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Polymeric heart valve

Ahmad Falahatpisheh, Daisuke Morisawa, Taraz T Toosky, Arash Kheradvar
The prevalence of aortic valve stenosis (AS) is increasing in the aging society. More recently, novel treatments and devices for AS, especially transcatheter aortic valve replacement (TAVR) have significantly changed the therapeutic approach to this disease. Research and development related to TAVR require testing these devices in the calcified heart valves that closely mimic a native calcific valve. However, no animal model of AS has yet been available. Alternatively, animals with normal aortic valve that are currently used for TAVR experiments do not closely replicate the aortic valve pathology required for proper testing of these devices...
November 16, 2016: Journal of Biomechanics
Mehrdad Namdari, Ali Eatemadi
Heart valves are currently under thorough investigation in tissue engineering (TE) research. Mechanical and biological heart valve prostheses which are recently used have several shortcomings. While allogenic and xenogenic biological prostheses are related to graft rejection, degeneration and thrombosis, resulting in a high rate of reoperation. Mechanical prostheses on the other hand are based on metallic, carbon, and polymeric components, and require continuous treatment with anticoagulant, which result in adverse reactions, e...
October 22, 2016: Biomedicine & Pharmacotherapy, Biomédecine & Pharmacothérapie
Z Riedelová-Reicheltová, E Brynda, T Riedel
Fibrin is a versatile biopolymer that has been extensively used in tissue engineering. In this paper fibrin nanostructures prepared using a technique based on the catalytic effect of fibrin-bound thrombin are presented. This technique enables surface-attached thin fibrin networks to form with precisely regulated morphology without the development of fibrin gel in bulk solution. Moreover, the influence of changing the polymerization time, along with the antithrombin III and heparin concentrations on the morphology of fibrin nanostructures was explored...
October 20, 2016: Physiological Research
Benyamin Rahmani, Spyros Tzamtzis, Rose Sheridan, Michael J Mullen, John Yap, Alexander M Seifalian, Gaetano Burriesci
AIMS: The aim of this study was to introduce and demonstrate the feasibility in an acute preclinical model of a new transcatheter heart valve concept with a self-expanding wire frame, polymeric leaflets and a sealing component. METHODS AND RESULTS: The TRISKELE valve was developed based on a previously validated polymeric leaflet design, an adaptive sealing cuff and a novel nitinol wire frame which reduces stress on the leaflets and radial pressure on the surrounding tissue...
September 18, 2016: EuroIntervention
Ricardo Moreira, Christine Neusser, Magnus Kruse, Shane Mulderrig, Frederic Wolf, Jan Spillner, Thomas Schmitz-Rode, Stefan Jockenhoevel, Petra Mela
The mechanical properties of tissue-engineered heart valves still need to be improved to enable their implantation in the systemic circulation. The aim of this study is to develop a tissue-engineered valve for the aortic position - the BioTexValve - by exploiting a bio-inspired composite textile scaffold to confer native-like mechanical strength and anisotropy to the leaflets. This is achieved by multifilament fibers arranged similarly to the collagen bundles in the native aortic leaflet, fixed by a thin electrospun layer directly deposited on the pattern...
August 2016: Advanced Healthcare Materials
Atieh Yousefi, David L Bark, Lakshmi P Dasi
Polymeric heart valves (PHV) can be engineered to serve as alternatives for existing prosthetic valves due to higher durability and hemodynamics similar to bioprosthetic valves. The purpose of this study is to evaluate the effect of geometry on PHVs coaptation and hemodynamic performance. The two geometric factors considered are stent profile and leaflet arch length, which were varied across six valve configurations. Three models were created with height to diameter ratio of 0.6, 0.7, and 0.88. The other three models were designed by altering arch height to stent diameter ratio, to be 0, 0...
June 15, 2016: Annals of Biomedical Engineering
M Serrani, J Brubert, J Stasiak, F De Gaetano, A Zaffora, M L Costantino, G D Moggridge
Styrene-based block copolymers are promising materials for the development of a polymeric heart valve prosthesis (PHV), and the mechanical properties of these polymers can be tuned via the manufacturing process, orienting the cylindrical domains to achieve material anisotropy. The aim of this work is the development of a computational tool for the optimization of the material microstructure in a new PHV intended for aortic valve replacement to enhance the mechanical performance of the device. An iterative procedure was implemented to orient the cylinders along the maximum principal stress direction of the leaflet...
