title: In vitro hemocompatibility of self-assembled monolayers displaying various functional groups.
abstract: Self-assembled monolayers (SAMs) of alkanethiols with various terminating groups (-OH, -CH3, -COOH) and binary mixtures of these alkanethiols were studied with respect to their hemocompatibility in vitro by means of freshly taken human whole blood. The set of smooth monomolecular films with graded surface characteristics was applied to scrutinize hypotheses on the impact of surface chemical-physical properties on distinct blood activation cascades, i.e. to analyze -OH surface groups vs. complement activation, acidic surface sites vs. contact activation/coagulation and surface hydrophobicity vs. thrombogenicity. Blood and model surfaces were analyzed after incubation for the related hemocompatibility parameters. Our results show that the adhesion of leukocytes is abolished on a -CH3 surface and greatly enhanced on surfaces with -OH groups. The opposite was detected for the adhesion of platelets. A strong correlation between the activation of the complement system and the adhesion of leukocytes with the content of -OH groups could be observed. The contact activation for hydrophilic surfaces was found to scale with the amount of acidic surface sites. However, the coagulation and platelet activation did not simply correlate with any surface property and were therefore concluded to be determined by a superposition of contact activation and platelet adhesion.
authors.affiliation: Department of Biocompatible Materials, Leibniz Institute of Polymer Research Dresden, The Max Bergmann Center of Biomaterials Dresden, 01069 Dresden, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Sperling
authors.forename: Rüdiger B
authors.initials: RB
authors.lastname: Schweiss
authors.forename: Uwe
authors.initials: U
authors.lastname: Streller
authors.forename: Carsten
authors.initials: C
authors.lastname: Werner
mesh_terms: D000327:Adsorption; D000473:Alkanes / Q000737:chemistry*; D001672:Biocompatible Materials / Q000737:chemistry*; D001769:Blood / Q000378:metabolism*; D001792:Blood Platelets / Q000378:metabolism; D001920:Bradykinin / Q000737:chemistry; D002448:Cell Adhesion; D003167:Complement Activation; D015936:Complement C5a / Q000737:chemistry; D003165:Complement System Proteins; D004797:Enzyme-Linked Immunosorbent Assay; D005337:Fibrin / Q000737:chemistry; D006801:Humans; D007962:Leukocytes / Q000166:cytology / Q000378:metabolism; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D015539:Platelet Activation; D010973:Platelet Adhesiveness; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
chemical_list: D000473:Alkanes; D001672:Biocompatible Materials; D013438:Sulfhydryl Compounds; D015936:Complement C5a; D005337:Fibrin; D003165:Complement System Proteins; D001920:Bradykinin