{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,19]],"date-time":"2026-06-19T05:50:57Z","timestamp":1781848257318,"version":"3.54.5"},"reference-count":46,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T00:00:00Z","timestamp":1781654400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"UTA","award":["4770-25"],"award-info":[{"award-number":["4770-25"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Surface engineering is a key strategy for modulating the biological behavior of TiO2-based nanomaterials, with potential relevance for future localized or adjuvant approaches targeting residual cancer cells. This study evaluated whether amine functionalization and subsequent gold decoration modify the effects of TiO2 nanoparticles (TiO2NPs) on MCF7 and MDA-MB-231 breast cancer cells. The synthesized materials preserved the anatase TiO2 framework, while surface modification altered their physicochemical and optical properties. After 24 h of exposure, pristine TiO2NPs produced minimal changes in cell viability, whereas NH2-functionalized TiO2NPs (TiO2NPs-NH2) and gold-decorated NH2-functionalized TiO2NPs (Au@TiO2NPs-NH2) reduced viability in a concentration-dependent and cell line-dependent manner. These effects were more evident in the MTT assay than in Trypan Blue exclusion counting, suggesting changes in metabolic activity before extensive membrane integrity loss. Overall, the findings indicate that surface modification, rather than the TiO2 core alone, is a major determinant of the cellular response to these nanomaterials. These results provide an initial in vitro basis for further mechanistic studies evaluating surface-engineered TiO2NPs as candidate platforms for future adjuvant breast cancer strategies.<\/jats:p>","DOI":"10.3390\/ijms27125475","type":"journal-article","created":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T15:11:22Z","timestamp":1781709082000},"page":"5475","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Amine-Functionalized and Gold-Decorated Amine-Functionalized TiO2 Nanoparticles Modulate Breast Cancer Cell Viability"],"prefix":"10.3390","volume":"27","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-1612-171X","authenticated-orcid":false,"given":"Juan P.","family":"Mu\u00f1oz","sequence":"first","affiliation":[{"name":"Laboratorio de Bioqu\u00edmica, Departamento de Qu\u00edmica, Facultad de Ciencias, Universidad de Tarapac\u00e1, Arica 1000007, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kiamara","family":"Mu\u00f1oz-Jaime","sequence":"additional","affiliation":[{"name":"Departamento de Qu\u00edmica, Facultad de Ciencias, Universidad de Tarapac\u00e1, Avda. General Vel\u00e1squez 1775, Arica 1000000, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Diego","family":"Soto-Jim\u00e9nez","sequence":"additional","affiliation":[{"name":"Laboratorio de Bioqu\u00edmica, Departamento de Qu\u00edmica, Facultad de Ciencias, Universidad de Tarapac\u00e1, Arica 1000007, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8505-9305","authenticated-orcid":false,"given":"Nachimuthu","family":"Venkatesh","sequence":"additional","affiliation":[{"name":"Centre of Excellence for Energy Research, International Research Centre, Sathyabama Institute of Science and Technology, Chennai 600119, Tamil Nadu, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7167-2694","authenticated-orcid":false,"given":"N\u00e9stor","family":"Novoa","sequence":"additional","affiliation":[{"name":"Laboratorio de Qu\u00edmica Inorg\u00e1nica y Organomet\u00e1lica, Departamento de Qu\u00edmica Anal\u00edtica e Inorg\u00e1nica, Facultad de Ciencias Qu\u00edmicas, Universidad de Concepci\u00f3n, Edmundo Larenas 129, Casilla 160-C, Concepci\u00f3n 4070371, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4531-9405","authenticated-orcid":false,"given":"Krishnamoorthy","family":"Shanmugaraj","sequence":"additional","affiliation":[{"name":"Departamento de Qu\u00edmica, Facultad de Ciencias, Universidad de Tarapac\u00e1, Avda. 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