Tang, LinVidal Figueroa, AnxoTorres Caldas, Ana MaríaRazansky, Daniel2026-03-132026-03-132024Tang, L., Nozdriukhin, D., Kalva, S. K., Zhou, Q., Özsoy, Ç., Lyu, S., Reiss, M., Vidal, A., Torres, A., Deán-Ben, X. L., & Razansky, D. (2025). Scalable Copper Sulfide Formulations for Super-Resolution Optoacoustic Brain Imaging in the Second Near-Infrared Window. Small Methods, 9(1). https://doi.org/10.1002/SMTD.202400927https://hdl.handle.net/10347/46368Optoacoustic imaging offers label-free multi-parametric characterization of cerebrovascular morphology and hemodynamics at depths and spatiotemporal resolution unattainable with optical microscopy. Effective imaging depth can greatly be enhanced by employing photons in the second near-infrared (NIR-II) window. However, diminished absorption by hemoglobin along with a lack of suitable contrast agents hinder an efficient application of the technique in this spectral range. Herein, copper sulfide (CuS) micro- and nano-formulations for multi-scale optoacoustic imaging in the NIR-II window are introduced. Dynamic contrast enhancement induced by intravenously administered CuS nanoparticles facilitated visualization of blood perfusion in murine cerebrovascular networks. The individual calcium carbonate microparticles carrying CuS are further shown to generate sufficient responses to enable super-resolution microvascular imaging and blood flow velocity mapping with localization optoacoustic tomography.eng© 2024 The Author(s). Small Methods published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.Attribution 4.0 Internationalhttp://creativecommons.org/licenses/by/4.0/Chemical imagingMicroparticle localizationNeuroimagingOptoacoustic imagingPhotoacousticsSecond near-infrared windowjournal article2025-12-0410.1002/SMTD.2024009272366-9608open access2366-9608