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Effective mosquito monitoring relies on the accurate identification and characterization of the target population. Since this process requires specialist knowledge and equipment that is not widely available, automated field-deployable systems are highly desirable. We present a centrifugal microfluidic cartridge, the VectorDisk, which integrates TaqMan PCR assays in two feasibility studies, aiming to assess multiplexing capability, specificity, and reproducibility in detecting disk-integrated vector-related assays. In the first study, pools of 10 mosquitoes were used as samples. We tested 18 disks with 27 DNA and RNA assays each, using a combination of multiple microfluidic chambers and detection wavelengths (geometric and color multiplexing) to identify mosquito and malaria parasite species as well as insecticide resistance mechanisms. In the second study, purified nucleic acids served as samples to test arboviral and malaria infective mosquito assays. Nine disks were tested with 14 assays each. No false positive results were detected on any of the disks. The coefficient of variation in reproducibility tests was

INTRODUCTION Radiolabelled particles are an attractive tool in the therapy of malignancies of the liver. Hepatic tumours receive their blood supply mainly from the arterial circulation, unlike normal liver tissue which is supplied by the portal vein. The intra-arterial application of microspheres with particle size > 10 m are trapped in the capillary bed and release a local radiotoxic dose with low levels of toxicity to the normal liver (1). The aim of this study was to determine the in vitro (incubation in human plasma and DTPA-Challenge) and in vivo characteristics of radiolabelled human serum albumin (HSA) microspheres and the valuation of suitability for radiotherapeutical treatment of liver malignancies. Covalent attachment of DOTA chelators onto the surface of the spheres opens up an easy access to Y-86-radiolabelled HSA microspheres. For in vivo experiments the labelled spheres were injected into the tail vein of Wistar rats. After 1, 12, 24 and 48 h the animals were sacrificed and the radioactivity concentration of isolated organs and tissue was determined. Furthermore, to investigate the influence of the surface structure we have used three different batches of HSA microspheres (smooth to rough; diameter 20-30 µm). RESULTS AND DISCUSSION Approximately 25 DOTA molecules per molecule HSA could be attached as estimated from elemental analysis of DOTA-HSA microspheres, independently of the surface characteristics of the spheres. They were Y-86 labelled under optimized conditions in 96 ± 1 % yield. No significant differences between smooth- and rough-surfaced spheres were found. In DTPA challenge experiments 98 % of the radioactivity was still particle-associated after 24 hours incubation at 37 °C. In vitro studies in human plasma resulted in 95 ± 4 % particle-associated radioactivity after 48 h incubation at 37 °C. In the in vivo experiments radiolabelled smooth and rough microspheres were completely trapped in the lungs, which served in our experiments as model for the vascular system of a solid tumour. Biodistribution of radioactivity was determined up to 48 h p.i. The estimated activity in the urine was below 1 %ID at 1 and 12 h p.i., and below 9 %ID at 24 and 48 h. Radioactivity level of other organs and tissues was marginal (< 2 %ID at all time points). The three batches of particles differed considerably in their radioactivity recovery in the lungs. For the clearance of radioactivity from the lungs decay-corrected half-lives of 85 h (rough microspheres) and 187 h (smooth microspheres) were calculated (2). We found a strong dependency between the in vivo stability of radiolabel fixation on the surface and the roughness of the particle. We concluded that for the preparation of HSA-derived microspheres for radiotherapeutic application smooth-surfaced spheres are superior to rough spheres due to their higher in vivo stability. REFERNCES 1. Murthy R et al., Yttrium-90 microsphere therapy for hepatic malignancy: devices, indications, technical considerations, and potential complications. Radiographics 25 (2005), 41-55. 2. Schiller E, Bergmann R, Pietzsch J, Noll B, Sterger A, Johannsen B, Wunderlich G, Pietzsch H-J, Yttrium-86-labelled human serum albumin microspheres: relation of surface structure with in vivo stability, Nucl. Med. Biol., doi: 10.1016/j.nucmedbio.2007.10.008.

