{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T22:08:01Z","timestamp":1774649281456,"version":"3.50.1"},"reference-count":42,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2022,4,1]],"date-time":"2022-04-01T00:00:00Z","timestamp":1648771200000},"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":["UIDB\/00709\/2020"],"award-info":[{"award-number":["UIDB\/00709\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Nucleic acid vaccines have become a revolutionary technology to give a fast, safe, cost-effective and efficient response against viral infections, such as SARS-CoV-2 or Human papillomavirus (HPV). However, to ensure their effectiveness, the development of adequate methods to protect, carry, and deliver nucleic acids is fundamental. In this work, nanoparticles (NPs) of chitosan (CS)-tripolyphosphate (TPP)-plasmid DNA (pDNA) were thoroughly modulated and characterized, by measuring the charge and size through dynamic light scattering (DLS) and morphology by scanning electron microscopy (SEM). Stability, cytotoxicity and cellular uptake of NPs were also evaluated. Finally, the effect of polyplexes on the expression of HPV E7 antigen in human fibroblast and RAW cells was investigated through polymerase chain reaction (PCR) and real-time PCR. The results showed NPs with a spherical\/oval shape, narrow size distribution &lt;180 nm and positive zeta potentials (&gt;20 mV) and good stability after one month of storage at 4 \u00b0C in formulation buffer or when incubated in culture medium and trypsin. In vitro studies of NPs cytotoxicity revealed that the elimination of formulation buffers led to an improvement in the rate of cell viability. The E7 antigen transcription was also increased for NPs obtained with high pDNA concentration (60 \u03bcg\/mL). The analyzed CS-TPP-pDNA polyplexes can offer a promising vehicle for nucleic acid vaccines, not only in the prevention or treatment of viral infections, but also to fight emergent and future pathogens.<\/jats:p>","DOI":"10.3390\/polym14071443","type":"journal-article","created":{"date-parts":[[2022,4,1]],"date-time":"2022-04-01T21:23:55Z","timestamp":1648848235000},"page":"1443","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":26,"title":["Modulation of Chitosan-TPP Nanoparticle Properties for Plasmid DNA Vaccines Delivery"],"prefix":"10.3390","volume":"14","author":[{"given":"Renato","family":"Nunes","sequence":"first","affiliation":[{"name":"CICS-UBI\u2014Health Sciences Research Center, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilh\u00e3, Portugal"},{"name":"InoCure s.r.o, R&D Laboratory Center, Prumyslov\u00e1 1960, 250 88 Cel\u00e1kovice, Czech Republic"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6632-9085","authenticated-orcid":false,"given":"Ana Sofia","family":"Serra","sequence":"additional","affiliation":[{"name":"CICS-UBI\u2014Health Sciences Research Center, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilh\u00e3, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4296-6842","authenticated-orcid":false,"given":"Aiva","family":"Simaite","sequence":"additional","affiliation":[{"name":"InoCure s.r.o, R&D Laboratory Center, Prumyslov\u00e1 1960, 250 88 Cel\u00e1kovice, Czech Republic"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9155-7581","authenticated-orcid":false,"given":"\u00c2ngela","family":"Sousa","sequence":"additional","affiliation":[{"name":"CICS-UBI\u2014Health Sciences Research Center, University of Beira Interior, Avenida Infante D. Henrique, 6200-506 Covilh\u00e3, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,4,1]]},"reference":[{"key":"ref_1","first-page":"12","article-title":"Sub-100 nm Chitosan-Triphosphate-DNA NPs for Delivery of DNA Vaccines","volume":"78","author":"Nunes","year":"2021","journal-title":"Proceedings"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"329","DOI":"10.1016\/S0169-409X(02)00228-4","article-title":"Biodegradable NPs for drug and gene delivery to cells and tissue","volume":"55","author":"Panyam","year":"2003","journal-title":"Adv. Drug Deliv. Rev."},{"key":"ref_3","first-page":"498","article-title":"Albumin microspheres for study of the reticuloendothelial system","volume":"13","author":"Scheffel","year":"1970","journal-title":"J Nucl. 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