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1

Digitale Medien

Hollow fiber membrane oxygenator (1971)

Skiens, W. E. ; Lipps, B. J. ; Clark, M. E. ; [weitere]

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 5 (1971), S. 135-148

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ISSN: 0021-9304

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Medizin , Technik allgemein

Notizen: Hollow fibers have been produced and evaluated for use as membrane oxygenators in an artificial heart device. Gas permeable capillaries now commercially available are unsuitable for this use because of: (1) low percent open cross-sectional area, (2) large internal diameter, and (3) high cost. A number of polymers were initially selected for evaluation because of their reported high gas permeabilities. Those selected include a number of rubbers of various compositions, certain poly-α-olefins and an experimental thermoplastic silicone rubber copolymer. These materials were first evaluated as flat membranes (films) for their gas permeabilities and also for ease of preparation in hollow fiber form. Hollow fibers were prepared from the most promising of those studied, poly-4-methylpentene-1 and the thermoplastic polydimethylsiloxane copolymer. Fibers, ranging in the size from 30 to 300 μ ID, were spun with open cross-sectional areas of 40-65%. Oxygen and carbon dioxide permeabilities measured on these fibers were compared to that of SilasticDow Corning medical grade poly (dimethylsiloxane). rubber membranes. These permeabilities range from 1/20 that of Silastic rubber for unmodified poly-4-methylpentene-1 to 2/3 for the thermoplastic silicone copolymer. Modification of poly-4-methylpentene-1 has made it possible to increase it's permeability by tenfold, while still maintaining physical properties necessary to spin and fabricate this material.

Zusätzliches Material: 1 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jbm.820050214

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2

Digitale Medien

Elemental carbon as a biomaterial (1971)

Benson, Jim

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 5 (1971), S. 41-47

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ISSN: 0021-9304

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Medizin , Technik allgemein

Notizen: Advanced forms of elemental carbon were identified as potential implantable prosthetic materials and a study was conducted to determine specific applications. A survey of the carbon industry established material sources and specifications on available types of material. Specimen materials were supplied to several research organizations for in-vivo evaluation and produced acceptable results. Specific designs have been generated for a broad range of implantable prosthetics and prototypes have been provided for preliminary evaluation. The feasibilty of an organic mechanical attachment between cortical bone tissues and elemental carbon has been successfully demonstrated.

Zusätzliches Material: 3 Tab.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jbm.820050607

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3

Digitale Medien

Initial surface interaction of blood and blood components with Al2O3 and TiO2 (1971)

Hulbert, S. F. ; King, F. M. ; Klawitter, J. J.

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 5 (1971), S. 69-89

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ISSN: 0021-9304

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Medizin , Technik allgemein

Notizen: The success of material implants in the vascular system has been limited by the fact that the intial events of blood coagulation on foreign material surfaces are not understood. Many materials have been evaluated in the search for a suitable implant material in this system. Recent success of porous ceramic materials in bone-ceramic compatibility studies stimulated the feeling that these materials should be tested in other body tissues such as the blood.Ceramic disks of Al2O3 and TiO2 were evaluated using a contact angle measurement technique to determine the characteristics of these material surfaces before and after exposure to a blood environment. This technique involved measuring the contact angle of sessile drops of various liquids on these surfaces with a microscope fitted with a goniometer eyepiece. By plotting these contact angles according to the procedure of Zisman, the characteristics of the surfaces could be evaluated.The clean ceramic disks were found to be extremely wettable even after exposure to a physiological saline environment. On exposure of these disks to a blood environment, it was observed that some type of film was adsorbed from the blood onto the ceramic surface during the initial minutes of exposure. This film had wetting characteristics consistent with layers of fibrinogen.

