Uniform volumetric encapsulation of antimicrobial agents into mesoporous silica for their slow release: the case of copper oxide

Uniform volumetric encapsulation of antimicrobial agents into mesoporous silica for their slow release: the case of copper oxide | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Uniform volumetric encapsulation of antimicrobial agents into mesoporous silica for their slow release: the case of copper oxide Aadil Shafi Bhat, Mariliis Sihtmäe, Kaja Kasemets, Mati Kook, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9497970/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 6 You are reading this latest preprint version Abstract In the present work, a modified Stöber approach was developed for direct encapsulation of copper(II) tetraammine complex solution within the mesopores of SiO 2 particles during their formation. It was shown that a developed synthetic approach allows to uniformly distribute loaded compounds, avoiding their concentration close to the silica particle surface, which is common for post-synthetic techniques of loading. In turn, uniform distribution of copper species led to their slow and sustained release into the surrounding media, both for as prepared and calcined nanocomposites. It was shown that upon 24h exposure to the solution, the release of copper species proceeds in almost linear fashion without any signs of rate decay. Both as prepared ([Cu(NH 3 ) 4 ] 2+ @SiO 2 ) and calcined (Cu x O@SiO 2 ) nanocomposites demonstrated antibacterial activity against Gram-negative bacteria Escherichia coli , Pseudomonas aeruginosa , and Gram-positive Staphylococcus aureus . However, the Cu x O@SiO 2 material appears to be more promising for antimicrobial applications due to its low cytotoxicity to human keratinocytes in vitro . Physical sciences/Chemistry Physical sciences/Materials science Biological sciences/Microbiology Physical sciences/Nanoscience and technology mesoporous silica particles antimicrobial materials nanocomposites encapsulation copper(II) release Stöber synthesis Full Text Additional Declarations No competing interests reported. Supplementary Files SupplementaryTable1BhatetalScientificReports.docx SupplementaryBhatetalScientificReports.pdf SupplementaryFigure3BhatetalScientificReports.tif SupplementaryFigure1BhatetalScientificReports.tif SupplementaryFigure2BhatetalScientificReports.tif Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 11 May, 2026 Reviewers agreed at journal 11 May, 2026 Reviewers invited by journal 30 Apr, 2026 Editor assigned by journal 25 Apr, 2026 Submission checks completed at journal 25 Apr, 2026 First submitted to journal 22 Apr, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9497970","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":635181834,"identity":"4607e30b-550f-4e10-bfe3-50d50b0542aa","order_by":0,"name":"Aadil Shafi Bhat","email":"","orcid":"","institution":"University of Tartu","correspondingAuthor":false,"prefix":"","firstName":"Aadil","middleName":"Shafi","lastName":"Bhat","suffix":""},{"id":635181836,"identity":"b00189d8-ced9-4fdf-998e-a29d360bcf6e","order_by":1,"name":"Mariliis Sihtmäe","email":"","orcid":"","institution":"National Institute of Chemical Physics and 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antimicrobial materials, nanocomposites, encapsulation, copper(II) release, Stöber synthesis","lastPublishedDoi":"10.21203/rs.3.rs-9497970/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9497970/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eIn the present work, a modified St\u0026ouml;ber approach was developed for direct encapsulation of copper(II) tetraammine complex solution within the mesopores of SiO\u003csub\u003e2\u003c/sub\u003e particles during their formation. It was shown that a developed synthetic approach allows to uniformly distribute loaded compounds, avoiding their concentration close to the silica particle surface, which is common for post-synthetic techniques of loading. In turn, uniform distribution of copper species led to their slow and sustained release into the surrounding media, both for as prepared and calcined nanocomposites. It was shown that upon 24h exposure to the solution, the release of copper species proceeds in almost linear fashion without any signs of rate decay. Both as prepared ([Cu(NH\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e4\u003c/sub\u003e]\u003csup\u003e2+\u003c/sup\u003e@SiO\u003csub\u003e2\u003c/sub\u003e) and calcined (Cu\u003csub\u003ex\u003c/sub\u003eO@SiO\u003csub\u003e2\u003c/sub\u003e) nanocomposites demonstrated antibacterial activity against Gram-negative bacteria \u003cem\u003eEscherichia coli\u003c/em\u003e, \u003cem\u003ePseudomonas aeruginosa\u003c/em\u003e, and Gram-positive \u003cem\u003eStaphylococcus aureus\u003c/em\u003e. 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