Novel monoketoheptuloses have been synthesized employing an amination step in a pre- and/or post-C1 chain elongation using a Petasis reagent by starting from aldohexoses or aldohexosamines. A series of gluco and manno configured 1-/3-deoxy-1-/3-amino-ketohept-2-uloses could be obtained.

Herein, we present a strategy for the glycoconjugation of nanoparticles (NPs), with a special focus on fluorescent quantum dots (QDs), recently described by us as "preassembly" approach. Therein, prior to the encapsulation of diverse nanoparticles by an amphiphilic poly(isoprene)-b-poly(ethylene glycol) diblock copolymer (PI-b-PEG), the terminal PEG appendage was modified by covalently attaching a carbohydrate moiety using Huisgen-type click-chemistry. Successful functionalization was proven by NMR spectroscopy. The terminally glycoconjugated polymers were subsequently used for the encapsulation of QDs in a phase transfer process, which fully preserved fluorescence properties. Binding of these nanoconstructs to the lectin Concanavalin A (Con A) was studied via surface plasmon resonance (SPR). Depending on the carbohydrate moiety, namely, D-manno-heptulose, D-glucose, D-galactose, 2-deoxy-2-{[methylamino)carbonyl]amino}-D-glucopyranose ("des(nitroso)-streptozotocin"), or D-maltose, the glycoconjugated QDs showed enhanced affinity constants due to multivalent binding effects. None of the constructs showed toxicity from 0.001 to 1 μM (particle concentration) using standard WST and LDH assays on A549 cells.

The assessment of the β-cell mass in experimental models of diabetes and ultimately in patients is a hallmark to understand the relationship between reduced β-cell mass/function and the onset of diabetes. It has been shown before that the GLUT-2 transporter is highly expressed in both β-cells and hepatocytes and that D-mannoheptulose (DMH) has high uptake specificity for the GLUT-2 transporter. As 19-fluorine MRI has emerged as a new alternative method for MRI cell tracking because it provides potential non-invasive localization and quantification of labeled cells, the purpose of this project is to validate β-cell and pancreatic islet imaging by using fluorinated, GLUT-2 targeting mannoheptulose derivatives ( 19 FMH) both in vivo and ex vivo. In this study, we confirmed that, similar to DMH, 19 FMHs inhibit insulin secretion and increase the blood glucose level in mice temporarily (approximately two hours). We were able to assess the distribution of 19 FMHs in vivo with a temporal resolution of about 20 minutes, which showed a quick removal of 19 FMH from the circulation (within two hours). Ex vivo MR spectroscopy confirmed a preferential uptake of 19 FMH in tissue with high expression of the GLUT-2 transporter, such as liver, endocrine pancreas and kidney. No indication of further metabolism was found. In summary, 19FMHs are potentially suitable for visualizing and tracking of GLUT-2 expressed cells. However, current bottlenecks of this technique related to the quick clearance of the compound and relative low sensitivity of 19 F MRI need to be overcome.

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The aim of the present study was to investigate the ex vivo results of four different endoluminal bipolar radiofrequency ablation (RFA) probes at different energy settings and using four different power generators. Ex vivo RFA was performed on bovine liver using four different bipolar RFA probes: i) Habib™ EndoHPB (EMcision); ii) Habib™ VesOpen (EMcision); iii) Celon ProCurve micro 300-C09 (Olympus Corporation); and iv) Celon ProCurve 1200 S15 (Olympus Corporation). The following generators were also used: Erbe Vio 300D, KLS Martin Maxium, Olympus CelonPOWER and Boston RF3000. Overall, 430 ablations were carried out. The results revealed significant differences in the size of the achieved lesions and the duration of ablation (P<0.05) between the four different ablation devices. The maximum lesion diameters achieved with the devises were as follows: HabibTM EndoHPB, 13 watts (W; mean ± standard deviation, 10.3±1.8 mm); Habib™ VesOpen, 12 W (11.3±0.6); Celon ProCurve micro, 2 W (7.9±2.2); and Celon ProCurve 1200, 10 W (9.2±1.1). The maximum lesion diameters induced by the various generators differed significantly. On the whole, the present study demonstrates that lesion size and ideal power settings vary between different endoluminal ablation devices and generators. The combination of the probe and generator should not be varied in clinical practice to ensure reliable results.