Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Language
Year
  • 1
    Language: English
    In: Journal of Controlled Release, 2011, Vol.154(1), pp.103-107
    Description: Drug delivery to the brain is restricted due to the blood–brain barrier (BBB). Previously, it has been shown that surfactant-coated doxorubicin-loaded nanoparticles were successful in overcoming the BBB and were effective in the treatment of rat brain tumours. However, drug distribution in brain tissue after crossing the BBB was never determined. To distinguish between the amounts of drug in the whole brain and the fraction of drug in the brain parenchyma after crossing the BBB a capillary depletion technique was employed. For this purpose rats were intravenously treated with a doxorubicin solution in 1% polysorbate 80, or doxorubicin-loaded poly-(n-butyl cyanoacrylate) (PBCA) nanoparticles without and with 1% polysorbate 80 coating, respectively. The dosage of doxorubicin was 5 mg per kg of rat body weight. At 30 min, 2 h, and 4 h following intravenous injection into the tail vein, the rats were sacrificed and their brains removed. Homogenates of the brains were prepared. In addition, one part of the homogenate was separated by centrifugation into a pellet (vascular elements) and supernatant (parenchyma) using a well established capillary depletion technique. The time-dependent distribution of doxorubicin in these brain fractions was studied. Clinically effective concentrations in all investigated brain fractions could only be detected in rats treated with surfactant-coated nanoparticles, indicating a significant transcytosis across the BBB. Only low concentrations were observed after 0.5 and 2 h with the uncoated nanoparticles. No uptake of doxorubicin into the brain was observable after administration of drug solution alone. These observations demonstrate the great potential of surface-coated PBCA nanoparticles for the delivery of drugs to the central nervous system. Doxorubicin concentration in different rat brain fractions 2 h after intravenous injection of 5 mg/kg doxorubicin solution, doxorubicin-loaded poly(butyl cyanoacrylate) (PBCA) nanoparticles (NP), or doxorubicin-loaded PBCA-NP coated with polysorbate 80 (PS80).
    Keywords: Nanoparticles ; Capillary Depletion ; Drug Targeting ; Blood–Brain Barrier ; Pharmacy, Therapeutics, & Pharmacology
    ISSN: 0168-3659
    E-ISSN: 1873-4995
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: PLoS ONE, 2011, Vol.6(5), p.e19121
    Description: Chemotherapy of glioblastoma is largely ineffective as the blood-brain barrier (BBB) prevents entry of most anticancer agents into the brain. For an efficient treatment of glioblastomas it is necessary to deliver anti-cancer drugs across the intact BBB. Poly(lactic-co-glycolic acid) (PLGA) nanoparticles coated with poloxamer 188 hold great promise as drug carriers for brain delivery after their intravenous injection. In the present study the anti-tumour efficacy of the surfactant-coated doxorubicin-loaded PLGA nanoparticles against rat glioblastoma 101/8 was investigated using histological and immunohistochemical methods. ; The particles were prepared by a high-pressure solvent evaporation technique using 1% polyvinylalcohol (PLGA/PVA) or human serum albumin (PLGA/HSA) as stabilizers. Additionally, lecithin-containing PLGA/HSA particles (Dox-Lecithin-PLGA/HSA) were prepared. For evaluation of the antitumour efficacy the glioblastoma-bearing rats were treated intravenously with the doxorubicin-loaded nanoparticles coated with poloxamer 188 using the following treatment regimen: 3×2.5 mg/kg on day 2, 5 and 8 after tumour implantation; doxorubicin and poloxamer 188 solutions were used as controls. On day 18, the rats were sacrificed and the antitumour effect was determined by measurement of tumour size, necrotic areas, proliferation index, and expression of GFAP and VEGF as well as Isolectin B4, a marker for the vessel density. ; The results reveal a considerable anti-tumour effect of the doxorubicin-loaded nanoparticles. The overall best results were observed for Dox-Lecithin-PLGA/HSA. These data demonstrate that the poloxamer 188-coated PLGA nanoparticles enable delivery of doxorubicin across the blood-brain barrier in the therapeutically effective concentrations.
