TY  - JOUR
AB  - 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.
AU  - Nunes, A.
AU  - Pansare, V.J.*
AU  - Bézière, N.
AU  - Kolokithas-Ntoukas, A.
AU  - Reber, J.
AU  - Bruzek, M.*
AU  - Anthony, J.*
AU  - Prud´homme, R.K.*
AU  - Ntziachristos, V.
C1  - 52515
C2  - 43993
CY  - Cambridge
SP  - 44-55
TI  - Quenched hexacene optoacoustic nanoparticles.
JO  - J. Mater. Chem. B
VL  - 6
IS  - 1
PB  - Royal Soc Chemistry
PY  - 2017
SN  - 2050-750X
ER  - 

TY  - JOUR
AB  - Luminescent core-shell particles are structures widely applied to biomedical purposes with the potential of combining multiple features within one single particle. The development of particles that are easily synthesised and tunable for each application, combining biocompatibility, easy bioconjugation and a high detection signal as a label, is highly desired. In this work, we describe a one-step synthesis of poly [styrene-co-(2-hydroxyethyl methacrylate)], PSHEMA, core-shell particles containing [Ru(4,4'-dicarboxilate- 2,2'-bpy)(3)] luminescent complexes. These particles show monodispersity, biocompatibility, easy functionalization and dye incorporation to focus on bioapplications, such as cell-tracking and diagnostics. The monomers assemble during the polymerization and produce core-shell structures with hydrophilic-hydrophobic character. This allows the concentration of hydrophilic ruthenium complexes onto the shell and incorporation of hydrophobic molecules (e.g. diphenylanthracene) due to the hydrophobic character of styrene. The incorporation of the Ru complex resulted in higher photostability compared to the free dye. Furthermore, carboxylic groups on the particle surface originated from carboxylated ligands of Ru complexes were used to immobilize biomolecules. The particles were successfully used as a diagnostic label for dengue fever (DF) infection. Using the complexes in the immunospot assay the test provided a detection limit (DL) of 187 ng mL(-1) for the viral non-structural glycoprotein NS1. The particles showed a considerable decrease in the DL and allowed the diagnosis of the infection 24 hours earlier compared to common available assays based on gold nanoparticles. In addition, the particles were tested with an adherent grown fibroblast cell line and showed potential biocompatibility.
AU  - Linares, E.M.
AU  - Formiga, A.*
AU  - Kubota, L.T.*
AU  - Galembeck, F.*
AU  - Thalhammer, S.
C1  - 24250
C2  - 31357
SP  - 2236-2244
TI  - One-step synthesis of polymer core-shell particles with a carboxylated ruthenium complex: A potential tool for biomedical applications.
JO  - J. Mater. Chem. B
VL  - 1
IS  - 17
PB  - Royal Soc. Chemistry
PY  - 2013
SN  - 2050-750X
ER  -