RESUMO
We present a surface coating with anticoagulant characteristics showing significantly reduced coagulation activation. The synthesis of a monomeric conjugate containing a benzamidine moiety was carried out and its inhibitory activity against human thrombin, the key enzyme of the blood coagulation cascade, was determined using a chromogenic assay. Based on that, low-thrombogenic interfaces were prepared by covalent attachment of this low-molecular weight thrombin inhibitor on poly(octadecene-alt-maleic anhydride) copolymer thin films and characterized using ellipsometry, XPS and dynamic contact angle measurements. The in vitro hemocompatibility tests using freshly drawn human whole blood showed, in agreement with the SEM images, that a PO-MA film modified with a benzamidine moiety using a PEG spacer decreased the activation of coagulation, platelets and the complement system. The decreased protein adsorption, in addition to the specific inhibition of thrombin, effectively enhanced the short-term hemocompatibility characteristics.
Assuntos
Benzamidinas/química , Benzamidinas/farmacologia , Plaquetas/citologia , Plaquetas/fisiologia , Sangue , Anidridos Maleicos/química , Ativação Plaquetária/fisiologia , Adsorção , Anticoagulantes/química , Anticoagulantes/farmacologia , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Plaquetas/efeitos dos fármacos , Células Cultivadas , Humanos , Teste de Materiais , Ativação Plaquetária/genética , Polímeros/química , Inibidores de Serina Proteinase/química , Inibidores de Serina Proteinase/farmacologia , Propriedades de Superfície , Trombina/metabolismoRESUMO
Two series of amphiphilic derivatives of lactose have been synthesized. Tensiometric investigations of the critical micellar concentration (CMC) and the area per molecule at interface (calculated by the Gibbs equation) of aqueous solutions were performed. The values measured depend on the number of methylene groups of the alkyl spacer n and that of the side chain m as well as on the ionic strength and temperature. The results show a behavior closely related to that of gemini surfactants: (1) self-assembly phenomena occur at concentrations below 1 mM, (2) at constant n log CMC increases linearly with higher m, and (3) the influence of the temperature on the aggregation phenomenon is comparable. Copyright 2001 Academic Press.
RESUMO
Synthetic glycolipids are of interest for their biological applications requiring interactions with membrane proteins. Depending on their structures, new series of glycolipids have applications in extraction of membrane proteins or medical applications as mimics of natural ligands of proteins.