    Keywords: Research Article ; Biology ; Medicine ; Immunology ; Oncology
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: International Journal of Pharmaceutics, 2011, Vol.415(1), pp.244-251
    Description: Glioblastomas belong to the most devastating cancer diseases. For this reason, polysorbate 80 (Tween 80 )-coated poly(isohexyl cyanoacrylate) (PIHCA) (Monorex ) nanoparticles loaded with doxorubicin were developed and tested for their use for the treatment of glioblastomas. The preparation of the nanoparticles resulted in spherical particles with high doxorubicin loading. The physico-chemical properties and the release of doxorubicin from the PIHCA-nanoparticles were analysed, and the influence on cell viability of the rat glioblastoma 101/8-cell line was investigated. In vitro, the empty nanoparticles did not show any toxicity, and the anti-cancer effects of the drug-loaded nanoparticles were increased in comparison to doxorubicin solution, represented by IC values. The in vivo efficacy was then tested in intracranially glioblastoma 101/8-bearing rats. Rats were treated with 3 × 1.5 mg/kg doxorubicin and were sacrificed 18 days after tumour transplantation. Histological and immunohistochemical analyses were carried out to assess the efficacy of the nanoparticles. Tumour size, proliferation activity, vessel density, necrotic areas, and expression of glial fibrillary acidic protein demonstrated that doxorubicin-loaded PIHCA-nanoparticles were much more efficient than the free drug. The results suggest that poly(isohexyl cyanoacrylate) nanoparticles hold great promise for the non-invasive therapy of human glioblastomas.
    Keywords: Doxorubicin ; Nanoparticles ; Poly(Isohexyl Cyanoacrylate) ; Glioblastoma ; Histology ; Pharmacy, Therapeutics, & Pharmacology
    ISSN: 0378-5173
    E-ISSN: 1873-3476
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Russian Journal of Physical Chemistry A, 2014, Vol.88(12), pp.2225-2235
    Description: Aqueous electrolyte solutions play an important role in many electrophysical and chemical processes in aerospace technology and industrial applications. As noncovalent interactions, the interactions between ions are crucially important for biomolecular structures as well (protein structure folding, molecular level processes followed by ionic pair correlations, the formation of flexible hydrate shells, and so on). Specifically, ions (cations and anions with the same valence charges) can form stable pairs if their sizes match. The formation of ionic pairs can substantially affect the thermodynamic stabilities of proteins in the alkali salts physiologically present in the human body. Research aims and problems impose severe demands on readjustments of the ionic force fields and potential parameters developed to describe aqueous solutions and electrolytic systems. Ionic solutions and their interaction with biomolecules have been observed for over 100 years [1], but the behavior of such solutions remains poorly studied today. New data obtained in this work deals with parameterization strategies and adjustments for the ionic force fields of the alkali cations and halide anions that should be helpful in biomolecular research. Using molecular dynamics (MD) models, four electrolytic systems (HCl-H 2 O, LiCl-H 2 O, NaCl-H 2 O, and KCl-H 2 O) are investigated as binary mixtures of water and cations and anions, respectively. The intermolecular interaction parameters are varied for two of the four model electrolytes (HCl-H 2 O and NaCl-H 2 O) to simulate the possibility of different ionic shells forming during interaction with water. It is found that varying the potential parameters strongly affects the dynamic and structural characteristics of electrolyte systems. MD simulations are performed in the temperature range of 300 to 600 K with a step of 50 K. MD simulations for all electrolyte models (HCl-H 2 O, LiCl-H 2 O, NaCl-H 2 O, KCl-H 2 O) are also conducted for different molar fractions of electrolyte concentration: 16, 8, and 1 mol/kg. Energies of diffusion activation are calculated using the Arrhenius equation, thereby constructing temperature dependence graphs of diffusion coefficients for all four electrolyte systems. The observed diffusion properties of the electrolyte systems are found to correlate well with the energy and structural radial distribution data.
    Keywords: molecular dynamics simulations ; electrolyte solutions ; microstructure analysis ; diffusion coefficient ; radial distribution function
    ISSN: 0036-0244
    E-ISSN: 1531-863X
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    In: Sovremennye tehnologii v medicine, 12/2018, Vol.10(4), p.105
    ISSN: 20764243
    E-ISSN: 2309995X
    Source: CrossRef
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: Journal of Controlled Release, 2007, Vol.117(1), pp.51-58
    Description: Poly(butyl cyanoacrylate) nanoparticles coated with poloxamer 188 (Pluronic® F68) and also, as shown previously, polysorbate 80 (Tween® 80) considerably enhance the anti-tumour effect of doxorubicin against an intracranial glioblastoma in rats. The investigation of plasma protein adsorption on the surface of the drug-loaded nanoparticles by two-dimensional electrophoresis (2-D PAGE) revealed that both surfactants, besides other plasma components, induced a considerable adsorption of apolipoprotein A-I (ApoA-I). It is hypothesized that delivery of doxorubicin to the brain by means of nanoparticles may be augmented by the interaction of apolipoprotein A-I that is anchored on the surface of the nanoparticles with the scavenger receptor class B type I (SR-BI) located at the blood–brain barrier. This is the first study that shows a correlation between the adsorption of apolipoprotein A-I on the nanoparticle surface and the delivery of the drug across the blood–brain barrier.
