Quenched hexacene optoacoustic nanoparticles.

Optoacoustic (photoacoustic) imaging enables high-resolution optical imaging at depths well beyond optical microscopy, revolutionizing optical interrogation of tissues. Operation in the near-infrared (NIR) is nevertheless necessary to capitalize on the technology potential and reach depths of several centimeters. Using Flash NanoPrecipitation for highly-scalable single-step encapsulation of hydrophobic hexacene at self-quenching concentrations, we propose quenched fluorescence-dye nanoparticles as a potent alternative to NIR metal nanoparticles for strong optoacoustic signal generation. Comprehensive hexacene-based nanoparticle characterization was based on a 5-step approach that examined the physicochemical features (Step 1), optoacoustic signal generation (Step 2), stability (Step 3), biocompatibility (Step 4) and spectral sensitivity (Step 5). Using this characterization framework we showcase the discovery of two nanoparticle formulations, QH2-50 nm and QH2-100 nm that attain superior stability characteristics and optimal optoacoustic properties compared to gold standards commonly employed for near-infrared optoacoustics. We discuss encapsulation and self-quenching (ESQ) of organic dyes as a promising strategy to generate optimal optoacoustic particles

Synthesis and evaluation of condensed magnetic nanocrystal clusters with<em> in&nbsp;vivo </em>multispectral optoacoustic tomography for tumour targeting.

Colloidal clusters of magnetic iron oxide nanocrystals (MIONs), particularly in the condensed pattern (co-CNCs), have emerged as new superstructures to improve further the performance of MIONs in applications pertaining to magnetic manipulation (drug delivery) and magnetic resonance imaging (MRI). Exploitation of the advantages they represent and their establishment in the area of nanomedicine demands a particular set of assets. The present work describes the development and evaluation of MION-based co-CNCs featuring for the first time such assets: High magnetization, as well as magnetic content and moment, high relaxivities (r2&nbsp;=&nbsp;400 and [Formula: see text] ) and intrinsic loss power (2.3&nbsp;nH&nbsp;m(2) kgFe(-1)) are combined with unprecedented colloidal stability and structural integrity, stealth and drug-loading properties. The reported nanoconstructs are endowed with additional important features such as cost-effective synthesis and storage, prolonged self-life and biocompatibility. It is finally showcased with in&nbsp;vivo multispectral optoacoustic tomography how these properties culminate in a system suitable for targeting breast cancer and for forceful in&nbsp;vivo manipulation with low magnetic field gradients

In vitro cytotoxicity analysis of doxorubicin-loaded/superparamagnetic iron oxide colloidal nanoassemblies on MCF7 and NIH3T3 cell lines

Katerina Tomankova,1 Katerina Polakova,2 Klara Pizova,1 Svatopluk Binder,1 Marketa Havrdova,2 Mary Kolarova,2 Eva Kriegova,3 Jana Zapletalova,1 Lukas Malina,1 Jana Horakova,1 Jakub Malohlava,1 Argiris Kolokithas-Ntoukas,4 Aristides Bakandritsos,4 Hana Kolarova,1 Radek Zboril2 1Department of Medical Biophysics, Institute of Translation Medicine, Faculty of Medicine and Dentistry, 2Regional Centre of Advanced Technologies and Materials, Departments of Physical Chemistry and&nbsp;Experimental Physics, Faculty of&nbsp;Science, 3Department of Immunology, Faculty of Medicine and Dentistry, Palacky University, Olomouc, Czech Republic; 4Department of Materials Science, University of&nbsp;Patras, Patras, Greece Abstract: One of the promising strategies for improvement of cancer treatment is based on magnetic drug delivery systems, thus avoiding side effects of standard chemotherapies. Superparamagnetic iron oxide (SPIO) nanoparticles have ideal properties to become a targeted magnetic drug delivery contrast probes, named theranostics. We worked with SPIO condensed colloidal nanocrystal clusters (MagAlg) prepared through a new soft biomineralization route in the presence of alginate as the polymeric shell and loaded with doxorubicin (DOX). The aim of this work was to study the in vitro cytotoxicity of these new MagAlg&ndash;DOX systems on mouse fibroblast and breast carcinoma cell lines. For proper analysis and understanding of cell behavior after administration of MagAlg&ndash;DOX compared with free DOX, a complex set of in vitro tests, including production of reactive oxygen species, comet assay, cell cycle determination, gene expression, and cellular uptake, were utilized. It was found that the cytotoxic effect of MagAlg&ndash;DOX system is delayed compared to free DOX in both cell lines. This was attributed to the different mechanism of internalization of DOX and MagAlg&ndash;DOX into the cells, together with the fact that the drug is strongly bound on the drug nanocarriers. We discovered that nanoparticles can attenuate or even inhibit the effect of DOX, particularly in the tumor MCF7 cell line. This is a first comprehensive study on the cytotoxic effect of DOX-loaded SPIO compared with free DOX on healthy and cancer cell lines, as well as on the induced changes in gene expression. Keywords: DOX/SPIO nanocarriers, superparamagnetic iron oxide nanoparticles, doxorubicin, in vitro cytotoxicity&nbsp