Introduction: The matrix protein tenascin-c (TN-C) represents an interesting target for molecular imaging in oncology due to it´s high abundance in a variety of human tumors such as lung, breast and brain tumors [1]. First radiolabeled anti-TN-C antibodies could successfully proof the concept of tumor-TN-C targeting [2]. However, a persistently high blood level hampers their use for targeted imaging. Aptamers, a class of rapidly clearing high affinity oligonucleotides, have been introduced successfully to molecular imaging by the application of the Tc-99m labeled TN-C Targeting Aptamer-1 (TTA-1) [3]. Here we report on the radiolabeling, binding affinity and biodistribution of this novel targeting aptamer labeled with metal PET isotopes. Experimental: Labeling with Ga(III), Y(III), and In(III) was performed in a one pot reaction after conjugation of a DOTA-type chelating moiety to TTA-1-MAG2. In-111 was included in the study as a surrogate for Ga and Y in long term stability and affinity tests. The labeling was carried out in the presence of the aptamer-chelator conjugate and the respective radiometal in acetate buffer. Degradation was investigated in human plasma employing PAGE. Affinity for human TN-C was determined in a nitrous cellulose filter binding assay. Athymic mice, bearing the human U251 tumor cell line, were injected with the radiolabeled TTA-1 derivatives. Results and Discussion: Addition of the radiometal salts yielded the respective labeled aptamer conjugates in high yields (60 – 80 %). Ultrafiltration of the products led to > 95 % of pure material as determined by PAGE and HPLC methods. The biological stability in human plasma ranged from 68 % (In-111) to 95 % (Y-86) of intact material after 6 hr. Binding affinity for human TN-C revealed a KD of 1 nM (In-111). A maximum tumor uptake of 2.0 % ID/g (Ga-68), 1 hr p.i. and T/Non Tumor ratios of 5.1 (T/blood), 0.2 (T/kidney), 0.7 (T/liver) 1 hr p.i. proved to be adequate to image the U251 tumor xenograft in mice. Tumor visualization was possible for both Ga-68 and Y-86 labeled TTA-1. Conclusion: The introduction of a DOTA-type chelating moiety could be successfully used to radiolabel the aptamer probe with In, Ga and Y. The stability against nuclease degradation along with a significant tumor accumulation, high T/ blood levels and the imaging capabilities in PET-scans make these compounds promising candidates for further evaluation as multi-tumor imaging agents. Acknowledgement: 1. R. Chiquet-Ehrismann, Cell 47, 131 (1986) 2. P. Riva, Cancer 73, 1076 (1994) 3. B.J. Hicke, J. Nuc. Med. 47, 668-678 (2006).

The synthesis of 1-(5-chloro-2-{2-[(2R)-4-(4-[18F]fluorobenzyl)-2methylpiperazin-1-yl]-2-oxoethoxy}phenyl)urea ([18F]4), a potent nonpeptide CCR1 antagonist, is described as a module-assisted two-step one-pot procedure. The final product was obtained utilizing the reductive amination of the formed 4-[18F]fluorobenaldehyde with a piperazine derivative and sodium cyanoborohydride. After HPLC purification of the final product ([18F]4, its solid phase extraction, formulation and sterile filtration, the isolated (not decay-corrected) radiochemical yields of ([18F]4 were between 7 and 13% (n=28). The time of the entire manufacturing process did not exceed 95 min. The radiochemical purity of ([18F]4 was higher than 95%, the chemical purity ≥60% and the enantiomeric purity >99.5%. The specific radioactivity was in the range of 59-226 GBq/µmol at starting radioactivities of 23.6-65.0 GBq ([18F]fluoride

