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Luu CH, Nguyen NT, Ta HT. Unravelling Surface Modification Strategies for Preventing Medical Device-Induced Thrombosis. Adv Healthc Mater 2024; 13:e2301039. [PMID: 37725037 DOI: 10.1002/adhm.202301039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Revised: 08/29/2023] [Indexed: 09/21/2023]
Abstract
The use of biomaterials in implanted medical devices remains hampered by platelet adhesion and blood coagulation. Thrombus formation is a prevalent cause of failure of these blood-contacting devices. Although systemic anticoagulant can be used to support materials and devices with poor blood compatibility, its negative effects such as an increased chance of bleeding, make materials with superior hemocompatibility extremely attractive, especially for long-term applications. This review examines blood-surface interactions, the pathogenesis of clotting on blood-contacting medical devices, popular surface modification techniques, mechanisms of action of anticoagulant coatings, and discusses future directions in biomaterial research for preventing thrombosis. In addition, this paper comprehensively reviews several novel methods that either entirely prevent interaction between material surfaces and blood components or regulate the reaction of the coagulation cascade, thrombocytes, and leukocytes.
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Affiliation(s)
- Cuong Hung Luu
- School of Environment and Science, Griffith University, Nathan, Queensland, 4111, Australia
- Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Queensland, 4111, Australia
| | - Nam-Trung Nguyen
- School of Environment and Science, Griffith University, Nathan, Queensland, 4111, Australia
- Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Queensland, 4111, Australia
| | - Hang Thu Ta
- School of Environment and Science, Griffith University, Nathan, Queensland, 4111, Australia
- Queensland Micro- and Nanotechnology Centre, Griffith University, Nathan, Queensland, 4111, Australia
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Coronel-Meneses D, Sánchez-Trasviña C, Ratera I, Mayolo-Deloisa K. Strategies for surface coatings of implantable cardiac medical devices. Front Bioeng Biotechnol 2023; 11:1173260. [PMID: 37256118 PMCID: PMC10225971 DOI: 10.3389/fbioe.2023.1173260] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 04/25/2023] [Indexed: 06/01/2023] Open
Abstract
Cardiac medical devices (CMDs) are required when the patient's cardiac capacity or activity is compromised. To guarantee its correct functionality, the building materials in the development of CMDs must focus on several fundamental properties such as strength, stiffness, rigidity, corrosion resistance, etc. The challenge is more significant because CMDs are generally built with at least one metallic and one polymeric part. However, not only the properties of the materials need to be taken into consideration. The biocompatibility of the materials represents one of the major causes of the success of CMDs in the short and long term. Otherwise, the material will lead to several problems of hemocompatibility (e.g., protein adsorption, platelet aggregation, thrombus formation, bacterial infection, and finally, the rejection of the CMDs). To enhance the hemocompatibility of selected materials, surface modification represents a suitable solution. The surface modification involves the attachment of chemical compounds or bioactive compounds to the surface of the material. These coatings interact with the blood and avoid hemocompatibility and infection issues. This work reviews two main topics: 1) the materials employed in developing CMDs and their key characteristics, and 2) the surface modifications reported in the literature, clinical trials, and those that have reached the market. With the aim of providing to the research community, considerations regarding the choice of materials for CMDs, together with the advantages and disadvantages of the surface modifications and the limitations of the studies performed.
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Affiliation(s)
- David Coronel-Meneses
- Tecnologico de Monterrey, The Institute for Obesity Research, Monterrey, Mexico
- Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Centro de Biotecnología-FEMSA, Monterrey, Mexico
| | - Calef Sánchez-Trasviña
- Tecnologico de Monterrey, The Institute for Obesity Research, Monterrey, Mexico
- Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Centro de Biotecnología-FEMSA, Monterrey, Mexico
| | - Imma Ratera
- Institute of Materials Science of Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra, Spain
- Centro de Investigación Biomédica en Red de Bioingeniería, Instituto de Salud Carlos IIIBellaterra, Spain
| | - Karla Mayolo-Deloisa
- Tecnologico de Monterrey, The Institute for Obesity Research, Monterrey, Mexico
- Tecnologico de Monterrey, Escuela de Ingeniería y Ciencias, Centro de Biotecnología-FEMSA, Monterrey, Mexico
- Institute of Materials Science of Barcelona (ICMAB-CSIC), Campus UAB, Bellaterra, Spain
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He W, Butcher JT, Rowlands GW, Antaki JF. Biological Response to Sintered Titanium in Left Ventricular Assist Devices: Pseudoneointima, Neointima, and Pannus. ASAIO J 2023; 69:1-10. [PMID: 35649199 DOI: 10.1097/MAT.0000000000001777] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Titanium alloys have traditionally been used in blood-contacting cardiovascular devices, including left ventricular assist devices (LVADs). However, titanium surfaces are susceptible to adverse coagulation, leading to thrombogenesis and stroke. To improve hemocompatibility, LVAD manufacturers introduced powder sintering on blood-wetted surfaces in the 1980s to induce endothelialization. This technique has been employed in multiple contemporary LVADs on the pump housing, as well as the interior and exterior of the inflow cannula. Despite the wide adoption of sintered titanium, reported biologic response over the past several decades has been highly variable and apparently unpredictable-including combinations of neointima, pseudoneoimtima, thrombus, and pannus. We present a history of sintered titanium used in LVAD, a review of accumulated clinical outcomes, and a synopsis of gross appearance and composition of various depositions found clinically and in animal studies, which is unfortunately confounded by the variability and inconsistency in terminology. Therefore, this review endeavors to introduce a unified taxonomy to harmonize published observations of biologic response to sintered titanium in LVADs. From these data, we are able to deduce the natural history of the biologic response to sintered titanium, toward development of a deterministic model of the genesis of a hemocompatible neointima.
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Borchers P, Winnersbach P, Kraemer S, Beckers C, Buhl EM, Leonhardt S, Rossaint R, Walter M, Breuer T, Bleilevens C. Comparison of the Hemocompatibility of an Axial and a Centrifugal Left Ventricular Assist Device in an In Vitro Test Circuit. J Clin Med 2022; 11:3431. [PMID: 35743501 DOI: 10.3390/jcm11123431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 06/08/2022] [Accepted: 06/13/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Hemocompatibility of left ventricular assist devices is essential for preventing adverse events. In this study, we compared the hemocompatibility of an axial-flow (Sputnik) to a centrifugal-flow (HeartMate 3) pump. METHODS Both pumps were integrated into identical in vitro test circuits, each filled with 75 mL heparinized human blood of the same donor. During each experiment (n = 7), the pumps were operated with equal flow for six hours. Blood sampling and analysis were performed on a regular schedule. The analytes were indicators of hemolysis, coagulation activation, platelet count and activation, as well as extracellular vesicles. RESULTS Sputnik induced higher hemolysis compared to the HeartMate 3 after 360 min. Furthermore, platelet activation was higher for Sputnik after 120 min onward. In the HeartMate 3 circuit, the platelet count was reduced within the first hour. Furthermore, Sputnik triggered a more pronounced increase in extracellular vesicles, a potential trigger for adverse events in left ventricular assist device application. Activation of coagulation showed a time-dependent increase, with no differences between both groups. CONCLUSIONS This experimental study confirms the hypothesis that axial-flow pumps may induce stronger hemolysis compared to centrifugal pumps, coming along with larger amounts of circulating extracellular vesicles and a stronger PLT activation.
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Kaufmann F, Hoermandinger C, Knosalla C, Falk V, Potapov E. Thrombus formation at the inflow cannula of continuous-flow left ventricular assist devices - a systematic analysis. Artif Organs 2022; 46:1573-1584. [PMID: 35230721 DOI: 10.1111/aor.14222] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 01/13/2022] [Accepted: 02/21/2022] [Indexed: 11/27/2022]
Abstract
BACKGROUND Despite numerous design iterations, thrombus formation at the inflow cannula of continuous-flow left ventricular assist devices (CF-LVAD) remains an unsolved problem. We systematically investigated the impact of cannula surface on thrombus formation. METHODS Thrombus appearance was photographically documented in 177 explanted hearts with the polished (N=46) or sintered (N=131) inflow cannula of the HVAD. Thrombus load was compared for both inflow cannula types. Mean thrombus length was correlated with protruding cannula length. Support duration and the extent of thrombus growth were examined. The prevalence of thrombi at the left ventricular entry site and at the sintered-to-polished transition zone was correlated with left ventricular geometry and hemodynamic parameters. RESULTS Polished inflow cannulas showed a greater percentage and also a greater mean length of thrombus formation at the entry site than sintered cannulas (91.3% [Pol] vs. 36.7% [sTi]; p<0.0001; mean 7.6 mm vs. 1.9 mm; p<0.0001). A comparison of the early postoperative period (POD1-90) with long-term support (POD>90) showed an increase in thrombus length originating from the transition zone (1.96, ±3.41 mm vs. 3.03 ±2.91 mm; p=0.013). CONCLUSIONS A sintered titanium surface at the entry site is crucial to enable anchoring of myocardial tissue to the cannula. As thrombus growth progresses on polished surfaces, a greater sintered length seems to be beneficial. After an initial three-month healing period, thrombus load appears to decline during prolonged support duration at the sintered entry site but not at the transition zone.
