation. Throughout my dissertation, I discuss investigations of H-FIRE with applications to treat malignant gliomas and other intracranial disorders. My PhD thesis focuses on: (1) characterizing H-FIRE effects for enhanced drug delivery to the brain; (2) the creation of a new, real-time electrical impedance spectroscopy technique (Fourier Analysis SpecTroscopy, FAST) using waveforms compatible with existing H-FIRE pulse generators; (3) development of FAST as a technique to determine H-FIRE treatment endpoints; (4) conducting a preliminary efficacy study of H-FIRE to ablate rodent glioma tumors; and (5) establishing the feasibility of MRI-guided H-FIRE for the ablation malignant gliomas in a spontaneous canine glioma model. The culmination of this thesis advances our understanding of H-FIRE in intracranial tissues, as well as develops a new impedance spectroscopy technique to be used in determining patient-specific ablation endpoints for intracranial H-FIRE procedures.

Cancer is a complex and dynamic disease that is difficult to treat due to its heterogeneous nature at multiple scales. Standard therapies such as surgery, radiation, and chemotherapy often fail, therefore superior therapies must be developed. Electroporation-based therapies offer an alternative to standard treatments, utilizing pulsed electric fields to permeabilize cell membranes to either enhance drug delivery (electrochemotherapy) or induce cancer cell death (irreversible electroporation). Electroporation treatments show promise in the clinic, however, are limited in the size of tumors that they can safely treat without increasing the applied voltage to an extent that induces thermal damage or muscle contractions in patients. A method to increase ablation size safely is needed. To make this advancement and to advance other cancer treatments as well, better in vitro tumor models are needed. Heterogeneity not only makes cancer difficult to treat, but also difficult to recapitulate in vitro. This dissertation addresses the complementary need to develop both better cancer therapies and more physiologically relevant in vitro tumor models. My results demonstrate that by using a calcium adjuvant with irreversible electroporation treatment, ablation size can be increased without using a higher applied voltage. Additional mechanistic studies identified signaling pathways that were differentially dysregulated under calcium and no calcium conditions, impacting cell death. Finally, I have successfully encapsulated cells in fibrin microgels which may enable the creation of more physiologically relevant and complex 3D in vitro and ex-vivo platforms to investigate IRE as well as other tumor therapies. / Doctor of Philosophy / Cancer is a complex and dynamic disease. Heterogeneity exists at the single cell, tumor, and patient levels making it difficult to establish a unified target for therapy. Standard therapies such as surgery, radiation, and chemotherapy often fail for this reason, therefore superior therapies must be developed. Electroporation-based therapies offer an alternative to standard treatments, utilizing pulsed electric fields to permeabilize cell membranes to either enhance drug delivery (electrochemotherapy) or induce cancer cell death (irreversible electroporation). Electroporation treatments show promise in the clinic, however, are limited in the size of tumors that they can safely treat without increasing the applied voltage to an extent that induces thermal damage or muscle contractions in patients. A method to increase ablation size safely is needed. To make this advancement and to advance other cancer treatments as well, better tumor models are needed. Many of the same challenges in treating cancer serve as challenges in creating physiologically relevant tumor models. In this dissertation, I have developed a simplified platform to test whether using a calcium additive with irreversible electroporation therapies enhances ablation size. My results demonstrate that by using a calcium additive with irreversible electroporation treatment, ablation size can be increased without using a higher applied voltage. In addition, the biological pathways responsible for cell death in irreversible electroporation treatment with and without calcium were studied. Finally, I have successfully encapsulated cells in fibrin microgels that can be used to create better tumor models that encompass the heterogeneity of tumors found in the body.

