{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,7]],"date-time":"2026-04-07T06:24:24Z","timestamp":1775543064545,"version":"3.50.1"},"reference-count":31,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T00:00:00Z","timestamp":1769644800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100007569","name":"Carl Zeiss Stiftung","doi-asserted-by":"publisher","award":["CZS Transfer 2024: Oberfl\u00e4chen"],"award-info":[{"award-number":["CZS Transfer 2024: Oberfl\u00e4chen"]}],"id":[{"id":"10.13039\/100007569","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>To investigate drug delivery in cancer therapy, we integrate fluorescence lifetime measurements, microspectrometry, and confocal laser scanning microscopy to track the uptake of inorganic\u2013organic hybrid nanoparticles (IOH-NPs) by breast cancer cells over incubation periods ranging from 2 to 24 h. Non-radiative energy transfer (FRET) from the LysoTracker Green to the IOH-NPs confirms their lysosomal localization and possibly improves their optical excitation. Beyond the resolution limits of light and electron microscopy, fluorescence lifetime kinetics\u2014including FRET\u2014can thus reveal the nanoscale cellular localization of IOH-NPs and guide the optimization of fluorescence excitation. Here, we extend optical microscopy into a fifth dimension\u2014picosecond fluorescence decay times\u2014complementing 3D spatial and spectral information, establishing lifetime measurements as a versatile tool to study nanoparticle uptake in cancer therapy.<\/jats:p>","DOI":"10.3390\/ijms27031339","type":"journal-article","created":{"date-parts":[[2026,1,29]],"date-time":"2026-01-29T10:08:57Z","timestamp":1769681337000},"page":"1339","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Monitoring Nanoparticle Interaction with Murine Breast Cancer Cells Using Multimodal Fluorescence Lifetime Microscopy"],"prefix":"10.3390","volume":"27","author":[{"given":"Steven","family":"Eckstein","sequence":"first","affiliation":[{"name":"Center for Optical Technologies, Aalen University, Beethovenstr. 1, 73430 Aalen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0004-4875-9769","authenticated-orcid":false,"given":"Louisa","family":"Herbsleb","sequence":"additional","affiliation":[{"name":"Center for Optical Technologies, Aalen University, Beethovenstr. 1, 73430 Aalen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Henriette","family":"Gr\u00f6ger","sequence":"additional","affiliation":[{"name":"Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2426-9461","authenticated-orcid":false,"given":"Claus","family":"Feldmann","sequence":"additional","affiliation":[{"name":"Institute of Inorganic Chemistry, Karlsruhe Institute of Technology (KIT), Engesserstr. 15, 76131 Karlsruhe, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6258-5409","authenticated-orcid":false,"given":"Frauke","family":"Alves","sequence":"additional","affiliation":[{"name":"Translational Molecular Imaging, Max-Planck-Institute for Multidisciplinary Sciences\u2014City Campus, Hermann-Rein Str. 3, 37075 G\u00f6ttingen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4096-1944","authenticated-orcid":false,"given":"Andreas","family":"Walter","sequence":"additional","affiliation":[{"name":"Center for Optical Technologies, Aalen University, Beethovenstr. 1, 73430 Aalen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5129-8474","authenticated-orcid":false,"given":"Herbert","family":"Schneckenburger","sequence":"additional","affiliation":[{"name":"Center for Optical Technologies, Aalen University, Beethovenstr. 1, 73430 Aalen, Germany"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,29]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"7329","DOI":"10.1021\/jacs.5b01172","article-title":"Multifunctional phosphate-based inorganic-organic hybrid nanoparticles","volume":"137","author":"Heck","year":"2015","journal-title":"J. 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