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Affiliation(s)
- Friedrich Kaufmann
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Christoph Hoermandinger
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany
| | - Christoph Knosalla
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
| | - Volkmar Falk
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany.,Department of Cardiovascular Surgery, Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany.,Department of Health Sciences and Technology, Eidgenössische Technische Hochschule Zürich, Translational Cardiovascular Technology, Zurich, Switzerland
| | - Evgenij Potapov
- Department of Cardiothoracic and Vascular Surgery, German Heart Center Berlin, Berlin, Germany.,DZHK (German Centre for Cardiovascular Research), Partner Site Berlin, Berlin, Germany
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Kuchinka J, Willems C, Telyshev DV, Groth T. Control of Blood Coagulation by Hemocompatible Material Surfaces-A Review. Bioengineering (Basel) 2021; 8:bioengineering8120215. [PMID: 34940368 PMCID: PMC8698751 DOI: 10.3390/bioengineering8120215] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/10/2021] [Accepted: 12/12/2021] [Indexed: 11/16/2022] Open
Abstract
Hemocompatibility of biomaterials in contact with the blood of patients is a prerequisite for the short- and long-term applications of medical devices such as cardiovascular stents, artificial heart valves, ventricular assist devices, catheters, blood linings and extracorporeal devices such as artificial kidneys (hemodialysis), extracorporeal membrane oxygenation (ECMO) and cardiopulmonary bypass. Although lower blood compatibility of materials and devices can be handled with systemic anticoagulation, its side effects, such as an increased bleeding risk, make materials that have a better hemocompatibility highly desirable, particularly in long-term applications. This review provides a short overview on the basic mechanisms of blood coagulation including plasmatic coagulation and blood platelets, as well as the activation of the complement system. Furthermore, a survey on concepts for tailoring the blood response of biomaterials to improve the hemocompatibility of medical devices is given which covers different approaches that either inhibit interaction of material surfaces with blood components completely or control the response of the coagulation system, blood platelets and leukocytes.
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Affiliation(s)
- Janna Kuchinka
- Department Biomedical Materials, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany; (J.K.); (C.W.)
| | - Christian Willems
- Department Biomedical Materials, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany; (J.K.); (C.W.)
| | - Dmitry V. Telyshev
- Institute of Biomedical Systems, National Research University of Electronic Technology, Zelenograd, 124498 Moscow, Russia;
- Laboratory of Biomedical Nanotechnologies, Institute of Bionic Technologies and Engineering, I.M. Sechenov First Moscow State University, 119991 Moscow, Russia
| | - Thomas Groth
- Department Biomedical Materials, Institute of Pharmacy, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany; (J.K.); (C.W.)
- Laboratory of Biomedical Nanotechnologies, Institute of Bionic Technologies and Engineering, I.M. Sechenov First Moscow State University, 119991 Moscow, Russia
- Interdisciplinary Center of Materials Science, Martin Luther University Halle-Wittenberg, 06120 Halle (Saale), Germany
- Correspondence: ; Tel.: +49-3455528460
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Abstract
There are limited therapeutic options for final treatment of end-stage heart failure. Among them, implantation of a total artificial heart (TAH) is an acceptable strategy when suitable donors are not available. TAH development began in the 1930s, followed by a dramatic evolution of the actuation mechanisms operating the mechanical pumps. Nevertheless, the performance of TAHs has not yet been optimized, mainly because of the low biocompatibility of the blood-contacting surfaces. Low hemocompatibility, calcification, and sensitivity to infections seriously affect the success of TAHs. These unsolved issues have led to the withdrawal of many prototypes during preclinical phases of testing. This review offers a comprehensive analysis of the pathophysiological events that may occur in the materials that compose TAHs developed to date. In addition, this review illustrates bioengineering strategies to prevent these events and describes the most significant steps toward the achievement of a fully biocompatible TAH.
