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Berlin Brandenburg

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  • 1
    Language: English
    In: European Journal of Pharmaceutics and Biopharmaceutics, 2009, Vol.71(2), pp.251-256
    Description: Human serum albumin (HSA) nanoparticles were manufactured by desolvation. Transferrin or transferrin receptor monoclonal antibodies (OX26 or R17217) were covalently coupled to the HSA nanoparticles using the NHS-PEG-MAL-5000 crosslinker. Loperamide was used as a model drug since it normally does not cross the blood–brain barrier (BBB) and was bound to the nanoparticles by adsorption. Loperamide-loaded HSA nanoparticles with covalently bound transferrin or the OX26 or R17217antibodies induced significant anti-nociceptive effects in the tail-flick test in ICR (CD-1) mice after intravenous injection, demonstrating that transferrin or these antibodies covalently coupled to HSA nanoparticles are able to transport loperamide and possibly other drugs across the BBB. Control loperamide-loaded HSA nanoparticles with IgG2a antibodies yielded only marginal effects.
    Keywords: Drug Targeting ; Human Serum Albumin (HSA) ; Nanoparticle Size ; Transferrin ; Transferrin Receptor ; Ox26 Mab ; Blood–Brain Barrier ; Loperamide ; Pharmacy, Therapeutics, & Pharmacology
    ISSN: 0939-6411
    E-ISSN: 1873-3441
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  • 2
    Language: English
    In: International Journal of Pharmaceutics, 2011, Vol.406(1), pp.128-134
    Description: Folic acid has been previously demonstrated to mediate intracellular nanoparticle uptake. Here, we investigated cellular uptake of folic acid-conjugated human serum albumin nanoparticles (HSA NPs). HSA NPs were prepared by desolvation and stabilised by chemical cross-linking with glutaraldehyde. Folic acid was covalently coupled to amino groups on the surface of HSA NPs by carbodiimide reaction. Preparation resulted in spherical HSA NPs with diameters of 239 ± 26 nm. As shown by size exclusion chromatography, 7.40 ± 0.90 μg folate was bound per mg HSA NPs. Cellular NP binding and uptake were studied in primary normal human foreskin fibroblasts (HFFs), the human neuroblastoma cell line UKF-NB-3, and the rat glioblastoma cell line 101/8 by fluorescence spectrophotometry, flow cytometry, and confocal laser scanning microscopy. Covalent conjugation of folic acid to HSA NPs increased NP uptake into cancer cells but not into HFFs. Free folic acid interfered with cancer cell uptake of folic acid-conjugated HSA NPs but not with uptake of folic acid-conjugated HSA NPs into HFFs. These data suggest that covalent linkage of folic acid can specifically increase cancer cell HSA NP uptake.
    Keywords: Nanoparticles ; Human Serum Albumin (HSA) ; Folic Acid ; Folate Receptor ; Cancer Targeting ; Pharmacy, Therapeutics, & Pharmacology
    ISSN: 0378-5173
    E-ISSN: 1873-3476
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  • 3
    Language: English
    In: Journal of Drug Targeting, 01 February 2011, Vol.19(2), pp.125-132
    Description: Human serum albumin (HSA) nanoparticles (NP) were prepared by desolvation. Insulin or an anti-insulin receptor monoclonal antibody (29B4) were covalently coupled to the HSA NP, using the NHS-PEG-MAL-5000 crosslinker. Loperamide-loaded HSA NP with covalently bound insulin or the 29B4 antibodies induced significant antinociceptive effects in the tail-flick test in ICR (CD-1) mice after intravenous injection, demonstrating that insulin or these antibodies covalently coupled to HSA NP are able to transport loperamide across the blood-brain barrier (BBB) which it normally is unable to cross. Control loperamide-loaded HSA NP with immunoglobulin G antibodies yielded only marginal effects. The loperamide transport across the BBB using the NP with covalently attached insulin could be totally inhibited by the pretreatment with the antibody 29B4.
