Search results for "Thrombogenicity"
showing 6 items of 6 documents
Wet Chemistry and Peptide Immobilization on Polytetrafluoroethylene for Improved Cell-adhesion
2016
Endowing materials surface with cell-adhesive properties is a common strategy in biomaterial research and tissue engineering. This is particularly interesting for already approved polymers that have a long standing use in medicine because these materials are well characterized and legal issues associated with the introduction of newly synthesized polymers may be avoided. Polytetrafluoroethylene (PTFE) is one of the most frequently employed materials for the manufacturing of vascular grafts but the polymer lacks cell adhesion promoting features. Endothelialization, i.e., complete coverage of the grafts inner surface with a confluent layer of endothelial cells is regarded key to optimal perfo…
Bioengineered vascular scaffolds: the state of the art
2014
To date, there is increasing clinical need for vascular substitutes due to accidents, malformations, and ischemic diseases. Over the years, many approaches have been developed to solve this problem, starting from autologous native vessels to artificial vascular grafts; unfortunately, none of these have provided the perfect vascular substitute. All have been burdened by various complications, including infection, thrombogenicity, calcification, foreign body reaction, lack of growth potential, late stenosis and occlusion from intimal hyperplasia, and pseudoaneurysm formation. In the last few years, vascular tissue engineering has emerged as one of the most promising approaches for producing …
Modified Silk with Cell-Adhesive and Non-Thrombogenic Properties as a Tissue Engineering Substrate
2016
IntroductionReplacement of damaged tissue is nowadays an aim of tissue engineering. This technique involves the use of porous or fibrous structures – the so-called scaffolds – that support the colonization with the desired cell type and which are degraded after fulfilling their temporary supporting function. Basic requirements for the prevailing materials used in this field are nontoxicity, low immunogenicity and cell-adhesiveness. Furthermore blood-contacting devices should exhibit low thrombogenicity.The biopolymer silk, mainly consisiting of the protein silk fibroin, matches some of these criteria but bare silk does not facilitate cellular adhesion and growth and unfortunately the materi…
Effectiveness of platinum wire microcoils for venous occlusion: A study on patients treated for venogenic impotence
1994
The purpose of this study was to determine the effectiveness of venous occlusions achieved by embolization with platinum microwire coils. Follow-up venographies in 19 patients, 1-20 months (average 8 months) after coil embolizations, were evaluated. Twenty-eight of 126 (22.2%) coil embolizations were found to be patent. Coils which had not formed or partially formed upon embolization had a patency/recanalization rate of 37.5% (12/32). Among coils which had formed nearly completely or completely only 16 of 95 (17%) showed venous patency. As coil embolization had been augmented by sclerotherapy in all patients, the effectiveness of long-term venous occlusion by platinum wire coils alone is pr…
Nonthrombogenic, Biodegradable Elastomeric Polyurethanes with Variable Sulfobetaine Content
2014
For applications where degradable polymers are likely to have extended blood contact, it is often important for these materials to exhibit high levels of thromboresistance. This can be achieved with surface modification approaches, but such modifications may be transient with degradation. Alternatively, polymer design can be altered such that the bulk polymer is thromboresistant and this is maintained with degradation. Toward this end a series of biodegradable, elastic polyurethanes (PESBUUs) containing different zwitterionic sulfobetaine (SB) content were synthesized from a polycaprolactone-diol (PCL-diol):SB-diol mixture (100:0, 75:25, 50:50, 25:75 and 0:100) reacted with diisocyanatobuta…
Effect of the Alterations in Contractility and Morphology Produced by Atrial Fibrillation on the Thrombosis Potential of the Left Atrial Appendage
2021
Atrial fibrillation (AF) is a common arrhythmia mainly affecting the elderly population, which can lead to serious complications such as stroke, ischaemic attack and vascular dementia. These problems are caused by thrombi which mostly originate in the left atrial appendage (LAA), a small muscular sac protruding from left atrium. The abnormal heart rhythm associated with AF results in alterations in the heart muscle contractions and in some reshaping of the cardiac chambers. This study aims to verify if and how these physiological changes can establish hemodynamic conditions in the LAA promoting thrombus formation, by means of computational fluid dynamic (CFD) analyses. In particular, sinus …