{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/110636"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/110636","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Manipulating lipid mesostructure using hard and soft material additives","abstract":"Lipids are biological amphiphilic molecules that at their most basic level form a simple but important structural framework for cells. Lipids have recently increasingly been viewed as complex and active components of biological systems, but the majority of research continues to focus on biological aspects of their interactions within the plasma membrane. This is of course important but misses their great potential as self-assembled materials with complex structures at the nm length scale. In this dissertation, I explore in a largely abiological fashion how new materials can be created from some of the most well-studied lipids. My approach to this, and how the dissertation is roughly organized, is representative of two opposing approaches to complexity used in materials science. In a deconstructing approach, the focus is on reducing the system by identifying how or which components work together. This is useful when starting with a biological system with a built-in complexity. In a developmental approach, the focus is on merging relatively simple components to achieve cooperative or complementary behaviour. This takes engineered systems where we don't know the system's limits and work to expand the boundary. I characterize multilamellar assemblies of phospholipids with the intent of understanding the possible structural roles of the major lipid components present in healthy and diseased lungs. Mammalian breath relies on large periodic changes in the lung surface area. Lipids are naturally present to reduce the energy required for this motion, however, the efficacy depends on maintaining a healthy composition. Small-angle x-ray scattering (SAXS) is used to probe simple models of lung surfactant with up to 5 components. Supporting evidence of the hierarchical structure of lipid mixtures is collected using wide-angle x-ray scattering, solid-state NMR, and confocal fluorescence microscopy of multilamellar vesicles. I demonstrate first that the mitochondrial lipid cardiolipin, which is associated with symptoms of pneumonia, in high-humidity conditions both increases the membrane disorder and decreases the lipid mobility at physiological concentrations. A broader investigation demonstrates that cardiolipin causes adjacent bilayers to connect and fuse across the interlamellar space. Separately, I observe for the first time the formation of periodic asymmetrically phase-separated membranes in a simple 3-component mixture: a saturated lipid zwitterionic lipid DPPC, an unsaturated anionic lipid DOPG, and cholesterol. Lipid mixtures are well-known to phase separate spontaneously but are tightly coupled across the bilayer. Asymmetric phase separation usually requires either an active process as seen in vivo or careful sample preparation to control the composition of each half of the bilayer. Because asymmetric phase separation is important for studying the plasma membrane but difficult to prepare artificially, this result will help develop future models for the plasma membrane. Inorganic nanomaterials are structured at length scales where their size, shape, and organization determine their fundamental material properties. The most effective use of these materials can depend on controlling their relative separation and orientation at the individual particle or nm length scale over macroscopic distances. Bilayer-forming lipids are known to interact favourably with hydrophobic nanospheres and incorporate them up to around 5 nm total particle diameter. Most experimental evidence finds that larger particles are excluded. Here I demonstrate that GMO:DOTAP, a lipid mixture typically studied in the context of drug delivery, forms a composite structure with fluorescent CdSe/CdS dot-in-rod that neither structure can form independently. Using glancing incidence SAXS I demonstrate that low-aspect-ratio nanorods co-assemble with lipids into a non-close-packed liquid crystalline phase with square-shaped symmetry. This is one of very few experimental systems that can induce rod-shaped particles to form a square lattice. I further discover that the assembly is kinetically controlled and that when dried quickly, the nanorod-composites self-assemble into a currently unidentified 3D structure. The new assembly can be oriented relative to a substrate using both drop-casting and spin-coating techniques. The lattice parameter of the structure and therefore the nanorod separation can be reversibly controlled using the relative humidity surrounding the films at length scales of a few nm. Because interactions between nanomaterials are determined over these distances, this structure is promising for future applications in responsive functional devices.","abstract_html":"Lipids are biological amphiphilic molecules that at their most basic level form a simple but important structural framework for cells. Lipids have recently increasingly been viewed as complex and active components of biological systems, but the majority of research continues to focus on biological aspects of their interactions within the plasma membrane. This is of course important but misses their great potential as self-assembled materials with complex structures at the nm length scale. In this dissertation, I explore in a largely abiological fashion how new materials can be created from some of the most well-studied lipids. My approach to this, and how the dissertation is roughly organized, is representative of two opposing approaches to complexity used in materials science. In a deconstructing approach, the focus is on