Comparative histological and electron microscopic study of mouse tissues at the site of implantation of Cousin mesh and unwoven
polypropylene endoprostheses was carried out. Implantation of unwoven endoprosthesis was associated with more pronounced inflammatory
reaction with longer elimination of neutrophilic granulocytes and macrophages from the adjacent tissues. The growth of connective
tissue components between the implant fibers with the formation of fine connective tissue capsule enveloping the prosthesis
was observed during earlier periods of the experiment.
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Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 143, No. 5, pp. 595–600, May, 2007 相似文献
This study investigates the efficiency of carbon nanotubes (CNTs) as reinforcement for polypropylene (PP) for biocompatible application as a function of different surface functionalization of CNTs. PP composites were reinforced using various CNTs: single- and multi-walled carbon nanotubes (SWCNTs, MWCNTs), SWCNTs were covalently functionalized by plasma, for comparison, the MWCNTs were functionalized noncovalently. Different CNTs were incorporated into PP by solution blending. The type of CNTs and surface functionalization affects the mechanical and biocompatibility results significantly. Differences in nanostructure and the chemical compositions, number of functional groups, and structural defects for the CNTs may be the key factors affecting the mechanical properties and biocompatibility of PP nanocomposites compared to the neat PP. Finally, suitable CNTs and surface functionalization of CNTs were selected for making the PP/CNTs composites. 相似文献
Background. A membrane oxygenator consisting of a microporous polypropylene hollow fiber with a 0.2-μm ultrathin silicone layer (cyclosiloxane) was developed. Animal experimental and preliminary clinical studies evaluated its reliability in bypass procedures.
Methods. Five 24-hour venoarterial bypass periods were conducted on dogs using the oxygenator (group A). In 5 controls, bypass periods were conducted using the same oxygenator without silicone coating (group B). As a preliminary clinical study, 14 patients underwent cardiopulmonary bypass with the silicone-coated oxygenator.
Results. Eight to 16 hours (mean, 12.2 hours) after initiation of bypass, plasma leakage occurred in all group B animals, but none in group A. The O2 and CO2 transfer rates after 24 hours in group A were significantly higher than at termination of bypass in group B (p < 0.005 and p < 0.03, respectively). Scanning electron microscopy of silicone-coated fibers after 24 hours of bypass revealed no damage to the silicone coating of the polypropylene hollow fibers. In the clinical study, the oxygenator showed good gas transfer, acceptable pressure loss, low hemolysis, and good durability.
Conclusions. This oxygenator is more durable and offers greater gas transfer capabilities than the previous generation of oxygenators. 相似文献