{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,14]],"date-time":"2026-10-14T23:47:25Z","timestamp":1792021645911,"version":"4.4.0"},"reference-count":38,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2023,8,3]],"date-time":"2023-08-03T00:00:00Z","timestamp":1691020800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"\u201cConsejo Mexiquense de Ciencia y Tecnolog\u00eda\u201d (COMECyT)","award":["FICDTEM-2023-152"],"award-info":[{"award-number":["FICDTEM-2023-152"]}]},{"name":"\u201cConsejo Mexiquense de Ciencia y Tecnolog\u00eda\u201d (COMECyT)","award":["F22075"],"award-info":[{"award-number":["F22075"]}]},{"name":"\u201cConsejo Mexiquense de Ciencia y Tecnolog\u00eda\u201d (COMECyT)","award":["F22078"],"award-info":[{"award-number":["F22078"]}]},{"name":"International Atomic Energy Agency","award":["FICDTEM-2023-152"],"award-info":[{"award-number":["FICDTEM-2023-152"]}]},{"name":"International Atomic Energy Agency","award":["F22075"],"award-info":[{"award-number":["F22075"]}]},{"name":"International Atomic Energy Agency","award":["F22078"],"award-info":[{"award-number":["F22078"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Current cancer therapies focus on reducing immunosuppression and remodeling the tumor microenvironment to inhibit metastasis, cancer progression, and therapeutic resistance. Programmed death receptor 1 (PD-1) is expressed on immune T cells and is one of the so-called checkpoint proteins that can suppress or stop the immune response. To evade the immune system, cancer cells overexpress a PD-1 inhibitor protein (PD-L1), which binds to the surface of T cells to activate signaling pathways that induce immune suppression. This research aimed to synthesize PD-L1 inhibitory peptides (PD-L1-i) labeled with lutetium-177 (177Lu-DOTA-PD-L1-i) and actinium-225 (225Ac-HEHA-PD-L1-i) and to preclinically evaluate their potential as radiopharmaceuticals for targeted radiotherapy at the tumor microenvironment level. Using PD-L1-i peptide as starting material, conjugation with HEHA-benzene-SCN and DOTA-benzene-SCN was performed to yield DOTA-PD-L1-i and HEHA-PD-L1-I, which were characterized by FT-IR, UV-vis spectroscopy, and HPLC. After labeling the conjugates with 225Ac and 177Lu, cellular uptake in HCC827 cancer cells (PD-L1 positive), conjugate specificity evaluation by immunofluorescence, radiotracer effect on cell viability, biodistribution, biokinetics, and assessment of radiation absorbed dose in mice with in duced lung micrometastases were performed. 225Ac-HEHA-PD-L1-i and 177Lu-DOTA-PD-L1-i, obtained with radiochemical purities of 95 \u00b1 3% and 98.5 \u00b1 0.5%, respectively, showed in vitro and in vivo specific recognition for the PD-L1 protein in lung cancer cells and high uptake in HCC287 lung micrometastases (&gt;30% ID). The biokinetic profiles of 177Lu-DOTA-PD-L1-i and 225Ac-DOTA-PD-L1-i showed rapid blood clearance with renal and hepatobiliary elimination and no accumulation in normal tissues. 225Ac-DOTA-PD-L1-i produced a radiation dose of 5.15 mGy\/MBq to lung micrometastases. In the case of 177Lu-DOTA-PD-L1-i, the radiation dose delivered to the lung micrometastases was ten times (43 mGy\/MBq) that delivered to the kidneys (4.20 mGy\/MBq) and fifty times that delivered to the liver (0.85 mGy\/MBq). Therefore, the radiotherapeutic PD-L1-i ligands of 225Ac and 177Lu developed in this research could be combined with immunotherapy to enhance the therapeutic effect in various types of cancer.<\/jats:p>","DOI":"10.3390\/ijms241512382","type":"journal-article","created":{"date-parts":[[2023,8,3]],"date-time":"2023-08-03T11:08:43Z","timestamp":1691060923000},"page":"12382","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":14,"title":["Synthesis and Evaluation of 177Lu-DOTA-PD-L1-i and 225Ac-HEHA-PD-L1-i as Potential Radiopharmaceuticals for Tumor Microenvironment-Targeted Radiotherapy"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4082-3816","authenticated-orcid":false,"given":"Myrna","family":"Luna-Guti\u00e9rrez","sequence":"first","affiliation":[{"name":"Department of Radioactive Materials, Instituto Nacional de Investigaciones Nucleares, Ocoyoacac 52750, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5719-7324","authenticated-orcid":false,"given":"Pedro","family":"Cruz-Nova","sequence":"additional","affiliation":[{"name":"Department of Radioactive Materials, Instituto Nacional de Investigaciones Nucleares, Ocoyoacac 