{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,15]],"date-time":"2026-04-15T21:24:45Z","timestamp":1776288285631,"version":"3.50.1"},"reference-count":41,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,5,25]],"date-time":"2025-05-25T00:00:00Z","timestamp":1748131200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"JSPS KAKENHI","award":["19H05458"],"award-info":[{"award-number":["19H05458"]}]},{"name":"JSPS KAKENHI","award":["22H02101"],"award-info":[{"award-number":["22H02101"]}]},{"name":"JSPS KAKENHI","award":["24K17702"],"award-info":[{"award-number":["24K17702"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Nanomaterials"],"abstract":"<jats:p>Photothermal therapy (PTT) is a promising approach for cancer treatment that has minimal side effects. It locally heats tumors using agents that convert near-infrared (NIR) light energy into heat. We previously reported that the NIR-absorbing hydrophobic diradical-platinum(II) complex PtL2 (L = 3,5-dibromo-1,2-diiminobenzosemiquinonato radical) can kill cancer cells through its photothermal conversion ability. In this study, we developed PtL2-loading nanoparticles (PtL2@RNPs) for the delivery of the complex to tumors based on the enhanced permeability and retention effect using an amphiphilic block copolymer that can scavenge reactive oxygen species. PtL2@RNPs exhibited particle diameters of 20\u201330 nm, an encapsulation efficiency exceeding 90%, and loading capacities of up to 12%. Under NIR laser irradiation, PtL2@RNPs stably generated heat with almost 100% photothermal conversion efficiency. Although the particles were not modified for cancer cell targeting, their uptake by cancer cells was approximately double that by normal cells. PtL2@RNPs exhibited NIR absorption and effectively killed cancer cells at a low irradiation power (0.15 W). Normal cells treated with PtL2@RNPs remained largely undamaged under identical irradiation conditions, demonstrating a cancer-cell-specific photothermal killing effect. These findings can provide insights for future basic studies on cancer cells and the development of effective cancer treatment modalities.<\/jats:p>","DOI":"10.3390\/nano15110796","type":"journal-article","created":{"date-parts":[[2025,5,25]],"date-time":"2025-05-25T20:39:36Z","timestamp":1748205576000},"page":"796","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Selective Photothermal Therapy Using Antioxidant Nanoparticles Encapsulating Novel Near-Infrared-Absorbing Platinum(II) Complexes"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8799-5869","authenticated-orcid":false,"given":"Ryota","family":"Sawamura","sequence":"first","affiliation":[{"name":"Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aramaki-Aoba, Aoba-ku, Sendai 980-8579, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hiromi","family":"Kurokawa","sequence":"additional","affiliation":[{"name":"Phycochemy Corporation, X\/S Worksite, 4-19-1 Midorigahara, Tsukuba 305-0035, Ibaraki, Japan"},{"name":"Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Ibaraki, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Atsushi","family":"Taninaka","sequence":"additional","affiliation":[{"name":"Institute of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, Ibaraki, Japan"},{"name":"Takano Co., Ltd., 137 Miyada-mura, Kamiina-gun 399-4301, Nagano, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takuto","family":"Toriumi","sequence":"additional","affiliation":[{"name":"Faculty of Materials for Energy, Shimane University, 1060 Nishikawatsu-cho, Matsue 690-8504, Shimane, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7975-6510","authenticated-orcid":false,"given":"Yukio","family":"Nagasaki","sequence":"additional","affiliation":[{"name":"Graduate School of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Ibaraki, Japan"},{"name":"Center of Applied Nanomedicine, National Cheng Kung University, No. 35, Xiaodong Rd., Tainan 701, Taiwan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hidemi","family":"Shigekawa","sequence":"additional","affiliation":[{"name":"Institute of Pure and Applied Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8573, Ibaraki, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7659-5093","authenticated-orcid":false,"given":"Hirofumi","family":"Matsui","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8575, Ibaraki, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4698-4992","authenticated-orcid":false,"given":"Nobuhiko","family":"Iki","sequence":"additional","affiliation":[{"name":"Graduate School of Environmental Studies, Tohoku University, 6-6-07 Aramaki-Aoba, Aoba-ku, Sendai 980-8579, Miyagi, Japan"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1219","DOI":"10.1021\/acs.molpharmaceut.2c00083","article-title":"Efficacy of Temozolomide-Conjugated Gold Nanoparticle Photothermal Therapy of Drug-Resistant Glioblastoma and Its Mechanism Study","volume":"19","author":"Yu","year":"2022","journal-title":"Mol. 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