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      1. Author :
        Aguilera, T. A.; Olson, E. S.; Timmers, M. M.; Jiang, T.; Tsien, R. Y.
      2. Title :
        Systemic in vivo distribution of activatable cell penetrating peptides is superior to that of cell penetrating peptides
      3. Type :
        Journal Article
      4. Year :
        2009
      5. Publication :
        Integrative Biology
      6. Products :
      7. Volume :
        1
      8. Issue :
        N/A
      9. Page Numbers :
        371
      10. Research Area :
        N/A
      11. Keywords :
        Animals, Antimicrobial Cationic Peptides/ chemistry/ pharmacokinetics, Cell Line, Tumor, Drug Delivery Systems/ methods, Humans, Metabolic Clearance Rate, Mice, Neoplasms/ metabolism, Organ Specificity, Tissue Distribution
      12. Abstract :
        Cell penetrating peptides (CPPs) have been developed as vehicles for payload delivery into cells in culture and in animals. However several biologic features limit their usefulness in living animals. Activatable cell penetrating peptides (ACPPs) are polycationic CPPs whose adsorption and cellular uptake are minimized by a covalently attached polyanionic inhibitory domain. Cleavage of the linker connecting the polyanionic and polycationic domains by specific proteases (tumor associated matrix metalloproteases discussed herein) dissociates the polyanion and enables the cleaved ACPP to enter cells. In contrast to their CPP counterpart, ACPPs are relatively nonadherent and distributed uniformly to normal tissues. While nonaarginine (r(9)) CPP administered intravenously into mice initially bind to the local vasculature and redistribute to the liver, where >90% of the injected dose accumulates 30 min after injection. Regardless of the presence of the polyanionic inhibitory domain, confocal imaging of live tissues reveals that the majority of the ACPP and CPP remain in punctate organelles, presumably endosomes. Therefore further improvements in the efficiency of delivery to the cytosol and nucleus are necessary. In addition to improved target specificity, a major advantage of ACPPs over CPPs for potential clinical applications is reduced toxicity. Systemically administered r(9) CPP causes acute toxicity in mice at a dose 4-fold lower than the MMP cleavable ACPP, a complication not observed with an uncleavable ACPP presumably because the polycationic charge remains masked systemically. These data suggest that ACPPs have greater potential than CPPs for systemic delivery of imaging and therapeutic agents.
      13. URL :
        N/A
      14. Call Number :
        135754
      15. Serial :
        8411
      1. Author :
        Hama, Y.; Urano, Y.; Koyama, Y.; Choyke, P. L.; Kobayashi, H.
      2. Title :
        Targeted optical imaging of cancer cells using lectin-binding BODIPY conjugated avidin
      3. Type :
        Journal Article
      4. Year :
        2006
      5. Publication :
        Biochemical and Biophysical Research Communications
      6. Products :
      7. Volume :
        348
      8. Issue :
        N/A
      9. Page Numbers :
        807
      10. Research Area :
        N/A
      11. Keywords :
        Animals, Avidin/metabolism, Boron Compounds/metabolism, Cell Line, Tumor, Female, Flow Cytometry, Fluorescent Dyes/metabolism, HT29 Cells, Humans, Lectins/ metabolism, Male, Mice, Mice, Nude, Microscopy, Fluorescence, Peritoneal Neoplasms/metabolism/ pathology, Staining and Labeling
      12. Abstract :
        Lectins (asialo-receptor family) are expressed on a number of tumors that develop peritoneal metastases. To demonstrate that fluorescence imaging based on lectin binding is applicable for a variety of tumors, we conjugated BODIPY to avidin (avidin-BODIPY), and studied the efficacy of tumor targeting in 9 cancer cell lines in vitro and an ovarian cancer cell line in vivo using a murine peritoneal cancer model. All 9 cell lines showed specific intracellular accumulation with avidin-BODIPY on fluorescence microscopy and flow cytometry. In vivo spectral molecular imaging clearly visualized the peritoneal tumor foci with avidin-BODIPY, whereas, deglycosylated avidin-BODIPY (neutravidin-BODIPY) showed only minimal fluorescence from the tumor foci and was accompanied by higher background signals. These results suggest the lectin-targeted molecular imaging technique using a targeted green fluorescence probe is potentially useful in a wide variety of cancers with a proclivity for dissemination in the peritoneal space.
      13. URL :
        N/A
      14. Call Number :
        138361
      15. Serial :
        8414
      1. Author :
        Bouchard, M. B.; MacLaurin, S. A.; Dwyer, P. J.; Mansfield, J.; Levenson, R.; Krucker, T.
