{"id":{"repo_id":"unsw","oai_identifier":"oai:unsworks.library.unsw.edu.au:1959.4/103257"},"canonical_url":"https://search.dev.ndltd.org/etd/unsw/oai:unsworks.library.unsw.edu.au:1959.4/103257","repository":{"repo_id":"unsw","name":"University of New South Wales","base_url":"https://unsworks.unsw.edu.au/oai/provider"},"display":{"title":"Development of a methodology for applying shear stress to suspended mammalian cells","abstract":"Fluid shear stress is a typical mechanical stimulation that mammalian cells are exposed to both in vivo and in vitro. In in-vivo conditions, the stress exists in the blood and lymphatic vessels as well as other body fluids transmission paths, including the tissue interstitial flow, the bone marrow, and the alveolar-capillary barrier. Such shear stress constitutes an important part of the growth environment of cells in vivo. When it comes to the in-vitro situation, cells are either deprived of such mechanical stimulations or exposed to excessive stresses, which is not their actual physiological growth environment. They can be exposed to undesired fluid shear stress in situations such as microfluidics, bioprinting and bioreactors. Being exposed to such stresses alters cell integrity, which affects their downstream applications, including drug screening and tissue regeneration. Current methods of loading shear stress onto suspended cells can be divided into three categories: (1) tubular shear equipment, (2) flow channel devices and (3) rheometer shear instruments. However, none of these methods accurately evaluates the shear stress levels that are loaded onto the cells while retaining a good biomimetic physiological condition. This thesis aims to advance the understanding of suspended cells’ responses to fluid shear stress by developing a method that quantifies the stress and demonstrates the corresponding cell conditions. To allow long-term shear stress loading on cells in suspension, a new method that evaluates cell density was developed. The method is simple and cost-effective and can determine cell density at a precision of 0.002 g/ml with iodixanol under an inverted microscope. A neutrally buoyant single-cell suspension recipe is tested. Cells cultured within the broth are not only capable of remaining suitable for long term shear exposure, but also presented enhanced health conditions. In loading shear stress onto the cells, a circulation system was built based on a novel pulled dumbbell-shaped borosilicate pipette that forms the constriction (internal diameter down to 40 μm). Being supported by PDMS, the constriction platform is capable of both loading consistent shear stress onto the cells and implementing visualization during the progress. Based on the applications of in-vitro tissue culture and tumour cell drug screening, the bronchial epithelial cell line (BEAS-2b) was trained with the shear loading system. Cell integrity properties before and after the stress imparting were evaluated and compared. Cellular deformation was captured during the process with a high speed camera to relate the cellular response with the physical shape variation. In summary, a new method was developed to load fluid shear stress onto the suspended mammalian cells. It is expected that the results will lead to future studies that systematically evaluate mammalian cells’ shear responses and thereby contribute to the field of in-vitro cell manipulations, including bioprinting, tissue engineering and drug screening.","abstract_html":"Fluid shear stress is a typical mechanical stimulation that mammalian cells are exposed to both in vivo and in vitro. In in-vivo conditions, the stress exists in the blood and lymphatic vessels as well as other body fluids transmission paths, including the tissue interstitial flow, the bone marrow, and the alveolar-capillary barrier. Such shear stress constitutes an important part of the growth environment of cells in vivo. When it comes to the in-vitro situation, cells are either deprived of such mechanical stimulations or exposed to excessive stresses, which is not their actual physiological growth environment. They can be exposed to undesired fluid shear stress in situations such as microfluidics, bioprinting and bioreactors. Being exposed to such stresses alters cell integrity, which affects their downstream applications, including drug screening and tissue regeneration. Current methods of loading shear stress onto suspended cells can be divided into three categories: (1) tubular shear equipment, (2) flow channel devices and (3) rheometer shear instruments. However, none of these methods accurately evaluates the shear stress levels that are loaded onto the cells while retaining a good biomimetic physiological condition. This thesis aims to advance the understanding of suspended cells’ responses to fluid shear stress by developing a method that quantifies the stress and demonstrates the corresponding cell conditions. To allow long-term shear stress loading on cells in suspension, a new method that evaluates cell density was developed. The method is simple and cost-effective and can determine cell density at a precision of 