{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,28]],"date-time":"2026-07-28T11:47:31Z","timestamp":1785239251191,"version":"3.55.0"},"reference-count":51,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2020,6,11]],"date-time":"2020-06-11T00:00:00Z","timestamp":1591833600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002261","name":"Russian Foundation for Basic Research","doi-asserted-by":"publisher","award":["19-33-70048"],"award-info":[{"award-number":["19-33-70048"]}],"id":[{"id":"10.13039\/501100002261","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The folate receptor (FR) is a promising cell membrane-associated target for molecular imaging and radionuclide therapy of cancer (FR-\u03b1) and potentially also inflammatory diseases (FR-\u03b2) through use of folic acid-based radioconjugate. FR is often overexpressed by cells of epithelial tumors, including tumors of ovary, cervix, endometrium, lungs, kidneys, etc. In healthy tissues, FR can be found in small numbers by the epithelial cells, mainly in the kidneys. Extremely high undesired accumulation of the folate radioconjugates in the renal tissue is a main drawback of FR-targeting concept. In the course of this work, we aimed to reduce the undesirable accumulation of folate radioconjugates in the kidneys by introducing a histidine\/glutamic acid tag into their structure. Two folic acid based compounds were synthesized: NODAGA-1,4-butanediamine-folic acid (FA-I, as control) and NODAGA-[Lys-(HE)2]-folic acid (FA-II) which contains a (His-Glu)2 fragment. In vitro studies with FR (+) cells (KB and others) showed that both compounds have specificity for FR. Introduction of (HE)2-tag does not affect FR binding ability of the conjugates. In vivo biodistribution studies with normal laboratory animals, as well as with KB tumor bearing animals, were carried out. The results showed that introduction of the (HE)2 tag into the structure of folate radioconjugates can significantly reduce the accumulation of these compounds in non-target tissues and important organs (the accumulation in the kidneys is reduced 2\u20134 times), leaving the accumulation in tumor at least at the same level, and even increasing it.<\/jats:p>","DOI":"10.3390\/molecules25112712","type":"journal-article","created":{"date-parts":[[2020,6,16]],"date-time":"2020-06-16T00:50:49Z","timestamp":1592268649000},"page":"2712","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Pharmacokinetic Properties of 68Ga-labelled Folic Acid Conjugates: Improvement Using HEHE Tag"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4810-4346","authenticated-orcid":false,"given":"Anton","family":"Larenkov","sequence":"first","affiliation":[{"name":"State Research Center\u2013Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Zhivopisnaya str., bld. 46, 123098 Moscow, Russia"},{"name":"Department of Chemistry, Lomonosov Moscow State University, GSP-1, Leninskie Gory, 119991 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marat","family":"Rakhimov","sequence":"additional","affiliation":[{"name":"State Research Center\u2013Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Zhivopisnaya str., bld. 46, 123098 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kristina","family":"Lunyova","sequence":"additional","affiliation":[{"name":"State Research Center\u2013Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Zhivopisnaya str., bld. 46, 123098 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Olga","family":"Klementyeva","sequence":"additional","affiliation":[{"name":"State Research Center\u2013Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Zhivopisnaya str., bld. 46, 123098 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2576-2338","authenticated-orcid":false,"given":"Alesya","family":"Maruk","sequence":"additional","affiliation":[{"name":"State Research Center\u2013Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Zhivopisnaya str., bld. 46, 123098 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7975-0346","authenticated-orcid":false,"given":"Aleksei","family":"Machulkin","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Lomonosov Moscow State University, GSP-1, Leninskie Gory, 119991 Moscow, Russia"},{"name":"Department of Semiconductor Electronics &amp; the Physics of Semiconductors, National University of Science and Technology MISiS, 9 Leninskiy pr., 119049 Moscow, Russia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2020,6,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Kim, E.E., and Yang, D.J. 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