June 2016: Journal of Biomechanical Engineering
Marco Bartosch, Heiner Peters, Hendrik Spriestersbach, Darach O H-Ici, Felix Berger, Boris Schmitt
Transcatheter heart valve implantation is an emerging technology and an alternative to surgical valve replacement. Most existing systems consist of valves sewn into balloon-expandable stents with a delivery catheter functioning with the specific valve only. The aim of this study was to develop a universally applicable delivery system (DS) for plane stents, valves sewn into both balloon-expandable and self-expandable stents and feasible for use with different access routes. A DS was designed and manufactured in five different diameters...
September 2016: Annals of Biomedical Engineering
Francesco De Gaetano, Marta Serrani, Paola Bagnoli, Jacob Brubert, Joanna Stasiak, Geoff D Moggridge, Maria Laura Costantino
PURPOSE: Only mechanical and biological heart valve prostheses are currently commercially available. The former show longer durability but require anticoagulant therapy; the latter display better fluid dynamic behavior but do not have adequate durability. New Polymeric Heart Valves (PHVs) could potentially combine the hemodynamic properties of biological valves with the durability of mechanical valves. This work presents a hydrodynamic evaluation of 2 groups of newly developed supra-annular, trileaflet prosthetic heart valves made from styrenic block copolymers (SBC): Poli-Valves...
November 2015: International Journal of Artificial Organs
Filippo Piatti, Francesco Sturla, Gil Marom, Jawaad Sheriff, Thomas E Claiborne, Marvin J Slepian, Alberto Redaelli, Danny Bluestein
Surgical valve replacement in patients with severe calcific aortic valve disease using either bioprosthetic or mechanical heart valves is still limited by structural valve deterioration for the former and thrombosis risk mandating anticoagulant therapy for the latter. Prosthetic polymeric heart valves have the potential to overcome the inherent material and design limitations of these valves, but their development is still ongoing. The aim of this study was to characterize the hemodynamics and thrombogenic potential of the Polynova polymeric trileaflet valve prototype using a fluid-structure interaction (FSI) approach...
October 15, 2015: Journal of Biomechanics
Isra Marei, Adrian Chester, Ivan Carubelli, Themistoklis Prodromakis, Tatiana Trantidou, Magdi H Yacoub
BACKGROUND: Scaffolds are a key component of tissue-engineered heart valves (TEHVs). Several approaches had been adopted in the design of scaffolds using both natural and synthetic resources. We have investigated the suitability of parylene C (PC), a vapor deposited polymeric material, for the use as a scaffold in TEHV. AIMS: To evaluate the adsorption of extracellular matrix components onto plasma-activated PC and study the biocompatibility of PC by measuring cellular adhesion, viability, apoptosis, and phenotypic expression of valve endothelial and interstitial cells...
October 2015: Tissue Engineering. Part A
Chetan Chaudhary, Tarun Garg
A scaffold is comprised of the polymeric central components, which are used to deliver cells, drugs, and genes into the body. Wounds, which lead to a loss of integrity of the skin and skin mortality, are common challenges encountered in plastic and reconstructive surgery. The primary goals of treatment are rapid closure, restoration of function, and aesthetic satisfaction. A paradigm shift is taking place in medicine from using synthetic implants and tissue grafts to a tissue-engineering approach that uses degradable porous material scaffolds integrated with biological cells or molecules to regenerate tissues...
2015: Critical Reviews in Therapeutic Drug Carrier Systems
Saleh Hassanzadeh Gharaie, Yos Morsi
INTRODUCTION: In this paper we propose a novel method for developing a polymeric heart valve that could potentially offer an optimum solution for a heart valve substitute. The valve design proposed will provide superior hydrodynamic performance and excellent structural integrity. A full description of the design process is given together with an analysis of the hemodynamic performance using a 2-way strongly coupled Fluid Structure Interaction (FSI). METHOD: A polymeric tri-leaflet heart valve is designed based on a patient's sinus of Valsalva (SOV) geometry...
