title: Fibronectin distribution on demixed nanoscale topographies.
abstract: OBJECTIVE
  It is known that surface nanotopography influences cell adhesion and differentiation. Our aim is to analyze the effect of nanoscale topography on fibronectin adsorption and, afterwards, on cell adhesion in order to rationalize the cell-material interaction by focusing on the state of the intermediate layer of adsorbed fibronectin at the material interphase.
  
  
  METHODS
  Nanotopographic surfaces were produced by demixing of thin film polymer blends - PLLA and PS - during a high speed spin-casting process. Fibronectin (FN) was adsorbed on the different nanotopographies and the protein distribution was directly observed by atomic force microscopy (AFM). The fraction of the surface covered by the protein was quantified by image analysis, as well as the distribution of FN between peaks and valleys. Focal adhesion protein -vinculin- was immunostained and quantified by image analysis on the different nanoscale surfaces.
  
  
  RESULTS
  Different nanoscale domains were obtained by changing the composition of the system within a height range of 3 nm to 30 nm. FN tends to adsorb on the peaks of nanoisland topographies, especially in compositions that did not enhance cell adhesion. Moreover, protein distribution between valleys and peaks alters the size of focal adhesion plaques, which grew larger on surfaces with an even distribution of fibronectin.
  
  
  CONCLUSIONS
  Our results suggest that the surface nanotopography is a key material property capable of influencing protein adsorption. Additionally, the distribution of the protein on the different samples was correlated to the initial ability of cells to adhere in terms of the size of the focal plaques.
authors.affiliation: Center for Biomaterials and Tissue Engineering, Universidad Politécnica de Valencia, Valencia - Spain.
authors.forename: Manuel
authors.initials: M
authors.lastname: Pérez-Garnes
authors.forename: Cristina
authors.initials: C
authors.lastname: González-García
authors.forename: David
authors.initials: D
authors.lastname: Moratal
authors.forename: Patricia
authors.initials: P
authors.lastname: Rico
authors.forename: Manuel
authors.initials: M
authors.lastname: Salmerón-Sánchez
mesh_terms: D016475:3T3 Cells; D000327:Adsorption; D000818:Animals; D002448:Cell Adhesion; D005353:Fibronectins / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure*; D022001:Focal Adhesions / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D019344:Lactic Acid / Q000737:chemistry*; D051379:Mice; D018625:Microscopy, Atomic Force; D036103:Nanotechnology / Q000379:methods*; D011091:Polyesters; D011108:Polymers / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D013499:Surface Properties; D054457:Tissue Scaffolds; D016596:Vinculin / Q000378:metabolism
chemical_list: D005353:Fibronectins; D011091:Polyesters; D011108:Polymers; D011137:Polystyrenes; D016596:Vinculin; D019344:Lactic Acid; C033616:poly(lactide)