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  • 1.
    Bexborn, Fredrik
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Engberg, Anna E.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Sandholm, Kerstin
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Mollnes, Tom Eirik
    Hong, Jaan
    Nilsson Ekdahl, Kristina
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Hirudin versus heparin for use in whole blood in vitro biocompatibility models2009Ingår i: Journal of Biomedical Materials Research. Part A, ISSN 1549-3296, E-ISSN 1552-4965, Vol. 89A, nr 4, s. 951-959Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Heparin has traditionally been a widely used anticoagulant in blood research, but has been shown to be inappropriate for work with the complement system because of its complement-interacting properties. In this work, we have compared the effects of heparin with those of the specific thrombin inhibitor hirudin on complement and blood cells in vitro.

    Methods: Whole blood collected in the presence of hirudin (50 µg/mL) or heparin (1 IU/mL) was incubated in the slide chamber model. The plasma was analyzed for complement activation markers C3a and sC5b-9, and the polyvinylchloride test slides were stained for adhering cells. The integrity of the complement system was tested by incubating serum and hirudin-treated plasma in the presence of various activating agents.

    Results: In contrast to heparin, the addition of hirudin generally preserved the complement reactivity, and complement activation in hirudin plasma closely resembled that in normal serum. Importantly, immunochemical staining of surface-bound cells demonstrated the inducible expression of tissue factor on bound monocytes from hirudin-treated blood, an effect that was completely abolished in heparin-treated blood.

    Conclusion: Our results indicate that hirudin as an anticoagulant produces more physiological conditions than heparin, making hirudin well-suited for in vitro studies, especially those addressing the regulation of cellular processes.

  • 2.
    Engberg, Anna E.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Biomaterials and Hemocompatibility2010Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    Biomaterials are commonly used in the medical clinic today; however, artificial materials can activate the cascade systems in the blood (complement-, coagulation-, contact- and fibrinolytic systems) as well as the platelets to various degrees. When an artificial surface comes in contact with blood, plasma proteins will be adsorbed to the surface within seconds. The composition of the layer of proteins differs between materials and is crucial for the hemocompatibility of the material.

    This thesis includes five projects.

    In Paper I the anticoagulants heparin and the thrombin inhibitor hirudin were evaluated in a whole blood model. Hirudin was found to be superior to low dose heparin since it did not affect the activation of the complement system nor the leukocytes. The most interesting observation was that expression of TF was seen on surface-attached monocytes in hirudin- treated blood but not heparin blood.

    In Paper II peptides from the streptococcal M-protein, which has affinity for the human complement inhibitor C4BP, were attached to a polymeric surface. When being exposed to blood the endogenous complement regulator was enriched at the surface of the material, via the M-peptides. With this new approach we created a self-regulatory surface, showing significant lowered material-induced complement activation.

    In Paper III apyrase, an enzyme which hydrolyzes nucleoside ATP and ADP, was immobilized on a polymer surface. Lower platelet activation and platelet-induced coagulation activation was seen for the apyrase-coated surface compared to control surfaces after exposure to whole human blood, due to the enzymes capability to degrade ADP released from activated platelets.

    In Paper IV and V we synthesized an array of polymeric materials which were characterized regarding physical-chemical properties, adsorption of plasma proteins, and hemocompatibility. The polymers showed widely heterogeneous protein adsorption. Furthermore, when the polymers were exposed to whole blood, two of the materials showed superior hemocompatibility (monitored as complement- and coagulation activation), compared to the reference poly(vinyl chloride).