52750, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9480-4621","authenticated-orcid":false,"given":"Nallely","family":"Jim\u00e9nez-Mancilla","sequence":"additional","affiliation":[{"name":"C\u00e1tedras, CONACyT, Instituto Nacional de Investigaciones Nucleares, Ocoyoacac 52750, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rigoberto","family":"Oros-Pantoja","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Universidad Aut\u00f3noma del Estado de M\u00e9xico, Toluca 50180, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7491-0598","authenticated-orcid":false,"given":"Nancy","family":"Lara-Almaz\u00e1n","sequence":"additional","affiliation":[{"name":"Department of Radioactive Materials, Instituto Nacional de Investigaciones Nucleares, Ocoyoacac 52750, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5903-1598","authenticated-orcid":false,"given":"Clara","family":"Santos-Cuevas","sequence":"additional","affiliation":[{"name":"Department of Radioactive Materials, Instituto Nacional de Investigaciones Nucleares, Ocoyoacac 52750, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7520-461X","authenticated-orcid":false,"given":"Erika","family":"Azor\u00edn-Vega","sequence":"additional","affiliation":[{"name":"Department of Radioactive Materials, Instituto Nacional de Investigaciones Nucleares, Ocoyoacac 52750, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5831-8412","authenticated-orcid":false,"given":"Blanca","family":"Ocampo-Garc\u00eda","sequence":"additional","affiliation":[{"name":"Department of Radioactive Materials, Instituto Nacional de Investigaciones Nucleares, Ocoyoacac 52750, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0296-7605","authenticated-orcid":false,"given":"Guillermina","family":"Ferro-Flores","sequence":"additional","affiliation":[{"name":"Department of Radioactive Materials, Instituto Nacional de Investigaciones Nucleares, Ocoyoacac 52750, Mexico"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2023,8,3]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Arneth, B. (2019). Tumor microenvironment. Medicina, 56.","DOI":"10.3390\/medicina56010015"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"737","DOI":"10.1016\/j.semcancer.2022.04.003","article-title":"Radiation therapy-induced remodeling of the tumor immune microenvironment","volume":"86","author":"Charpentier","year":"2022","journal-title":"Semin. Cancer Biol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"11740","DOI":"10.1021\/acsnano.8b05893","article-title":"Nanoparticle-mediated remodeling of the tumor microenvironment to enhance immunotherapy","volume":"12","author":"Musetti","year":"2018","journal-title":"ACS Nano"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"14181","DOI":"10.1073\/pnas.1817442116","article-title":"Noninvasive imaging of tumor progression, metastasis, and fibrosis using a nanobody targeting the extracellular matrix","volume":"116","author":"Jailkhani","year":"2019","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1789","DOI":"10.1002\/cmdc.201100320","article-title":"PET imaging of CXCR4 receptors in cancer by a new optimized ligand","volume":"6","author":"Demmer","year":"2011","journal-title":"ChemMedChem"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1007\/s10967-020-07043-6","article-title":"Synthesis and preclinical evaluation of the 99m Tc-\/177 Lu-CXCR4-L theranostic pair for in vivo chemokine-4 receptor-specific targeting","volume":"324","year":"2020","journal-title":"J. Radioanal. Nucl. Chem."},{"key":"ref_7","first-page":"17","article-title":"Development of a 99mTc-labeled CXCR4 antagonist derivative as a new tumor radiotracer","volume":"33","author":"Mikaeili","year":"2018","journal-title":"Cancer Biother. Radiopharm."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1415","DOI":"10.2967\/jnumed.118.210443","article-title":"Development of quinoline-based theranostic ligands for the targeting of fibroblast activation protein","volume":"59","author":"Lindner","year":"2018","journal-title":"J. Nucl. Med."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Trujillo-Ben\u00edtez, D., Luna-Guti\u00e9rrez, M., Ferro-Flores, G., Ocampo-Garc\u00eda, B., Santos-Cuevas, C., Bravo-Villegas, G., Morales-\u00c1vila, E., Cruz-Nova, P., D\u00edaz-Nieto, L., and Garc\u00eda-Quiroz, J. (2022). Design, Synthesis and Preclinical Assessment of 99mTc-iFAP for In Vivo Fibroblast Activation Protein (FAP) Imaging. Molecules, 27.","DOI":"10.3390\/molecules27010264"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1421","DOI":"10.2967\/jnumed.118.224469","article-title":"Development of fibroblast activation protein\u2013targeted radiotracers with improved tumor retention","volume":"60","author":"Loktev","year":"2019","journal-title":"J. Nucl. Med."