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  • 1
    Electronic Resource
    Electronic Resource
    Synthesis and characterization of SPUU-PEO-heparin graft copolymers (1991)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 29 (1991), S. 1725-1737 
    Details
    ISSN: 0887-624X
    Keywords: (heparin-PEO) grafted segmented polyurethaneurea ; surface modification ; nonthrombogenic surface ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new synthetic approach for the preparation of segmented polyurethaneurea (SPUU)-PEO-Heparin graft copolymers (B-PEO-Hep) has been developed. The procedure involved the coupling of hexamethylene diisocyanate (HMDI) to soluble Biomer® (B) through an allophanate/biuret reaction. The free isocyanate (NCO) groups attached to Biomer® were then coupled to PEO terminal hydroxyl groups to form PEO grafted Biomer® (B-PEO). B-PEO free hydroxy groups were modified with HMDI to introduce terminal isocyanate groups. The NCO functionalized B-PEO was then coupled to heparin (Hep) functional groups (—OH, —NH2) producing B-PEO-Hep graft copolymer. Synthetic intermediates were confirmed by FTIR, NCO group determination, and toluidine blue heparin assay. Physical characterization techniques, such as contact angle measurements, water swelling, light scattering measurements, and DSC thermal analysis, detailed properties of the graft copolymer containing covalently bound heparin. This new heparinized copolymer can be applied as a coating on other existing blood contacting surfaces without changing bulk properties. The heparin bioactivity observed attests to the usefulness of this new procedure as a coating to improve the blood compatibility of blood-contacting surfaces.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1991.080291206
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  • 2
    Electronic Resource
    Electronic Resource
    Effect of the incorporation of amino groups in a glucose-responsive polymer complex having phenylboronic acid moieties (1991)
    New York, NY : Wiley-Blackwell
    Polymers for Advanced Technologies 2 (1991), S. 261-264 
    Details
    ISSN: 1042-7147
    Keywords: Polymer complex ; diabetes ; phenylboronic acid ; stimuli-responsive polymer drug delivery system ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: A novel polymer complex system sensitive to glucose was studied as a candidate material for formulating a chemically regulated insulin release system. A ternary copolymer of N-vinyl-2-pyrrolidone (NVP), 3-acrylamidophenylboronic acid (AAm-PBA) and N,N-dimethylaminopropylacrylamide (DMAPAA) (poly(NVP-co-PBA-co-DMAPAA)) was synthesized by radical copolymerization. The phenylboronic acid group in this copolymer serves as a glucose sensor moiety. Poly(NVP-co-PBA-co-DMAPAA) was soluble in water in the pH range of 3-12, in sharp contrast to a binary copolymer of NVP and AAm-PBA (poly(NVP-co-PBA)) which showed solubility only under alkaline aqueous conditions, where the boronic acid group is in a tetrahedral ionized form. The protonated amino group in poly(NVP-co-PBA-DMAPAA) contributed to increase the solubility of the polymer under physiological and acidic aqueous conditions. Furthermore, poly(NVP-co-PBA-co-DMAPAA) formed a stable polymer complex gel with poly(vinyl alcohol) (PVA) in pH 7.4 phosphate buffered solution due to the formation of a covalent linkage between the boronic acid groups in ternary copolymer and diol units in PVA. The release of myoglobin as model protein from the complex gel was increased immediately after the addition of glucose, due to the transition of gel into sol state, indicating the feasibility of this complex gel as a candidate material for a glucose-responsive delivery system for insulin.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pat.1991.220020508
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  • 3
    Electronic Resource
    Electronic Resource
    Thermal and structural analysis of heparin-PEO-PDMS-PEO-heparin pentablock copolymers (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 54 (1994), S. 1863-1872 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: ABCBA-type amphiphilic block copolymers comprising polydimethylsiloxane (PDMS), poly(ethylene oxide) (PEO), and heparin segments were synthesized by coupling reactions between end-functionalized oligomers. These multiblock copolymers were characterized to examine bulk properties using 1H-NMR, FTIR, end-group analysis, and sulfur elemental analysis. Block copolymers were further characterized in bulk using differential scanning calorimetry and X-ray diffraction measurements. The PDMS glass transition remains unchanged with increasing PEO content, indicating coexistence of pure PDMS with mixed phases. Furthermore, endothermic melting of the block copolymers shifts to higher temperatures and becomes more intense with increasing PEO molecular weight. Additionally, the crystallinity of the PEO segment in the block copolymers increases with increasing PEO molecular weight. The PEO melting endotherm peak shifts from near 318 to 323 K with annealing. In the cooling thermogram, the block copolymers exhibit two crystallization exotherms, one near 303 K and the other near 193 K, attributed to PEO and PDMS recrystallization and nucleation, respectively. © 1994 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1994.070541209