Zusätzliches Material: 4 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jbm.820050609

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4

Digitale Medien

Skeletal extension of limb prosthetic attachments-problems in tissue reaction (1971)

Mooney, Vert ; Predecki, Paul K. ; Renning, James ; [weitere]

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 5 (1971), S. 143-159

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ISSN: 0021-9304

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Medizin , Technik allgemein

Notizen: The skeletal attachment of a limb prosthesis approaches two specific and separate problems in tissue reaction to prosthetic materials: Skeletal fixation and trancutaneous interface.The skeletal fixation problem must be looked upon as a method to distribute the stress concentration of prosthetic material in such a manner so that living tissue is not embarrassed by prolonged excessive pressures. One must consider the functional mechanical stresses separate from the toxicological reaction of living tissues to prosthetic materials. Our current experience identifies the fact that vitreous carbon is extremely benign from the standpoint of living tissue reaction. Moreover, when placed in the configuration of irregular surfaces, it apparently encourages bone growth contiguous with the material. To this point, however, the reaction of living material to broad surfaces contiguous with vitreous carbon has not placed under concentration of functional stresses. Porous ceramic to this date has not supplied an appropriate answer to this problem.Transcutaneous perforation is available in the clinical sense only when a method can be presented which requires no specific hygiene and dressing. No drainage at all must be the rule at a transcutaneous perforation. Vitreous carbon in our experience so far has made contiguous epithealization feasible down the neck of a skin perforation. Four millimeters, from our experience, seems to be an appropriate location of epithelial downgrowth before transition into non epithealized connective tissue is available. The use of fixation skirts is felt to be necessary to provide stable, transcutaneous perforation.This paper presents evidence of the favorable tissue reaction both from a skeletal and cutaneous standpoint to vitreous carbon materials. A specific design for the successful skeletal fixation limb prosthesis is as yet not currently available and must await further clinical experience with human skin reaction to transcutaneous devices.

Zusätzliches Material: 12 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jbm.820050612

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5

Digitale Medien

Ceramics in surgery (1971)

Welsh, R. P. ; Macnab, Ian

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 5 (1971), S. 231-249

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ISSN: 0021-9304

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Medizin , Technik allgemein

Notizen: A study has been made of the ceramic-epoxy composite “Cerosium.” Experiments were conducted to evaluate the tissue reaction to such material and the extent of bonding established between ceramic and the tissues in which it was implanted. It was found that this material was well tolerated by the body and obtained definite fixation within the tissues when implanted into both bone and tendon. This occurred, however, not by the active infiltration of tissue but by fibrous encapsulation and it is recommended that for more meaningful stabilization, material of larger pore size is required.When Cerosium was implanted into the knee joints of rabbits, it was found to be unsuitable for intra-articular use because of the abrasive effect on the opposing cartilage and bone surfaces and the susceptibility of the material itself to abrasive wear. Furthermore, a full mechanical evaluation of standard specimens of Cerosium showed it to be degraded within the body due to a breakdown of the impregnating polymer.Ceramic-epoxy composites require a strong matrix and a totally stable impregnating material. While mechanically suited to replacing weight bearing surfaces, a smooth surface glaze is essential to avoid abrasive effects upon the opposing bone surface. Further investigation is required before these materials can be fully accepted into the armamentarium of the implant surgeon.

Zusätzliches Material: 19 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jbm.820050614

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6

Digitale Medien

An evaluation of inert and resorbale ceramics for future clinical orthopedic applicationsResearch Supported by the University of Dayton, Dayton, Ohio. (1971)

Hentrich, R. L. ; Graves, G. A. ; Stein, H. G. ; [weitere]

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 5 (1971), S. 25-51

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ISSN: 0021-9304

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Medizin , Technik allgemein

Notizen: The compatibility of implanted ceramic materials with autogenous bone, and the subsequently noted influence of the ceramic on the rate of new bone formation, were investigated to evaluate such materials for use in orthopedic implants. Three ceramic materials, aluminium oxide (Al2O3), zirconium oxide (ZrO2), and calcium aluminate (yCaO · xAl2O3) were tested. These were placed in the femurs of rhesus monkeys for periods of 50, 100, and 350 days. Definite compatability between the autogenous bone and the materials was exhibited for the implant time periods evaluated. No toxicogenic activity was noted in any of the biochemical, biomedical, and ceramographic evolutions. An added benefit resulted from the calcium aluminate composition, which was fabricated as a two-phase oxide material to make it slightly soluble in the body fluids. In the 50- and 100- day implants, the bone penetrated the ceramic for distances up to 100 μ while the ceramic dissolved and the pores enlarged. In addition, the mineralization in the area of the calcium aluminate was greater than that found around the other ceramics. Radiographs over the entire 350-day implant period confirmed the increased callus formation around all of the materials with no signs of rejection evident in the surrounding osseous or soft tissues. After 350 days the entire pore area of the calcium aluminate ceramic was infiltrated with a columnar substance which on the basis of scanning electron microscope procedures was considered to be mineralized osteoid.