reducing the system by identifying how or which components work together. This is useful when starting with a biological system with a built-in complexity. In a developmental approach, the focus is on merging relatively simple components to achieve cooperative or complementary behaviour. This takes engineered systems where we don't know the system's limits and work to expand the boundary. I characterize multilamellar assemblies of phospholipids with the intent of understanding the possible structural roles of the major lipid components present in healthy and diseased lungs. Mammalian breath relies on large periodic changes in the lung surface area. Lipids are naturally present to reduce the energy required for this motion, however, the efficacy depends on maintaining a healthy composition. Small-angle x-ray scattering (SAXS) is used to probe simple models of lung surfactant with up to 5 components. Supporting evidence of the hierarchical structure of lipid mixtures is collected using wide-angle x-ray scattering, solid-state NMR, and confocal fluorescence microscopy of multilamellar vesicles. I demonstrate first that the mitochondrial lipid cardiolipin, which is associated with symptoms of pneumonia, in high-humidity conditions both increases the membrane disorder and decreases the lipid mobility at physiological concentrations. A broader investigation demonstrates that cardiolipin causes adjacent bilayers to connect and fuse across the interlamellar space. Separately, I observe for the first time the formation of periodic asymmetrically phase-separated membranes in a simple 3-component mixture: a saturated lipid zwitterionic lipid DPPC, an unsaturated anionic lipid DOPG, and cholesterol. Lipid mixtures are well-known to phase separate spontaneously but are tightly coupled across the bilayer. Asymmetric phase separation usually requires either an active process as seen in vivo or careful sample preparation to control the composition of each half of the bilayer. Because asymmetric phase separation is important for studying the plasma membrane but difficult to prepare artificially, this result will help develop future models for the plasma membrane. Inorganic nanomaterials are structured at length scales where their size, shape, and organization determine their fundamental material properties. The most effective use of these materials can depend on controlling their relative separation and orientation at the individual particle or nm length scale over macroscopic distances. Bilayer-forming lipids are known to interact favourably with hydrophobic nanospheres and incorporate them up to around 5 nm total particle diameter. Most experimental evidence finds that larger particles are excluded. Here I demonstrate that GMO:DOTAP, a lipid mixture typically studied in the context of drug delivery, forms a composite structure with fluorescent CdSe/CdS dot-in-rod that neither structure can form independently. Using glancing incidence SAXS I demonstrate that low-aspect-ratio nanorods co-assemble with lipids into a non-close-packed liquid crystalline phase with square-shaped symmetry. This is one of very few experimental systems that can induce rod-shaped particles to form a square lattice. I further discover that the assembly is kinetically controlled and that when dried quickly, the nanorod-composites self-assemble into a currently unidentified 3D structure. The new assembly can be oriented relative to a substrate using both drop-casting and spin-coating techniques. The lattice parameter of the structure and therefore the nanorod separation can be reversibly controlled using the relative humidity surrounding the films at length scales of a few nm. Because interactions between nanomaterials are determined over these distances, this structure is promising for future applications in responsive functional devices.","abstract_has_math":false,"creators":["Steer, Dylan J"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Materials Science & Engr","degree_department":null,"school":null,"contributors":["Leal, Cecilia","Diao, Ying","Schweizer, Kenneth","Shim, Moonsub"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2021,"date_issued":"2021-09-17T02:34:18Z","date_published":"2021-09-17T02:34:18Z","updated_at":"2026-07-22T22:24:52Z","subjects":["Small-angle x-ray scattering","SAXS","x-ray diffraction","lipid","soft-matter","self assembly","monoolein","nanomaterial","mesostructure","heirarchical structure","liquid crystal","smectic","lung surfactant","pulmonary surfactant","dot-in-rod","nanorod"],"languages":["en"],"rights":["Copyright 2021 Dylan Steer"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/110636","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Leal, Cecilia","Diao, Ying","Schweizer, Kenneth","Shim, Moonsub"]},{"key":"dc:creator","label":"Author","values":["Steer, Dylan J"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2021-09-17T02:34:18Z","2023-09-17T02:34:57Z","2021-03-09","2021-05"]},{"key":"dc:type","label":"Dc Type","values":["text","Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science & Engr"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Small-angle x-ray scattering","SAXS","x-ray diffraction","lipid","soft-matter","self assembly","monoolein","nanomaterial","mesostructure","heirarchical structure","liquid crystal","smectic","lung surfactant","pulmonary surfactant","dot-in-rod","nanorod"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2021 Dylan Steer"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/110636"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Lipids are biological amphiphilic molecules that at their most basic level form a simple but important structural framework for cells. Lipids have recently increasingly been viewed as complex and active components of