Ryota Sawamura, Atsuko Masuya-Suzuki, Nobuhiko Iki
{"title":"利用高光谱成像、分光光度法和分光荧光测定法研究白蛋白溶解的疏水性近红外吸收二拉德铂(II)复合物的细胞吸收。","authors":"Ryota Sawamura, Atsuko Masuya-Suzuki, Nobuhiko Iki","doi":"10.1007/s44211-024-00621-8","DOIUrl":null,"url":null,"abstract":"<div><p>Owing to its biopenetrability and minimal invasiveness, near-infrared (NIR) light in the region between 700–1100 nm has attracted attention in cancer diagnosis and therapy. Our group previously reported that the hydrophobic diradical-platinum(II) complex PtL<sub>2</sub> is a promising agent for cancer photothermal therapy (L = 3,5-dibromo-1,2-diiminobenzosemiquinonate radical). Because PtL<sub>2</sub> does not fluoresce, its intercellular uptake of PtL<sub>2</sub> cannot be observed with a fluorescence microscope. In this study, we clarified the uptake and intracellular behavior of PtL<sub>2</sub> solubilized by bovine serum albumin (BSA) using hyperspectral imaging enabling spectrophotometric analysis of the image. The spectral changes in the obtained images indicated that the internalization of PtL<sub>2</sub> was followed by crystallization of the complex during the long incubation period (> 4 h). Additionally, the binding constant <i>K</i><sub>b</sub> = 5.91 × 10<sup>4</sup> M<sup>–1</sup> could be estimated upon fluorescence quenching analysis of BSA upon binding of PtL<sub>2</sub>; <i>K</i><sub>b</sub> is two orders of magnitude smaller than that of albumin–common drugs. Considering the small <i>K</i><sub>b</sub> and low solubility of PtL<sub>2</sub> in water, we ultimately proposed the internalization path and fate of PtL<sub>2</sub> in the cell: release of PtL<sub>2</sub> from BSA near cellular membranes and subsequent cellular uptake via membrane permeation followed by saturation, resulting in crystallization.</p><h3>Graphical abstract</h3>\n<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":7802,"journal":{"name":"Analytical Sciences","volume":null,"pages":null},"PeriodicalIF":1.8000,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11422251/pdf/","citationCount":"0","resultStr":"{\"title\":\"Study on cellular uptake of a hydrophobic near-infrared-absorbing diradical-platinum(II) complex solubilized by albumin using hyperspectral imaging, spectrophotometry, and spectrofluorimetry\",\"authors\":\"Ryota Sawamura, Atsuko Masuya-Suzuki, Nobuhiko Iki\",\"doi\":\"10.1007/s44211-024-00621-8\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>Owing to its biopenetrability and minimal invasiveness, near-infrared (NIR) light in the region between 700–1100 nm has attracted attention in cancer diagnosis and therapy. Our group previously reported that the hydrophobic diradical-platinum(II) complex PtL<sub>2</sub> is a promising agent for cancer photothermal therapy (L = 3,5-dibromo-1,2-diiminobenzosemiquinonate radical). Because PtL<sub>2</sub> does not fluoresce, its intercellular uptake of PtL<sub>2</sub> cannot be observed with a fluorescence microscope. In this study, we clarified the uptake and intracellular behavior of PtL<sub>2</sub> solubilized by bovine serum albumin (BSA) using hyperspectral imaging enabling spectrophotometric analysis of the image. The spectral changes in the obtained images indicated that the internalization of PtL<sub>2</sub> was followed by crystallization of the complex during the long incubation period (> 4 h). Additionally, the binding constant <i>K</i><sub>b</sub> = 5.91 × 10<sup>4</sup> M<sup>–1</sup> could be estimated upon fluorescence quenching analysis of BSA upon binding of PtL<sub>2</sub>; <i>K</i><sub>b</sub> is two orders of magnitude smaller than that of albumin–common drugs. Considering the small <i>K</i><sub>b</sub> and low solubility of PtL<sub>2</sub> in water, we ultimately proposed the internalization path and fate of PtL<sub>2</sub> in the cell: release of PtL<sub>2</sub> from BSA near cellular membranes and subsequent cellular uptake via membrane permeation followed by saturation, resulting in crystallization.</p><h3>Graphical abstract</h3>\\n<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>\",\"PeriodicalId\":7802,\"journal\":{\"name\":\"Analytical Sciences\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":1.8000,\"publicationDate\":\"2024-06-19\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11422251/pdf/\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Analytical Sciences\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s44211-024-00621-8\",\"RegionNum\":4,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"CHEMISTRY, ANALYTICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Analytical Sciences","FirstCategoryId":"92","ListUrlMain":"https://link.springer.com/article/10.1007/s44211-024-00621-8","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"CHEMISTRY, ANALYTICAL","Score":null,"Total":0}
Study on cellular uptake of a hydrophobic near-infrared-absorbing diradical-platinum(II) complex solubilized by albumin using hyperspectral imaging, spectrophotometry, and spectrofluorimetry
Owing to its biopenetrability and minimal invasiveness, near-infrared (NIR) light in the region between 700–1100 nm has attracted attention in cancer diagnosis and therapy. Our group previously reported that the hydrophobic diradical-platinum(II) complex PtL2 is a promising agent for cancer photothermal therapy (L = 3,5-dibromo-1,2-diiminobenzosemiquinonate radical). Because PtL2 does not fluoresce, its intercellular uptake of PtL2 cannot be observed with a fluorescence microscope. In this study, we clarified the uptake and intracellular behavior of PtL2 solubilized by bovine serum albumin (BSA) using hyperspectral imaging enabling spectrophotometric analysis of the image. The spectral changes in the obtained images indicated that the internalization of PtL2 was followed by crystallization of the complex during the long incubation period (> 4 h). Additionally, the binding constant Kb = 5.91 × 104 M–1 could be estimated upon fluorescence quenching analysis of BSA upon binding of PtL2; Kb is two orders of magnitude smaller than that of albumin–common drugs. Considering the small Kb and low solubility of PtL2 in water, we ultimately proposed the internalization path and fate of PtL2 in the cell: release of PtL2 from BSA near cellular membranes and subsequent cellular uptake via membrane permeation followed by saturation, resulting in crystallization.
期刊介绍:
Analytical Sciences is an international journal published monthly by The Japan Society for Analytical Chemistry. The journal publishes papers on all aspects of the theory and practice of analytical sciences, including fundamental and applied, inorganic and organic, wet chemical and instrumental methods.
This publication is supported in part by the Grant-in-Aid for Publication of Scientific Research Result of the Japanese Ministry of Education, Culture, Sports, Science and Technology.