    Keywords: Apolipoprotein A-I ; Chemotherapy ; Glioblastoma ; Nanoparticles ; Poly(Butyl Cyanoacrylate) ; Poloxamer 188 ; Polysorbate 80 ; Rats ; Pharmacy, Therapeutics, & Pharmacology
    ISSN: 0168-3659
    E-ISSN: 1873-4995
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: 2016 19th Conference of Open Innovations Association (FRUCT), 2016, pp.72-79
    Description: The complexity of software grows every year, and while there are many programming techniques and new languages that accommodate the need to provide high abstractions, still many languages that require attention to low-level details are in use as of yet In order to avoid tedious debugging which needs time that could be spent on dealing with high-level logic, static analysis of source code can be used to more efficiently find common problems. We have studied the process of creation of algorithms for static analysis tools by building a simple value range analysis mechanism, that is, a way to detect some cases of integers not matching a predicate involving arithmetic and comparison operations. This algorithm provides means to detect possible division by zero and integer overflow and is easily extended to find cases of out-of-bounds addressing of containers. While there is a multitude of value range analysis mechanisms that are more sophisticated by orders of magnitude, the works in which they are presented focus on the properties of the resulting tools such as estimated amount of false positives, performance, memory usage, or soundness. We, on the other hand, are going to present the process of extension of static analysis algorithm from ground up. An ad hoc programming language is developed in multiple stages to separate the creation of algorithm from numerous details of its implementation which would necessarily arise were we to build it on a real-world language.
    Keywords: Algorithm Design and Analysis ; Semantics ; Computer Languages ; Buildings ; Memory Management ; Software Algorithms ; Complexity Theory
    ISBN: 9789526839752
    E-ISSN: 2305-7254
    E-ISSN: 23430737
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
  • 9
    Language: English
    In: European Journal of Pharmaceutics and Biopharmaceutics, 2010, Vol.74(2), pp.157-163
    Description: Poly(lactide-co-glycolide) (PLGA) nanoparticles coated with poloxamer 188 (Pluronic F-68) or polysorbate 80 (Tween 80) enable an efficient brain delivery of the drugs after intravenous injection. This ability was evidenced by two different pharmacological test systems employing as model drugs the anti-tumour antibiotic doxorubicin and the agonist of opioid receptors loperamide, which being P-gp substrates can cross the blood–brain barrier (BBB) only in pharmacologically insignificant amounts: binding of doxorubicin to the surfactant-coated PLGA nanoparticles, however, enabled a high anti-tumour effect against an intracranial 101/8 glioblastoma in rats, and the penetration of nanoparticle-bound loperamide into the brain was demonstrated by the induction of central analgesic effects in mice. Both pharmacological tests could demonstrate that therapeutic amounts of the drugs were delivered to the sites of action in the brain and showed the high efficiency of the surfactant-coated PLGA nanoparticles for brain delivery. The results of the study also demonstrated that the efficacy of brain delivery by nanoparticles not only is influenced by the coating surfactants but also by other formulation parameters such as core polymer, drug, and stabilizer.
    Keywords: Blood–Brain Barrier ; Doxorubicin ; Glioblastoma ; Loperamide ; Mice ; Nanoparticles ; Poly(Lactide-Co-Glycolide) ; Poloxamer 188 ; Polysorbate 80 ; Rats ; Tail-Flick Test ; Pharmacy, Therapeutics, & Pharmacology
    ISSN: 0939-6411
    E-ISSN: 1873-3441
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Neuroscience Letters, 1991, Vol.133(2), pp.284-286
    Description: Neurochordins are a family of high M r P-epitope-bearing neural tissue glycoproteins. Comparison of SDS-agarose electrophoretic patterns of extracts from human, rat, mouse and chicken brain after immunostaining of blots with an anti-P-epitope MAb At5 demonstrated that in each case neurochordins from the A, B and C group were present. A similar result was obtained when polyclonal serum against total human neurochordin was used. The data favours the idea of high evolutional conservatism of neurochordins of higher vertebrate species. Expression of the P-epitope on glial cells in culture was studied. Strong immunostaining of oligodendrocytes with MAb At5 and the absence of this staining in astrocytes and Schwann cells make it possible to use At5 for identification of cell types in tissue culture experiments as well as for differential diagnostics of brain tumours.
    Keywords: Neurochordin ; Neural Tissue Specificity ; High Mr Glycoprotein ; Evolutionary Conservatism ; Oligodendrocyte ; Medicine ; Anatomy & Physiology
    ISSN: 0304-3940
    E-ISSN: 1872-7972
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages