Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    ISSN: 1520-5835
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1476-4687
    Quelle: Nature Archives 1869 - 2009
    Thema: Biologie , Chemie und Pharmazie , Medizin , Allgemeine Naturwissenschaft , Physik
    Notizen: [Auszug] Poly(J/Vr-isopropylacrylamide) (PIPAAm) is soluble in aqueous media at solution temperatures below 32 á°C, its critical solution temperature15. Above this point, it undergoes a discontinuous phase transition, precipitating from solution suddenly and reversibly over a narrow temperature ...
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Springer
    Pharmaceutical research 16 (1999), S. 597-600 
    ISSN: 1573-904X
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    ISSN: 1573-904X
    Schlagwort(e): boronic acid ; poly(vinyl alcohol) ; amino group ; glucose gel
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Purpose. To design glucose-responsive gels based on the complexation between polymers having phenylboronic acid groups and poly (vinyl alcohol). Specifically, high-glucose sensitivity at physiological pH was achieved through the interaction of phenylborate with amino groups. Method. Terpolymers of m-acrylamidophenylboronic acid, N,N-dimethylaminopropylacrylamide (DMA-PAA), and N,N-dimethylacrylamide were prepared. DMAPAA was introduced in the terpolymer to stabilize phenylborate-polyol complex at physiological pH. The effect of amino groups on complex stabilization was estimated from viscosity as well as UV spectrum measurements. Results. A good correlation was observed between complexation rate and fraction of phenylborate as well as DMAPAA in the terpolymers. In line with this increased complexation rate. UV difference spectra measurement revealed that ionization of phenylboronic acid was facilitated in the terpolymer due to the interaction with DMAPAA. Further, sensitive change in the complexation rate was demonstrated with a variation in glucose concentration, which is in sharp contrast with the poor glucose-sensitivity of the polymer without DMAPAA. Conclusions. The introduction of an amino group into phenylborate polymers was quite effective for increasing the complexation ability and the glucose responsivity at physiological pH. These results suggest the feasibility of this complex-gel system in designing a self-regulated insulin-releasing device.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Pharmaceutical research 15 (1998), S. 1721-1726 
    ISSN: 1573-904X
    Schlagwort(e): polymeric micelles ; AFM ; DLS ; pyrene
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Purpose. To directly visualize and evaluate the aqueous block copolymeric micelles, poly(ethylene oxide)-poly(β-benzyl L-aspartate) (PEO-PBLA) chemically conjugated with pyrene fluorescence molecule, by nanotechnology of atomic force microscopy (AFM). Methods. The block copolymers' PEO-PBLA-Pyrene was first synthesized by reacting with pyrene sulfonyl chloride and PEO-PBLA in tetrahydrofuran (THF) solution and were identified by GPC reflect index, UV and fluorescence detectors. The characterization of physical and chemical properties of PEO-PBLA-Pyrene polymeric micellar solution were examined by the dynamic light scattering (DLS) and critical micelles concentrations (CMC). In addition, the nanotechnology of AFM was used to directly visualize the size and shape of nanopolymeric micelles. Results. The pyrene fluorescence molecule were successfully conjugated at the amino group of the end of PBLA chain by GPC with three different detectors. The size of the aqueous PEO-PBLA-Pyrene polymeric micelles was detected around 57 nm with unimodal distribution by DLS measurement. As a result of this finding, the CMC test was also found out that the fluorescence intensity was increasing around 0.01 ∼ 0.05 mg/ml. Using AFM evaluation of polymeric micellar solution, the morphology of aqueous PEO-PBLA-Pyrene polymeric micelles was observed on round shape and with the narrow dispersity of size range 50 ∼ 80 nm. Conclusions. The presence of PEO-PBLA copolymers with pyrene in an aqueous system formed in a spherical and nano range of polymeric micelles.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Springer
    Pharmaceutical research 16 (1999), S. 213-220 
    ISSN: 1573-904X
    Schlagwort(e): polymeric micelles ; FITC ; endothelial ; endocytosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Purpose. To determine aortic endothelial cells permeation ability and mechanisms of the aqueous block copolymeric micelles, poly(ethylene oxide)-poly ((β-benzyl L-aspartate) (PEO-PBLA) chemically conjugated with fluroescein isothiocyanate (FITC) by transport study and confocal laser scanning microscopy. Methods. The block copolymers' PEO-PBLA-FITC was first synthesized and characterized by gel permeation chromatography (GPC) reflect index, UV, fluorescence detectors, and critical micelles concentrations (CMC), and atomic force microscopy (AFM). Permeation ability and mechanisms of polymeric micelles in aortic endothelial cells were evaluated by incubating with NaF, NaN3, wortmannin, cytochalasin B inhibitors, at 20°C, and under reverse conditions. FITC and latex particles (40 nm) were also used for comparison of transport ability. The extent of localization of uptake polymeric micelles was established by confocal laser scanning microscopy. Results. The size of the aqueous PEO-PBLA-FITC polymeric micelles was detected at around 56 nm with unimodal distribution by AFM. The CMC test revealed the fluorescence intensity increased to around 0.01 ∼ 0.05 mg/ml. NaF, NaN3, wortmannin, cytochalasin B, 20°C, and reverse experiments inhibited the absorption of polymeric micelles through aortic endothelial cells with apparent permeability coefficients (P) of 18.07 ± 1.03 to 12.98 ± 0.93, 11.31 ± 0.77, 12.44 ±1.23, 6.40 ± 0.23, 11.11 ± 0.46, and 10.22 ± 1.09 X 10−7 cm/sec, respectively. Also, the permeation of FITC and latex on aortic endothelial cells was 70.02 ±4.71, and 2.05± 0.41 X 10−7 cm/sec, respectively. Confocal laser microscopy showed that fluorescent compounds were distributed in the intracellular cytoplasm and nucleus. Conclusions. PEO-PBLA-FITC copolymeric micelles in an aqueous system were transported by energy-dependent endocytosis with 18.07 X 10−7 cm/sec penetrated range and were localized on intracellular and nucleus endothelial cells.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    ISSN: 1573-904X