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Vallejo-Armenta, P., Ferro-Flores, G., Santos-Cuevas, C., Garc\u00eda-P\u00e9rez, F.O., Casanova-Trivi\u00f1o, P., Sandoval-Bonilla, B., Ocampo-Garc\u00eda, B., Azor\u00edn-Vega, E., and Luna-Guti\u00e9rrez, M. (2022). [99mTc] Tc-iFAP\/SPECT Tumor Stroma Imaging: Acquisition and Analysis of Clinical Images in Six Different Cancer Entities. Pharmaceuticals, 15.","DOI":"10.3390\/ph15060729"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"324","DOI":"10.1007\/s11307-022-01759-5","article-title":"Distinguishing benign and malignant findings on [68 ga]-FAPI PET\/CT based on quantitative SUV measurements","volume":"25","author":"Dabir","year":"2023","journal-title":"Mol. Imaging Biol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Ludwig, B.S., Kessler, H., Kossatz, S., and Reuning, U. (2021). RGD-binding integrins revisited: How recently discovered functions and novel synthetic ligands (re-) shape an ever-evolving field. Cancers, 13.","DOI":"10.3390\/cancers13071711"},{"key":"ref_14","first-page":"919","article-title":"PSMA expression on neovasculature of solid tumors","volume":"35","author":"Sathekge","year":"2020","journal-title":"Histol. Histopathol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"3973","DOI":"10.1007\/s00259-022-05905-7","article-title":"PSMA-targeted theranostics of solid tumors: Applications beyond prostate cancers","volume":"49","author":"An","year":"2022","journal-title":"Eur. J. Nucl. Med. Mol. Imaging"},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Hofstetter, G., Grech, C., Pils, D., Pammer, J., Neudert, B., P\u00f6tsch, N., Baltzer, P., Traub-Weidinger, T., Seebacher, V., and Aust, S. (2022). Prostate-Specific Membrane Antigen (PSMA) Expression in Tumor-Associated Neovasculature Is an Independent Prognostic Marker in Patients with Ovarian Cancer. J. Pers. Med., 12.","DOI":"10.3390\/jpm12040551"},{"key":"ref_17","first-page":"1","article-title":"[99mTc] Tc-iPSMA SPECT brain imaging as a potential specific diagnosis of metastatic brain tumors and high-grade gliomas","volume":"96","year":"2021","journal-title":"Nucl. Med. Biol."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"Hern\u00e1ndez-Jim\u00e9nez, T., Cruz-Nova, P., Ancira-Cortez, A., Gibbens-Bandala, B., Lara-Almaz\u00e1n, N., Ocampo-Garc\u00eda, B., Santos-Cuevas, C., Morales-Avila, E., and Ferro-Flores, G. (2022). Toxicity Assessment of [177Lu]Lu\u2212iFAP\/iPSMA Nanoparticles Prepared under GMP-Compliant Radiopharmaceutical Processes. Nanomaterials, 12.","DOI":"10.3390\/nano12234181"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Luna-Guti\u00e9rrez, M., Ocampo-Garc\u00eda, B., Jim\u00e9nez-Mancilla, N., Ancira-Cortez, A., Trujillo-Ben\u00edtez, D., Hern\u00e1ndez-Jim\u00e9nez, T., Ram\u00edrez-Nava, G., Hern\u00e1ndez-Ram\u00edrez, R., Santos-Cuevas, C., and Ferro-Flores, G. (2022). Targeted Endoradiotherapy with Lu2O3-iPSMA\/-iFAP Nanoparticles Activated by Neutron Irradiation: Preclinical Evaluation and First Patient Image. Pharmaceutics, 14.","DOI":"10.3390\/pharmaceutics14040720"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Ocampo-Garc\u00eda, B., Lara, L.A., Ferro-Flores, G., Morales-Avila, E., and Isaac-Oliv\u00e9, K. (2022). Role of Nanotechnology in Biological Therapies. Nanomater. Nanotechnol. Med., 115\u2013151.","DOI":"10.1002\/9781119558026.ch5"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"215005","DOI":"10.1016\/j.ccr.2022.215005","article-title":"Zirconium immune-complexes for PET molecular imaging: Current status and prospects","volume":"479","author":"Bolzati","year":"2023","journal-title":"Coord. Chem. Rev."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1056\/NEJMoa1305133","article-title":"Safety and tumor responses with lambrolizumab (anti\u2013PD-1) in melanoma","volume":"369","author":"Hamid","year":"2013","journal-title":"N. Engl. J. Med."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1992","DOI":"10.1200\/JCO.22.01989","article-title":"Pembrolizumab plus pemetrexed and platinum in nonsquamous non\u2013small-cell lung cancer: 5-year outcomes from the phase 3 KEYNOTE-189 study","volume":"41","author":"Garassino","year":"2023","journal-title":"J. Clin. Oncol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"258","DOI":"10.1016\/j.bbrc.2016.12.156","article-title":"Rapid PD-L1 detection in tumors with PET using a highly specific peptide","volume":"483","author":"Chatterjee","year":"2017","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"3946","DOI":"10.1021\/acs.molpharmaceut.8b00399","article-title":"Peptide-based 68Ga-PET radiotracer for imaging PD-L1 expression in cancer","volume":"15","author":"Kumar","year":"2018","journal-title":"Mol. Pharm."