Combination of paclitaxel and nitric oxide as a novel treatment for the reduction of restenosis.

The combination of a nitric oxide (NO) donor and a paclitaxel-NO donor conjugate coated on a vascular stent was tested in a rabbit iliac artery model of stenosis as a potential therapy for restenosis. Paclitaxel was conjugated with a NO donor at the 7-position to give compound 7. An adamantane-based NO donor 14 was synthesized and combined with 7 to provide a burst of NO in the first few critical hours following injury to the vessel wall. Both 7 and 14 demonstrated antiproliferative activity (IC(50) = 20 nM and 15 microM, respectively) and antiplatelet activity (IC(50) = 10 and 1 microM, respectively). Stents were coated with a layer of a polymer containing test compounds. The total amount of NO eluted from the stents after a 6 h implantation in the rabbit iliac artery was 35%, 95%, and 69% of the original content for the stents coated with 7, 14, and the combination of 7 and 14, respectively. The antistenotic activity of 7 and 14 was determined in a 28-day rabbit model with two control groups (uncoated stents and polymer-coated stents) and two study groups (paclitaxel-coated stents and stents coated with the combination of 7 and 14). Polymer-coated stents caused inflammation and increased stenosis by 39% when compared to the uncoated stents. The stents coated with 7 plus 14 were as good as the uncoated stents, 41% better than the polymer-coated stents and 34% better than the paclitaxel-coated stents. These data indicate a beneficial effect of adding NO to an antiproliferative agent (paclitaxel) and suggest a potential therapeutic combination for the treatment of stenotic vessel disease.

Inactivation of protozoan parasites in red blood cells using INACTINE PEN110 chemistry.

BACKGROUND: The transmission of parasites, including Babesia, plasmodia, and Trypanosoma cruzi, via transfusions is an important public health concern. INACTINE technology is a pathogen-reduction process that utilizes PEN110, an electrophilic agent that inac-tivates a wide range of pathogens by disrupting nucleic acid replication. The present study investigated the effect of PEN110 treatment on the viability of protozoa in RBCs. STUDY DESIGN AND METHODS: B. microti-parasitized RBCs from infected hamsters were treated with PEN110 and inoculated to naïve animals. Parasitemia was detected by blood smears and PCR. Human RBCs infected with P. falciparum were treated with PEN110 and incubated with fresh RBCs. P. falciparum multiplication was detected by blood smears. Human RBCs spiked with T. cruzi and treated with PEN110 were analyzed for the presence of live parasites using in-vitro infectivity assay or by inoculating susceptible mice. RESULTS: Treatment of RBCs infected with B. microti or P. falciparum with 0.01 to 0.1 percent (vol/vol) PEN110 resulted in parasite inactivation to below the limit of detection during 24 hours. T. cruzi inoculated into human RBCs was inactivated below the limit of detection by 0.1 percent PEN110 after 3 hours. CONCLUSION: The study demonstrates that treatment of blood with PEN110 is highly effective in eradicating transfusion-transmitted protozoan parasites.

West Nile virus in blood: stability, distribution, and susceptibility to PEN110 inactivation.

BACKGROUND: The outbreak of West Nile virus (WNV) is the most recent reminder that the blood supply continues to be vulnerable to emerging and reemerging pathogens. A potentially prospective approach to reducing the risk of transfusion-transmitted infections of a known or newly emerging microbe is implementation of a broad-spectrum pathogen reduction technology. The purpose of this study was to evaluate the susceptibility of WNV to PEN110 inactivation in RBCs and to characterize the WNV interaction with blood, including the stability of WNV in RBCs stored at 1 to 6 degrees C, its distribution and infectivity, and its ability to infect WBCs. STUDY DESIGN AND METHODS: Inactivation was performed with three WNV isolates spiked into WBC-reduced RBCs. The stability of the virus was evaluated by spiking two viral loads into RBCs followed by storing at 1 to 6 degrees C for up to 42 days. The distribution of the virus in plasma, RBCs, and PBMCs was evaluated with whole blood from infected hamsters. Finally, in vitro propagation of WNV was evaluated with the THP-1 cell line and primary monocytes. RESULTS: The kinetics of PEN110 inactivation of WNV isolates RI-44, NJ-176, and 99-3494031 were fast and complete within 24 hours with reduction factors of 5 to 7 log plaque-forming units per mL. WNV remained infectious for up to 42 days at 1 to 6 degrees C. The WNV titers in whole blood, plasma, RBCs, and PBMC fractions were equally distributed and ranged from 2 to 3 log tissue culture infectious dose 50 percent per mL. Productive infection of stimulated monocytes and THP-1 cells was also demonstrated. CONCLUSIONS: These studies demonstrated that PEN110 efficiently inactivated WNV in RBCs and whole blood from infected hamsters to the limit of detection. WNV survived in RBCs stored at 1 to 6 degrees C with a gradual loss of titer but infectivity could still be observed for up to 42 days. In addition, it was observed that WNV was equally distributed in all blood fractions including PBMCs and it was possible to establish productive infection of a human monocytic cell line and stimulated human monocytes.

Prevention of Yersinia enterocolitica, Pseudomonas fluorescens, and Pseudomonas putida outgrowth in deliberately inoculated blood by a novel pathogen-reduction process.

BACKGROUND: Yersinia enterocolitica, Pseudomonas fluorescens, and P. putida are responsible for a significant amount of the bacterial sepsis cases attributed to RBC transfusions. INACTINE is a pathogen-reduction process for RBCs, which consists of incubation of RBCs with PEN110 (proprietary compound) followed by automated washing of the RBCs. INACTINE is an electrophilic agent, which inactivates a wide range of viruses and WBCs by disruption of nucleic acid replication. The present study investigated the effect of the PEN110 process on Y. enterocolitica, P. fluorescens, and P. putida. STUDY DESIGN AND METHODS: Identical units of reduced CPD/ADSOL additive solution (AS-1) or CP2D/Nutricel additive solution (AS-3) RBCs were inoculated with 10 to 100 CFU per mL of either Y. enterocolitica, P. fluorescens, or P. putida. The control units were put on storage immediately after the bacterial spike. The test units were subjected to the PEN110 process and then stored. Sham control units were processed the same way as test units without addition of PEN110. Bacterial titer in all units was monitored during the 6-week storage period. RESULTS: No bacteria were detected in any of the RBC units (n = 9 for each microorganism) prepared using the PEN110 process throughout 6 weeks of storage. Substantial bacterial growth occurred in all control and in a majority of sham control units (11 out of 15 experiments). The bacterial inactivation by the INACTINE process was found to be equally effective in CPD/AS-1 and CP2D/AS-3 RBC units. CONCLUSION: The INACTINE process effectively prevented the outgrowth of Y. enterocolitica, P. fluorescens, and P. putida deliberately inoculated into WBC-reduced CPD/AS-1 and CP2D/AS-3 RBCs. The results demonstrated the crucial bactericidal role of PEN110 in the INACTINE process.