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    Silica/gold nanoplatform combined with a thermosensitive gel for imaging-guided interventional therapy in PDX of pancreatic cancer
    (Amsterdam [u.a.] : Elsevier, 2020) Xinga, Lingxi; Lib, Xin; Xingd, Zehua; Lie, Fan; Shenb, Mingwu; Wanga, Hong; Shib, Xiangyang; Du, Lianfang
    Imaging-guided interventional therapy is a promising means of minimally invasive and targeted drug delivery for patients with advanced pancreatic cancer. The effectiveness of the method depends on clear imaging and complete removal of cancer cells, especially peripheral infiltration and distant metastasis, to prevent recurrence. We synthesized hollow mesoporous silica-based nanoparticles, Gem-PFH-Au star-HMS-IGF1, with gemcitabine (Gem) and perfluorohexane (PFH) encapsulated internally, gold nanostars (Au NSs) and insulin-like growth factor-1 (IGF1) modified outwardly, to enhance multimode ultrasound (US)/computed tomography (CT)/photoacoustic (PA)/thermal imaging, guide photothermal therapy, and evaluate the effect in real time. We also prepared a type of thermosensitive gel that solidified at body temperature to facilitate the controlled release of Gem and achieve a single-administration interventional therapy. A patient-derived xenograft (PDX) mouse model was established in this study. The PDX was precisely ablated by photothermal therapy under the guidance of US/CT/PA imaging, and the residual pancreatic cancer cells were completely inhibited by Gem to prevent recurrence. This strategy ingeniously simulated the approach of surgical resection and postoperative chemotherapy in clinical procedures to treat malignancy and paves the way for interventional therapy. © 2019 The Authors
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    Solvent effects on catalytic activity and selectivity in amine-catalyzed D-fructose isomerization
    (Amsterdam [u.a.] : Elsevier, 2022) Drabo, Peter; Fischer, Matthias; Emondts, Meike; Hamm, Jegor; Engelke, Mats; Simonis, Marc; Qi, Long; Scott, Susannah L.; Palkovits, Regina; Delidovich, Irina
    Rational catalyst design and optimal solvent selection are key to advancing biorefining. Here, we explored the organocatalytic isomerization of D-fructose to a valuable rare monosaccharide, D-allulose, as a function of solvent. The isomerization of D-fructose to D-allulose competes with its isomerization to D-glucose and sugar degradation. In both water and DMF, the catalytic activity of amines towards D-fructose is correlated with their basicity. Solvents impact the selectivity significantly by altering the tautomeric distribution of D-fructose. Our results suggest that the furanose tautomer of D-fructose is isomerized to D-allulose, and the fractional abundance of this tautomer increases as follows: water < MeOH < DMF ≈ DMSO. Reaction rates are also higher in aprotic than in protic solvents. The best D-allulose yield, 14 %, was obtained in DMF with 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as the catalyst. The reaction kinetics and mechanism were explored using operando NMR spectroscopy.