0.002 g/ml with iodixanol under an inverted microscope. A neutrally buoyant single-cell suspension recipe is tested. Cells cultured within the broth are not only capable of remaining suitable for long term shear exposure, but also presented enhanced health conditions. In loading shear stress onto the cells, a circulation system was built based on a novel pulled dumbbell-shaped borosilicate pipette that forms the constriction (internal diameter down to 40 μm). Being supported by PDMS, the constriction platform is capable of both loading consistent shear stress onto the cells and implementing visualization during the progress. Based on the applications of in-vitro tissue culture and tumour cell drug screening, the bronchial epithelial cell line (BEAS-2b) was trained with the shear loading system. Cell integrity properties before and after the stress imparting were evaluated and compared. Cellular deformation was captured during the process with a high speed camera to relate the cellular response with the physical shape variation. In summary, a new method was developed to load fluid shear stress onto the suspended mammalian cells. It is expected that the results will lead to future studies that systematically evaluate mammalian cells’ shear responses and thereby contribute to the field of in-vitro cell manipulations, including bioprinting, tissue engineering and drug screening.","abstract_has_math":false,"creators":["Zhang, Yani"],"institution":"UNSW, Sydney","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2024,"date_issued":"2024","date_published":"2024","updated_at":"2026-07-24T05:32:27Z","subjects":["Shear stress","3D Bioprinting","Suspended mammalian cells","Circulation system","Fluid dynamics","Microfluidics","anzsrc-for: 4017 Mechanical engineering","anzsrc-for: 400303 Biomechanical engineering"],"languages":[],"rights":["embargoed access","CC BY 4.0"],"rights_urls":["http://purl.org/coar/access_right/c_f1cf","https://creativecommons.org/licenses/by/4.0/"],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["https://doi.org/10.26190/unsworks/30573"],"render_values":[{"text":"https://doi.org/10.26190/unsworks/30573","href":"https://doi.org/10.26190/unsworks/30573","code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/1959.4/103257","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Zhang, Yani"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2024"]},{"key":"dc:publisher","label":"Institution","values":["UNSW, Sydney"]},{"key":"dc:relation","label":"Dc Relation","values":["10.1088/1758-5090/ad22ee"]},{"key":"dc:type","label":"Dc Type","values":["doctoral thesis","http://purl.org/coar/resource_type/c_db06"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Shear stress","3D Bioprinting","Suspended mammalian cells","Circulation system","Fluid dynamics","Microfluidics","anzsrc-for: 4017 Mechanical engineering","anzsrc-for: 400303 Biomechanical engineering"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["embargoed access","http://purl.org/coar/access_right/c_f1cf","CC BY 4.0","https://creativecommons.org/licenses/by/4.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/1959.4/103257","https://doi.org/10.26190/unsworks/30573"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Fluid shear stress is a typical mechanical stimulation that mammalian cells are exposed to both in vivo and in vitro. In in-vivo conditions, the stress exists in the blood and lymphatic vessels as well as other body fluids transmission paths, including the tissue interstitial flow, the bone marrow, and the alveolar-capillary barrier. Such shear stress constitutes an important part of the growth environment of cells in vivo. When it comes to the in-vitro situation, cells are either deprived of such mechanical stimulations or exposed to excessive stresses, which is not their actual physiological growth environment. They can be exposed to undesired fluid shear stress in situations such as microfluidics, bioprinting and bioreactors. Being exposed to such stresses alters cell integrity, which affects their downstream applications, including drug screening and tissue regeneration. Current methods of loading shear stress onto suspended cells can be divided into three categories: (1) tubular shear equipment, (2) flow channel devices and (3) rheometer shear instruments. However, none of these methods accurately evaluates the shear stress levels that are loaded onto the cells while retaining a good biomimetic physiological condition. This thesis aims to advance the understanding of suspended cells’ responses to fluid shear stress by developing a method that quantifies the stress and demonstrates the corresponding cell conditions. To allow long-term shear stress loading on cells in suspension, a new method that evaluates cell density was developed. The method is simple and cost-effective and can determine cell density at a precision of 0.002 g/ml with iodixanol under an inverted microscope. A neutrally buoyant single-cell suspension recipe is tested. Cells cultured within the broth are not only capable of remaining suitable for long term shear exposure, but also presented enhanced