    Keywords: Blood-Brain Barrier ; Human Serum Albumin (HSA) Nanoparticles ; Insulin ; Insulin Monoclonal Antibody ; Loperamide ; Pharmacy, Therapeutics, & Pharmacology
    ISSN: 1061-186X
    E-ISSN: 1029-2330
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  • 4
    Language: English
    In: Behavioral Ecology and Sociobiology, 2010, Vol.64(3), pp.337-347
    Description: Trivers' and Willard's hypothesis that natural selection favors sex allocation in relation to maternal condition assumes iteropary. Though this assumption is not met in most solitary Aculeata, the reproductive life span of semelparous females may be divided into discrete successive cycles by the risk of open-cell parasitism. Females can avoid losing their investment to parasites attacking the open cell only by limiting the provision time for each cell. The restriction of time available for the investment in a single progeny irrespective of the condition of the female leads to de facto iteropary. Moreover, in Hymenoptera, there are no costs for sex allocation due to the haplodiploid mode of sex determination. In sexually size dimorphic species, females in poor condition are predicted to invest in the smaller sex and vice versa. The resulting prediction of a conditional sex allocation in solitary Aculeata was tested in the Red Mason bee, Osmia rufa ( Osmia bicornis ), a stem or hole-nesting, polylectic, univoltine megachilid bee. Body size is a key component of condition in females of nest-constructing solitary bees. Large females collect the same amount of pollen and nectar in a shorter time than small ones and should suffer less from parasitism. We found that small females dealt with their handicap of a low provisioning performance by shifting the sex ratio toward sons (the smaller sex) and by reducing the body size of daughters. Large females, however, shifted their offspring sex ratio toward daughters, the sex that depends more on body size in its reproductive value. The sex ratio in the population met the expected Fisherian sex ratio. Although females allocated their investment in the sexes according to their body mass, the population-level investment was balanced.
    Keywords: Parental investment ; Conditional sex allocation ; Progeny body size ; Mass provisioning
    ISSN: 0340-5443
    E-ISSN: 1432-0762
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  • 5
    Language: English
    In: Molecular Imaging and Biology, April, 2013, Vol.15(2), p.148(7)
    Description: Byline: Huedayi Korkusuz (1), Karsten Ulbrich (2), Katerina Welzel (10), Verena Koeberle (3), Waralee Watcharin (2), Ute Bahr (4), Valery Chernikov (5), Thomas Knobloch (2), Sabine Petersen (10), Frank Huebner (10), Hanns Ackermann (6), Svetlana Gelperina (7), Wolfgang Kromen (10), Renate Hammerstingl (10), Joerg Haupenthal (3,9), Frank Gruenwald (1), Jens Fiehler (8), Stefan Zeuzem (3), Joerg Kreuter (2), Thomas J. Vogl (10), Albrecht Piiper (3) Keywords: Contrast agent; Nanoparticles; Gd-DTPA-human serum albumin-transferrin; Biodistribution; Human serum albumin Abstract: Purpose In this study, the contrasting properties of human serum albumin nanoparticles (HSA-NPs) loaded with gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) and coated with transferrin in MRI in mice are evaluated. Procedures HSA-NPs were conjugated with Gd-DTPA (Gd-HSA-NPs) and coupled with transferrin (Gd-HSA-NP-Tf). Mice underwent MRI before or after injection of Gd-DTPA, Gd-HSA-NP, or Gd-HSA-NP-Tf. Results All the studied contrast agents provided a contrast enhancement (CE) in the blood, heart muscle, and liver. Compared to Gd-DTPA, CE with HSA-NP was achieved at lower Gd doses. Gd-HSA-NP-Tf yielded significantly higher CE than Gd-HSA-NP in the skeletal muscle, blood, cardiac muscle, and liver (p〈0.05). Gd-HSA-NP-Tf achieved a significantly higher CE than Gd-HSA-NP and Gd-DTPA in the blood, cardiac muscle, and liver (p〈0.05). In the brain, only Gd-HSA-NP-Tf was found to cause a significant CE (p〈0.05). Conclusions The Gd-HSA nanoparticles have potential as MRI contrast agents. In particular, Gd-HSA-NP-Tf has a potential as a specific contrast agent for the brain, while the blood--brain barrier is still intact, as well as in the heart, liver, and skeletal muscle. Author Affiliation: (1) Department of Nuclear Medicine, Johann Wolfgang Goethe University Hospital, Theodor-Stern-Kai 7, 60590, Frankfurt/Main, Germany (2) Institute of Pharmaceutical Technology, Biocenter of Johann Wolfgang Goethe University, Max-von-Laue -Str. 9, 