摘要:

AbstractMaterials to enhance cell adhesion were synthesized by surface integration of peptide, Arg‐Gly‐Asp‐Ser(RGDS), which is an active‐site sequence of cell‐adhesive proteins. Polystyrene film was glowdischarged and graft‐copolymerized with acrylic acid. Then the peptide was immobilized to the poly(acrylic acid) grafts by using water‐soluble carbodimide. The cell‐adhesive activity of the RGDS‐immobilized film increased with increasing amount of immobilized peptide, and approached the activity of fibronectin(FN)‐immobilized film. The RGDS‐immobilized film was more stable against heat treatment and pH variation than the FN‐immobilized film. In addition, the RGDS‐immobilized film enhanced cell growth more strongly tha

ISSN:0021-9304    

DOI:10.1002/jbm.820251102

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractThe influence of aluminum ions introduced either directly or with sorbitol, in collagen and skin, has been investigated by Thermally Stimulated Current/TSC spectoscopy. The intramolecular mobility of collagen has been found to be significantly reduced by aluminum ions. The substitution of water molecules by aluminum ions on intramolecular hydrophilic sites is suggested to be responsible for this evolution. The presence of sorbitol minimizes this effect. The intermolecular mobility of collagen is decreased upon introduction of aluminum ions introduction of aluminum ions in presence of sorbitol. This result can be explained by the interaction of sorbitol‐aluminum entities with the telopeptidic regions of collagen molecules. In skin samples, the intra‐ and intermolecular mobilities are restored due to the combined actions of sorbitol and noncollagenous proteins and other macromolecu

ISSN:0021-9304    

DOI:10.1002/jbm.820251103

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractSynthesis of nonthrombogenic materials without using biologically active substances was explored. Poly(sodium vinyl sulfonate) is a water‐soluble synthetic polymer and activates antithrombin III to exert nonthrombogenicity that was dependent on the molecular weight. Polyetherurethaneurea film was plasmatreated and graft‐polymerized with sodium vinyl sulfonate. The graft film showed excellentin vitroandex vivononthrombogenicity by suppressing interactions with plasma proteins and platelets as well as by inactivating bloodclotting fact

ISSN:0021-9304    

DOI:10.1002/jbm.820251104

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractPrevious studies on surface structural changesin vitroas well asin vivoof bioactive A‐W‐type glass‐ceramics and Bioglass‐type glasses showed that the essential condition for glasses and glassceramics to bond to living bone is formation of a bonelike apatite layer on their surfaces in the body. Gross et al., however, had explained the bone‐bonding mechanism of Ceravital‐type apatitecontaining glass‐ceramic without mentioning formation of the surface apatite layer. In the present study, apatite formation on the surface of one of Ceravitaltype glass‐ceramics was investigatedin vitroas well asin vivo.An apatitecontaining glass‐ceramic of the composition Na2O 5, CaO 33, SiO246, Ca(PO3)216 wt%, which was named KGS by Gross et al., was soaked in an acellular simulated body fluid which had ion concentrations almost equal to those of the human blood plasma. The same kind of glassceramic was implanted into a rabbit tibia. Thin‐film x‐ray diffraction, Fourier transform infrared reflection spectroscopy, and scanning electron microscopic observation of the surfaces of the specimens soaked in the simulated body fluid showed that Ceravital‐type glass‐ceramic also forms a layer of carbonate‐containing hydroxyapatite of small crystallites and/or a defective structure on its surface in the fluid. Electron probe x‐ray microanalysis of the interface between the glassceramic and the surrounding bone showed that a thin layer rich in Ca and P is present at the interface. These findings indicated that Ceravital‐type glassceramics also form the bonelike apatite layer on its surface in the body and bond to living