May 2015: International Journal of Artificial Organs
Marco Nestola, Rainer Friedrich, Patrick Bluhme, Torsten C Schmidt
Analysis of polycyclic aromatic hydrocarbons (PAHs) in complex foodstuff is associated with complicated and work-intensive sample preparation. Chromatographic interference has to be faced in many situations. The scope of the current work was the development of a highly efficient two-dimensional heart-cut LC-LC-GC-MS method. Detection was performed with a time-of-flight mass spectrometer (TOF-MS) to allow for a comprehensive evaluation of the obtained data in terms of cleanup efficiency. Additionally, routine detection was performed with single quadrupole MS...
June 16, 2015: Analytical Chemistry
Arash Kheradvar, Elliott M Groves, Lakshmi P Dasi, S Hamed Alavi, Robert Tranquillo, K Jane Grande-Allen, Craig A Simmons, Boyce Griffith, Ahmad Falahatpisheh, Craig J Goergen, Mohammad R K Mofrad, Frank Baaijens, Stephen H Little, Suncica Canic
As the first section of a multi-part review series, this section provides an overview of the ongoing research and development aimed at fabricating novel heart valve replacements beyond what is currently available for patients. Here we discuss heart valve replacement options that involve a biological component or process for creation, either in vitro or in vivo (tissue-engineered heart valves), and heart valves that are fabricated from polymeric material that are considered permanent inert materials that may suffice for adults where growth is not required...
April 2015: Annals of Biomedical Engineering
Deon Bezuidenhout, David F Williams, Peter Zilla
Efficient function and long-term durability without the need for anticoagulation, coupled with the ability to be accommodated in many different types of patient, are the principal requirements of replacement heart valves. Although the clinical use of valves appeared to have remained steady for several decades, the evolving demands for the elderly and frail patients typically encountered in the developed world, and the needs of much younger and poorer rheumatic heart disease patients in the developing world have now necessitated new paradigms for heart valve technologies and associated materials...
January 2015: Biomaterials
Yosry S Morsi
The occurrence of dysfunctional aortic valves is increasing every year, and current replacement heart valves, although having been shown to be clinically successful, are only short-term solutions and suffer from many agonizing long-term drawbacks. The tissue engineering of heart valves is recognized as one of the most promising answers for aortic valve disease therapy, but overcoming current shortcomings will require multidisciplinary efforts. The use of a polymeric scaffold to guide the growth of the tissue is the most common approach to generate a new tissue for an aortic heart valve...
September 2014: International Journal of Artificial Organs
Cora Lueders, Ben Jastram, Roland Hetzer, Hartmut Schwandt
Three-dimensional (3D) printing technologies have reached a level of quality that justifies considering rapid manufacturing for medical applications. Herein, we introduce a new approach using 3D printing to simplify and improve the fabrication of human heart valve scaffolds by tissue engineering (TE). Custom-made human heart valve scaffolds are to be fabricated on a selective laser-sintering 3D printer for subsequent seeding with vascular cells from human umbilical cords. The scaffolds will be produced from resorbable polymers that must feature a number of specific properties: the structure, i...
October 2014: European Journal of Cardio-thoracic Surgery
Joanna Stasiak, Jacob Brubert, Marta Serrani, Sukumaran Nair, Francesco de Gaetano, Maria Laura Costantino, Geoff D Moggridge
It is well known that block copolymers with cylindrical morphology show alignment with shear, resulting in anisotropic mechanical properties. Here we show that well-ordered bi-directional orientation can be achieved in such materials by slow injection moulding. This results in a microstructure, and anisotropic mechanical properties, similar to many natural tissues, making this method attractive for engineering prosthetic fibrous tissues. An application of particular interest to us is prosthetic polymeric heart valve leaflets, mimicking the shape, microstructure and hence performance of the native valve...
August 28, 2014: Soft Matter
Adnan Kara, Haluk Celik, Ali Seker, Hasan Basri Sezer, Eray Kilinc, Metin Uzun
INTRODUCTION: Ochronosis is a rare disorder which is defined as the deposition of metabolites of oxidation and polymerization of homogentisic acid, which have high affinity to collogen, in the connective tissues. It is a clinical condition characterized with ochronotic pigmentation of tissues, degenerative arthropathy of especially large joints and black discoloration of urine. In this paper we present a case of ochronosis diagnosed with biopsy and additional tests when a black discoloration of menisci and joint cartilage were detected during arthroscopic intervention for a degenerative meniscus tear...
2014: International Journal of Surgery Case Reports
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