Isopeptide bonds between the varepsilon-amino group of lysine and the gamma-carboxamide group of glutamine are formed during strong heating of pure proteins or, more important, by enzymatic reaction mediated by transglutaminases. Despite the wide use of a microbial transglutaminase in food biotechnology, up to now little is known about the metabolic fate of the isopeptide N(varepsilon)-(gamma-glutamyl)-L-lysine. In the present study, N-succinimidyl-4-[18F]fluorobenzoate was used to modify N(varepsilon)-(gamma-glutamyl)-L-lysine at each of its two alpha-amino groups, resulting in the 4-[18F]fluorobenzoylated derivatives, for which biodistribution, catabolism, and elimination were investigated in male Wistar rats. A significant different biochemical behavior of the two labelled isopeptides was observed in terms of in vitro stability, in vivo metabolism as well as biodistribution. The results suggest that the metabolic fate of isopeptides is likely to be dependent on how they are reabsorbed - free or peptide bound.

Aim: Aptamers (synthetic oligonucleotides), can be generated by a combinatorial approach (SELEX1) and are promising probes for radiodiagnostic imaging and therapy due to their high affinity and target specificity. The aptamer, TTA1 is characterized by a low nanomolar affinity and a high selectivity for the human matrix protein tenascin-C. Tenascin-C concentration in normal adult matrix tissue is rather low, whereas it is overexpressed in the stroma of a variety of malignant tumors2, making this target potentially suitable as a multi tumor imaging agent. The aim of this study was to evaluate the pharmacokinetic properties of 99mTc(I) and 188Re(I) carbonyl radiometal chelates attached to TTA1 in tumor animal models in vivo. Material and Methods: [Carboxymethyl-(2-ethylsulfanyl-ethyl)-amino]-acetic acid, an appropriate chelating unit for coordination of 99mTc(I) or 188Re(I), was conjugated to the aptamer and a 99mTc(I) carbonyl precursor was synthesized3. Labeling of the aptamer with the 99mTc(I) carbonyl precursor was achieved in 15 min at 100°C. Synthesis of the 188Re(I) carbonyl labeled aptamer was performed in a one pot reaction at 60°C for 30 min. Both, binding affinity for human tenascin-C and in vitro stability in human plasma were measured. The biodistribution and elimination of the 99mTc-tracer was evaluated in a human U251 xenograft NMRI nude mouse model. Results: The radiochemical purity of the products was >95 % after purification by spin dialysis. Reaction yields ranged from 65 % to 72 % for the 99mTc(I) carbonyl labeled aptamer and from 25 % to 35 % for the 188Re(I) carbonyl labeled aptamer. The specific activity of the Tc(I) carbonyl labeled aptamer was 37 MBq/nmol and the stability in human blood plasma proved to be 65 % after incubation at 37°C for 24h. The binding affinity of the compound against human tenascin-C lies in the low nanomolar range. Significant tumor uptake was observed in the U251 tumor xenograft model after i.v. injection of the 99mTc(I) carbonyl complex. Conclusion: Aptamers can be labeled with both 99mTc(I) and 188Re(I) carbonyls in acceptable yields and good purity. Further investigations are ongoing to fully characterize the potential of the compounds for their use as diagnostic and therapeutic agents. Lit: 1. C. Tuerk, L. Gold, Science, 249, 505-510, 1990; 2. H. P. Erickson, M. A. Bourdon, Annu. Rev. Cell Biol., 5, 71-92, 1989; 3. R. Alberto, R. Schibli, A. P. Schubiger, J. Am. Chem. Soc. 121,6076 - 6077, 1999

