136279 20260217205522.0 doi 10.3390/nano14131149 sideral 139262 ART-2024-139262 eng Baselga, Marta (orcid)0000-0003-2672-5790 Melanin-based nanoparticles for lymph node tattooing: experimental, histopathological and ultrastructural study 2024 Access copy available to the general public Unrestricted In breast cancer, Targeted Axillary Dissection (TAD) allows for the selective excision of the sentinel lymph node (SLN) during primary tumor surgery. TAD consists of the resection of labelled SLNs prior to neoadjuvant chemotherapy (NACT). Numerous clinical and preclinical studies have explored the use of carbon-based colloids for SLN tattooing prior to NACT. However, carbon vectors show varying degrees of inflammatory reactions and, in about one fifth of cases, carbon particles migrate via the lymphatic pathway to other nodes, causing the SLN to mismatch the tattooed node. To overcome these limitations, in this study, we explored the use of melanin as a staining endogenous pigment. We synthesized and characterized melanin-loaded polymeric nanoparticles (Mel-NPs) and used them to tattoo lymph nodes in pig animal models given the similarity in the size of the human and pig nodes. Mel-NPs tattooed lymph nodes showed high identification rates, reaching 83.3% positive identification 16 weeks after tattooing. We did not observe any reduction in the identification as time increased, implying that the colloid is stable in the lymph node tissue. In addition, we performed histological and ultrastructural studies to characterize the biological behavior of the tag. We observed foreign-body-like granulomatous inflammatory responses associated with Mel-NPs, characterized by the formation of multinucleated giant cells. In addition, electron microscopy studies showed that uptake is mainly performed by macrophages, and that macrophages undergo cellular damage associated with particle uptake. info:eu-repo/grantAgreement/ES/ISCIII/DTS2019-00131 info:eu-repo/grantAgreement/ES/ISCIII/MS19-00092 info:eu-repo/semantics/openAccess by https://creativecommons.org/licenses/by/4.0/deed.es 4.3 2024 MATERIALS SCIENCE, MULTIDISCIPLINARY 177 / 461 = 0.384 2024 Q2 T2 NANOSCIENCE & NANOTECHNOLOGY 69 / 147 = 0.469 2024 Q2 T2 CHEMISTRY, MULTIDISCIPLINARY 81 / 239 = 0.339 2024 Q2 T2 PHYSICS, APPLIED 57 / 187 = 0.305 2024 Q2 T1 0.811 2024 Chemical Engineering (miscellaneous) 2024 Q1 Materials Science (miscellaneous) 2024 Q2 9.2 2024 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Güemes, Antonio Universidad de Zaragoza (orcid)0000-0002-4437-2581 Yus, Cristina Universidad de Zaragoza (orcid)0000-0002-1505-498X Alejo, Teresa Sebastián, Víctor Universidad de Zaragoza (orcid)0000-0002-6873-5244 Arribas, Dolores Universidad de Zaragoza (orcid)0000-0002-3592-820X Mendoza, Gracia (orcid)0000-0003-2293-363X Monleón, Eva Universidad de Zaragoza (orcid)0000-0002-7453-1766 Arruebo, Manuel Universidad de Zaragoza (orcid)0000-0003-3165-0156 1003 443 Universidad de Zaragoza Dpto. Anatom.Histolog.Humanas Area Histología 5005 555 Universidad de Zaragoza Dpto. Ing.Quím.Tecnol.Med.Amb. Área Ingeniería Química 1013 090 Universidad de Zaragoza Dpto. Cirugía Área Cirugía 14, 13 (2024), 1149 [16 pp.] Nanomaterials (Basel) Nanomaterials 2079-4991 9467195 http://zaguan.unizar.es/record/136279/files/texto_completo.pdf Versión publicada 2709510 http://zaguan.unizar.es/record/136279/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:136279 articulos driver 2026-02-17-20:29:07 ARTICLE