  • 3.
    Engberg, Anna E.
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Region Skåne.
    Nilsson, Per H.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Oslo Univ Hosp, Rikshosp, Norway;Univ Oslo, Norway.
    Huang, Shan
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB).
    Fromell, Karin
    Uppsala University.
    Hamad, Osama A.
    Uppsala University.
    Mollnes, Tom Eirik
    Univ Oslo, Norway;Univ Tromsö, Norway.
    Rosengren-Holmberg, Jenny P.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Swedish Natl Lab Forens Sci, Linköping.
    Sandholm, Kerstin
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB).
    Teramura, Yuji
    Uppsala University;Univ Tokyo, Japan.
    Nicholls, Ian A.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Uppsala University.
    Nilsson, Bo
    Uppsala University.
    Nilsson Ekdahl, Kristina
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Uppsala University.
    Prediction of inflammatory responses induced by biomaterials in contact with human blood using protein fingerprint from plasma2015Ingår i: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 36, s. 55-65Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Inappropriate complement activation is often responsible for incompatibility reactions that occur when biomaterials are used. Complement activation is therefore a criterion included in legislation regarding biomaterials testing. However, no consensus is yet available regarding appropriate complement-activation-related test parameters. We examined protein adsorption in plasma and complement activation/cytokine release in whole blood incubated with well-characterized polymers. Strong correlations were found between the ratio of C4 to its inhibitor C4BP and generation of 10 (mainly pro-inflammatory) cytokines, including IL-17, IFN-gamma, and IL-6. The levels of complement activation products correlated weakly (C3a) or not at all (C5a, sC5b-9), confirming their poor predictive values. We have demonstrated a direct correlation between downstream biological effects and the proteins initially adhering to an artificial surface after contact with blood. Consequently, we propose the C4/C4BP ratio as a robust, predictor of biocompatibility with superior specificity and sensitivity over the current gold standard. (C) 2014 Elsevier Ltd. All rights reserved.

  • 4.
    Engberg, Anna E.
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Nilsson, Per H.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Mollnes, Tom Eirik
    Rosengren-Holmberg, Jenny P.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Nicholls, Ian A.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Nilsson, Bo
    Nilsson Ekdahl, Kristina
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    The ratio between C4 and C4BP adsorbed from plasma predicts cytokine generation induced by artificial polymers in contact with whole blood2012Ingår i: Immunobiology, ISSN 0171-2985, E-ISSN 1878-3279, Vol. 217, nr 11, s. 1211-1211Artikel i tidskrift (Övrigt vetenskapligt)
  • 5.
    Engberg, Anna E.
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB).
    Nilsson, Per H.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Univ Oslo, Rikshosp, Univ Hosp, Norway.
    Sandholm, Kerstin
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB).
    Huang, Shan
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB).
    Mollnes, T. E.
    Nicholls, Ian A.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Uppsala University.
    Nilsson, Bo
    Uppsala university.
    Nilsson Ekdahl, Kristina
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Uppsala university.
    The ratio between C4 and C4BP adsorbed to artificial materials is a new predictor for biocompatibility2013Ingår i: Molecular Immunology, ISSN 0161-5890, E-ISSN 1872-9142, Vol. 56, nr 3, s. 309-309Artikel i tidskrift (Övrigt vetenskapligt)
  • 6.
    Engberg, Anna E.
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Rosengren-Holmberg, Jenny
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nicholls, Ian A.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nilsson Ekdahl, Kristina
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Development of novel biomaterial surfaces and evaluation of their hemocompatibility*2008Ingår i: Journal of Molecular Immunology 45, 2008Konferensbidrag (Refereegranskat)
  • 7.
    Engberg, Anna E.
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Rosengren-Holmberg, Jenny
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nicholls, Ian A.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nilsson Ekdahl, Kristina
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Development of novel biomaterial surfaces and evaluation of their hemocompatibility2008Konferensbidrag (Refereegranskat)
  • 8.
    Engberg, Anna E.
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Rosengren-Holmberg, Jenny P.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nilsson Ekdahl, Kristina
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nicholls, Ian A.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Synthesis of new polymers and evaluation of their hemocompatibility2009Konferensbidrag (Refereegranskat)
  • 9.
    Engberg, Anna E.
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Rosengren-Holmberg, Jenny P
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nilsson, Per H.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bäck,
    Department of Oncology, Radiology and Clinical Immunology, Section of Clinical Immunology, Rudbeck Laboratory C5, Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
    Mollnes, Tom Eirik
    Institute of Immunology, Rikshospitalet University Hospital, Oslo, Norway,Research Laboratory, Nordland Hospital, Bodø, and University of Tromsø, Norway.
    Nicholls, Ian A.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Nilsson, Bo
    Department of Oncology, Radiology and Clinical Immunology, Section of Clinical Immunology, Rudbeck Laboratory C5, Uppsala University Hospital, SE-751 85 Uppsala, Sweden.
    Nilsson Ekdahl, Kristina
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    EVALUATION OF THE HEMOCOMPATIBILITY OF NOVEL POLYMERIC MATERIALSManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    When a biomaterial surface comes in contact with blood an immediate adsorption of plasma proteins to the surface will occur, and the cascade systems in the blood, such as the complement, coagulation and contact system, will be activated to various degrees. The intensity of this reaction will determine the hemocompatibility of the materials. Here we present an evaluation of the link between the composition, the physico-chemical properties and the protein adsorption properties of six newly synthesized polymers (P1-P6) and the hemocompatibility.The hemocompatibility of the polymeric surfaces was evaluated in human blood plasma and whole blood. Commercially available polyvinylchloride (PVC) was used as reference material. The hemocompatibility of the polymeric surfaces was evaluated with regard to complement activation (C3a and sC5-9 generation) and coagulation activation (platelet loss and TAT-formation) and cytokine productions (27 analytes in multiplex assay) after contact with whole blood. Contact activation was quantified by analyses of FXIIa-C1INH, FXIa-C1INH, and kallikrein-C1INH complexes.Polymers P2 (p<0.05 for C3a), P3, P5 and P6 showed less complement activation, and polymers P1 and P4 (p<0.05 for platelet loss), as well as P5 and P6 showed less coagulation activation compared with reference PVC. Polymers P1-P3 induced activation of the contact system, P3 being the most potent. Secretion of 17 cytokines including chemokines and growth factors were differentially influenced by the polymers, P1 and P3 being significantly (p<0.05) more compatible for five of the analytes.Collectively these data demonstrate that the composition of the polymers clearly leads to different biological properties as a consequence of distinctive physico-chemical properties and protein adsorption patterns.1

