Purpose: This study was designed to evaluate the pharmacologic and biological properties of a paclitaxel-hyaluronan bioconjugate (ONCOFID-P) against IGROV-1and OVCAR-3 human ovarian cancer xenografts following i.p. administration. Experimental Design: In vitro tumor sensitivity to ONCOFID-P was analyzed by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, whereas bioconjugate interaction with cells was studied cytofluorimetrically and by confocal microscopy. In vivo toxicity was assessed by a single-dose maximum-tolerated dose, peripheral blood cell count determination and by histologic analysis. Biodistribution of the compound was evaluated with a small animald edicated scintigraphy gamma camera following injection of 99mTc-labeled ONCOFID-P. Pharmacokinetic analysis was also carried out. Female severe combined immunodeficiency mice implanted with ovarian cancer cells underwent treatment with ONCOFID-P or free paclitaxel starting from day 7 or 14 after tumor injection, and survivals were compared. Results: ONCOFID-P interacted with CD44, entered cells through a receptor-mediated mechanism, and exerted a concentration-dependent inhibitory effect against tumor cell growth. After i.p. administration, the bioconjugate distributed quite uniformly within the peritoneal cavity, was well-tolerated, and was not associated with local histologic toxicity. Pharmacokinetic studies revealed that blood levels of bioconjugate-derived paclitaxel were much higher and persisted longer than those obtained with the unconjugated free drug. Intraperitoneal treatment of tumorbearing mice with the bioconjugate revealed that ONCOFID-P exerted a relevant increase in therapeutic activity compared with free drug. Conclusions: ONCOFID-P significantly improved results obtained with conventional paclitaxel, in terms of in vivo tolerability and therapeutic efficacy; these data strongly support its development for locoregional treatment of ovarian cancer.Ovarian cancer is the most common cause of death from gynecologic malignancy and is the fifth leading cause of cancerrelated death (1). Intravenous administration of taxane-and platinum-based chemotherapy represents the current standard of postoperative care for patients with advanced neoplasia. This therapeutic regimen is also considered for high-risk patients with early stage tumors in an adjuvant setting, to eradicate residual disease following surgical debulking. Despite these approaches having resulted in improved survival over the last decade, nonetheless, relapses still occur in the majority of cases and represent the major problem for patients with advanced disease (2).A potential solution to these obstacles takes into consideration the biological behavior of ovarian cancer, which is mainly confined to the peritoneal cavity for most of its initial natural course. The biology of the tumor offers the possibility of delivering drugs directly within the peritoneum to achieve a theoretical potential for increased exposure of the tumor to the antineoplastic agen...

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Purpose:The purpose is to evaluate the CD44-mediated cellular targeting of HA-But, a hyaluronic acid esterified with butyric acid (But) residues, to hepatocellular carcinoma cell lines in vitro and to hepatic tumor metastases in vivo.Experimental Design: In vitro, the CD44-dependent cytotoxicity in two human hepatocellular carcinoma cell lines (HepB3 and HepG2) with high and low CD44 expression was investigated; in vivo, the effect on liver metastases originating from intrasplenic implants of Lewis lung carcinoma (LL3) or B16-F10 melanoma in mice was compared with the pharmacokinetics of organ and tissue distribution using different routes of administration.Results: HepB3 and HepG2 cell lines showed different expression of CD44 (78 and 18%, respectively), which resulted in a CD44-dependent HA-But inhibitory effect as demonstrated also by the uptake analysis performed using radiolabeled HA-But ( Conclusions: HA-But tends to concentrate in the liver and spleen and appears to be a promising new drug for the treatment of intrahepatic tumor lesions.

The aim of this study was to investigate whether technetium-99m labelled fluconazole can distinguish fungal from bacterial infections. Fluconazole was labelled with (99m)Tc and radiochemical analysis showed less than 5% impurities. The labelling solution was injected into animals with experimental infections. For comparison, we used two peptides for infection detection, i.e. UBI 29-41 and hLF 1-11, and human IgG, all labelled with (99m)Tc. Mice were infected with Candida albicans or injected with heat-killed C. albicans or lipopolysaccharides to induce sterile inflammation. Also, mice were infected with Staphylococcus aureus or Klebsiella pneumoniae. Next, accumulation of (99m)Tc-fluconazole and (99m)Tc-labelled peptides/IgG at affected sites was determined scintigraphically. (99m)Tc-fluconazole detected C. albicans infections (T/NT ratio=3.6+/-0.47) without visualising bacterial infections (T/NT ratio=1.3+/-0.04) or sterile inflammatory processes (heat-killed C. albicans: T/NT ratio=1.3+/-0.2; lipopolysaccharide: T/NT ratio=1.4+/-0.1). C. albicans infections were already seen within the first hour after injection of (99m)Tc-fluconazole (T/NT ratio=3.1+/-0.2). A good correlation (R(2)=0.864; P<0.05) between T/NT ratios for this tracer and the number of viable C. albicans was found. Although (99m)Tc-UBI 29-41 and (99m)Tc-hLF 1-11 were able to distinguish C. albicans infections from sterile inflammatory processes in mice, these (99m)Tc-labelled peptides did not distinguish these fungal infections from bacterial infections. It is concluded that (99m)Tc-fluconazole distinguishes infections with C. albicans from bacterial infections and sterile inflammations.

The transmetallation reaction between zinc dithiocarbamates and rhenium carbonyls has been used as a new strategy to link biomolecules to transition metals.The zinc(II) dithiocarbamate of isonipecotic acid (1) and the succinimidyl ester derivative (2) were prepared by straight forward procedures and were fully characterized by spectroscopic and X-ray diffraction methods, showing in both cases the presence of dinuclear complexes. Complex 2 reacted with all the primary and secondary amines studied (glycine methyl ester, β-alanine methyl ester, 1-(2-methoxyphenyl)piperazine and D-(+)-glucosamine) through the activated succinimidyl ester group, linking the metallic fragment with the biomolecule by the formation of a peptidic bond, and leading to the respective bioconjugated zinc complexes 3-6. In all cases, these zinc complexes could be isolated from the reaction medium by simple precipitation.These results evidence the potential of complex 2 to be used as a synthon to link the zinc dithiocarbamate fragment to biomolecules that contain an amine group. Complexes 3-6 were characterized by the usual spectroscopic methods and all data agree with the proposed structures, which do not contain significant interactions between the zinc fragment and the functional groups of these biomolecules.The transmetallation reaction between the zinc complexes 3-6 and the rhenium carbonyl [ReBr 3 (CO) 3 ] 2-led to the expected rhenium dithiocarbamates 7-10 with no change in the organic dithiocarbamate fragments, confirming the viability of this reaction as a tool for linking biomolecules to transition elements. All complexes were characterized by spectroscopic methods and the crystal structure of 8 was studied by Xray diffraction analysis. All data demonstrated that the biomolecule is positioned far away from the fac-{Re(CO) 3 } fragment and the octahedral coordination around the metal is completed by the functionalized dithiocarbamate and a phosphine ligand.3 Finally, the analysis by ESI-MS spectrometry of the reaction between the zinc complex 4 and a water solution of [Re(H 2 O) 3 (CO) 3 ] + at a very low concentration (10 ppm) showed that the transmetallation reaction took place even though the solubility of the zinc complex in water medium was as low as 0.66 ppm. This preliminary result supports the viability of this approach for the preparation of rhenium and technetium target specific radiopharmaceuticals since the preparation of these compounds are always performed in water medium.