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Affiliation(s)
- Eleonora Dal Sasso
- Cardiovascular Regenerative Medicine Group, Department of Cardiac, Thoracic and Vascular Sciences and Public Health, University of Padua and Veneto Institute of Molecular Medicine, 35128 Padua, Italy; , , .,Padua Heart Project, Division of Cardiac Surgery, University Hospital of Padua, 35128 Padua, Italy;
| | - Andrea Bagno
- Department of Industrial Engineering, University of Padua, 35128 Padua, Italy;
| | - Silvia T G Scuri
- Padua Heart Project, Division of Cardiac Surgery, University Hospital of Padua, 35128 Padua, Italy;
| | - Gino Gerosa
- Cardiovascular Regenerative Medicine Group, Department of Cardiac, Thoracic and Vascular Sciences and Public Health, University of Padua and Veneto Institute of Molecular Medicine, 35128 Padua, Italy; , , .,Padua Heart Project, Division of Cardiac Surgery, University Hospital of Padua, 35128 Padua, Italy;
| | - Laura Iop
- Cardiovascular Regenerative Medicine Group, Department of Cardiac, Thoracic and Vascular Sciences and Public Health, University of Padua and Veneto Institute of Molecular Medicine, 35128 Padua, Italy; , , .,Padua Heart Project, Division of Cardiac Surgery, University Hospital of Padua, 35128 Padua, Italy;
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Abstract
The use of blood-contacting implantable devices is limited by surface-induced thrombosis, which has led to the development of thromboresistant surfaces. Multidisciplinary efforts have promoted the development of surface modifications to minimize thrombosis by targeting surface-induced coagulation. To this date, no material has been identified that remains irrevocably hemocompatible with time but many options are now available with their own limitations. Essential to this review is the understanding of some of the challenges in this field and newer opportunities for hemocompatibility research. This report will also briefly review many of the achievements in the development of hemocompatible biomaterial coating, including surface modifications against protein adsorption and platelet adhesion, biomimetism, and endothelialization.
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Meyer AL, Malehsa D, Budde U, Bara C, Haverich A, Strueber M. Acquired von Willebrand syndrome in patients with a centrifugal or axial continuous flow left ventricular assist device. JACC Heart Fail 2015; 2:141-5. [PMID: 24720921 DOI: 10.1016/j.jchf.2013.10.008] [Citation(s) in RCA: 162] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2013] [Revised: 10/11/2013] [Accepted: 10/17/2013] [Indexed: 02/06/2023]
Abstract
OBJECTIVES The aim of this study was to determine whether differences in continuous flow left ventricular assist devices (LVADs) may lead to differences in the von Willebrand profile and the occurrence of bleeding and thromboembolic events. BACKGROUND The HeartMate II (Thoratec Corp., Pleasanton, California) and HeartWare Ventricular Assist Device (HVAD) (HeartWare, Inc., Framingham, Massachusetts) systems are the most frequently implanted LVADs worldwide. In all patients with an axial-flow HeartMate II, acquired von Willebrand syndrome (AvWS) due to the loss of large molecular weight multimers was found. The large molecular weight multimers of the von Willebrand factor (vWF) play a key role in primary hemostasis through interactions with platelets. METHODS This was a retrospective study of the vWF profile and incidence of bleeding and thromboembolic events in 102 patients receiving the HeartMate II (n = 51) and HVAD (n = 51). Between January 2003 and December 2010, vWF testing was performed in 102 of 175 consecutive patients after LVAD implantation. RESULTS AvWS was found in all patients, demonstrated by a decrease in the high molecular weight multimers of vWF to 30 ± 14% in HeartMate II patients and 34 ± 13% in patients with an HVAD. Significant predictors of vWF antigen included age (p = 0.011), number of days on the device (p = 0.035), C-reactive protein (p < 0.001), and blood group (p = 0.007). Bleeding and thromboembolic event rates were similar. However, lower fractions of vWF antigen and high molecular weight multimers did not correlate with the rate of bleeding complications or thromboembolic events. CONCLUSIONS AvWS developed in all patients after centrifugal or axial flow pump implantation. Different patterns of AvWS were seen between the devices as well as individually. However, the complication rates after implantation were similar.
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Affiliation(s)
- Anna L Meyer
- Heart Center Leipzig University, Clinic for Heart Surgery, Leipzig, Germany
| | - Doris Malehsa
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | | | - Christoph Bara
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Axel Haverich
- Department of Cardiothoracic, Transplantation and Vascular Surgery, Hannover Medical School, Hannover, Germany
| | - Martin Strueber
- Heart Center Leipzig University, Clinic for Heart Surgery, Leipzig, Germany.