  • 10.
    Engberg, Anna E.
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Sandholm, Kerstin
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bexborn, Fredrik
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Persson, Jenny
    Lund University.
    Nilsson, Bo
    Uppsala University.
    Lindahl, Gunnar
    Lund University.
    Nilsson Ekdahl, Kristina
    Högskolan i Kalmar, Naturvetenskapliga institutionen. Uppsala University.
    Inhibition of complement activation on a model biomaterial surface by streptococcal M protein-derived peptides2009Ingår i: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 30, nr 13, s. 2653-2659Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to evaluate a new approach to inhibit complement activation triggered by biomaterial surfaces in contact with blood. In order to inhibit complement activation initiated by the classical pathway (CP), we used streptococcal M protein-derived peptides that specifically bind human C4BP, an inhibitor of the CP. The peptides were used to coat polystyrene microtiter wells which served as a model biomaterial. The ability of coated peptides to bind C4BP and to attenuate complement activation via the CP (monitored as generation of fluid-phase C3a and binding of fragments of C3 and C4 to the surface) was investigated using diluted normal human serum, where complement activation by the AP is minimal, as well as serum from a patient lacking alternative pathway activation. Complement activation (all parameters) was significantly decreased in serum incubated in well surfaces coated with peptides. Total inhibition of complement activation was obtained at peptide coating concentrations as low as 1-5 mu g/mL. Successful use of Streptococcus-derived peptides shows that it is feasible to control complement activation at a model biomaterial surface by capturing autologous complement regulatory molecules from plasma. (C) 2009 Elsevier Ltd. All rights reserved.

