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You searched for +publisher:"McMaster University" +contributor:("Selvaganapathy, Ravi P."). Showing records 1 – 3 of 3 total matches.

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McMaster University

1. Islam, Md. Shehadul. A Low Power Electrical Method for Cell Accumulation and Lysis Using Microfluidics.

Degree: MASc, 2012, McMaster University

Microbiological contamination from bacteria such as Escherichia coli and Salmonella is one of the main reasons for waterborne illness. Real time and accurate monitoring of water is needed in order to alleviate this human health concern. Performing multiple and parallel analysis of biomarkers such as DNA and mRNA that targets different regions of pathogen functionality provides a complete picture of its presence and viability in the shortest possible time. These biomarkers are present inside the cell and need to be extracted for analysis and detection. Hence, lysis of these pathogenic bacteria is an important part in the sample preparation for rapid detection. In addition, collecting a small amount of bacteria present in a large volume of sample and concentrating them before lysing is important as it facilitates the downstream assay. Various techniques, categorized as mechanical, chemical, thermal and electrical, have been used for lysing cells. In the electrical method, cells are lysed by exposure to an external electric field. The advantage of this method, in contrast to other methods, is that it allows lysis without the introduction of any chemical and biological reagents and permits rapid recovery of intercellular organelles. Despite the advantages, issues such as high voltage requirement, bubble generation and Joule heating are associated with the electrical method. To alleviate the issues associated with electrical lysis, a new design and associated fabrication process for a microfluidic cell lysis device is described in this thesis. The device consists of a nanoporous polycarbonate (PCTE) membrane sandwiched between two PDMS microchannels with electrodes embedded at the reservoirs of the microchannels. Microcontact printing is used to attach this PCTE membrane with PDMS. By using this PCTE membrane, it was possible to intensify the electric field at the interface of two channels while maintaining it low in the other sections of the device. Furthermore, the device also allowed electrophoretic trapping of cells before lysis at a lower applied potential. For instance, it could trap bacteria such as E. coli from a continuous flow into the intersection between two channels for lower electric field (308 V/cm) and lyse the cell when electric field was increased more than 1000 V/cm into that section. Application of lower DC voltage with pressure driven flow alleviated adverse effect from Joule heating. Moreover, gas evolution and bubble generation was not observed during the operation of this device. Accumulation and lysis of bacteria were studied under a fluorescence microscope and quantified by using intensity measurement. To observe the accumulation and lysis, LIVE/DEAD BacLight Bacterial Viability Kit consisting of two separate components of SYTO 9 and propidium iodide (PI) into the cell suspension in addition to GFP expressed E. coli were used. Finally, plate counting was done to determine the efficiency of the device and it was observed that the device… Advisors/Committee Members: Selvaganapathy, Ravi P., Mechanical Engineering.

Subjects/Keywords: Cell Lysis; Microfluidics; Electrical Lysis; Bacterial Lysis; Electroporation; Polycarbonate Membrane; Biochemical and Biomolecular Engineering; Bioimaging and biomedical optics; Biological Engineering; Biomedical; Electro-Mechanical Systems; Membrane Science; Molecular, cellular, and tissue engineering; Nanoscience and Nanotechnology; Other Mechanical Engineering; Biochemical and Biomolecular Engineering

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APA (6th Edition):

Islam, M. S. (2012). A Low Power Electrical Method for Cell Accumulation and Lysis Using Microfluidics. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/12526

Chicago Manual of Style (16th Edition):

Islam, Md Shehadul. “A Low Power Electrical Method for Cell Accumulation and Lysis Using Microfluidics.” 2012. Masters Thesis, McMaster University. Accessed February 21, 2019. http://hdl.handle.net/11375/12526.

MLA Handbook (7th Edition):

Islam, Md Shehadul. “A Low Power Electrical Method for Cell Accumulation and Lysis Using Microfluidics.” 2012. Web. 21 Feb 2019.

Vancouver:

Islam MS. A Low Power Electrical Method for Cell Accumulation and Lysis Using Microfluidics. [Internet] [Masters thesis]. McMaster University; 2012. [cited 2019 Feb 21]. Available from: http://hdl.handle.net/11375/12526.