60438, Frankfurt, Germany (3) Department of Medicine I, Johann Wolfgang Goethe University Hospital, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany (4) Institute of Pharmaceutical Chemistry, Johann Wolfgang Goethe University, Max-von-Laue-Str. 9, 60438, Frankfurt, Germany (5) Institute of Human Morphology, Russian Academy of Medical Sciences, Zurupa st. 3, 117418, Moscow, Russia (6) Department of Biomathematics, Johann Wolfgang Goethe University Hospital Frankfurt, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany (7) Nanosystem Ltd, 7-th Kozhuhovskaya st., 20, 115193, Moscow, Russia (8) Department of Diagnostic and Interventional Neuroradiology, University Medical Center Hamburg-Eppendorf, Martinistrasse 52, 20246, Hamburg, Germany (9) Helmholtz Institute for Pharmaceutical Research Saarland, Department of Drug Design and Optimization, University of Saarland, 66123, Saarbrucken, Germany (10) Department of Diagnostic and Interventional Radiology, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590, Frankfurt, Germany Article History: Registration Date: 06/07/2012 Online Date: 19/07/2012 Article note: Karsten Ulbrich, Katerina Welzel, and Verena Koeberle contributed equally to this work. Joerg Kreuter, Thomas J. Vogl, and Albrecht Piiper shared senior authorship.
    ISSN: 1536-1632
    Source: Cengage Learning, Inc.
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  • 6
    Language: English
    In: Molecular Imaging and Biology, 2013, Vol.15(2), pp.148-154
    Description: In this study, the contrasting properties of human serum albumin nanoparticles (HSA-NPs) loaded with gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) and coated with transferrin in MRI in mice are evaluated. HSA-NPs were conjugated with Gd-DTPA (Gd-HSA-NPs) and coupled with transferrin (Gd-HSA-NP-Tf). Mice underwent MRI before or after injection of Gd-DTPA, Gd-HSA-NP, or Gd-HSA-NP-Tf. All the studied contrast agents provided a contrast enhancement (CE) in the blood, heart muscle, and liver. Compared to Gd-DTPA, CE with HSA-NP was achieved at lower Gd doses. Gd-HSA-NP-Tf yielded significantly higher CE than Gd-HSA-NP in the skeletal muscle, blood, cardiac muscle, and liver (pâ[euro][per thousand]〈â[euro][per thousand]0.05). Gd-HSA-NP-Tf achieved a significantly higher CE than Gd-HSA-NP and Gd-DTPA in the blood, cardiac muscle, and liver (pâ[euro][per thousand]〈â[euro][per thousand]0.05). In the brain, only Gd-HSA-NP-Tf was found to cause a significant CE (pâ[euro][per thousand]〈â[euro][per thousand]0.05). The Gd-HSA nanoparticles have potential as MRI contrast agents. In particular, Gd-HSA-NP-Tf has a potential as a specific contrast agent for the brain, while the bloodâ[euro]"brain barrier is still intact, as well as in the heart, liver, and skeletal muscle.[PUBLICATION ]
    Keywords: Contrast agent ; Nanoparticles ; Gd-DTPA-human serum albumin-transferrin ; Biodistribution ; Human serum albumin
    ISSN: 1536-1632
    E-ISSN: 1860-2002
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  • 7
    Language: English
    In: Molecular Imaging, 01 July 2012, Vol.11(4)
    Description: Different from regular small molecule contrast agents, nanoparticle-based contrast agents have a longer circulation time and can be modified with ligands to confer tissue-specific contrasting properties. We evaluated the tissue distribution of polymeric nanoparticles (NPs) prepared from human serum albumin (HSA), loaded with gadolinium–diethylenetriaminepentaacetic acid (Gd-DTPA) (Gd-HSA-NP), and coated with folic acid (FA) (Gd-HSA-NP-FA) in mice by magnetic resonance imaging (MRI). FA increases the affinity of the Gd-HSA-NP to FA receptor–expressing cells. Clinical 3 T MRI was used to evaluate the signal intensities in the different organs of mice injected with Gd-DTPA, Gd-HSA-NP, or Gd-HSA-NP-FA. Signal intensities were measured and standardized by calculating the signal to noise ratios. In general, the NP-based contrast agents provided stronger contrasting than Gd-DTPA. Gd-HSA-NP-FA provided a significant contrast enhancement (CE) in the brain (p = .0032), whereas Gd-DTPA or Gd-HSA-NP did not. All studied MRI contrast agents showed significant CE in the blood, kidney, and liver (p 〈 .05). Gd-HSA-NP-FA elicited significantly higher CE in the blood than Gd-HSA-NP (p = .0069); Gd-HSA-NP and Gd-HSA-NP-FA did not show CE in skeletal muscle and gallbladder; Gd-HSA-NP, but not Gd-HSA-NP-FA, showed CE in the cardiac muscle. Gd-HSA-NP-FA has potential as an MRI contrast agent in the brain.