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Eckmann DM, Tsai IY, Tomczyk N, Weisel JW, Composto RJ. Hyaluronan and dextran modified tubes resist cellular activation with blood contact. Colloids Surf B Biointerfaces 2013; 108:44-51. [PMID: 23524078 PMCID: PMC3646946 DOI: 10.1016/j.colsurfb.2013.02.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 02/05/2013] [Accepted: 02/06/2013] [Indexed: 12/24/2022]
Abstract
This study was undertaken to evaluate the effects of thin film hyaluronic acid and dextran surface coatings to blunt cellular activation in a laboratory model of extracorporeal blood circulation. The inner lumen surface of polyurethane (PU) and poly(vinyl) chloride (PVC) tubing was grafted with hyaluronic acid and dextran. Surfaces were characterized for the presence of the grafted layer using ellipsometry, atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). Persistence of the surface layer was maintained for up to 5 days of continuous exposure to shear flow using a Chandler loop apparatus. The Chandler loop method was used to study human whole blood activation activity. Whole blood aggregometry and flow cytometry measures of CD18, CD62L, CD62P, Annexin V and myeloperoxidase performed on blood samples exposed to the tubing for up to three hours were complemented by scanning electron microscopy (SEM) analysis of adherent cells and state of activation. In these studies commercial hospital products and uncoated PVC and PU tubes were used as controls. We found that hyaluranized PU and PVC conferred the greatest resistance to blood activation and that dextranization of the PU and PU tubing also provided significant diminution of the bioresponses measured. Based on our findings, we suggest that surface coating with hyaluronic acid or dextran acts as a potent shield from blood cellular activation during forms of extracorporeal circulation.
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Affiliation(s)
- David M Eckmann
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Slaughter MS, Pederson B, Graham JD, Sobieski MA, Koenig SC. Evaluation of new Forcefield technology: Reducing platelet adhesion and cell coverage of pyrolytic carbon surfaces. J Thorac Cardiovasc Surg 2011; 142:921-5. [DOI: 10.1016/j.jtcvs.2011.01.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2010] [Revised: 12/07/2010] [Accepted: 01/07/2011] [Indexed: 11/26/2022]
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Stachelek SJ, Finley MJ, Alferiev IS, Wang F, Tsai RK, Eckells EC, Tomczyk N, Connolly JM, Discher DE, Eckmann DM, Levy RJ. The effect of CD47 modified polymer surfaces on inflammatory cell attachment and activation. Biomaterials 2011; 32:4317-26. [PMID: 21429575 DOI: 10.1016/j.biomaterials.2011.02.053] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 02/25/2011] [Indexed: 02/04/2023]
Abstract
CD47 is a transmembrane protein that is a marker of "self". CD47 binding to its cognate receptor in leukocytes and macrophages, signal-regulatory protein alpha (SIRPα), causes inhibition of inflammatory cell attachment. We hypothesized that immobilization of recombinant CD47 on polymeric surfaces would reduce inflammation. Recombinant CD47 was appended to polyvinyl chloride (PVC) or polyurethane (PU) surfaces via photoactivation chemistry. Cell culture studies showed that CD47 immobilization significantly reduced human neutrophil (HL-60) and human monocyte derived macrophage (MDM) (THP-1) attachment to PVC and PU respectively. A neutralizing antibody, directed against SIRPα, inhibited THP-1 and HL-60 binding to PU and PVC surfaces respectively. This antibody also increased the level of SIRPα tyrosine phosphorylation, thereby indicating a direct role for SIRPα mediated signaling in preventing inflammatory cell attachment. Studies using human blood in an ex vivo flow-loop showed that CD47 modified PVC tubing significantly reduced cell binding and neutrophil activation compared to unmodified tubing or poly-2-methoxy-ethylacrylate (PMEA) coated tubing. In ten-week rat subdermal implants, CD47 functionalized PU films showed a significant reduction in markers of MDM mediated oxidative degradation compared to unmodified PU. In conclusion, CD47 functionalized surfaces can resist inflammatory cell interactions both in vitro and in vivo.
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Abstract
This article focuses on the surface engineering of ventricular assist devices (VADs) for the treatment of heart failure patients, which involves the modification of surfaces contacting blood in order to improve the blood compatibility (hemocompatibility) of the VADs. Following an introduction to the categorization and the complications of VADs, this article pays attention on the hemocompatibility, applications and limitations of six types of surface coatings for VADs: titanium nitride coatings, diamond-like carbon coatings, 2-methacryloyloxyethyl phosphorylcholine polymer coatings, heparin coatings, textured surfaces and endothelial cell linings. In particular, diamond-like coatings and heparin coatings are the most commonly used for VADs owing to their excellent hemocompatibility, durability and technical maturity. For high performance and a long lifetime of VADs, surface modification with coatings to ensure hemocompatibility is as important as the mechanical design of the device.
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Affiliation(s)
- Dong-Choon Sin
- Institute of Health and Biomedical Innovation, Queensland University of Technology, 2 George Street, GPO Box 2434, Brisbane, QLD 4059, Australia.
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