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  • 1
    Electronic Resource
    Electronic Resource
    Fracture of porous polyethylene-bone composite (1983)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 17 (1983), S. 59-70 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Porous high-density polyethylene specimens were implanted in the femurs of mongrel canines. At the end of the residency period (3 or 6 months), the animals were sacrificed and the implants were retrieved. The work-of-fracture of the implant specimens was then determined using the technique of Tattersall and Tappin. The work required to fracture a specimen in three-point bending by controlled crack propagation through a triangular cross section was obtained directly from the load-deflection curve. The area of the resulting fracture surface was measured by macro-photographic techniques, and the work-of-fracture was calculated as work per unit area. The implants were subsequently sectioned and examined microradiographically to determine the extent of bone ingrowth. Bone specimens adjacent to the implants and porous high-density polyethylene controls (no ingrowth) were also tested to determine their work-of-fracture. The results showed that bone adjacent to the implant specimens had a higher work-of-fracture than normal medial, canine femoral bone and was not appreciably different from the composite. The work-of-fracture of porous high-density polyethylene was not significantly increased by an increase in bone infiltration, and this anomalous behavior was attributed to a degradation of the polyethylene during implant residence. Control studies supported this hypothesis.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820170106
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  • 2
    Electronic Resource
    Electronic Resource
    Grafted synthetic sorbents for enhanced removal of toxic chemical agents from plasma (1983)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 17 (1983), S. 993-1002 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: A series of porous polymeric sorbents and activated carbon were used to remove di-isopropyl methylphosphonate (DIMP) from human plasma and normal saline. The sorptive capacities of the commercially available sorbents Amberlite XAD-4, XAD-2, XN1010, and XE348, and Calgon 400 were determined. Butyl- and palmityl-grafted XAD-4 were prepared with graft efficiencies of 32 and 6%, respectively, and tested for sorptive capacities. DIMP removal efficiencies were compared to dialysis with a 1.8 m2 Cordis-Dow hollow fiber artificial kidney (HFAK). Butyl-grafted XAD-4 and active carbon outperformed the other sorbents in removing DIMP from both saline and plasma. An order of magnitude reduction in removal ability was noted for all the adsorbents when the mobile media was plasma. Pronounced plasma precipitation was elicited by activated carbon, an effect not observed with any of the polymeric resins tested. The removal efficiencies on a 18.0 g basis of XAD-4, butyl-grafted XAD-4, and active carbon were comparable to that of the HFAK used in this study. These sorbents, however, possess a macroscopic surface area of approximately 0.1 m2, an order of magnitude lower than that of the HFAK. This reduction in contact area is believed to reduce substantially the possibility of undesirable molecular and cellular effects.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820170609
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  • 3
    Electronic Resource
    Electronic Resource
    Comments on the origin of platelet deposition1 and on cell adhesion to biomaterial surfaces2 (1983)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 17 (1983), S. 375-381 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820170213
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  • 4
    Electronic Resource
    Electronic Resource
    Stiffness and inelastic deformation in acrylic-titanium composite implant materials under compression (1983)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 17 (1983), S. 973-991 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: A variety of acrylic bone cement-metal composite materials were prepared and tested in simple compression at 37°C in order to evaluate the mechanical behavior of these materials for possible use in bone replacement. The stiffness of the composite was of particular concern, and a simple rule of mixture was used to raise the modulus of acrylic bone cement. The reinforcement of the cement was accomplished by titanium and Ti-6A1-4V in different forms, e.g., wire, sheet, wire mesh, and powder. Test results demonstrated that the stiffness of the bone cement could indeed be increased by a desired amount to that of bone. A 16% volume fraction consisting of 25 0.10 cm diam Ti-6A1-4V wires increased the modulus of the bone cement by 380% to a value comparable to the modulus of cortical bone. Titanium sheet was nearly as effective as wires in increasing the modulus of bone cement, while titanium mesh was not a significantly effective reinforcing material. The amount of titanium powder added to the bone cement did not alter the compliance of the matrix material. In addition, as the flow strength increased, the strain to the point of load instability decreased. It was concluded that the extent of stiffening was governed by nonuniform deformation in the metal and the adjacent matrix which could be explained on the basis of geometrical considerations. Some of the limitations of the test results as well as methods of predicting the composite implant material behavior are also outlined.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820170608
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  • 5
    Electronic Resource
    Electronic Resource
    Suitability of pigmented polyvinylide fluoride encapsulated wire for implantation in the dog (1981)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 15 (1981), S. 111-113 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820150115
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  • 6
    Electronic Resource
    Electronic Resource
    Erratum (1983)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 17 (1983), S. 392-392 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820170216
