title: Human plasma protein adsorption on carbon-based materials.
abstract: In this study the initial reactions of different carbon-based materials with human blood were investigated by short-time exposure to platelet poor plasma (PPP). Extent of protein adsorption and conformational changes of proteins adsorbed on material surfaces are known to be keys factors affecting further biological reactions. Plasma protein adsorption on multi-walled carbon nanotubes (MWCNTs), highly oriented pyrolytic graphite (HOPG) and nanocrystalline graphite (NG) were investigated and the results obtained on these materials were compared with those obtained studying pyrolytic carbon (PyC), a material showing good anti-trombogenic properties. The quantification of adsorbed plasma proteins on sample surfaces was obtained by Micro BCA Protein Assay, while immunofluorescence analysis was employed to monitor the surface density and distribution of two selected proteins, namely fibrinogen (Fg) and Hageman factor (FXII), proteins playing a leading role in mediating platelet adhesion. The dependence of the biological response on the surface chemical and morphological properties were also investigated and data obtained using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and atomic force microscopy (AFM) are presented. After PPP incubation PyC is characterized by the presence of low level of whole proteins and FXII adsorption, in contrast to a high adhesion of Fg. Compared to PyC the analysis of the other carbon-based materials result in a higher whole protein adsorption with an increasing trend moving from MWCNTs, NG and HOPG respectively. The Fg surface density on PyC, NG and MWCNTs is about four times higher than on HOPG while only HOPG show a detectable fluorescent signal of FXII. If AFM data indicate that surface morphology does not play a crucial role in protein adhesion, XPS analysis show chemical differences that can be correlated with this biological response.
authors.affiliation: FBK-irst, Via Sommarive 18, 38050 Povo, TN, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Vinante
authors.forename: Gabriella
authors.initials: G
authors.lastname: Digregorio
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Lunelli
authors.forename: Stefania
authors.initials: S
authors.lastname: Forti
authors.forename: Simone
authors.initials: S
authors.lastname: Musso
authors.forename: Lia
authors.initials: L
authors.lastname: Vanzetti
authors.forename: Alberto
authors.initials: A
authors.lastname: Lui
authors.forename: Laura
authors.initials: L
authors.lastname: Pasquardini
authors.forename: Mauro
authors.initials: M
authors.lastname: Giorcelli
authors.forename: Alberto
authors.initials: A
authors.lastname: Tagliaferro
authors.forename: Mariano
authors.initials: M
authors.lastname: Anderle
authors.forename: Cecilia
authors.initials: C
authors.lastname: Pederzolli
mesh_terms: D000327:Adsorption; D001798:Blood Proteins / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D006801:Humans; D008855:Microscopy, Electron, Scanning
chemical_list: D001798:Blood Proteins; D002244:Carbon