      2. Title :
        Technical considerations in longitudinal multispectral small animal molecular imaging
      3. Type :
        Journal Article
      4. Year :
        2007
      5. Publication :
        Journal of Biomedical Optics
      6. Products :
      7. Volume :
        12
      8. Issue :
        N/A
      9. Page Numbers :
        51601
      10. Research Area :
        N/A
      11. Keywords :
        Animals, Artifacts, Image Enhancement/ methods, Image Interpretation, Computer-Assisted/ methods, Male, Mice, Mice, Inbred C57BL, Mice, Nude, Microscopy, Fluorescence, Multiphoton/ methods, Technology Assessment, Biomedical, Whole Body Imaging/ methods
      12. Abstract :
        In a previous study, we investigated physical methods to reduce whole-body, diet-related autofluorescence interference in several mouse strains through changes in animal diet. Measurements of mice with an in vivo multispectral imaging system over a 21-day period allowed for the quantification of concentration changes in multiple in vivo fluorophores. To be an effective instrument, a multispectral imaging system requires a priori spectral knowledge, the form and importance of which is not necessarily intuitive, particularly when noninvasive in vivo longitudinal imaging studies are performed. Using an optimized spectral library from a previous autofluorescence-reduction study as a model, we investigated two additional spectral definition techniques to illustrate the results of poor spectral definition in a longitudinal fluorescence imaging study. Here we systematically evaluate these results and show how poor spectral definition can lead to physiologically irrelevant results. This study concludes that the proper selection of robust spectra corresponding to each specific fluorescent molecular label of interest is of integral importance to enable effective use of multispectral imaging techniques in longitudinal fluorescence studies.
      13. URL :
        N/A
      14. Call Number :
        136360
      15. Serial :
        8416
      1. Author :
        Ogawa, M.; Kosaka, N.; Choyke, P. L.; Kobayashi, H.
      2. Title :
        Tumor-specific detection of an optically targeted antibody combined with a quencher-conjugated neutravidin “quencher-chaser”: a dual “quench and chase” strategy to improve target to nontarget ratios for molecular imaging of cancer
      3. Type :
        Journal Article
      4. Year :
        2009
      5. Publication :
        Bioconjugate Chemistry
      6. Products :
      7. Volume :
        20
      8. Issue :
        N/A
      9. Page Numbers :
        147
      10. Research Area :
        N/A
      11. Keywords :
        Animals, Antibodies, Monoclonal/ administration & dosage, Avidin, Biotin, Diagnostic Imaging/ methods, Fluorescence Resonance Energy Transfer, Humans, Mice, Neoplasm Transplantation, Neoplasms/ diagnosis, Receptor, erbB-2/ metabolism, Streptavidin
      12. Abstract :
        In vivo molecular cancer imaging with monoclonal antibodies has great potential not only for cancer detection, but also for cancer characterization. However, the prolonged retention of intravenously injected antibody in the blood causes low target tumor-to-background ratio (TBR). Avidin has been used as a “chase” to clear the unbound, circulating biotinylated antibody and decrease the background signal. Here, we utilize a combined approach of a fluorescence resonance energy transfer (FRET) quenched antibody with an “avidin chase” to increase TBR. Trastuzumab, a humanized monoclonal antibody against human epidermal growth factor receptor type 2 (HER2), was biotinylated and conjugated with the near-infrared (NIR) fluorophore Alexa680 to synthesize Tra-Alexa680-biotin. Next, the FRET quencher, QSY-21, was conjugated to avidin, neutravidin (nAv), or streptavidin (sAv), thus creating Av-QSY21, nAv-QSY21, or sAv-QSY21 as “chasers”. The fluorescence was quenched in vitro by binding Tra-Alexa680-biotin to Av-QSY21, nAv-QSY21, or sAv-QSY21. To evaluate if the injection of quencher-conjugated avidin derivatives can improve target TBR by using a dual “quench and chase” strategy, both target (3T3/HER2+) and nontarget (Balb3T3/ZsGreen) tumor-bearing mice were employed. The “FRET quench” effect induced by all the QSY21 avidin-based conjugates reduced but did not totally eliminate background signal from the blood pool. The addition of nAv-QSY21 administration increased target TBR mainly because of the “chase” effect where unbound conjugated antibody was preferentially cleared to the liver. The relatively slow clearance of unbound nAv-QSY21 leads to further reductions in background signal by leaking out of the vascular space and binding to unbound antibodies in the extravascular space of tumors, resulting in decreased nontarget tumor-to-background ratios but increased target TBR due to the “FRET quench” effect, because target-bound antibodies were internalized and could not bind to nAv-QSY21. In conclusion, the proposed “quench-and-chase” system combines two strategies, fluorescent quenching and avidin chasing, to improve target TBR and reduce nontarget TBR, which should result in both improved tumor sensitivity and improved specificity.