Council of Science Editors:

Islam MS. A Low Power Electrical Method for Cell Accumulation and Lysis Using Microfluidics. [Masters Thesis]. McMaster University; 2012. Available from: http://hdl.handle.net/11375/12526


McMaster University

2. Piazza, Justin E. Novel Antipsychotic Drug Carriers: The Development of Nanoparticle and Microgel Drug Carriers for Antipsychotic Delivery in the Treatment of Schizophrenia.

Degree: MSc, 2013, McMaster University

Lectin-functionalized, Poly [oligo(ethylene glycol) methyl ether methacrylate] (POEGMA) loaded with 3(R)-[(2(S)-pyrrolidinylcarbonyl)amino]-2-oxo-1-pyrrolidineacetamide (PAOPA) and poly(ethylene glycol)–block-poly(D,L-lactic-co-glycolic acid) (PEG-PLGA) nanoparticles loaded with haloperidol were prepared with narrow size distributions and sizes < 135 nm. The microgels and nanoparticles exhibited high Solanum tuberosum lectin (STL) conjugation efficiencies, encapsulation efficiencies, and drug loading capacities. The in vitro release of PAOPA and haloperidol was slow in physiological conditions over 96 hours, demonstrating minimal drug leakage and the potential for efficient drug transport to the targeted brain tissue. POAPA, POEGMA and the STL-functionalized POEGMA microgels were found to be non-toxic in both cell lines, indicating that they would not be toxic when administered intranasally or when they reach the brain. The nasal epithelial cell uptake of rhodamine-labelled microgels was higher in cells when the STL-functionalization was present. All haloperidol-loaded nanoparticle formulations were found to be highly effective at inducing catalepsy, while intranasal administration of STL-functionalized nanoparticles using the intranasal spray device increased the brain tissue haloperidol concentrations by 2-3.5 fold compared to STL-functionalized particles administered intranasally with a pipette. For the first time, brain tissue concentrations of rhodamine-labelled microgels confirmed that microgels are capable of passing the blood-brain barrier and that this uptake is size dependent. These formulations demonstrate promise in the reduction of the drug dose necessary to produce a therapeutic effect with antipsychotic drugs for the treatment of schizophrenia using a non-invasive route of administration.

Master of Science (MSc)

Advisors/Committee Members: Mishra, Ram K., Hoare, Todd, Selvaganapathy, Ravi P., Neuroscience.

Subjects/Keywords: nanoparticle; microgel; antipsychotic; allosteric modulator; PAOPA; Amino Acids, Peptides, and Proteins; Biochemistry; Biomaterials; Cell Biology; Medicinal Chemistry and Pharmaceutics; Molecular and Cellular Neuroscience; Molecular Biology; Nanomedicine; Nervous System Diseases; Pharmaceutics and Drug Design; Polymer Science; Psychiatric and Mental Health; Toxicology; Amino Acids, Peptides, and Proteins

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Piazza, J. E. (2013). Novel Antipsychotic Drug Carriers: The Development of Nanoparticle and Microgel Drug Carriers for Antipsychotic Delivery in the Treatment of Schizophrenia. (Masters Thesis). McMaster University. Retrieved from http://hdl.handle.net/11375/13291

Chicago Manual of Style (16th Edition):

Piazza, Justin E. “Novel Antipsychotic Drug Carriers: The Development of Nanoparticle and Microgel Drug Carriers for Antipsychotic Delivery in the Treatment of Schizophrenia.” 2013. Masters Thesis, McMaster University. Accessed February 21, 2019. http://hdl.handle.net/11375/13291.

MLA Handbook (7th Edition):

Piazza, Justin E. “Novel Antipsychotic Drug Carriers: The Development of Nanoparticle and Microgel Drug Carriers for Antipsychotic Delivery in the Treatment of Schizophrenia.” 2013. Web. 21 Feb 2019.

Vancouver:

Piazza JE. Novel Antipsychotic Drug Carriers: The Development of Nanoparticle and Microgel Drug Carriers for Antipsychotic Delivery in the Treatment of Schizophrenia. [Internet] [Masters thesis]. McMaster University; 2013. [cited 2019 Feb 21]. Available from: http://hdl.handle.net/11375/13291.

