{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,9]],"date-time":"2026-01-09T19:53:59Z","timestamp":1767988439899,"version":"3.49.0"},"reference-count":37,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2022,12,5]],"date-time":"2022-12-05T00:00:00Z","timestamp":1670198400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/NAN-MAT\/1431\/2021"],"award-info":[{"award-number":["PTDC\/NAN-MAT\/1431\/2021"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["2021.08095.BD"],"award-info":[{"award-number":["2021.08095.BD"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"CEECIND and Ph.D.","doi-asserted-by":"publisher","award":["PTDC\/NAN-MAT\/1431\/2021"],"award-info":[{"award-number":["PTDC\/NAN-MAT\/1431\/2021"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"CEECIND and Ph.D.","doi-asserted-by":"publisher","award":["2021.08095.BD"],"award-info":[{"award-number":["2021.08095.BD"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Copolymers composed of low-molecular-weight polyethylenimine (PEI) and amphiphilic Pluronics\u00ae are safe and efficient non-viral vectors for pDNA transfection. A variety of Pluronic\u00ae properties provides a base for tailoring transfection efficacy in combination with the unique biological activity of this polymer group. In this study, we describe the preparation of new copolymers based on hydrophilic Pluronic\u00ae F68 and PEI (F68PEI). F68PEI polyplexes obtained by doping with free F68 (1:2 and 1:5 w\/w) allowed for fine-tuning of physicochemical properties and transfection activity, demonstrating improved in vitro transfection of the human bone osteosarcoma epithelial (U2OS) and oral squamous cell carcinoma (SCC-9) cells when compared to the parent formulation, F68PEI. Although all tested systems condensed pDNA at varying polymer\/DNA charge ratios (N\/P, 5\/1\u2013100\/1), the addition of free F68 (1:5 w\/w) resulted in the formation of smaller polyplexes (&lt;200 nm). Analysis of polyplex properties by transmission electron microscopy and dynamic light scattering revealed varied polyplex morphology. Transfection potential was also found to be cell-dependent and significantly higher in SCC-9 cells compared to the control bPEI25k cells, as especially evident at higher N\/P ratios (&gt;25). The observed selectivity towards transfection of SSC-9 cells might represent a base for further optimization of a cell-specific transfection vehicle.<\/jats:p>","DOI":"10.3390\/polym14235315","type":"journal-article","created":{"date-parts":[[2022,12,5]],"date-time":"2022-12-05T05:31:32Z","timestamp":1670218292000},"page":"5315","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Novel Non-Viral Vectors Based on Pluronic\u00ae F68PEI with Application in Oncology Field"],"prefix":"10.3390","volume":"14","author":[{"given":"In\u00eas","family":"Silva","sequence":"first","affiliation":[{"name":"Laboratory of Drug Development and Technologies, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8432-9839","authenticated-orcid":false,"given":"C\u00e1tia","family":"Domingues","sequence":"additional","affiliation":[{"name":"Laboratory of Drug Development and Technologies, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal"},{"name":"REQUIMTE\/LAQV, Group of Pharmaceutical Technology, University of Coimbra, 3000-548 Coimbra, Portugal"},{"name":"Institute for Clinical and Biomedical Research (iCBR) Area of Environment Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal"}]},{"given":"Ivana","family":"Jarak","sequence":"additional","affiliation":[{"name":"Laboratory of Drug Development and Technologies, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal"}]},{"given":"Rui A.","family":"Carvalho","sequence":"additional","affiliation":[{"name":"Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, 3000-548 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7785-5275","authenticated-orcid":false,"given":"Rosemeyre A.","family":"Cordeiro","sequence":"additional","affiliation":[{"name":"CNC\u2014Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal"},{"name":"Institute for Interdisciplinary Research (IIIUC), University of Coimbra, 3000-548 Coimbra, Portugal"}]},{"given":"Mar\u00edlia","family":"Dourado","sequence":"additional","affiliation":[{"name":"Institute for Clinical and Biomedical Research (iCBR) Area of Environment Genetics and Oncobiology (CIMAGO), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal"},{"name":"Center for Health Studies and Research of the University of Coimbra (CEISUC), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal"},{"name":"Center for Studies and Development of Continuous and Palliative Care (CEDCCP), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal"}]},{"given":"Francisco","family":"Veiga","sequence":"additional","affiliation":[{"name":"Laboratory of Drug Development and Technologies, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal"},{"name":"REQUIMTE\/LAQV, Group of Pharmaceutical Technology, University of Coimbra, 3000-548 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5554-7829","authenticated-orcid":false,"given":"Henrique","family":"Faneca","sequence":"additional","affiliation":[{"name":"CNC\u2014Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal"},{"name":"Institute for Interdisciplinary Research (IIIUC), University of Coimbra, 3000-548 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8170-1113","authenticated-orcid":false,"given":"Ana","family":"Figueiras","sequence":"additional","affiliation":[{"name":"Laboratory of Drug Development and Technologies, Faculty of Pharmacy, University of Coimbra, 3000-548 Coimbra, Portugal"},{"name":"REQUIMTE\/LAQV, Group of Pharmaceutical Technology, University of Coimbra, 3000-548 Coimbra, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,12,5]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"101217","DOI":"10.1016\/j.apmt.2021.101217","article-title":"Multifunctional polymeric micelle-based nucleic acid delivery: Current advances and future perspectives","volume":"25","author":"Jarak","year":"2021","journal-title":"Appl. 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