    Keywords: Medicine
    E-ISSN: 1536-0121
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  • 8
    In: Journal of the National Cancer Institute, 2004, Vol.96(3), pp.210-218
    Description: Background: Antiestrogens of the selective estrogen receptor modulator (SERM) type, such as tamoxifen, have two major limitations: their mixed agonist and antagonist profile and the development of tumor resistance. We characterized two new pure antiestrogensZK-703 and ZK-253that belong to the class of specific estrogen receptor destabilizers (SERDs), which includes fulvestrant, and compared their activity with that of fulvestrant and tamoxifen. Methods: Effects of antiestrogens on the growth of estrogen-dependent breast tumors in vivo were determined using several mouse xenograft models (including the tamoxifen-sensitive tumors MCF7, T47D, and MV3366 and the tamoxifen-resistant tumors ZR75-1 and MCF7/TAM) and chemically induced (nitrosomethyl urea NMU and dimethylbenzanthracene DMBA) rat breast cancer models (groups of 10 animals). We determined the initial response and effects on hormone receptor levels and the time to relapse after treatment (i.e., time to reach a predetermined tumor size threshold). Estrogen receptor (ER) levels were determined by immunoassay. Results: ZK-703 (administered subcutaneously) and ZK-253 (administered orally) were more effective than tamoxifen or fulvestrant at inhibiting the growth of ER-positive breast cancer in all xenograft models. For example, MCF7 tumors relapsed (i.e., reached the size threshold) in 10 weeks in mice treated with tamoxifen but in 30 weeks in mice treated with ZK-703. ZK-703 and ZK-253 also prevented further tumor progression in tamoxifen-resistant breast cancer models to a similar extent (more than 30 weeks in mice with ZR75-1 and MCF7/TAM tumors). In the chemically induced rat breast cancer models, orally administered ZK-703 and ZK-253 caused a nearly complete (80) inhibition of tumor growth. ER levels were dramatically reduced in MCF7 tumors after 5 weeks of ZK-703 treatment compared with ER levels in vehicle-treated tumors; by contrast, ER levels in tamoxifen-treated tumors were higher than those in control tumors. Conclusion: ZK-703 and ZK-253 are potent, long-term inhibitors of growth in both tamoxifen-sensitive and tamoxifen-resistant breast cancer models.
    Keywords: 9,10-Dimethyl-1,2-Benzanthracene–Administration & Dosage ; Administration, Oral–Blood ; Animals–Pharmacology ; Antineoplastic Agents, Hormonal–Chemically Induced ; Antineoplastic Agents, Hormonal–Drug Therapy ; Antineoplastic Agents, Hormonal–Metabolism ; Breast Neoplasms–Analogs & Derivatives ; Breast Neoplasms–Pharmacology ; Breast Neoplasms–Administration & Dosage ; Disease Models, Animal–Blood ; Disease Progression–Pharmacology ; Drug Resistance, Neoplasm–Blood ; Estradiol–Chemically Induced ; Estradiol–Drug Therapy ; Estrogen Receptor Modulators–Metabolism ; Estrogen Receptor Modulators–Drug Effects ; Estrogen Receptor Modulators–Administration & Dosage ; Estrogens–Pharmacology ; Female–Pharmacology ; Humans–Pharmacology ; Injections, Subcutaneous–Pharmacology ; Methylnitrosourea–Pharmacology ; Mice–Pharmacology ; Neoplasms, Hormone-Dependent–Pharmacology ; Neoplasms, Hormone-Dependent–Pharmacology ; Neoplasms, Hormone-Dependent–Pharmacology ; Receptors, Estrogen–Pharmacology ; Selective Estrogen Receptor Modulators–Pharmacology ; Selective Estrogen Receptor Modulators–Pharmacology ; Tamoxifen–Pharmacology ; Transplantation, Heterologous–Pharmacology ; Estrogen ; Drug Therapy ; Breast Cancer ; Oncology ; Antineoplastic Agents, Hormonal ; Estrogen Receptor Modulators ; Estrogens ; Receptors, Estrogen ; Selective Estrogen Receptor Modulators ; Zk253 ; Zk703 ; Tamoxifen ; Estradiol ; 9,10-Dimethyl-1,2-Benzanthracene ; Methylnitrosourea;
    ISSN: 0027-8874
    E-ISSN: ONLINEISSN=""
    E-ISSN: 14602105
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  • 9