biological systems, but the majority of research continues to focus on biological aspects of their interactions within the plasma membrane. This is of course important but misses their great potential as self-assembled materials with complex structures at the nm length scale. In this dissertation, I explore in a largely abiological fashion how new materials can be created from some of the most well-studied lipids. My approach to this, and how the dissertation is roughly organized, is representative of two opposing approaches to complexity used in materials science. In a deconstructing approach, the focus is on reducing the system by identifying how or which components work together. This is useful when starting with a biological system with a built-in complexity. In a developmental approach, the focus is on merging relatively simple components to achieve cooperative or complementary behaviour. This takes engineered systems where we don't know the system's limits and work to expand the boundary. I characterize multilamellar assemblies of phospholipids with the intent of understanding the possible structural roles of the major lipid components present in healthy and diseased lungs. Mammalian breath relies on large periodic changes in the lung surface area. Lipids are naturally present to reduce the energy required for this motion, however, the efficacy depends on maintaining a healthy composition. Small-angle x-ray scattering (SAXS) is used to probe simple models of lung surfactant with up to 5 components. Supporting evidence of the hierarchical structure of lipid mixtures is collected using wide-angle x-ray scattering, solid-state NMR, and confocal fluorescence microscopy of multilamellar vesicles. I demonstrate first that the mitochondrial lipid cardiolipin, which is associated with symptoms of pneumonia, in high-humidity conditions both increases the membrane disorder and decreases the lipid mobility at physiological concentrations. A broader investigation demonstrates that cardiolipin causes adjacent bilayers to connect and fuse across the interlamellar space. Separately, I observe for the first time the formation of periodic asymmetrically phase-separated membranes in a simple 3-component mixture: a saturated lipid zwitterionic lipid DPPC, an unsaturated anionic lipid DOPG, and cholesterol. Lipid mixtures are well-known to phase separate spontaneously but are tightly coupled across the bilayer. Asymmetric phase separation usually requires either an active process as seen in vivo or careful sample preparation to control the composition of each half of the bilayer. Because asymmetric phase separation is important for studying the plasma membrane but difficult to prepare artificially, this result will help develop future models for the plasma membrane. Inorganic nanomaterials are structured at length scales where their size, shape, and organization determine their fundamental material properties. The most effective use of these materials can depend on controlling their relative separation and orientation at the individual particle or nm length scale over macroscopic distances. Bilayer-forming lipids are known to interact favourably with hydrophobic nanospheres and incorporate them up to around 5 nm total particle diameter. Most experimental evidence finds that larger particles are excluded. Here I demonstrate that GMO:DOTAP, a lipid mixture typically studied in the context of drug delivery, forms a composite structure with fluorescent CdSe/CdS dot-in-rod that neither structure can form independently. Using glancing incidence SAXS I demonstrate that low-aspect-ratio nanorods co-assemble with lipids into a non-close-packed liquid crystalline phase with square-shaped symmetry. This is one of very few experimental systems that can induce rod-shaped particles to form a square lattice. I further discover that the assembly is kinetically controlled and that when dried quickly, the nanorod-composites self-assemble into a currently unidentified 3D structure. The new assembly can be oriented relative to a substrate using both drop-casting and spin-coating techniques. The lattice parameter of the structure and therefore the nanorod separation can be reversibly controlled using the relative humidity surrounding the films at length scales of a few nm. Because interactions between nanomaterials are determined over these distances, this structure is promising for future applications in responsive functional devices.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2023-05-01","The student, Dylan Steer, accepted the attached license on 2021-03-03 at 11:03.","The student, Dylan Steer, submitted this Dissertation for approval on 2021-03-03 at 13:55.","This Dissertation was approved for publication on 2021-03-09 at 16:30.","DSpace SAF Submission Ingestion Package generated from Vireo submission #16189 on 2021-09-16 at 17:01:55","Made available in DSpace on 2021-09-17T02:34:18Z (GMT). 