{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T02:22:02Z","timestamp":1760149322009,"version":"build-2065373602"},"reference-count":48,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2023,7,26]],"date-time":"2023-07-26T00:00:00Z","timestamp":1690329600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Portuguese Foundation for Science and Technology (FCT)","award":["SFRH\/BD\/146032\/2019"],"award-info":[{"award-number":["SFRH\/BD\/146032\/2019"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pharmaceutics"],"abstract":"<jats:p>Djeya1 (RKLAFRYRRIKELYNSYR) is a very effective cell penetrating peptide (CPP) that mimics the \u03b15 helix of the highly conserved Eya domain (ED) of eyes absent (Eya) proteins. The objective of this study was to bioengineer analogues of Djeya1 that, following effective translocation into planarian tissues, would reduce the ability of neoblasts (totipotent stem cells) and their progeny to regenerate the anterior pole in decapitated S. mediterranea. As a strategy to increase the propensity for helix formation, molecular bioengineering of Djeya1 was achieved by the mono-substitution of the helicogenic aminoisobutyric acid (Aib) at three species-variable sites: 10, 13, and 16. CD analyses indicated that Djeya1 is highly helical, and that Aib-substitution had subtle influences upon the secondary structures of bioengineered analogues. Aib-substituted Djeya1 analogues are highly efficient CPPs, devoid of influence upon cell viability or proliferation. All three peptides increase the migration of PC-3 cells, a prostate cancer line that expresses high concentrations of Eya. Two peptides, [Aib13]Djeya1 and [Aib16]Djeya1, are bioportides which delay planarian head regeneration. As neoblasts are the only cell population capable of division in planaria, these data indicate that bioportide technologies could be utilised to directly manipulate other stem cells in situ, thus negating any requirement for genetic manipulation.<\/jats:p>","DOI":"10.3390\/pharmaceutics15082018","type":"journal-article","created":{"date-parts":[[2023,7,27]],"date-time":"2023-07-27T01:50:37Z","timestamp":1690422637000},"page":"2018","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Stem Cell Bioengineering with Bioportides: Inhibition of Planarian Head Regeneration with Peptide Mimetics of Eyes Absent Proteins"],"prefix":"10.3390","volume":"15","author":[{"given":"Sarah","family":"Jones","sequence":"first","affiliation":[{"name":"Research Institute in Healthcare Science, Faculty of Science & Engineering, University of Wolverhampton, Wulfruna Street, Wolverhampton WV1 1LY, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9570-1819","authenticated-orcid":false,"given":"B\u00e1rbara","family":"Matos","sequence":"additional","affiliation":[{"name":"Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine\u2014iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4863-9607","authenticated-orcid":false,"given":"Sarah","family":"Dennison","sequence":"additional","affiliation":[{"name":"School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, UK"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7459-9173","authenticated-orcid":false,"given":"Margarida","family":"Fardilha","sequence":"additional","affiliation":[{"name":"Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine\u2014iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal"}]},{"given":"John","family":"Howl","sequence":"additional","affiliation":[{"name":"Research Institute in Healthcare Science, Faculty of Science & Engineering, University of Wolverhampton, Wulfruna Street, Wolverhampton WV1 1LY, UK"}]}],"member":"1968","published-online":{"date-parts":[[2023,7,26]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"361","DOI":"10.1080\/14712598.2021.1823368","article-title":"Status update in the use of cell-penetrating peptides for the delivery of macromolecular therapeutics","volume":"21","author":"Kurrikoff","year":"2021","journal-title":"Expert Opin. 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