Publications by authors named "Tomoya Inose"

3 Publications

  • Page 1 of 1

The anti-angiogenic agent lenvatinib induces tumor vessel normalization and enhances radiosensitivity in hepatocellular tumors.

Med Oncol 2021 Apr 21;38(6):60. Epub 2021 Apr 21.

Department of Medical Physics, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan.

The evaluation of angiogenesis inhibitors requires the analysis of the precise structure and function of tumor vessels. The anti-angiogenic agents lenvatinib and sorafenib are multi-target tyrosine kinase inhibitors that have been approved for the treatment of hepatocellular carcinoma (HCC). However, the different effects on tumor vasculature between lenvatinib and sorafenib are not well understood. In this study, we analyzed the effects of both drugs on vascular structure and function, including vascular normalization, and investigated whether the normalization had a positive effect on a combination therapy with the drugs and radiation using micro X-ray computed tomography with gold nanoparticles as a contrast agent, as well as immunohistochemical analysis and interstitial fluid pressure (IFP) measurement. In mice subcutaneously transplanted with mouse HCC cells, treatment with lenvatinib or sorafenib for 14 days inhibited tumor growth and reduced the tumor vessel volume density. However, analysis of integrated data on vessel density, rates of pericyte-covering and perfused vessels, tumor hypoxia, and IFP measured 4 days after drug treatment showed that treatment with 3 mg/kg of lenvatinib significantly reduced the microvessel density and normalized tumor vessels compared to treatment with 50 mg/kg of sorafenib. These results showed that lenvatinib induced vascular normalization and improved the intratumoral microenvironment in HCC tumors earlier and more effectively than sorafenib. Moreover, such changes increased the radiosensitivity of tumors and enhanced the effect of lenvatinib and radiation combination therapy, suggesting that this combination therapy is a powerful potential application against HCC.
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http://dx.doi.org/10.1007/s12032-021-01503-zDOI Listing
April 2021

Development of X-ray contrast agents using single nanometer-sized gold nanoparticles and lactoferrin complex and their application in vascular imaging.

Colloids Surf B Biointerfaces 2021 Apr 1;203:111732. Epub 2021 Apr 1.

Department of Medical Physics, Graduate School of Medicine, Tohoku University, 2-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi, 980-8575, Japan; International Center for Synchrotron Radiation InnovationSmart (SRIS), Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577, Japan. Electronic address:

The technology to accurately image the morphology of tumor vessels with X-ray contrast agents is important to clarify mechanisms underlying tumor progression and evaluate the efficacy of chemotherapy. However, in clinical practice, iodine-based contrast agents present problems such as short blood retention owing to a high clearance ability and insufficient X-ray absorption capacity when compared with other high atomic number elements. To resolve these issues, gold nanoparticles (AuNPs), with a high atomic number, have attracted a great deal of attention as contrast agents for angiography, and have been employed in small animal models. Herein, we developed novel contrast agents using AuNPs and captured changes in tumor vessel morphology with time using X-ray computed tomography (CT). First, glutathione-supported single nanometer-sized AuNPs (sAu/GSH) (diameter, 2.2 nm) were fabricated using tetrakis(hydroxymethyl)phosphonium chloride as a reducing agent. The sAu/GSH particles were intravenously injected into mice, remained in vessels for a few minutes, and were then excreted by the kidneys after 24 h, similar to the commercial contrast agent iopamidol. Next, the Au/GSH and lactoferrin (sAu/GSH-LF) (long axis size, 17.3 nm) complex was produced by adding lactoferrin to the sAu/GSH solution under the influence of a condensing agent. On intravenously administering sAu/GSH-LF to mice, the blood retention time was 1-3 h, which was considerably longer than that observed with iopamidol and sAu/GSH. Moreover, we succeeded in imaging morphological changes in identical tumor vessels for several days using X-ray CT with sAu/GSH-LF.
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http://dx.doi.org/10.1016/j.colsurfb.2021.111732DOI Listing
April 2021

Fabrication of silica-coated gold nanorods and investigation of their property of photothermal conversion.

Biochem Biophys Res Commun 2017 03 23;484(2):318-322. Epub 2017 Jan 23.

Department of Biomolecular Functional Engineering, College of Engineering, Ibaraki University, 4-12-1 Naka-narusawa-cho, Hitachi, Ibaraki 316-8511, Japan. Electronic address:

This study described the preparation of silica-coated Au nanorods (AuNR/SiO) in a colloidal solution, assessed their property of photothermal conversion, and investigated their ability to kill cancer cells using photothermal conversion. Au-seed nanoparticles were produced by reducing hydrogen tetrachloroaurate (HAuCl) with sodium borohydride (NaBH) in aqueous n-hexadecyltrimethylammonium bromide (CTAB) solution. AuNRs were then fabricated by reducing HAuCl and silver nitrate (AgNO) with l-ascorbic acid in the aqueous CTAB solution in the presence of Au-seed nanoparticles. The as-prepared AuNRs were washed by a process composed mainly of centrifugation to remove the CTAB. The washed AuNRs were coated with silica by mixing the AuNR colloidal solution, an aqueous solution of (3-aminopropyl)trimethoxysilane, and tetraethylorthosilicate/ethanol solution with a water/ethanol solution. We found that the addition of AuNR/SiO in water, in mice, and in a culture medium with cancer cells, followed by irradiation with a laser, cause an increase in temperature, demonstrating that AuNR/SiO have the ability of photothermal conversion. In addition, the cancer cells in the culture medium were found to be killed due to the increase in temperature caused by the photothermal conversion.
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http://dx.doi.org/10.1016/j.bbrc.2017.01.112DOI Listing
March 2017