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  • 4
    Electronic Resource
    Electronic Resource
    The influence of hydrophilic and hydrophobic domains on water wettability of 2-hydroxyethyl methacrylate-styrene copolymers (1978)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 22 (1978), S. 369-377 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Cooligomers and ABA-type block copolymers composed of a hydrophilic monomer, 2-hydroxyethyl methacrylate (HEMA), and a hydrophobic monomer, styrene, were synthesized to study the relation between their microstructure and hydrophilic and hydrophobic functions. Films of cooligomers and ABA-type block copolymers were cast from DMF solutions at 40°C. The wettability, which was determined from the contact angle with water, increased considerably when HEMA mole fraction reached around 0.8 in the cooligomer system and around 0.9 in the ABA-type block copolymer system. The microstructures of the copolymer films were observed by electron microscopy using the osmium tetroxide fixation technique. The morphologic change in the domain structure was observed at an HEMA mole fraction of about 0.8 in the cooligomer system and about 0.9 in the ABA-type block copolymer system. It is suggested that hydrophilic and hydrophobic functions are largely influenced by the state of aggregation of each segment, that is, the size and geometry of the hydrophilic and hydrophobic domains.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1978.070220206
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  • 5
    Electronic Resource
    Electronic Resource
    Effect of crystallinity of condensation polymers on platelet adhesion (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 4207-4216 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Various polyamides and polyesters having different numbers of methylene groups in their repeating units have been synthesized and their blood compatibilities have been evaluated in terms of the adhesion behavior of blood platelets on the surface of these condensation polymers by a micro-sphere-column method. The number of methylene groups in the repeating units of polyamides and polyesters influenced the adhesion behavior of platelets and there was an optimum number of methylene groups each in polyamides and polyesters. Poly(hexamethylene terephthalamide) and poly(pentamethylene terephthalate) adsorbed platelets in the smallest number in the polyamide and polyester series, respectively. Blood platelets were adsorbed on polyamides in smaller numbers than on corresponding polyesters. It was found that the platelet adhesion on the surface of polyamides and polyesters was closely related to their crystallinities and the number of the adsorbed platelets decreased linearly with increasing their relative crystallinity.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1981.070261221
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  • 6
    Electronic Resource
    Electronic Resource
    Cellular affinity of polyamides having various functional groups. I. Platelet adhesionManuscript complete January 25, 1981 (1981)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 26 (1981), S. 2293-2303 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Various polyamides having a different density of hydrogen bonding, of hydrophilic character, and containing ionic groups have been synthesized and their blood compatibilities were evaluated in terms of the adhesion behavior of blood platelets on polyamide by the microsphere column method. Polyamides containing anionically charged groups such as carboxylate or sulfonate groups adsorbed fewer blood platelets than those with undissociated carboxylate groups. Polyamides having thioether groups adsorbed fewer platelets than those having ether groups. Introduction of a rigid piperazine unit caused an increase in platelet adhesion.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1981.070260716
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  • 7
    Electronic Resource
    Electronic Resource