  • 11.
    Engberg, Anna
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Rosengren-Holmberg, Jenny
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Chen, Hui
    Department of Pathology, University of Pennsylvania, 401 Stellar Chance, Philadelphia, PA 19104, USA.
    Lambris, John
    Department of Pathology, University of Pennsylvania, 401 Stellar Chance, Philadelphia, PA 19104, USA.
    Nicholls, Ian
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    N. Ekdahl, Kristina
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    BLOOD PROTEIN-POLYMER ADSORPTION FINGERPRINTING:IMPLICATIONS FOR UNDERSTANDING HEMOCOMPATIBILITYAND FOR BIOMATERIAL DESIGNManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Within seconds after an artificial material has been implanted into the blood thesurface will be covered by adsorbed plasma proteins. The composition of theprotein layer is determined by the physical-chemical properties of the surface. Asthe layer itself will become the new interface between the material and blood, itis of major importance for the hemocompatibility. In this project we have studiedthe adsorption of proteins to a model material (polystyrene, PS) with the peptidemass fingerprint technique (PMF) analyzed on a Matrix Assisted LaserDesorption/Ionization Time-of-Flight (MALDI-TOF). To further be able to studythe adsorption of plasma proteins to polymer surfaces, we have synthesized 33new polymer compositions with variable surface properties. Six of thosepolymers were selected and their protein binding ability was determined as wellas quantification of adsorption of 20 plasma proteins to the surface of thepolymers. Our results showed that fourteen high abundant plasma proteins werepositively identified on the PS-surface by MALDI-TOF. Further, the resultsshowed that the synthesized polymers had very distinctive adsorption patterns,with enrichment of different proteins after incubation in plasma and serum. Oneof the polymers was shown to adsorb large amounts of the complementactivating recognition protein C1q, which makes this polymer to a potentialactivating surface. Two of the polymers showed a clear enrichment of thecomplement regulating protein vitronectin as well as two apolipoproteins (AI andAIV) to the surface of the polymers, while some of the polymers bound proteinsapproximately in correlation to the concentration found in plasma.

  • 12.
    Huang, Shan
    et al.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB).
    Engberg, Anna E.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). University and Regional Laboratories Region Skåne.
    Jonsson, Nina
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Uppsala University.
    Sandholm, Kerstin
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB).
    Nicholls, Ian A.
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Uppsala University.
    Mollnes, Tom Eirik
    Oslo University Hospital Rikshopsitalet, Norway;University of Oslo, Norway;Nordland Hospital, Norway; University of Tromsø, Norway;Norwegian University of Science and Technology, Norway.
    Fromell, Karin
    Uppsala University.
    Nilsson, Bo
    Uppsala University.
    Nilsson Ekdahl, Kristina
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för kemi och biomedicin (KOB). Uppsala University.
    Reciprocal relationship between contact and complement system activation on artificial polymers exposed to whole human blood.2016Ingår i: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 77, s. 111-119Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    BACKGROUND: Inappropriate and uncontrolled activation of the cascade systems in the blood is a driving force in adverse inflammatory and thrombotic reactions elicited by biomaterials, but limited data are available on the activation of the contact system by polymers and the present study was undertaken to investigate these mechanisms in established models.

    METHODS: Polymer particles were incubated in (1) EDTA-plasma (10 mM) to monitor the adsorption of 20 selected proteins; (2) lepirudin-anticoagulated plasma to evaluate contact system activation, monitored by the formation of complexes between the generated proteases factor[F]XIIa, FXIa and kallikrein and the serpins C1-inhibitor [C1INH] and antithrombin [AT]; (3) lepirudin-anticoagulated whole blood to determine cytokine release.

    RESULTS: Strong negative correlations were found between 10 cytokines and the ratio of deposited FXII/C1INH, generated FXIIa-C1INH complexes, and kallikrein-C1INH complexes. Formation of FXIIa-C1INH complexes correlated negatively with the amount of C3a and positively with deposited IgG.

    CONCLUSIONS: A reciprocal relationship was found between activation of the contact system and the complement system induced by the polymers studied here. The ratios of FXII/C1INH or C4/C4BP, adsorbed from EDTA-plasma are useful surrogate markers for cytokine release and inflammatory response to materials intended for blood contact.

