Changes in adsorbed fibrinogen and albumin interactions with polymers indicated by decreases in detergent elutability

Bohnert, Janice L.; Horbett, Thomas A.

doi:10.1016/0021-9797(86)90040-8

Cited by 193 publications

(99 citation statements)

References 31 publications

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“…During the adsorption (immobilization) process, the protein molecules (which are initially folded and able to contact the surface on only one side) begin to unfold following contact, thus creating multiple binding sites. 18 This results in greater accessibility of immobilized lipase by the substrate molecules than that achieved by the free lipase and, consequently, greater esterification activity in the immobilized system. Moreover, in an anhydrous organic medium, there is no place for the enzyme to escape from the Celite, since the environment has low water content.…”

Section: Enantioselective Esterification For Resolution Of Racemic Ibmentioning

confidence: 99%

Characterization and catalytic activity of free and immobilized lipase from Aspergillus niger: a comparative study

Silva

Contesini

Carvalho

2008

J. Braz. Chem. Soc.

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Lipase de Aspergillus niger foi imobilizada por deposição utilizando Celite e as atividades de hidrólise e esterificação, a estabilidade e a enantioseletividade das formas livre e imobilizada foram comparadas. Ambas as preparações mostraram propriedades bioquímicas similares, com atividade máxima em pH 6,0 e temperatura de 30-40 o C. Não foram observadas diferenças na atividade hidrolítica em função do pH para as duas formas da enzima. Os efeitos mais importantes observados após a imobilização foram a estabilidade térmica e a melhoria da atividade de esterificação na reação do (R,S)-ibuprofeno com 1-propanol em presença do isooctano. Além disso, a lipase na forma imobilizada manteve, pelo menos, 73% de sua atividade de esterificação após 5 dias de armazenamento a 40 o C e pôde ser reciclada e reutilizada por pelo menos 6 vezes.Aspergillus niger lipase was immobilized by deposition on Celite and the hydrolytic and esterification activities, stability and enantioselectivity of both free and immobilized enzyme were compared. Both the free and immobilized preparations showed similar biochemical properties, with maximum activity at pH 6.0 and a temperature of 30-40 o C. The most important effects observed when the lipase was immobilized were thermal stability and an improved esterification activity during the reaction of (R,S)-ibuprofen with 1-propanol in isooctane. Moreover, immobilized Aspergillus niger lipase maintained an esterification activity of at least 73% after 5 days of storage at 40 o C and can be recycled and reused at least 6 times.

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Section: Enantioselective Esterification For Resolution Of Racemic Ibmentioning

confidence: 99%

Characterization and catalytic activity of free and immobilized lipase from Aspergillus niger: a comparative study

Silva

Contesini

Carvalho

2008

J. Braz. Chem. Soc.

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“…The ability to remove fibrinogen or albumin from a variety of polymeric surfaces with the detergent sodium dodecylsulfate (SDS) was found to gradually decrease if the time between adsorption and elution was lengthened (19).…”