ISSN:0021-9304    

DOI:10.1002/jbm.820251105

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractPolyurethanes chain extended withN,N‐bis(2‐hydroxyethyl)‐2‐aminoethanefulfonic acid (BES) were synthesized. The effect of the sulfonic acid group on the polymers' bulk, surface, and bloodcontacting properties was evaluated by comparing the BES‐based polymers with polyurethanes based onN‐ethyldiethanolamine (EDEA). In addition, the effect of soft‐segment polarity was addressed by comparing polyurethanes based on polyetetramethylene oxide (PTMO) (MW = 1000) with polymers based on polyethylene oxide (PEO) (MW = 1000). The EDEA control samples had physical properties similar to a viscous fluid. The presence of the sulfonic acid group dramatically enhanced the degree of microphase separation and the mechanical strength of all the polymers. The more polar PEO soft segment resulted in polymers which were more phase mixed than the PTMO‐based polyurethanes. Surface characterization studies revealed that in vacuum, all the surfaces were enriched in the polyether soft‐segment phase. After 24‐h equilibration in water, all the surfaces had similar surface polarities independent of the SO3H content. The canineex vivoblood‐contacting results showed that the sulfonic acid group in the PTMO‐based polymers significantly reduced the number and activation of the adherent platelets. Fibrinogen deposition, however, increased with increasing sulfonic acid content. In contrast, platelet and fibrinogen deposition on the sulfonic acidcontaining PEO‐based poly

ISSN:0021-9304    

DOI:10.1002/jbm.820251106

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractProtein adsorption from human plasma was investigated on phospholipid polymers, poly (2‐methacryloyloxyethyl phos‐phorylcholine (MPC)‐co‐n‐butyl methacrylate (BMA)) or glass by radioim‐munoassay and immunogold labeling techniques. In the present studies the focus was to determine the composition and distribution of proteins at the surface of these materials after contact with human blood plasma. On all materials, protein adsorption was detected and included identification of albumin, IgG, fibrinogen, fibronectin, Hageman factor (factor XII), factor VIII/von Willebrand factor, high‐molecular‐weight kininogen (HMWK) and the complement protein C5. The amount of protein adsorbed decreased with an increase in MPC composition and appeared to adsorb to the surfaces in a uniform and evenly distributed manner. Therefore, we suggest that MPC moieties play an important role in suppression of protein adsorption. From these findings, it is concluded that the reduction of protein adsorption at the blood contacting surface of phospholipid polymers may result in the inhibition of thr

ISSN:0021-9304    

DOI:10.1002/jbm.820251107

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

摘要:

AbstractIn a recent study, we showed that the presence of gentamicin in Palacos R or erythromycin plus colistin in Simplex P bone cement did not significantly decrease the fatigue strength of the cement. [J. P. Davies, D. O. O'Connor, D. W. Burke, and W. H. Harris, “Influence of antibiotic impregnation on the fatigue life of Simplex P and Palacos R acrylic bone cements, with and without centrifugation,”J. Biomed. Mater. Res.,23, 379–397 (1989)] However, the commercially prepared Palacos R with Gentamicin and A K Z (Simplex P with colistin and erythromycin) which were tested are not approved by the FDA for use in the United States. Because of this, many surgeons in the United States hand mix tobramycin with the cement in the operating room if a case calls for the use of antibioticimpregnated cement. In this study, we determined the effect of adding 1.2 g of tobramycin to one pack (40 g) of Simplex P powder on the fatigue strength of the cement. The effect of centrifugation on the fatigue strength of Simplex P with the tobramycin added was also assessed. Simplex P was prepared according to the manufacturer's instructions with and without the addition of 1.2 g tobramycin per 40‐g pack and with and without centrifugation. Fifteen specimens of each of the four cement preparations were tested in fully reversed tension‐compression fatigue at ± 15 MP a, 2 H z. The fatigue strength of the uncentrifuged and centrifuged Simplex P was not significantly reduced by the tobramycin. Centrifugation significantly increased the fatigue life of Simplex P both with and without the addition of tobramycin. The fatigue life of the Simplex P with tobramycin was increased by a factor of 8 by cent

ISSN:0021-9304    

DOI:10.1002/jbm.820251108

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820251109

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820251101

出版商:John Wiley&Sons, Inc.    

年代:1991

数据来源: WILEY