Penetration of Enrofloxacin in Aqueous Humour of Avian Eyes.

Enrofloxacin has been shown to be appropriate to treat bacterial eye infections in mammals. However, the anatomy and physiology of the avian eye substantially differ from those in mammals, and pharmacokinetic data substantiating the clinical efficacy of enrofloxacin in birds are still lacking. In total, 40 chickens (Gallus gallus, Lohman Selected Leghorn) received single intramuscular administration of enrofloxacin at a dosage of 25 mg/kg body weight (BW). Serial blood and aqueous humour samples were taken at 12 different time points after administration (0-60 min and 2-32 h) and were analysed for their fluoroquinolone concentrations using a competitive enzyme immunoassay. The metabolization of enrofloxacin to ciprofloxacin was determined using liquid chromatography-mass spectrometry. The maximum serum concentrations of fluoroquinolones were observed at the time point of 2.82 ± 0.1 h and amounted to 10.67 ± 0.5 µg/mL. Fluoroquinolones redistributed to a minor extent into the aqueous humour reaching maximum concentrations of 4.52 ± 1.2 µg/mL after 7.54 ± 1.0 h of drug administration. The mean residence time (MRT), volume of distribution (Vd), and terminal half-life (t1/2 ß) were 1.68-, 2.84-, and 2.01-fold higher in aqueous humour than in serum, indicating that fluoroquinolones were trapped in aqueous humour. Enrofloxacin was only marginally metabolized into ciprofloxacin. A single intramuscular injection of a therapeutical dose of enrofloxacin (25 mg/kg BW) thus generated sustained and therapeutically active levels of enrofloxacin in the aqueous humour of chicken eyes.

Mapping of drug distribution in the rabbit liver tumor model by complementary fluorescence and mass spectrometry imaging.

This study describes the use of fluorescence imaging and mass spectrometry imaging, for imaging the anti-angiogenic drug sunitinib, used to treat liver cancer. These techniques allowed for the assessment of local delivery of the unlabeled therapeutic drug. More specifically, the spatial distribution of the drug and its metabolites after local administration was investigated, and drug levels in tumor and liver tissue over time were quantified. For this purpose, sunitinib-eluting microspheres were locoregionally injected into the tumor feeding arteries of rabbits bearing liver tumors. In adjacent areas of tumor and non-targeted contralateral liver tissue, sunitinib distribution was mapped around beads in occluded vessels 7, 12, 13 and 14days after embolization by means of the two imaging methods. Presence of sunitinib metabolites was assessed by mass spectrometry imaging. Sunitinib was found around microspheres in the tumor at day 7, 12, and 13. The drug was retained by the necrotic tumor tissue, resulting in homogeneously distributed and high levels of up to 40µg/g tissue in a 1.5mm radius around the beads. The drug was almost completely eliminated from the contralateral liver tissue. Several of the drug's metabolites, including its primary active metabolite SU12662, were detected in the tumor tissue over 13days. Sunitinib diffused from the beads and was retained at high, therapeutic levels during 13days. This was confirmed independently by complementary fluorescence and mass spectrometry imaging, which served as tools to confirm effective drug delivery after hepatic transarterial administration in situ. Compound: Sunitinib: PubChem CID 5329102.

Drug-eluting embolic microspheres for local drug delivery - State of the art.

Embolic microspheres or beads used in transarterial chemoembolization are an established treatment method for hepatocellular carcinoma patients. The occlusion of the tumor-feeding vessels by intra-arterial injection of the beads results in tumor necrosis and shrinkage. In this short review, we describe the utility of using these beads as devices for local drug delivery. We review the latest advances in the development of non-biodegradable and biodegradable drug-eluting beads for transarterial chemoembolization. Their capability to load different drugs, such as chemotherapeutics and anti-angiogenic compounds with different physicochemical properties, like charge and hydrophilicity/hydrophobicity, are discussed. We specifically address controlled and sustained drug release from the microspheres, and the resulting in vivo pharmacokinetics in the plasma vs. drug distribution in the targeted tissue.

Antitumoral Effect of Sunitinib-eluting Beads in the Rabbit VX2 Tumor Model.

Purpose To measure plasmatic sunitinib concentration (PSC) and intratumoral sunitinib concentration (ITSC) after transcatheter arterial chemoembolization (TACE) with two different sizes of sunitinib-eluting beads (SEBs) in rabbits with VX2 hepatic allografts and to investigate treatment effects on vascular endothelial growth factor receptor type 2 (VEGFR2) phosphorylation, tumor volume, and histopathologic changes. Materials and Methods The protocol was approved by the French Ethics Committee for Animal Experiments (Comité d'Ethique en Expérimentation Animale du Centre INRA de Jouy-en-Josas et AgroParisTech, or COMETHEA, approval no. 11/028). Two experiments were performed. In the first, seven animals received 0.05 mL of 100-300-µm SEBs (1.5 mg of sunitinib) in the hepatic artery, and six animals received saline injections. In the second, eight animals received 0.05 mL of 70-150-µm SEBs (1.5 mg of sunitinib), seven received 0.05 mL of 70-150-µm unloaded beads, and seven received oral sunitinib (6 mg every day). Tumor size was monitored with ultrasonography. PSC, ITSC, and phosphorylation of VEGFR2 were assessed on days 1 and 14. After the animals were sacrificed, histopathologic analysis was performed. The Kruskal-Wallis test, Mann-Whitney U test, and Fisher exact test were used to look for statistically significant differences between groups. Results Maximum PSC after TACE with 100-300-µm SEBs was 0.002 µg/mL on day 1. ITSC was 17.8 µg/g on day 1 and 0.16 µg/g on day 14. After TACE with 70-150-µm SEBs, ITSC was 40.4 µg/g on day 1 and 27.4 µg/g on day 14. Phosphorylation of VEGFR2 was inhibited until day 14 after TACE with both sizes of SEBs. The size of VX2 tumors treated with 70-150-µm SEB TACE increased less (-2%) than that of tumors treated with unloaded beads (+42%) and oral sunitinib (6 mg every day; +1853%; P = .044). Conclusion SEB TACE resulted in minimal PSC, high ITSC, and sustained VEGFR2 phosphorylation inhibition until day 14. (©) RSNA, 2016.