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Lipids have recently increasingly been viewed as complex and active components of biological systems, but the majority of research continues to focus on biological aspects of their interactions within the plasma membrane. This is of course important but misses their great potential as self-assembled materials with complex structures at the nm length scale. In this dissertation, I explore in a largely abiological fashion how new materials can be created from some of the most well-studied lipids. My approach to this, and how the dissertation is roughly organized, is representative of two opposing approaches to complexity used in materials science. In a deconstructing approach, the focus is on reducing the system by identifying how or which components work together. This is useful when starting with a biological system with a built-in complexity. In a developmental approach, the focus is on merging relatively simple components to achieve cooperative or complementary behaviour. This takes engineered systems where we don't know the system's limits and work to expand the boundary. I characterize multilamellar assemblies of phospholipids with the intent of understanding the possible structural roles of the major lipid components present in healthy and diseased lungs. Mammalian breath relies on large periodic changes in the lung surface area. Lipids are naturally present to reduce the energy required for this motion, however, the efficacy depends on maintaining a healthy composition. Small-angle x-ray scattering (SAXS) is used to probe simple models of lung surfactant with up to 5 components. Supporting evidence of the hierarchical structure of lipid mixtures is collected using wide-angle x-ray scattering, solid-state NMR, and confocal fluorescence microscopy of multilamellar vesicles. I demonstrate first that the mitochondrial lipid cardiolipin, which is associated with symptoms of pneumonia, in high-humidity conditions both increases the membrane disorder and decreases the lipid mobility at physiological concentrations. A broader investigation demonstrates that cardiolipin causes adjacent bilayers to connect and fuse across the interlamellar space. Separately, I observe for the first time the formation of periodic asymmetrically phase-separated membranes in a simple 3-component mixture: a saturated lipid zwitterionic lipid DPPC, an unsaturated anionic lipid DOPG, and cholesterol. Lipid mixtures are well-known to phase separate spontaneously but are tightly coupled across the bilayer. Asymmetric phase separation usually requires either an active process as seen in vivo or careful sample preparation to control the composition of each half of the bilayer. Because asymmetric phase separation is important for studying the plasma membrane but difficult to prepare artificially, this result will help develop future models for the plasma membrane. Inorganic nanomaterials are structured at length scales where their size, shape, and organization determine their fundamental material properties. The most effective use of these materials can depend on controlling their relative separation and orientation at the individual particle or nm length scale over macroscopic distances. Bilayer-forming lipids are known to interact favourably with hydrophobic nanospheres and incorporate them up to around 5 nm total particle diameter. Most experimental evidence finds that larger particles are excluded. Here I demonstrate that GMO:DOTAP, a lipid mixture typically studied in the context of drug delivery, forms a composite structure with fluorescent CdSe/CdS dot-in-rod that neither structure can form independently. Using glancing incidence SAXS I demonstrate that low-aspect-ratio nanorods co-assemble with lipids into a non-close-packed liquid crystalline phase with square-shaped symmetry. This is one of very few experimental systems that can induce rod-shaped particles to form a square lattice. I further discover that the assembly is kinetically controlled and that when dried quickly, the nanorod-composites self-assemble into a currently unidentified 3D structure. The new assembly can be oriented relative to a substrate using both drop-casting and spin-coating techniques. The lattice parameter of the structure and therefore the nanorod separation can be reversibly controlled using the relative humidity surrounding the films at length scales of a few nm. Because interactions between nanomaterials are determined over these distances, this structure is promising for future applications in responsive functional devices.","Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2023-05-01","The student, Dylan Steer, accepted the attached license on 2021-03-03 at 11:03.","The student, Dylan Steer, submitted this Dissertation for approval on 2021-03-03 at 13:55.","This Dissertation was approved for publication on 2021-03-09 at 16:30.","DSpace SAF Submission Ingestion Package generated from Vireo submission #16189 on 2021-09-16 at 17:01:55","Made available in DSpace on 2021-09-17T02:34:18Z (GMT). No. of bitstreams: 6 STEER-DISSERTATION-2021.pdf: 322262232 bytes, checksum: e2a3d153a991006e3bf8cfd2760ad3a5 (MD5) Conformational Changes as Driving Force for Phase Recognition - rights.pdf: 119486 bytes, checksum: 40e95a4001e1852d2b868a7051aebc08 (MD5) Investigation into Biological Environments through (Non)linear Optics_ A Multiscale Study of Laurdan Derivatives - rights.pdf: 119216 bytes, checksum: 7781125fe6b21df0a2eb9bf92f3fad86 (MD5) LICENSE.txt: 4208 bytes, checksum: 93a58d3912efd1b1eb0ad9270d26f362 (MD5) MyLSPaper_Right.pdf: 119221 bytes, checksum: 0d29e80240e9e43148d2ebf96ebdbc19 (MD5) PROQUEST_LICENSE.txt: 4554 bytes, checksum: df012a76db45fedd0537cd329504f818 (MD5) Previous issue date: 2021-03-09","Embargo set by: Seth Robbins for item 118479 Lift date: 2023-09-17T02:34:57Z Reason: Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","Author requested U of Illinois access only (OA after 2yrs) in Vireo ETD system","U of I Only"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/110636"],"dc:language":["en"],"dc:rights":["Copyright 2021 Dylan Steer"],"dc:subject":["Small-angle x-ray scattering","SAXS","x-ray diffraction","lipid","soft-matter","self assembly","monoolein","nanomaterial","mesostructure","heirarchical structure","liquid crystal","smectic","lung surfactant","pulmonary surfactant","dot-in-rod","nanorod"],"dc:title":["Manipulating lipid mesostructure using hard and soft material additives"],"dc:type":["text","Thesis"],"thesis:degree_discipline":["Materials Science & Engr"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:24:52Z"}