Section: Surface Activity Of Hemoglobin Genetic Variantsmentioning

confidence: 99%

Proteins at Interfaces: Current Issues and Future Prospects

Horbett

Brash

1987

ACS Symposium Series

155

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The ability of proteins to influence a wide variety of processes that occur at interfaces is well recognized. The biocompatibility of clinical implants, mammalian and bacterial cell adhesion to surfaces, initiation of blood coagulation, complement activation by surfaces, solid phase immunoassays, and protein binding to cell surface receptors all involve proteins at interfaces. Furthermore, practical problems such as contact lens fouling, foaming of protein solutions, and fouling of equipment in the food processing industry, are direct consequences of the relatively high surface activity of proteins. In general, any process involving an interface in which contact with a protein solution occurs is likely to be influenced by protein adsorption to the interface. Thus, several reviews of protein adsorption have been published (1-5).Since previous reviews provide excellent coverage of the generally well understood or frequently studied aspects of the interfacial behavior of proteins, this chapter will focus on several facets of protein adsorption that have so far not been examined in much detail.While this approach is atypical for an overview chapter, it is in keeping with the intent of this book to provide information to the reader that reflects more recent developments in this field. Furthermore, as will be seen, the topics to be discussed necessitate reexamination of previous studies and provide some unifying views of this rather diverse science.The main topics to be presented include the origins of the surface activity of proteins, multiple states of adsorbed proteins, and the competitive adsorption behavior of proteins. These topics were chosen because it appears that a better understanding of each is necessary The molecular properties of proteins that are thought to be responsible for their tendency to reside at surfaces are summarized in Table I. The size, charge, structure, and other chemical properties of proteins that presumably influence surface activity are all fundamentally related to their amino acid sequence, which is fixed for each type of protein but varies greatly among proteins. Thus, differences in surface activity among proteins arise from variations in their primary structure. At this point, further enquiries into the origin of surface activity differences among proteins become quite problematical because little detailed information is available that relates variation in the primary structure of proteins to changes in the surface activity of the molecules. However, a discussion of specific factors will serve to clarify our concepts in this regard. 0097Size ie presumably an important determinant of surface activity because proteins and other macromolecules are thought to form multiple contact points when adsorbed to a surface. The irreversibility typically observed for proteins adsorbed to surfaces is thought to be due to the fact that simultaneous dissociation of all the contacts with the surface is an unlikely event. Multiple bonding is also indicated by the relatively large number of protein ca...

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“…The question of why materials with diverse surface properties elicit the same FBR has troubled investigators for more than two decades (3)(4)(5). It is believed that implants acquire a protein coat immediately after implantation, which serves as a stimulus for the development of the FBR (6)(7)(8)(9)(10), and it has been suggested that fibrinogen is a critical component of this protein coat (10,11). Adsorption of proteins can be influenced by the surface properties of the material and may lead to modification of the FBR (3,(12)(13)(14)(15).…”

mentioning

confidence: 99%

Mice that lack the angiogenesis inhibitor, thrombospondin 2, mount an altered foreign body reaction characterized by increased vascularity

Kyriakides

Leach

Hoffman

et al. 1999

Proc. Natl. Acad. Sci. U.S.A.

144

104

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Disruption of the thrombospondin 2 gene (Thbs2) in mice results in a complex phenotype characterized chief ly by abnormalities in fibroblasts, connective tissues, and blood vessels. Consideration of this phenotype suggested to us that the foreign body reaction (FBR) might be altered in thrombospondin 2 (TSP2)-null mice. To investigate the participation of TSP2 in the FBR, polydimethylsiloxane (PDMS) and oxidized PDMS (ox-PDMS) disks were implanted in TSP2-null and control mice. Growth of TSP2-null and control skin fibroblasts in vitro also was evaluated on both types of disks. Normal fibroblasts grew as a monolayer on both surfaces, but attachment of the cells to ox-PDMS was weak and sensitive to movement. TSP2-null fibroblasts grew as aggregates on both surfaces, and their attachment was further compromised on ox-PDMS. After a 4-week implantation period, both types of PDMS elicited a similar FBR with a collagenous capsule in both TSP2-null and control mice. However, strikingly, the collagenous capsule that formed in TSP2-null mice was highly vascularized and thicker than that formed in normal mice. In addition, abnormally shaped collagen fibers were observed in capsules from mutant mice. These observations indicate that the presence or absence of an extracellular matrix component, TSP2, can inf luence the nature of the FBR, in particular its vascularity. The expression of TSP2 therefore could represent a molecular target for local inhibitory measures when vascularization of the tissue surrounding an implanted device is desired.

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Changes in adsorbed fibrinogen and albumin interactions with polymers indicated by decreases in detergent elutability

Cited by 193 publications

References 31 publications

Characterization and catalytic activity of free and immobilized lipase from Aspergillus niger: a comparative study

Characterization and catalytic activity of free and immobilized lipase from Aspergillus niger: a comparative study

Proteins at Interfaces: Current Issues and Future Prospects

Mice that lack the angiogenesis inhibitor, thrombospondin 2, mount an altered foreign body reaction characterized by increased vascularity

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