Biological development and progression are managed by a diverse macromolecular group called proteins. Protein structure results from a complex folding process that leads to a final active form. This protein state is susceptible to changes in the surrounding environment and an incorrect structure can be produced. Changes in the protein conformation can lead to the formation of protein aggregates. Adsorption of proteins onto surfaces is utilized in many research analyses, but is capable of irreversibly changing the protein structure and causing aggregation. Albumin is a plasma protein that adsorbs on many different surfaces because the structure easily rearranges. The structure of albumin once adsorbed has been shown to deteriorate; however, outcomes of both stabilization and aggregation have been found. A dynamic laser light scattering instrument will be utilized to measure the differences in size and determine the amount of aggregation. Our lab has developed a z-axis translating laser light scattering device (ZATLLS) that has been used to measure the sedimentation velocity of several different materials in solution. In this case, bovine serum albumin (BSA) will be adsorbed onto polystyrene particles and the particle settling velocity determined. The settling solution viscosity and density will also be ascertained, so Stoke's law can infer the average aggregate size of each experiment. BSA-coated polystyrene particles displayed a more controlled settling behavior compared to non-coated polystyrene particles. Although the BSA-coated particles had a smaller sedimentation velocity, a larger aggregate size was found due to the greater solution viscosity. Therefore, the ZATLLS instrument can be employed to measure sedimentation velocities of multiple interactions and the aggregation level inferred. Although most albumin molecules are remarkably similar, there are subtle differences in amino acid residues, length, and charge. Sedimentation velocities for human serum albumin (HSA) coated polystyrene particles and BSA-coated polystyrene particles only had a small difference. However an almost 50% higher solution viscosity was measured in BSA experiment solutions, and resulted in the slower settling of the larger aggregates compared to HSA-coated particles. Viscosity calibration curves for each albumin species were used to determine the amount of protein desorbed from the particles during the settling process. The larger solution viscosity for BSA-coated particle experiments led to a much larger degree of desorption. HSA was shown to be the more stable albumin species when adsorbed onto polystyrene particles. Temperature denaturing was performed to aid in the determination of the stability of BSA. Reversible and irreversible conformational changes in BSA were produced at 46ºC and 76ºC respectively. The solutions were cooled to room temperature before adsorption ontopolystyrene particles and the sedimentation velocities measured. A 50% difference in average viscosity between the reversibly and irreversibly changed BSA was found. This caused the larger aggregates formed in the 76ºC BSA experiments to have an almost equivalent sedimentation velocity to those in the reversibly denatured BSA experiments. Average aggregate size for reversibly denatured BSA was well within the ranges found for non-denatured BSA. In conclusion, irreversibly denatured BSA formed larger aggregates and was more likely to desorb from the polystyrene particles than reversibly changed BSA. / Master of Science

Getriebener Transport wechselwirkender Teilchen ist im direkten oder übertragenen Sinne von großer Bedeutung für viele Forschungsfelder. Zur Untersuchung grundlegender Fragestellungen wird auf einfache Modellsysteme zurückgegriffen, die analytische Zugänge ermöglichen und zugleich wesentliche Aspekte der Nichtgleichgewichtsdynamik in realen Applikationen erfassen. Im ersten Teil dieser Arbeit wird ein eindimensionales Gittergas mit Nächsten-Nachbar-Wechselwirkungen betrachtet, um den Einfluss von Wechselwirkungen auf den Teilchentransport in getriebenen Diffusionsprozessen zu studieren. Mit einem auf der zeitabhängigen Dichtefunktionaltheorie klassischer Fluide basierenden Verfahren werden Evolutionsgleichungen für Dichten, Korrelationsfunktionen und Ströme aufgestellt, deren numerische Lösung eine gute Beschreibung der Transportkinetik liefert. Für Sprungdynamiken, welche bestimmte Relationen erfüllen, werden exakte Strom-Dichte-Beziehungen in geschlossenen Ringsystemen hergeleitet. Hierzu zählen insbesondere die für viele Applikationen relevanten Glauber-Raten. In offenen Kanälen, die zwei Reservoire verbinden, kommt es zu Phasenübergängen der Teilchendichte im Inneren des Kanals. Anhand allgemeiner Überlegungen auf Grundlage der Extremalprinzipien bezüglich des Stroms und der Strom-Dichte-Relation im Bulk kann ein Überblick aller möglichen Phasen, ungeachtet der konkreten System-Reservoir-Kopplung, erhalten werden. Welche Phasen im randinduzierten Phasendiagramm erscheinen, wird durch die System-Reservoir-Kopplung festgelegt. Dies wird anhand zweier unterschiedlicher Randankopplungen demonstriert. Im zweiten Teil der Dissertationsschrift werden stochastische Transportvorgänge in Brownschen Pumpen und in organischen Solarzellen mit Heteroübergang modelliert. Hierbei zeigen Brownsche Pumpen Phasenübergänge in periodengemittelten Dichten und Strömen, falls Ausschlusswechselwirkungen berücksichtigt werden. Ein Minimalmodell organischer Solarzellen erlaubt Elementarprozesse an der Donator-Akzeptor-Grenzfläche abzubilden, wodurch Einblicke in das Strom- und Effizienzverhalten des photovoltaischen Systems gewonnen werden.