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"536","DOI":"10.2967\/jnumed.121.262045","article-title":"First-in-humans evaluation of a PD-L1\u2013binding peptide PET radiotracer in non\u2013small cell lung cancer patients","volume":"63","author":"Zhou","year":"2022","journal-title":"J. Nucl. Med."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Krutzek, F., Kopka, K., and Stadlbauer, S. (2022). Development of Radiotracers for Imaging of the PD-1\/PD-L1 Axis. Pharmaceuticals, 15.","DOI":"10.3390\/ph15060747"},{"key":"ref_28","unstructured":"Miller, M.M., Mapelli, C., Allen, M.P., Bowsher, M.S., Boy, K.M., Gillis, E.P., Langley, D.R., Mull, E., Poirier, M.A., and Sanghvi, N. (2016). Macrocyclic Inhibitors of the pd-1\/pd-l1 and cd80 (b7-1)\/pd-l1 Protein\/Protein Interactions. Bristol Myers Squibb Co. U. S. A. 20161093pp. (WO2016039749A1)."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"339","DOI":"10.2174\/157341206778699555","article-title":"Third generation radiopharmaceuticals for imaging and targeted therapy","volume":"2","year":"2006","journal-title":"Curr. Pharm. Anal."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"32","DOI":"10.1016\/j.mednuc.2017.12.002","article-title":"Targeted alpha and beta radiotherapy: An overview of radiopharmaceutical and clinical aspects","volume":"42","author":"Lacoeuille","year":"2018","journal-title":"M\u00e9decine Nucl\u00e9aire"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2988","DOI":"10.1021\/jm990141f","article-title":"Improved in vivo stability of actinium-225 macrocyclic complexes","volume":"42","author":"Deal","year":"1999","journal-title":"J. Med. Chem."},{"key":"ref_32","first-page":"336","article-title":"Actinium-225 for Targeted a Therapy: Coordination Chemistry and Current Chelation Approaches","volume":"33","author":"Thiele","year":"2018","journal-title":"Cancer Biother. Radiopharm."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Hern\u00e1ndez-Jim\u00e9nez, T., Ferro-Flores, G., Morales-\u00c1vila, E., Isaac-Oliv\u00e9, K., Ocampo-Garc\u00eda, B., Aranda-Lara, L., Santos-Cuevas, C., Luna-Guti\u00e9rrez, M., De Nardo, L., and Rosato, A. (2022). 225Ac-rHDL Nanoparticles: A Potential Agent for Targeted Alpha-Particle Therapy of Tumors Overexpressing SR-BI Proteins. Molecules, 27.","DOI":"10.3390\/molecules27072156"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"18489","DOI":"10.1038\/s41598-019-54884-7","article-title":"Radiobiological effects of the alpha emitter Ra-223 on tumor cells","volume":"9","author":"Bannik","year":"2019","journal-title":"Sci. Rep."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"162","DOI":"10.1177\/23993693211050410","article-title":"177Lu-dotatate use in chronic kidney disease patients: A single center experience","volume":"5","author":"Manohar","year":"2021","journal-title":"J. Onco-Nephrol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1039\/D2CS00437B","article-title":"Nanomedicine embraces cancer radio-immunotherapy: Mechanism, design, recent advances, and clinical translation","volume":"52","author":"Li","year":"2023","journal-title":"Chem. Soc. Rev."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/j.currproblcancer.2015.10.001","article-title":"Systematic review of case reports on the abscopal effect","volume":"40","author":"Abuodeh","year":"2016","journal-title":"Curr. Probl. Cancer"},{"key":"ref_38","first-page":"1636","article-title":"Combined Targeted Radiopharmaceutical Therapy and Immune Checkpoint Blockade: From Preclinical Advances to the Clinic","volume":"63","author":"Bellavia","year":"2022","journal-title":"J. Nucl. Med."}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/24\/15\/12382\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T20:24:58Z","timestamp":1760127898000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/24\/15\/12382"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,8,3]]},"references-count":38,"journal-issue":{"issue":"15","published-online":{"date-parts":[[2023,8]]}},"alternative-id":["ijms241512382"],"URL":"https:\/\/doi.org\/10.3390\/ijms241512382","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,8,3]]}}}