Journal Article

Xen10, Xen 10, Streptococcus pneumoniae Xen10, IVIS, Animals; Bacterial Adhesion; Bacterial Processes; Bacterial Proteins/*physiology; *Carrier State; Colony Count, Microbial; Female; Host-Pathogen Interactions; Lung/microbiology; Meningitis, Pneumococcal/microbiology; Mice; Models, Animal; Mutation; Nasopharynx/*microbiology; Pneumonia, Pneumococcal/complications; Sepsis/*microbiology; Streptococcus pneumoniae/*pathogenicity; Virulence Factors/physiology

Summary The pneumococcal cell surface protein PavA is a virulence factor associated with adherence and invasion in vitro. In this study we show in vivo that PavA is necessary for Streptococcus pneumoniae D39 colonization of the murine upper respiratory tract in a long-term carriage model, with PavA-deficient pneumococci being quickly cleared from nasopharyngeal tissue. In a pneumonia model, pavA mutants were not cleared from the lungs of infected mice and persisted to cause chronic infection, whereas wild-type pneumococci caused systemic infection. Hence, under the experimental conditions, PavA-deficient pneumococci appeared to be unable to seed from lung tissue into blood, although they survived in blood when administered intravenously. In a meningitis model of infection, levels of PavA-deficient pneumococci in blood and brain following intercisternal injection were significantly lower than wild type. Taken collectively these results suggest that PavA is involved in successful colonization of mucosal surfaces and in translocation of pneumococci across host barriers. Pneumococcal sepsis is a major cause of mortality worldwide so identification of factors such as PavA that are necessary for carriage and for translocation from tissue to blood is of clinical and therapeutic importance.

Journal Article

VivoTag, IVIS, Vivotag, Animals; BRCA1 Protein/*genetics; Drug Carriers; Drug Delivery Systems; Female; Humans; Mice; Nanoparticles/*chemistry; Nanotechnology/methods; Neoplasm Transplantation; Ovarian Neoplasms/*genetics/*therapy; Poly(ADP-ribose) Polymerases/*genetics; RNA Interference; RNA, Small Interfering/*metabolism; Treatment Outcome

Inhibition of the DNA repair enzyme poly(ADP-ribose) polymerase 1 (PARP1) with small molecules has been shown to be an effective treatment for ovarian cancer with BRCA mutations. Here, we report the in vivo administration of siRNA to Parp1 in mouse models of ovarian cancer. A unique member of the lipid-like materials known as lipidoids is shown to deliver siRNA to disseminated murine ovarian carcinoma allograft tumors following intraperitoneal (i.p.) injection. siParp1 inhibits cell growth, primarily by induction of apoptosis, in Brca1-deficient cells both in vitro and in vivo. Additionally, the treatment extends the survival of mice bearing tumors derived from Brca1-deficient ovarian cancer cells but not from Brca1 wild-type cells, confirming the proposed mechanism of synthetic lethality. Because there are 17 members of the Parp family, the inherent complementarity of RNA affords a high level of specificity for therapeutically addressing Parp1 in the context of impaired homologous recombination.

Journal Article

VivoTag, IVIS, Vivotag

Biomarkers are becoming increasingly important in the clinical management of complex diseases, yet our ability to discover new biomarkers remains limited by our dependence on endogenous molecules. Here we describe the development of exogenously administered 'synthetic biomarkers' composed of mass-encoded peptides conjugated to nanoparticles that leverage intrinsic features of human disease and physiology for noninvasive urinary monitoring. These protease-sensitive agents perform three functions in vivo: they target sites of disease, sample dysregulated protease activities and emit mass-encoded reporters into host urine for multiplexed detection by mass spectrometry. Using mouse models of liver fibrosis and cancer, we show that these agents can noninvasively monitor liver fibrosis and resolution without the need for invasive core biopsies and substantially improve early detection of cancer compared with current clinically used blood biomarkers. This approach of engineering synthetic biomarkers for multiplexed urinary monitoring should be broadly amenable to additional pathophysiological processes and point-of-care diagnostics.

Journal Article

valves; stenosis; inflammation; atherosclerosis; hypercholesterolemia; imaging; ProSense; OsteoSense

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Journal Article

U-87 MG-luc2, U-87-MG-luc2, Glioma, Bioware, IVIS, Animals; Brachytherapy/*methods; Brain Neoplasms/pathology/*radiotherapy; Convection; Glioblastoma/pathology/*radiotherapy; Glioma/pathology/*radiotherapy; Liposomes; Nanoparticles/therapeutic use; Radioisotopes/*therapeutic use; Rats; Rhenium/*therapeutic use; Tumor Burden; Xenograft Model Antitumor Assays

Although external beam radiation is an essential component to the current standard treatment of primary brain tumors, its application is limited by toxicity at doses more than 80 Gy. Recent studies have suggested that brachytherapy with liposomally encapsulated radionuclides may be of benefit, and we have reported methods to markedly increase the specific activity of rhenium-186 ((186)Re)-liposomes. To better characterize the potential delivery, toxicity, and efficacy of the highly specific activity of (186)Re-liposomes, we evaluated their intracranial application by convection-enhanced delivery in an orthotopic U87 glioma rat model. After establishing an optimal volume of 25 microL, we observed focal activity confined to the site of injection over a 96-hour period. Doses of up to 1850 Gy were administered without overt clinical or microscopic evidence of toxicity. Animals treated with (186)Re-liposomes had a median survival of 126 days (95% confidence interval [CI], 78.4-173 days), compared with 49 days (95% CI, 44-53 days) for controls. Log-rank analysis between these 2 groups was highly significant (P = .0013) and was even higher when 100 Gy was used as a cutoff (P < .0001). Noninvasive luciferase imaging as a surrogate for tumor volume showed a statistically significant separation in bioluminescence by 11 days after 100 Gy or less treatment between the experimental group and the control animals (chi(2)[1, N= 19] = 4.8; P = .029). MRI also supported this difference in tumor size. Duplication of tumor volume differences and survival benefit was possible in a more invasive U251 orthotopic model, with clear separation in bioluminescence at 6 days after treatment (chi(2)[1, N= 9] = 4.7; P = .029); median survival in treated animals was not reached at 120 days because lack of mortality, and log-rank analysis of survival was highly significant (P = .0057). Analysis of tumors by histology revealed minimal areas of necrosis and gliosis. These results support the potential efficacy of the highly specific activity of brachytherapy by (186)Re-liposomes convection-enhanced delivery in glioma.