    Schlagwort(e): Adriamycin ; polymeric micelles ; AB block copolymer ; drug delivery systems
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract The entrapment of Adriamycin (ADR) in micelles composed of AB block copolymers (poly(ethylene oxide-co-β-benzyl L-aspartate) (PEO-PBLA)) was investigated. The loading process involved transfer of ADR and PEO-PBLA into an aqueous milieu from dimethyl-formamide (DMF) through a dialysis procedure. Evidence for the physical entrapment of ADR in the polymeric micelles was derived from fluorescence spectroscopy and gel permeation chromatography (GPC). The total fluorescence intensity of ADR was low, suggesting that the drug was self-associated in the micelles. In addition, quenching experiments, using a water-soluble quencher (iodide (I–)), showed that the fluorescence of ADR present in micellar solutions was largely unaffected by I–, whereas the fluorescence of free ADR was readily quenched. From Stern-Volmer plots, quenching constants (KSV) of 2.2 and 17 M−l were determined for ADR in micellar solutions and free ADR, respectively. As a result of the entrapment of ADR in the micelles, ADR binds only slightly serum albumin as evidenced by GPC. In contrast, ADR readily binds serum albumin in aqueous solutions. The findings suggest that ADR is stably entrapped in PEO-PBLA micelles. ADR entrapment in polymeric micelles is expected to affect markedly the pharmacokinetics of ADR.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 40 (1998), S. 631-639 
    ISSN: 0021-9304
    Schlagwort(e): thermoresponsive polymer surface ; interpenetrating network ; cell culture ; cell detachment ; epithelial cell ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin , Technik allgemein
    Notizen: A novel UV crosslinkable co-polymer of 4-(N-cinnamoylcarbamide)methylstyrene (CCMS) and N-isopropylacrylamide (IPAAm) was partially entrapped in traditional tissue-culture-treated polystyrene and crosslinked by UV light irradiation. Dishes modified by this method showed a change in contact angle with respect to temperature as compared to tissue culture polystyrene controls. Surface chemical analysis indicated that the crosslinked hydrogel does not detach from the surface after successive rinsing in ethanol and water, keeping the cells or cell construct free of unwanted soluble polymer after detachment. Cultures of both bovine endothelium and human retinal pigmented epithelium were confirmed to be able to attach and grow on the polymer-modified surfaces morphologically identical to that on control tissue culture polystyrene surfaces. Corresponding to a change in temperature, these cultures would detach and could be transplanted to another culture surface without functional and structural changes. These results show that the new, photo-crosslinkable hydrogel system can utilize the hydrophobic/hydrophilic change of the surface for cell culture detachment while being permanently applicable to any tissue culture geometry. © 1998 John Wiley & Sons, Inc. J Biomed Mater Res, 40, 631-639, 1998.
    Zusätzliches Material: 5 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    Digitale Medien
    Digitale Medien
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 42 (1998), S. 148-155 
    ISSN: 0021-9304
    Schlagwort(e): platelet ; biomaterials ; block copolymer ; microdomain ; blood-polymer interaction ; Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Medizin , Technik allgemein
    Notizen: The early motion and interaction of platelets on a microdomain-structured block copolymer surface composed of 2-hydroxyethyl methacrylate (HEMA)-styrene were analyzed and compared with those on a compositionally identical random copolymer, homopolymer poly (HEMA) (hydrophilic) and polystyrene (hydrophobic) surfaces. Contacting platelets were quantitatively more active, with motions including rolling, detachment, oscillatory vibration, and change of direction only on the HEMA-St block copolymer surface. Active platelet movements were observed for long time periods (〉20 min) on HEMA-St block copolymer surfaces and were distinct from those for inert PSt latex particles on these same surfaces, demonstrating that platelet movements were not due to physical forces such as convection, hydrophobic interactions, or microbrownian movement. To study the cause and mechanism underlying the platelet movements, platelets treated with an adenosine triphosphate (ATP) synthesis inhibition, NaN3, or a membrane skeleton-disrupting chemical agent, dibucaine, were also studied on these surfaces. Both treatments reduced platelet movement and demonstrated that platelets in contact with the HEMA-St block copolymer surface require metabolic processes consuming ATP and involve dynamics of their membrane skeleton. These energy-consuming active movements might explain the previously observed lower platelet activation and low thrombogenicity of the HEMA-St block copolymers. Enhanced platelet movements on the HEMA-St block copolymer surface show that the microdomain surface interacts uniquely with platelets to hinder activation and preserve passive platelet function despite surface contact. © 1998 John Wiley & Sons, Inc. J. Biomed Mater Res, 42, 148-155, 1998.
    Zusätzliches Material: 8 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...