  • 13.
    Nilsson Ekdahl, Kristina
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Engberg, Anna E.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Rosengren-Holmberg, Jenny P.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Chen, H
    University of Pennsylvania.
    Lambris, JD
    University of Pennsylvania.
    Nicholls, Ian A.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Blood protein-polymer adsorption fingerprinting: Implications for understanding hemoocompatibility and for biomaterial design.2011Ingår i: Journal of Biomedical Materials Research. Part A, ISSN 1549-3296, E-ISSN 1552-4965, Vol. 97A, nr 1, s. 74-84Artikel i tidskrift (Refereegranskat)
  • 14.
    Nilsson, Per
    et al.
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Engberg, Anna
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    Bäck, Jennie
    Div. Clinical Immunology, Rudbeck Laboratory, University Hospital, Uppsala.
    Faxälv, Lars
    Department of Clinical Chemistry, Laboratory Medicine, University Hospital, Linköping.
    Lindahl, Thomas
    Department of Clinical Chemistry, Laboratory Medicine, University Hospital, Linköping.
    Nilsson, Bo
    Div. Clinical Immunology, Rudbeck Laboratory, University Hospital, Uppsala.
    Nilsson Ekdahl, Kristina
    Högskolan i Kalmar, Naturvetenskapliga institutionen.
    IMMOBILIZATION OF APYRASE CREATES AN ANTITHROMBOTIC BIOMATERIAL SURFACEManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Blood incompatibility reactions caused by surfaces often involve platelet activation and subsequent platelet-initiated activation of the coagulation and complement cascades. The goal of this proof-of-principle study was to immobilize apyrase on a biomaterial surface in order to develop an enzymatically active surface that would have the capacity to inhibit platelet activation by degradating ADP. We were able to immobilize apyrase on a polystyrene surface with preservation of the enzymatic activity. We then analyzed the hemocompatibility of the apyrase surface and of control surfaces (serum albumin, avidin, polystyrene, and glass) by incubation with platelet-rich plasma (PRP) or whole blood. Monitoring of markers of platelet, coagulation, and complement activation and staining of the surfaces revealed decreased levels of platelet and coagulation activation parameters on the apyrase surface. The level of complex formation between antithrombin and thrombin or factor XIa and the extent of the platelet loss were significantly lower on the apyrase surface than on any of the control surfaces. No significant differences were seen in complement activation (C3a levels). Staining of the apyrase surface revealed low platelet adherence and no formation of granulocyte-platelet complexes. These results demonstrate that it is possible to create an anti-thrombotic surface targeting the ADP amplification of platelet activation by immobilizing apyrase.

  • 15.
    Nilsson, Per H.
    et al.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Engberg, Anna E.
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    Bäck, Jennie
    Div. Clinical Immunology, Rudbeck Laboratory, University Hospital, Uppsala.
    Faxälv, Lars
    Department of Clinical Chemistry, Laboratory Medicine, University Hospital, Linköping.
    Lindahl, Tomas
    Department of Clinical Chemistry, Laboratory Medicine, University Hospital, Linköping.
    Nilsson, Bo
    Div. Clinical Immunology, Rudbeck Laboratory, University Hospital, Uppsala.
    Nilsson Ekdahl, Kristina
    Linnéuniversitetet, Fakultetsnämnden för naturvetenskap och teknik, Institutionen för naturvetenskap, NV.
    The creation of an antithrombotic surface by apyrase immobilization2010Ingår i: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 31, nr 16, s. 4484-4491Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Blood incompatibility reactions caused by surfaces often involve platelet activation and subsequent platelet-initiated activation of the coagulation and complement cascades. The goal of this study was to immobilize apyrase on a biomaterial surface in order to develop an enzymatically active surface that would have the capacity to inhibit platelet activation by degrading ADP. We were able to immobilize apyrase on a polystyrene surface with preservation of the enzymatic activity. We then analyzed the hemocompatibility of the apyrase surface and of control surfaces by incubation with platelet-rich plasma (PRP) or whole blood. Monitoring of markers of platelet, coagulation, and complement activation and staining of the surfaces revealed decreased levels of platelet and coagulation activation parameters on the apyrase surface. The formation of antithrombin-thrombin and antithrombin-factor XIa complexes and the extent of platelet consumption were significantly lower on the apyrase surface than on any of the control surfaces. No significant differences were seen in complement activation (C3a levels). Staining of the apyrase surface revealed low platelet adherence and no formation of granulocyte platelet complexes. These results demonstrate that it is possible to create an antithrombotic surface targeting the ADP amplification of platelet activation by immobilizing apyrase.

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