health conditions. In loading shear stress onto the cells, a circulation system was built based on a novel pulled dumbbell-shaped borosilicate pipette that forms the constriction (internal diameter down to 40 μm). Being supported by PDMS, the constriction platform is capable of both loading consistent shear stress onto the cells and implementing visualization during the progress. Based on the applications of in-vitro tissue culture and tumour cell drug screening, the bronchial epithelial cell line (BEAS-2b) was trained with the shear loading system. Cell integrity properties before and after the stress imparting were evaluated and compared. Cellular deformation was captured during the process with a high speed camera to relate the cellular response with the physical shape variation. In summary, a new method was developed to load fluid shear stress onto the suspended mammalian cells. It is expected that the results will lead to future studies that systematically evaluate mammalian cells’ shear responses and thereby contribute to the field of in-vitro cell manipulations, including bioprinting, tissue engineering and drug screening."]},{"key":"dc:title","label":"Title","values":["Development of a methodology for applying shear stress to suspended mammalian cells"]}]}],"canonical_facts":{"dc:creator":["Zhang, Yani"],"dc:date":["2024"],"dc:description":["Fluid shear stress is a typical mechanical stimulation that mammalian cells are exposed to both in vivo and in vitro. In in-vivo conditions, the stress exists in the blood and lymphatic vessels as well as other body fluids transmission paths, including the tissue interstitial flow, the bone marrow, and the alveolar-capillary barrier. Such shear stress constitutes an important part of the growth environment of cells in vivo. When it comes to the in-vitro situation, cells are either deprived of such mechanical stimulations or exposed to excessive stresses, which is not their actual physiological growth environment. They can be exposed to undesired fluid shear stress in situations such as microfluidics, bioprinting and bioreactors. Being exposed to such stresses alters cell integrity, which affects their downstream applications, including drug screening and tissue regeneration. Current methods of loading shear stress onto suspended cells can be divided into three categories: (1) tubular shear equipment, (2) flow channel devices and (3) rheometer shear instruments. However, none of these methods accurately evaluates the shear stress levels that are loaded onto the cells while retaining a good biomimetic physiological condition. This thesis aims to advance the understanding of suspended cells’ responses to fluid shear stress by developing a method that quantifies the stress and demonstrates the corresponding cell conditions. To allow long-term shear stress loading on cells in suspension, a new method that evaluates cell density was developed. The method is simple and cost-effective and can determine cell density at a precision of 0.002 g/ml with iodixanol under an inverted microscope. A neutrally buoyant single-cell suspension recipe is tested. Cells cultured within the broth are not only capable of remaining suitable for long term shear exposure, but also presented enhanced health conditions. In loading shear stress onto the cells, a circulation system was built based on a novel pulled dumbbell-shaped borosilicate pipette that forms the constriction (internal diameter down to 40 μm). Being supported by PDMS, the constriction platform is capable of both loading consistent shear stress onto the cells and implementing visualization during the progress. Based on the applications of in-vitro tissue culture and tumour cell drug screening, the bronchial epithelial cell line (BEAS-2b) was trained with the shear loading system. Cell integrity properties before and after the stress imparting were evaluated and compared. Cellular deformation was captured during the process with a high speed camera to relate the cellular response with the physical shape variation. In summary, a new method was developed to load fluid shear stress onto the suspended mammalian cells. It is expected that the results will lead to future studies that systematically evaluate mammalian cells’ shear responses and thereby contribute to the field of in-vitro cell manipulations, including bioprinting, tissue engineering and drug screening."],"dc:identifier":["http://hdl.handle.net/1959.4/103257","https://doi.org/10.26190/unsworks/30573"],"dc:publisher":["UNSW, Sydney"],"dc:relation":["10.1088/1758-5090/ad22ee"],"dc:rights":["embargoed access","http://purl.org/coar/access_right/c_f1cf","CC BY 4.0","https://creativecommons.org/licenses/by/4.0/"],"dc:subject":["Shear stress","3D Bioprinting","Suspended mammalian cells","Circulation system","Fluid dynamics","Microfluidics","anzsrc-for: 4017 Mechanical engineering","anzsrc-for: 400303 Biomechanical engineering"],"dc:title":["Development of a methodology for applying shear stress to suspended mammalian cells"],"dc:type":["doctoral thesis","http://purl.org/coar/resource_type/c_db06"]},"updated_at":"2026-07-24T05:32:27Z"}