Zusätzliches Material: 17 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jbm.820050104

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7

Digitale Medien

Amino acid polymers for biomedical applications. I. Permeability properties of L-leucine DL-methionine copolymers (1971)

Martin, E. C. ; May, P. D. ; McMahon, W. A.

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 5 (1971), S. 53-62

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ISSN: 0021-9304

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Medizin , Technik allgemein

Notizen: A series of DL-methionine/L-leucine copolymers was prepared from the coresponding N-carboxy-anhydrides. The copolymers formed clear flexible films having low water vapor transmission rates. Peroxide oxidation of the pendant methyl-theioethyl groups to methyl-sulfinoethyl groups enhanced the hydrophilic properties of the membranes, and the water vapor transmission rates rapidly increased with an increase in the number of pendant methyl-sulfinoethyl groups. Increasing the leucine content of the membranes produced a 13-fold increase in the carbon dioxide permeability and a 6-fold increase in oxygen permeability, whereas, an increase in the methionine content doubled the carbon dioxide-oxygen separation factor.Synthetic poly (α-amino acids) are very similar to naturally occurring proteins with respect to composition and conformation. Because of these similarities, they are being considered in aerosol spray bandages, synthetic skin applications and as coatings for plastic prostheses. The unusual permeability characteristics of the DL-methionine/L-leucine copolymers make them interesting membranes for possible use in artificial kidney machines and blood oxygenators.

Zusätzliches Material: 4 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jbm.820050105

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8

Digitale Medien

Flexural properties of equine metacarpus (1971)

Bynum, D. ; Ledbetter, W. B. ; Boyd, C. L. ; [weitere]

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 5 (1971), S. 63-79

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ISSN: 0021-9304

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Medizin , Technik allgemein

Notizen: The flexural tests on 37 whole equine metacarpus bones are described and the results are given in terms of fundamental material properties as a function of age. The moduli of elasticity, rupture, and failure increase then decrease with increasing age. The rupture and failure deformations decrease with age. The stiffness and fragility indices increase with age. Averaging the data for all ages, the modulus of rupture was 35 ksi, the deflection at rupture was 0.22 inches, and the modulus of elasticity was 1.7 × 10 psi. The flexural rupture strength is about twice the uniaxial compression strength and about five times greater than the torsional strength for whole bone tests. The moduli of elasticity are about the same for flexure and uniaxial compression, and about five times greater than the torsional modulus of rigidity for whole equine bone.

Zusätzliches Material: 9 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jbm.820050106

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9

Digitale Medien

Masthead (1971)

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 5 (1971)

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ISSN: 0021-9304

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Medizin , Technik allgemein

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jbm.820050201

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10

Digitale Medien

Microvascular and histogenic responses to implantation of a porous ceramic into boneThis paper was presented in part at the annual meeting of the American Academy of Implant Dentists, Washington, D. C., Dec. 1967, and at the Gordon Research Conference on Science and Technology of Biomaterials, Holderness, N. H., June 1968. (1971)

Rhinelander, Frederic W. ; Rouweyha, Marwan ; Milner, John C.

Hoboken, NJ : Wiley-Blackwell

Journal of Biomedical Materials Research 5 (1971), S. 81-112

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ISSN: 0021-9304

Schlagwort(e): Chemistry ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Medizin , Technik allgemein

Notizen: A porous ceramic, in the form of small discs, has been implanted into the upper tibiae of adult mongrel dogs in survival experiments. A similar sized disc of a metal (vitallium, titanium, or stainless steel) was also implanted, for comparison, into each tibia. The tissue specimens were studied by microangiography and correlated histology. At the 4-month, and longer, intervals, the specimens were sectioned with the ceramic disc in situ. Injected capillaries were then observed to have penetrated the ceramic.The metals became surrounded by a shell of new-bone, lined by a fibrous membrane of varying thickness. The ceramic implants, on the other hand, appeared to have remained inert within the cancellous area of the tibiae, not surrounded by either a membrane or an osseous shell.Implications of these findings were discussed and further experiments, some of which are in progress, were proposed.

Zusätzliches Material: 22 Ill.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1002/jbm.820050107

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