摘要:

AbstractA significant variation occurred in the inflammatory response to polyethylene and polyurethane when embedded subcutaneously in experimental animals. This variation apparently is related to the composition of the plastic and adsorption of proteins. The attraction of polymorphonuclear leucocytes by plastics apparently is related to the electrostatic and/or electrokinetic imbalance that occurs at or near the site of implantation.Polyurethane and polyethylene were selected for this study since preliminary observations had shown a variation in inflammatory response when they were embedded subcutaneously in the mouse. From this study it is evident that: (1) variations occurred in the inflammatory reaction in the subcutaneous tissue of mice and rabbits following the embedding of polyethylene and polyurethane; (2) polymorphonuclear leucocytes began to emigrate within hours after these two plastics were implanted, reaching their maximum number within 24 to 48 hr; (3) polymorphonuclear leucocytes usually were absent after the 6th experimental day in mice with polyurethane, but were present for 232 days in mice with polyethylene; (4) polymorphonuclear leucocytes were present in the rabbit for only a few days following subcutaneous implantation of polyethylene and polyurethane; and (5) leucocytes around the implanted polyurethane in the rabbit began to degenerate within 48 hr. The mechanism for this degeneration is not known.

ISSN:0021-9304    

DOI:10.1002/jbm.820080202

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractA controlled surface shear stress produced by laminar flow in a rotating disk or parallel plate flow system has been used to study red cell adhesion to glass, siliconized glass, polythylene and Teflon. The results indicate that the shear stress at the surface must exceed a minimum critical value before cells will detach, and that this minimum critical shear stress increases as the time of cellsurface contact is increased. The results also indicate that the minimum critical shear stress for detachment from clean surfaces correlates with the critical surface tension of the material for the four materials studied. Studies with proteincoated surfaces indicate that albumin causes a moderate reduction in the strength of adhesion. The magnitude of the effect was found to be influenced significantly by the substratum material.

ISSN:0021-9304    

DOI:10.1002/jbm.820080203

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractMany types of materials are being used as biomaterials, and there is a continuing search for more and better materials for specific pur poses. In this investigation, a new method was employed in screening materials in an effort to cut costs, save time, and have a worthwhile indication of the prospect of a new material. Samples of twenty gauge wires of stainless steel 316, stainless steel 304, Titanium 40, Vitallium, and copper were introduced into leg or wing muscles of 18‐day‐old chick embryos.This was accomplished by opening the egg shell with a dental drill, implanting the material, and reclosing the shell. The chicks were allowed to hatch and were later sacrificed after eleven days, giving a total implant time of 14 days. This time period allowed for the acute inflammation that occurred during wound healing to subside. The sections were retrieved, embedded in epon 812, sectioned with a diamond saw, and histologically evaluated.Copper was used for the negative control and showed the greatest adverse tissue response. Titanium 40 showed almost no response and stainless steel 316 showed very little. Stainless steel 304 exhibited a somewhat greater response than the stainless steel 316. All of the materials except wrought Vitallium used in this experiment gave predicted resu

ISSN:0021-9304    

DOI:10.1002/jbm.820080204

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractIn our earlier papers1–4we reported on the biocompatibility of esters and substituted amides of methacrylic and acrylic acids which are suitable for the development of specific biological functions.5The results described in these papers1–4enabled some relationships to be formulated which exist between the chemical and physical structure of the implants, on the one hand, and the process of their healing‐in and calcification, on the other.6.A number of biological applications require materials having rubber‐like mechanical properties. With this aim we started in our laboratory the development of hydrophilic elastomers based on dienes containing hydrophilic groups. Poly(2,4‐pentadiene‐1‐ol)7was the first polymer of this type obtained which had mechanical properties suited for biomedical applications. Its biocompatibility with living tissue is reported

ISSN:0021-9304    

DOI:10.1002/jbm.820080205

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

摘要:

AbstractWe examined the formation of platelet aggregate emboli and factors that affect platelet aggregate formation and embolization in prototype hollow‐fiber membrane oxygenators used to perfuse dogs. Platelet aggregates formed on the inlet surface of the oxygenator. Many aggregates subsequently formed emboli which passed through the fibers and sometimes lodges in them. Aggregates also developed on the outlet surface. Aggregates that adhered to the oxygenator surfaces contained tightly packed platelets having multiple pseudopodia extracellular granules, and occassional fibrin strands and white cells. The number of platelet aggregate emboli found downstream to the oxygenator varied between 0 and 4 emboli/ml blood. These emboli did not contain fibrin and extracellular granules. Platelet aggregate formation and embolization was reduced or eliminated by increasing the dose of heparin or by using a circuit with a large priming volume of albumin solution and a large surface area oxygenato

ISSN:0021-9304    

DOI:10.1002/jbm.820080206

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820080207

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820080208

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY

ISSN:0021-9304    

DOI:10.1002/jbm.820080201

出版商:John Wiley&Sons, Inc.    

年代:1974

数据来源: WILEY