Diese Arbeit ist Teil unserer Bemühungen, Chelatbildner zur stabilen und unkomplizierten Bindung von Rhenium-188 an biologische interessante Strukturen zu entwickeln. Aufgrund der hohen in vivo Stabilität von [188ReO(DMSA)2]- (1) soll dieses Koordinationssystem zum Design von neuen 188ReO(V) Chelaten, die bezüglich Reoxidation zu Perrhenat und Ligandenaustausch unter allen Bedingungen radiopharmazeutischer Anwendungen stabil sind, ausgenutzt werden. Dieser neuartige Typ tetradentater Liganden wurde durch Überbrückung zweier DMSA-Moleküle mittels einer Alkylentriaminkette dargestellt. Durch Ligandenaustauschreaktionen von NBu4[ReOCl4] in Methanol liefert der stereoisomere Tetrathiolato-S4-Ligand 1 die fünffach koordinierten Oxo-Rhenium(V) Komplexe 2 (exo-cis) und 3 (exo-trans). Ohne Zusatz von Base werden die Verbindungen als Betain, [ReO(S4)], isoliert. Der protonierte Stickstoff der Brücke dient als internes Gegenion. Röntgenstrukturbestimmungen bieder Isomeren zeigen die quadratisch pyramidale Koordinationsgeometrie des ReOS4. Die Orientierung des Metall-oxo core ist exo bezüglich der Carbamidgruppen in beiden Isomeren. Der aktivierte BFC 4 ermöglicht die Kupplung an terminale Aminogruppen von Biomolekülen. Nichtradioaktive Modelladukte mit Tripeptiden wurden mittels Electrospray Massenspektrometrie identifiziert. Die Re-188-Markierungen verlaufen schnell, in guten Ausbeuten und unter milden Bedingungen. Daher bieten diese neuartigen ReOS4-Komplexe einen weiteren Zugang zu stabilen Rhenium-188-Radiotherapeutika.

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Es werden radiolytisch und metabolisch stabile Metallkomplexe vorgeschlagen, die zur Konjugation mit Biomolekülen geeignet sind sowie ein Verfahren zu ihrer Herstellung.

Suicide gene therapy with the herpes simplex virus type-1 thymidine kinase gene (HSV-1 tk) is considered to be a promising approach to the treatment of cancer. Making use of the lower specificity of the viral enzyme compared to human thymidine kinase, the therapy involves the administration of antiviral agents (e.g. ganciclovir) as prodrugs to induce enzymatic cell death in those cells that express the transferred gene. 18F labeled derivatives have been described for monitoring location, duration and magnitude of the viral kinase enzyme activity by positron emission tomography (PET). Since an optimal radiotracer has not been developed, novel substances were synthesized for monitoring gene expression. A group of 13 nucleoside analogues were synthesized, among them N1-methyl-9-[(1,3-dihydroxy-2-propoxy)methyl]guanine 5 and N1-methyl-9-[(4-hydroxy)-3-hydroxy-methylbutyl]guanine 7 as methyl analogues of ganciclovir and penciclovir and their related fluoro compounds (6, 8). Further novel derivatives include N6-methyl-9-[(1,3-dihydroxy-2-propoxy)methyl]-, N6-methyl-9-[(4-hydroxy)-3-hydroxymethylbutyl]adenine (9, 10) as well as the uracil derivatives 5-hydroxy-1-[(1,3-dihydroxy-2-propoxy)methyl]uracil 11, 6-methyl-1-[(1,3-dihydroxy-2-propoxy)-methyl]uracil 12 and its 3-fluoro-derivative 13.

Der Erfindung liegt die Aufgabe zugrunde, diese Nachteile zu überwinden und ein schnelles, reproduzierbares Herstellungsverfahren für chemisch und radiochemisch reine 16a- [18F]Fluorestradiolsulfamate, die wahlweise in 3-oder 17-Stellung monosulfamoyliert bzw. in 3, 17-Stellung disulfamoyliert worden sind, vorzustellen. Die Synthese kann, ausgehend von den 16,17-O-Sulfuryl-16-epiestriolderivaten, ohne Zwischenisolierung der intermediär anfallenden 16a-[18F]Fluorestradiolderivate in eigens für die Markierung vorgesehenen käuflichen Modulen mittels computergestützter Programme durchgeführt werden. Dadurch wird die Kontaminierungsgefahr mit radioaktivem Material auf ein Mindestmaß reduziert.