{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T02:11:25Z","timestamp":1783649485943,"version":"3.55.0"},"reference-count":40,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,6,28]],"date-time":"2025-06-28T00:00:00Z","timestamp":1751068800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Next Generation EU","award":["BG-RRP-2.004-0008-C01"],"award-info":[{"award-number":["BG-RRP-2.004-0008-C01"]}]},{"name":"Next Generation EU","award":["76-123-661"],"award-info":[{"award-number":["76-123-661"]}]},{"name":"Next Generation EU","award":["BG16RFPR002-1.014-0015"],"award-info":[{"award-number":["BG16RFPR002-1.014-0015"]}]},{"name":"Next Generation EU","award":["80-10-134\/03.06.2025"],"award-info":[{"award-number":["80-10-134\/03.06.2025"]}]},{"name":"European Regional Development Fund","award":["BG-RRP-2.004-0008-C01"],"award-info":[{"award-number":["BG-RRP-2.004-0008-C01"]}]},{"name":"European Regional Development Fund","award":["76-123-661"],"award-info":[{"award-number":["76-123-661"]}]},{"name":"European Regional Development Fund","award":["BG16RFPR002-1.014-0015"],"award-info":[{"award-number":["BG16RFPR002-1.014-0015"]}]},{"name":"European Regional Development Fund","award":["80-10-134\/03.06.2025"],"award-info":[{"award-number":["80-10-134\/03.06.2025"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pharmaceuticals"],"abstract":"<jats:p>Background: The present work is devoted to the biological effects of sol\u2013gel-derived silica (Si)\u2013copper (Cu) nanomaterials. Methods and Results: Tetraethyl orthosilane (TEOS) was used as a silica precursor; copper was introduced as a solution in ethanol with Cu(OH)2. The obtained samples were denoted as Si\/Cu (gel) and Si\/Cu\/500 (500 \u00b0C heat-treated). Their phase formation and morphology were studied by XRD and SEM. The antibacterial activity was tested by two Gram-positive bacteria, three Gram-negative bacteria, and two types of eukaryotic species. Most bacteria were more sensitive to Si\/Cu\/500 materials than to Si\/Cu (gel). The yeasts were more sensitive to Si\/Cu (gel). The new nanomaterials were tested for oxidant activity at pH 7.4 (physiological) and pH 8.5 (optimal) in three model systems by the chemiluminescent method. They significantly inhibited the generation of free radicals and ROS. This result underlines their potential as regulators of the free radical processes in living systems. The epithelial tumor cell lines appeared more sensitive than the non-transformed fibroblasts, likely due to their metabolic activity and proliferation rates, leading to greater accumulation of the substances. Using Daphnia magna, the ecotoxicity study showed that the LC50 was reached at 1 mg\/L of Si\/Cu\/500. Si\/Cu (gel) was more toxic. Conclusions: Our results reveal the potential of these nanohybrids to be applied in living, eukaryotic systems. The cytotoxicity evaluation showed higher tolerance of normal, non-transformed cells, in concurrence with the oxidation tests.<\/jats:p>","DOI":"10.3390\/ph18070976","type":"journal-article","created":{"date-parts":[[2025,7,2]],"date-time":"2025-07-02T07:55:43Z","timestamp":1751442943000},"page":"976","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Antimicrobial, Oxidant, Cytotoxic, and Eco-Safety Properties of Sol\u2013Gel-Prepared Silica\u2013Copper Nanocomposite Materials"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-5492-9897","authenticated-orcid":false,"given":"Lilia","family":"Yordanova","sequence":"first","affiliation":[{"name":"Faculty of Biology, Sofia University \u201cSt. Kliment Ohridski\u201d, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3452-908X","authenticated-orcid":false,"given":"Lora","family":"Simeonova","sequence":"additional","affiliation":[{"name":"Department of Virology, Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 26 G. Bonchev Str., 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miroslav","family":"Metodiev","sequence":"additional","affiliation":[{"name":"Department of Virology, Stephan Angeloff Institute of Microbiology, Bulgarian Academy of Sciences, 26 G. Bonchev Str., 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7697-466X","authenticated-orcid":false,"given":"Albena","family":"Bachvarova-Nedelcheva","sequence":"additional","affiliation":[{"name":"Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 11 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8644-6470","authenticated-orcid":false,"given":"Yoanna","family":"Kostova","sequence":"additional","affiliation":[{"name":"Institute of Metal Science, Equipment and Technologies with Hydro- and Aerodynamics Centre \u201cAcad. A. Balevski\u201d, Bulgarian Academy of Sciences, 67 Shipchenski Prohod Str., 1574 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1239-3249","authenticated-orcid":false,"given":"Stela","family":"Atanasova-Vladimirova","sequence":"additional","affiliation":[{"name":"Institute of Physical Chemistry, Bulgarian Academy of Sciences, 11 Acad. G. Bonchev Str., 1113 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4590-1553","authenticated-orcid":false,"given":"Elena","family":"Nenova","sequence":"additional","affiliation":[{"name":"Faculty of Biology, Sofia University \u201cSt. Kliment Ohridski\u201d, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5964-0609","authenticated-orcid":false,"given":"Iliana","family":"Ivanova","sequence":"additional","affiliation":[{"name":"Faculty of Biology, Sofia University \u201cSt. Kliment Ohridski\u201d, 8 Dragan Tsankov Blvd., 1164 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lyubomira","family":"Yocheva","sequence":"additional","affiliation":[{"name":"Faculty of Medicine, Sofia University \u201cSt. Kliment Ohridski\u201d, 1 Kozyak Str., 1407 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5708-3482","authenticated-orcid":false,"given":"Elitsa","family":"Pavlova","sequence":"additional","affiliation":[{"name":"Faculty of Physics, Sofia University \u201cSt. Kliment Ohridski\u201d, 5 James Boucher Blvd., 1164 Sofia, Bulgaria"},{"name":"Center of Competence \u201cClean Technologies for Sustainable Environment\u2014Water, Waste, Energy for Circular Economy\u201d, 1000 Sofia, Bulgaria"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"24923","DOI":"10.1021\/jp0656779","article-title":"Preparation and characterization of the antibacterial Cu nanoparticle formed on the surface of SiO2 nanoparticles","volume":"110","author":"Kim","year":"2006","journal-title":"J. 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