    Language: English
    In: Biomacromolecules, 12 March 2012, Vol.13(3), pp.652-63
    Description: Preclinical in vivo characterization of new polymeric drug conjugate candidates is crucial for understanding the effects of certain chemical modifications on distribution and elimination of these carrier systems, which is the basis for rational drug design. In our study we synthesized dual fluorescent HPMA copolymers of different architectures and molecular weights, containing one fluorescent dye coupled via a stable hydrazide bond functioning as the carrier label and the other one modeling the drug bound to a carrier via a pH-sensitive hydrolytically cleavable hydrazone bond. Thus, it was possible to track the in vivo fate, namely distribution, elimination and tumor accumulation, of the polymer drug carrier and a cleavable model drug simultaneously and noninvasively in nude mice using multispectral optical imaging. We confirmed our in vivo results by more detailed ex vivo characterization (imaging and microscopy) of autopsied organs and tumors. There was no significant difference in relative biodistribution in the body between the 30 KDa linear and 200 KDa star-like polymer, but the star-like polymer circulated much longer. We observed a moderate accumulation of the polymeric carriers in the tumors. The accumulation of the pH-sensitive releasable model drug was even higher compared to the polymer accumulation. Additionally, we were able to follow the long-term in vivo fate and to prove a time-dependent tumor accumulation of HPMA copolymers over several days.
    Keywords: Drug Carriers ; Drug Delivery Systems ; Antineoplastic Agents -- Pharmacology ; Carbocyanines -- Pharmacology ; Colonic Neoplasms -- Drug Therapy ; Indoles -- Pharmacology ; Methacrylates -- Chemistry ; Polymers -- Pharmacology
    ISSN: 15257797
    E-ISSN: 1526-4602
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  • 10
    Language: English
    In: Journal of Controlled Release, 10 December 2013, Vol.172(2), pp.504-512
    Description: In recent years, polymer drug carriers based on -(2-hydroxypropyl)methacrylamide (HPMA) copolymers with pH-triggered drug release have shown enhanced uptake in solid tumors and excellent antitumor activity. Here, the impact of the structure of the acid-labile spacer between the drug and the polymer carrier on the biodistribution of both the drug and the carrier was studied using noninvasive multispectral optical imaging of dual fluorescently labeled HPMA copolymers. Five different spacers containing a pH-sensitive hydrazone bond were synthesized and used to combine a fluorescent model drug with a polymer backbone, conjugated with another non-releasable fluorescent dye. Two copolymers differing in polymer chain structure (linear and star-like) and molecular weight (30 and 200 kDa) were used to distinguish between carriers with molecular weights above and below the limit for renal filtration. The rate of model drug release from the conjugates was determined . The biodistributions of the six most promising conjugates were investigated in athymic nude mice inoculated with human colon carcinoma xenograft. The structure of the spacer in the vicinity of the hydrazone bond significantly influenced the release rate of the model drug. The slow release rate of a pyridyl group bearing spacer resulted in a greater amount of the model drug being transported to the tumor, which was independent of the carrier structure. The results of this study emphasize the importance of careful selection of the structure and appropriate spacer when designing polymer conjugates intended for passive tumor targeting.
    Keywords: Hpma Copolymers ; Ph-Responsive Drug Release ; Tumor Accumulation ; Passive Tumor Targeting ; Multispectral Optical Imaging ; Xenograft Tumor Model ; Pharmacy, Therapeutics, & Pharmacology
    ISSN: 0168-3659
    E-ISSN: 1873-4995
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