Sunitinib-eluting beads for chemoembolization: methods for in vitro evaluation of drug release.

Drug-eluting microspheres are used for embolization of hypervascular tumors and allow for local controlled drug release. Although the drug release from the microspheres relies on fast ion-exchange, so far only slow-releasing in vitro dissolution methods have been correlated to in vivo data. Three in vitro release methods are assessed in this study for their potential to predict slow in vivo release of sunitinib from chemoembolization spheres to the plasma, and fast local in vivo release obtained in an earlier study in rabbits. Release in an orbital shaker was slow (t50%=4.5h, 84% release) compared to fast release in USP 4 flow-through implant cells (t50%=1h, 100% release). Sunitinib release in saline from microspheres enclosed in dialysis inserts was prolonged and incomplete (t50%=9 days, 68% release) due to low drug diffusion through the dialysis membrane. The slow-release profile fitted best to low sunitinib plasma AUC following injection of sunitinib-eluting spheres. Although limited by lack of standardization, release in the orbital shaker fitted best to local in vivo sunitinib concentrations. Drug release in USP flow-through implant cells was too fast to correlate with local concentrations, although this method is preferred to discriminate between different sphere types.

Drug-eluting beads loaded with antiangiogenic agents for chemoembolization: in vitro sunitinib loading and release and in vivo pharmacokinetics in an animal model.

PURPOSE: The combination of embolic beads with a multitargeted tyrosine kinase inhibitor that inhibits tumor vessel growth is suggested as an alternative and improvement to the current standard doxorubicin-eluting beads for use in transarterial chemoembolization. This study demonstrates the in vitro loading and release kinetics of sunitinib using commercially available embolization microspheres and evaluates the in vitro biologic efficacy on cell cultures and the resulting in vivo pharmacokinetics profiles in an animal model. MATERIALS AND METHODS: DC Bead microspheres, 70-150 µm and 100-300 µm (Biocompatibles Ltd., Farnham, United Kingdom), were loaded by immersion in sunitinib solution. Drug release was measured in saline in a USP-approved flow-through apparatus and quantified by spectrophotometry. Activity after release was confirmed in cell culture. For pharmacokinetics and in vivo toxicity evaluation, New Zealand white rabbits received sunitinib either by intraarterial injection of 100-300 µm sized beads or per os. Plasma and liver tissue drug concentrations were assessed by liquid chromatography-tandem mass spectroscopy. RESULTS: Sunitinib loading on beads was close to complete and homogeneous. A total release of 80% in saline was measured, with similar fast-release profiles for both sphere sizes. After embolization, drug plasma levels remained below the therapeutic threshold (< 50 ng/mL), but high concentrations at 6 hours (14.9 µg/g) and 24 hours (3.4 µg/g) were found in the liver tissue. CONCLUSIONS: DC Bead microspheres of two sizes were efficiently loaded with sunitinib and displayed a fast and almost complete release in saline. High liver drug concentrations and low systemic levels indicated the potential of sunitinib-eluting beads for use in embolization.

High Frequency of Aneuploidy Defines Ulcerative Colitis-Associated Carcinomas: A Prognostic Comparison to Sporadic Colorectal Carcinomas.

OBJECTIVE: Aneuploidy is an independent risk factor for forthcoming carcinogenesis in ulcerative colitis (UC). An inferior prognosis of patients with ulcerative colitis-associated colorectal cancer (UCC) compared with those with sporadic colorectal cancer (SCC) has been reported, but remains controversial. This prompted us to investigate if aneuploidy can be observed in UCCs as frequently as in their sporadic counterpart and if aneuploidy per se might be a driving feature of poor prognosis in UCC. BACKGROUND DATA: We obtained clinical follow-up for 257 SCC patients (average observation time 57 months) and 31 UCC patients (51 months). Touch preparation slides or tissue sections were prepared of all 288 carcinomas for ploidy analysis. METHODS: Ploidy status was assessed for 260 SCCs and 31 UCCs by image cytometry and correlated to clinical features. Survival data were analyzed using Kaplan-Meier estimates. RESULTS: Aneuploidy was detected in 74.6% of SCCs and in all 31 UCCs. Logistic regression analysis yielded age (odds ratio [OR], 1.05; 95% CI, 1.02-1.09; P = 0.003) and aneuploidy (OR, 4.07; 95% CI, 1.46-11.36; P = 0.007) as independent prognostic factors for R0-resected patients devoid of metastases. Diploid SCCs had a more favorable 5-year survival (88.2%) than aneuploid SCCs (69.0%) and UCCs (73.1%) (P = 0.074). CONCLUSIONS: UC-associated carcinomas presented aneuploidy at significantly higher frequency than sporadic colorectal carcinomas (P < 0.0006). UCCs and aneuploid SCCs share a similar prognosis inferior to that of diploid SCCs. Aneuploidy proved to be the strongest independent prognostic marker for R0-resected colorectal cancer patients overall.