{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T05:02:05Z","timestamp":1787029325395,"version":"build-2736575974"},"reference-count":36,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2022,4,24]],"date-time":"2022-04-24T00:00:00Z","timestamp":1650758400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT)","award":["NRF-2021R1A2B5B01001932"],"award-info":[{"award-number":["NRF-2021R1A2B5B01001932"]}]},{"name":"Bio-Industrial Technology Development Program","award":["20008628"],"award-info":[{"award-number":["20008628"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pharmaceutics"],"abstract":"<jats:p>In this study, we developed ultra-small hyaluronate dot particles that selectively release phototoxic drugs into a hypoxic tumor microenvironment. Here, the water-soluble hyaluronate dot (dHA) was covalently conjugated with 4,4\u2032-azodianiline (Azo, as a hypoxia-sensitive linker) and Ce6 (as a photodynamic antitumor agent), producing dHA particles with cleavable Azo bond and Ce6 (dHA-Azo-Ce6). Importantly, the inactive Ce6 (self-quenched state) in the dHA-Azo-Ce6 particles was switched to the active Ce6 (dequenched state) via the Azo linker (\u2013N=N\u2013) cleavage in a hypoxic environment. In vitro studies using hypoxia-induced HeLa cells (treated with CoCl2) revealed that the dHA-Azo-Ce6 particle enhanced photodynamic antitumor inhibition, suggesting its potential as an antitumor drug candidate in response to tumor hypoxia.<\/jats:p>","DOI":"10.3390\/pharmaceutics14050928","type":"journal-article","created":{"date-parts":[[2022,4,24]],"date-time":"2022-04-24T22:22:41Z","timestamp":1650838961000},"page":"928","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Hypoxia-Responsive Azobenzene-Linked Hyaluronate Dot Particles for Photodynamic Tumor Therapy"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-7789-4108","authenticated-orcid":false,"given":"Sohyeon","family":"Lee","sequence":"first","affiliation":[{"name":"Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro, Bucheon-si 14662, Gyeonggi-do, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yoonyoung","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro, Bucheon-si 14662, Gyeonggi-do, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4087-2407","authenticated-orcid":false,"given":"Eun Seong","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Biotechnology, The Catholic University of Korea, 43 Jibong-ro, Bucheon-si 14662, Gyeonggi-do, Korea"},{"name":"Department of Biomedical-Chemical Engineering, The Catholic University of Korea, 43 Jibong-ro, Bucheon-si 14662, Gyeonggi-do, Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,4,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1007\/s10555-007-9055-1","article-title":"Hypoxia in cancer: Significance and impact on clinical outcome","volume":"26","author":"Vaupel","year":"2007","journal-title":"Cancer Metastasis Rev."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"393","DOI":"10.1038\/nrc3064","article-title":"Targeting hypoxia in cancer therapy","volume":"11","author":"Wilson","year":"2011","journal-title":"Nat. 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