{"doi":"10.1101/694620","title":"<i>In situ</i>\n                  , fluorescence lifetime-based measurements of cell membrane micromechanics","abstract":"<jats:title>ABSTRACT</jats:title>\n                <jats:p>\n                  Microscopic\n                  <jats:italic>in situ</jats:italic>\n                  measurements of the mechanical properties of lipid bilayers were derived from the mean and variance of the fluorescence lifetime distributions of 1’-dioctadecyl-3,3,3’3’-tetramethylindocarbocyanine perchlorate (DiI). In this method, DiI, incorporated into membranes, acts as a membrane-targeted molecular rotor whose fluorescence lifetime is sensitive to local lipid viscosity. A new model was developed in which changes in area per lipid were derived from the first and second moments of a stretched exponential distribution of fluorescence lifetimes of DiI, which were subsequently used to compute mean area per lipid and its variance, quantities directly related to bilayer compressibility and bending moduli. This method enabled molecular scale assays of surface micromechanics of membrane-bound entities, such as nanoliposomes and human red blood cells.\n                </jats:p>\n                <jats:sec>\n                  <jats:title>STATEMENT OF SIGNIFICANCE</jats:title>\n                  <jats:p>Despite the progress in cell deformability studies, and in understanding mechanical properties of purified lipid bilayers, there has not, to date, been a method to measure the mechanics of the lipid bilayer in cells in situ. The current manuscript describes such a method. Using a fluorescent molecular rotor, DiI, embedded in the membrane, along with time resolved fluorescence, we directly measure area per lipid, and its temporal and spatial variance, properties directly related to bilayer mechanical moduli. Such a method will allow investigators to start exploring the relationship between lipid bilayer mechanics and cellular health and disease.</jats:p>\n                </jats:sec>","journal":null,"year":null,"id":676416,"datarank":0.10397207708399181,"base_score":0.6931471805599453,"endowment":0.6931471805599453,"self_citation_contribution":0.10397207708399181,"citation_network_contribution":0.0,"self_endowment_contribution":0.10397207708399181,"citer_contribution":0.0,"corpus_percentile":null,"corpus_rank":null,"citation_count":1,"citer_count":0,"citers_with_citation_signal":0,"citers_with_endowment":0,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":null,"is_data_producer":false,"deposit_databanks":null,"is_oa":false,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":null,"fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":1767382,"name":"HS Muddana","orcid":null,"position":1,"is_corresponding":false},{"id":1767384,"name":"C Huang","orcid":null,"position":2,"is_corresponding":false},{"id":188646,"name":"S Zhang","orcid":null,"position":3,"is_corresponding":false},{"id":1767387,"name":"PJ Butler","orcid":null,"position":4,"is_corresponding":false},{"id":1767380,"name":"S Son","orcid":null,"position":0,"is_corresponding":false}],"reference_count":0,"raw_metadata":{"has_enrichment":true,"resolved":true,"title":"<i>In situ</i>\n                  , fluorescence lifetime-based measurements of cell membrane micromechanics","abstract":"<jats:title>ABSTRACT</jats:title>\n                <jats:p>\n                  Microscopic\n                  <jats:italic>in situ</jats:italic>\n                  measurements of the mechanical properties of lipid bilayers were derived from the mean and variance of the fluorescence lifetime distributions of 1’-dioctadecyl-3,3,3’3’-tetramethylindocarbocyanine perchlorate (DiI). In this method, DiI, incorporated into membranes, acts as a membrane-targeted molecular rotor whose fluorescence lifetime is sensitive to local lipid viscosity. A new model was developed in which changes in area per lipid were derived from the first and second moments of a stretched exponential distribution of fluorescence lifetimes of DiI, which were subsequently used to compute mean area per lipid and its variance, quantities directly related to bilayer compressibility and bending moduli. This method enabled molecular scale assays of surface micromechanics of membrane-bound entities, such as nanoliposomes and human red blood cells.\n                </jats:p>\n                <jats:sec>\n                  <jats:title>STATEMENT OF SIGNIFICANCE</jats:title>\n                  <jats:p>Despite the progress in cell deformability studies, and in understanding mechanical properties of purified lipid bilayers, there has not, to date, been a method to measure the mechanics of the lipid bilayer in cells in situ. The current manuscript describes such a method. Using a fluorescent molecular rotor, DiI, embedded in the membrane, along with time resolved fluorescence, we directly measure area per lipid, and its temporal and spatial variance, properties directly related to bilayer mechanical moduli. Such a method will allow investigators to start exploring the relationship between lipid bilayer mechanics and cellular health and disease.</jats:p>\n                </jats:sec>","is_dataset_classified":null,"base_score":0.6931471805599453,"endowment":0.6931471805599453,"datacite_reuse_total":0,"file_count":0,"downloads":0,"views":0,"has_version_chain":false,"is_dataset":false,"is_oa":false,"pmid":"21097893","pmcid":null,"openalex_id":"https://openalex.org/W2958756013","authors":[],"funders":[{"funder_name":"National Science Foundation","grant_id":"1334847","title":"Regulation of Focal Adhesion Initiation by Lipids and Membrane Bending"}],"total_grants":1,"fwci":null,"citation_percentile":null,"influential_citations":0,"citation_trend":[{"year":2023,"count":1}],"oa_status":"green","license":"cc-by-nc-nd","oa_locations":[{"url":"https://www.biorxiv.org/content/biorxiv/early/2019/07/16/694620.full.pdf","host_type":"repository"},{"url":"https://www.biorxiv.org/content/biorxiv/early/2019/07/16/694620.full.pdf","host_type":"repository"},{"url":"https://syndication.highwire.org/content/doi/10.1101/694620","host_type":"publisher"},{"url":"https://doi.org/10.1101/694620","host_type":"repository"},{"url":"https://dx.doi.org/10.1101/694620","host_type":""},{"url":"http://dx.doi.org/10.1101/694620","host_type":""}],"fields_of_study":["Lipid Membrane Structure and Behavior","RNA Interference and Gene Delivery","Supramolecular Self-Assembly in Materials","0301 basic medicine","0303 health sciences","03 medical and health sciences"],"mesh_terms":[],"keywords":["Lipid bilayer","Lipid bilayer mechanics","Membrane","Micromechanics","Biophysics","Bilayer","Membrane biophysics","Biological membrane","Lipid bilayer phase behavior","Materials science","Membrane fluidity","Fluorescence","Chemistry","Analytical Chemistry (journal)","Biochemistry","Composite material","Physics","Biology","Chromatography","Optics"],"sdg_mappings":[{"sdg_number":0,"sdg_label":"Good health and well-being"}],"linked_datasets":[],"clinical_trials":[],"software_tools":[],"database_accessions":[],"source":"live","citation_network_status":"fetched"},"created_at":"2026-08-17T02:31:22.788627Z","pmid":null,"pmcid":null,"fwci":null,"citation_percentile":null,"influential_citations":0,"oa_status":null,"license":null,"views":0,"total_file_size_bytes":0,"version_count":0,"fair_f":null,"fair_a":null,"fair_i":null,"fair_r":null,"fair_zscore":null,"fair_rationale":null,"fair_model":null,"fair_agent_version":null,"fair_fulltext_source":null,"fair_has_llm":null,"fair_computed_at":null,"clinical_trials":[],"software_tools":[],"db_accessions":[],"linked_datasets":[],"topics":[]}