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  • 7
    Electronic Resource
    Electronic Resource
    Surface modification and evaluation of some commonly used catheter materials. I. Surface propertiesSubmitted by P. T. in partial fulfillment of the requirements for the M.S. Degree in Bioengineering, University of Utah, Salt Lake City, UT 84112. (1983)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 17 (1983), S. 129-147 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Double catheter systems consisting of a stiff outer catheter and a flexible, buoyant, flow-directed, inner catheter which is often balloon-tipped have been employed with increasing frequency recently in both therapeutic and diagnostic procedures. Their use, however, has been restricted because of the excessive friction generated between the two catheters. In an attempt to decrease friction between polymers commonly used as catheter materials, oxidation of polyethylene, fluorinated ethylene-propylene copolymer, poly(vinyl chloride), silicone rubber, and polystyrene surfaces was induced by exposing the polymers to radio frequency glow discharge (RFGD) in a helium environment. All polymers were surface characterized utilizing x-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and contact angle measurements before and after oxidation. This article describes the materials and methods used to fabricate and characterize the polymer surfaces and the results of the characterization. The results indicate that increases in oxygen concentration at the surface of the polymers and decreases in air-water contact angles occur with increased RFGD exposure time. Plateau values were usually obtained after 5-30 s exposure time, yet no apparent changes in surface topography were noted by scanning electron microscopy. The hydrophilic surfaces produced were stable for up to three months storage time in air.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820170111
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  • 8
    Electronic Resource
    Electronic Resource
    Effect of surface texture on the soft tissue response to polymer implants (1983)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 17 (1983), S. 205-227 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Ion beam etching has provided a system which can produce a controllable surface morphology in the micron range without altering surface chemistry or surface energy. PTFE (polytetrafluoroethylene) develops a surface texture having conical projections with average dimensions: height = 12 μm, base width = 4 μm, tip radius = 0.1 μm. Smooth and textured PTFE disks (1 cm diam. × 250 μm thick) were implanted subcutaneously into the dorsum of Sprague-Dawley rats for time periods of 1 and 3 days and 1,2,3,4, and 8 weeks. Smooth control samples consisted of untreated surfaces and surfaces that were exposed to an ion beam environment producing a smooth surface. All smooth surfaces behaved identically by both histochemical and histological methods. Consequently, the ion beam environment had no effect on the soft tissue response. Textured surfaces, however, demonstrated increased cell adhesion and increased succinic dehydrogenase and acid phosphatase staining in the interfacial cells. Interfacial cells consisted of foreign body giant cells and macrophages. These macrophages possessed increases in the cytoplasmic-to-nuclear ratio, number and interdigitation of filopodia, and vacuolization as demonstrated by TEM. The textured surfaces also influence the kinetics of fibrous capsule formation. At 8 weeks, capsules associated with textured interfaces were reduced in thickness by 30% when compared to smooth surfaces. The results of this investigation demonstrate that the surface texture of an implant is a critical variable in determining the soft tissue response to a material.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820170202
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  • 9
    Electronic Resource
    Electronic Resource
    In vivo and in vitro aging of orthopedic aluminas (1983)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 17 (1983), S. 395-410 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: The flexural strength, microstructure and relative Ca and Si concentration at the surface of two commercial orthopedic aluminas were studied before and after aging up to 52 weeks in simulated body fluids or in subcutaneous implantation in rodents. There was no significant reduction in flexural strength after aging, but there was evidence of Ca and Si dissolution from the external grain boundary surfaces, particularly for specimens aged in demineralized water. No change occurred in the Ca and Si concentrations within the specimen's bulk during either in vivo or in vitro aging.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820170302
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  • 10
    Electronic Resource
    Electronic Resource
    Biochemical features of pseudomembrane at the bone-cement interface of loosened total hip prostheses (1983)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Biomedical Materials Research 17 (1983), S. 669-678 
    Details
    ISSN: 0021-9304
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine , Technology
    Notes: Biochemical features of pseudomembrane formed at the bone-cement interface of 13 failed total hip replacements were studied and histological examination of the pseudomembrane was conducted. The results of biochemical analyses revealed on average hydroxyproline, 86 μg/mg; water content, 57%; hexosamine, 12 μg/mg; glucosamine/galactosamine, 1.4%; and calcium, 2.1%. Approximately 78% of collagen was extracted with pepsin, whereas only 8 and 0.3% collagen were extracted with acetic acid and neutral salt, respectively. On further differential salting out of the extracted collagen, about 77% was type I collagen, 19% type III, and 2.6% type V. Unlike pseudoarthrosis of fracture, no type II collagen was identified. Overall biochemical features in the light of the histological appearance suggested that pseudomembrane resembles granulation tissue. Bone healing mechanisms at the bone-cement interface appear to differ from that of fracture healing.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jbm.820170411
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