    Photo-induced change in wettability and binding ability of azoaromatic polymers (1982)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 27 (1982), S. 239-245 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Photochromic polymers containing p-phenylazoacrylanilide were synthesized and the photo-induced hydrophobicity change on the surface of the polymer film was studied by measuring water wettability. The wettability increased with UV irradiation and returned to the original value with visible light irradiation. This photo-induced reversible change in wettability was considered to be caused by the large change of dipole moment across the azo bonds due to the isomerization of azo dye from trans to cis form. Furthermore, the photoresponsive polymeric adsorbent prepared from the azo polymer having adsorption behavior of a low molecular weight compound was studied. The binding ability of this polymeric adsorbent was decreased by UV irradiation. These results were attributed to the decreased hydrophobic interaction between the adsorbent and the adsorbate.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1982.070270125
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  • 8
    Electronic Resource
    Electronic Resource
    Glucose-Responsive Gel from Phenylborate Polymer and Poly (Vinyl Alcohol): Prompt Response at Physiological pH Through the Interaction of Borate with Amino Group in the Gel (1997)
    Springer
    Pharmaceutical research 14 (1997), S. 289-293 
    Details
    ISSN: 1573-904X
    Keywords: boronic acid ; poly(vinyl alcohol) ; amino group ; glucose gel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: 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.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1012033718302
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  • 9
    Electronic Resource
    Electronic Resource
    Preparation of photoresponsive polymeric adsorbent containing amphiphilic polymer with azobenzene moiety and its application for cell adhesion chromatography (1983)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 28 (1983), S. 1321-1329 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: In order to develop a new type column chromatography, a polymeric adsorbent was prepared by grafting a photoresponsive polymer containing an azobenzene moiety on the surface of controlled pore glass beads. The polarity of the surface of the polymeric adsorbent was increased by UV irradiation because of trans-cis isomerization of azobenzene moiety. Adhesion chromatography of erythrocytes was carried out using the photoresponsive polymeric adsorbent. The erythrocytes were adhered to the adsorbent in the dark and separated from the adsorbent by UV irradiation. This behavior appears to be caused by the photoresponse of the polarity change on the surface of the polymeric adsorbent. The morphology of the erythrocytes which adhered on the surface of the photoresponsive polymeric adsorbent remained unchanged both in the dark and after UV irradiation. The amount of erythrocytes which adhered to the adsorbent increased with increasing the molecular weight of the grafted polymer and the hydrophobicity of the surface.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1983.070280406
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  • 10
    Electronic Resource
    Electronic Resource
    Effect of hydrophilic and hydrophobic microdomains on mode of interaction between block polymer and blood platelets (1981)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 15 (1981), S. 393-402 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: ABA-type block copolymers composed of 2-hydroxyethyl methacrylate (HEMA), a hydrophilic monomer, and styrene (St), a hydrophobic monomer, were synthesized by the coupling reaction of telechelic oligomers used as prepolymers. These block copolymers may be represented as microphase-separated structures. It is therefore possible to change the balance between hydrophilicity and hydrophobicity in the level of an assembled order of macromolecules. In response to the relative composition of the copolymers, three typical morphological patterns were observed in electron microscopic photographs: dispersed domains of continuous St chains in the region of HEMA chains, alternate HEMA and St lamellae and finally, dispersed phases of continuous HEMA chains in the region of St chains. The effect of the hydrophilic and hydrophobic microdomains of the copolymers on the mode of interaction between polymers and platelets was studied by the microsphere column method. In the case of homopolymers and random copolymers, a significant degree of platelet adhesion and aggregation was observed. However, the degree of platelet adhesion and deformation was suppressed on the surfaces of the block copolymers containing 0.608 and 0.347 mole fractions of HEMA whose microdomains were hydrophilic-hydrophobic lamellae and isolated hydrophilic islands in hydrophobic areas, respectively. These results show that the microphase-separated structures were antithrombogenic and prevented platelet adhesion and deformation. On the basis of the results obtained, the interaction between platelets and polymer surfaces was described in terms of the effect of hydrophilic and hydrophobic microdomains.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820150310
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