Council of Science Editors:

Piazza JE. Novel Antipsychotic Drug Carriers: The Development of Nanoparticle and Microgel Drug Carriers for Antipsychotic Delivery in the Treatment of Schizophrenia. [Masters Thesis]. McMaster University; 2013. Available from: http://hdl.handle.net/11375/13291


McMaster University

3. Wu, Wen-I. Rectified electroosmotic flow in microchannels using Zeta potential modulation – Characterization and its application in pressure generation and particle transport.

Degree: PhD, 2011, McMaster University

Microfluidic devices using electroosmotic flows (EOFs) in microchannels have been developed and widely applied in chemistry, biology and medicine. Advantages of using these devices include the reduction of reagent consumption and duration for analysis. Moreover the velocity profile of EOFs, in contrast to the parabolic profile found in pressure-driven flows, has a plug-like profile which contributes significantly less to solute dispersion. It also requires no valve to control the flow, which is done with the appropriate application of electrical potentials, thus becomes one of the favourite techniques for sample separation. However, high potentials of several hundred volts are usually required to generate sufficient EOF. These high potentials are not practical for general usage and could cause electrical hazard in some applications. One of the possible solutions is the introduction of zeta potential modulation. The EOF in a microchannel can be controlled by the zeta potential at the liquid/solid interface upon the application of external gate potentials across the channel walls. Combined with AC EOF, it can rectify the oscillating flows and generate pressure that can be used for microfluidic pumping applications. Since the flow induced by the alternating electric field is unsteady and periodic, it is critical to visualize the flow with high spatial and temporal resolutions in order to understand fluid dynamics. A novel method to obtain high temporal resolution for high frequency periodic electrokinetic flows using phase sampling technique in micro particle image velocimetry (PIV) measurements are first developed in order to characterize the AC electroosmotic flow. After that, the principle of zeta potential modulation is demonstrated to transport particles, cells, and other micro organisms using rectified AC EOF in open microchannels. The rectified flow is obtained by synchronous zeta-potential modulation with the driving potential in the microchannel. Subsequently, we found that PDMS might not be the best material for some pumping and biomedical applications as its hydrophobic surface property makes the priming process more difficult in small microchannels and also causes significant protein adsorption from biological samples. A more hydrophilic and biocompatible material, polyurethane (PU), was chosen to replace PDMS. A polyurethane-based soft-lithography microfabrication including its bonding, interconnect integration and in-situ surface modification was developed providing better biocompatibility and pumping performance. Finally, an electroosmotic pumping device driven by zeta potential modulation and fabricated by PU soft lithography was presented. The problem of channel priming is solved by the capillary force induced by the hydrophilic surface. Its flow rate and pressure output were found to be controllable through several parameters such as driving potential, gate potential, applied frequency, and phase lag between the driving and gate potentials.

Doctor of Philosophy (PhD)

Advisors/Committee Members: Selvaganapathy, Ravi P., Chan Ching, Philip Britz McKibbin, Mechanical Engineering.

Subjects/Keywords: microfluidics; zeta potential; electroosmotic flow; polyurethane; particle image velocimetry; Biomechanical Engineering; Biomechanical Engineering

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wu, W. (2011). Rectified electroosmotic flow in microchannels using Zeta potential modulation – Characterization and its application in pressure generation and particle transport. (Doctoral Dissertation). McMaster University. Retrieved from http://hdl.handle.net/11375/11775

Chicago Manual of Style (16th Edition):

Wu, Wen-I. “Rectified electroosmotic flow in microchannels using Zeta potential modulation – Characterization and its application in pressure generation and particle transport.” 2011. Doctoral Dissertation, McMaster University. Accessed February 21, 2019. http://hdl.handle.net/11375/11775.

MLA Handbook (7th Edition):

Wu, Wen-I. “Rectified electroosmotic flow in microchannels using Zeta potential modulation – Characterization and its application in pressure generation and particle transport.” 2011. Web. 21 Feb 2019.

Vancouver:

Wu W. Rectified electroosmotic flow in microchannels using Zeta potential modulation – Characterization and its application in pressure generation and particle transport. [Internet] [Doctoral dissertation]. McMaster University; 2011. [cited 2019 Feb 21]. Available from: http://hdl.handle.net/11375/11775.

Council of Science Editors:

Wu W. Rectified electroosmotic flow in microchannels using Zeta potential modulation – Characterization and its application in pressure generation and particle transport. [Doctoral Dissertation]. McMaster University; 2011. Available from: http://hdl.handle.net/11375/11775

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