      13. URL :
        N/A
      14. Call Number :
        141763
      15. Serial :
        8420
      1. Author :
        Hama, Y.; Koyama, Y.; Choyke, P. L.; Kobayashi, H.
      2. Title :
        Two-color in vivo dynamic contrast-enhanced pharmacokinetic imaging
      3. Type :
        Journal Article
      4. Year :
        2007
      5. Publication :
        Journal of Biomedical Optics
      6. Products :
      7. Volume :
        12
      8. Issue :
        N/A
      9. Page Numbers :
        34016
      10. Research Area :
        N/A
      11. Keywords :
        Animals, Contrast Media, Fluorescent Dyes, Galactosamine/ pharmacokinetics, Image Enhancement/methods, Liver/cytology/ metabolism, Metabolic Clearance Rate, Mice, Mice, Nude, Microscopy, Fluorescence/ methods, Microscopy, Fluorescence, Multiphoton/ methods, Pharmacokinetics, Serum Albumin, Bovine/ pharmacokinetics, Tissue Distribution, Whole Body Imaging/ methods
      12. Abstract :
        Optical imaging is unique among in vivo imaging methods because it is possible to simultaneously resolve two or more probes emitting at different wavelengths of light. We employed two near-infrared (NIR) fluorescent optical probes, each labeled with a different protein, to simultaneously evaluate the pharmacokinetics of each probe. Dynamic optical imaging was performed in live mice after the coinjection of bovine serum albumin (BSA) and galactosamine-conjugated bovine serum albumin (GmSA) labeled with either Cy5.5 or Cy7 NIR dyes. The pharmacokinetics of BSA and GmSA were independently and simultaneously visualized. Next, two-color dynamic imaging of biotinylated BSA (b-BSA) and BSA labeled with Cy5.5 or Cy7 was performed before and after an avidin “chase.” Following avidin injection, fluorescently labeled b-BSA rapidly accumulated in the liver, while minimal liver uptake of BSA was noted. Thus, multicolor dynamic contrast-enhanced optical imaging can be performed to noninvasively track the pharmacokinetics of different proteins. This imaging technique can be applied to a wide variety of optically labeled proteins in order to simultaneously track their biodistribution.
      13. URL :
        N/A
      14. Call Number :
        138349
      15. Serial :
        8421
      1. Author :
        Hama, Y.; Koyama, Y.; Urano, Y.; Choyke, P. L.; Kobayashi, H.
      2. Title :
        Two-color lymphatic mapping using Ig-conjugated near infrared optical probes
      3. Type :
        Journal Article
      4. Year :
        2007
      5. Publication :
        Journal of Investigative Dermatology
      6. Products :
      7. Volume :
        127
      8. Issue :
        N/A
      9. Page Numbers :
        2351
      10. Research Area :
        N/A
      11. Keywords :
        Animals, Biocompatible Materials, Color, Diagnostic Imaging/methods, Fluorescent Dyes, Immunoglobulin G/ diagnostic use, Infrared Rays/ diagnostic use, Lymph Nodes/pathology, Lymphatic System/ pathology, Lymphedema/diagnosis/etiology/pathology, Lymphography/adverse effects/ methods, Mice, Mice, Nude, Models, Animal, Risk Factors, Sentinel Lymph Node Biopsy/methods
      12. Abstract :
        To map the drainage patterns of the lymphatic system, multicolor optical probes must be developed, which can be interstitially administered. These agents must be of sufficient size to be retained by the lymphatic system and permit the conjugation or incorporation of fluorescent probes with varying emission wavelengths. Quantum dots fulfill these criteria, but their potential toxicity limits their application to research settings. Here, we describe the synthesis of lymphatic optical probes based on Igs conjugated with Cy5.5 and Cy7 and demonstrate in animal models that these agents can map the lymphatic drainage patterns within axillary nodes draining both the breast and upper extremity, cervical nodes draining both the ear and upper extremity, and sentinel lymph nodes draining different anatomic locations. The ability to separately and simultaneously visualize the drainage patterns from two separate lymphatic vessels may have implications for the preoperative mapping of lymph nodes before lymph node resection. The biocompatibility of fluorescently labeled Igs in comparison to other nanoparticulate fluorophores improves the chances of clinical translation. This noninvasive and biocompatible multicolor method of optical lymphangiography may elucidate the complex human lymphatic system and reduce the risk of lymphedema after surgery for melanoma and other cancers.
      13. URL :
        N/A
      14. Call Number :
        138355
      15. Serial :
        8422
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