title: Effect of tissue scaffold topography on protein structure monitored by fluorescence spectroscopy.
abstract: The impact of surface topography on the structure of proteins upon adhesion was assessed through non-invasive fluorescence monitoring. This study aimed at obtaining a better understanding about the role of protein structural status on cell-scaffold interactions. The changes induced upon adsorption of two model proteins with different geometries, trypsin (globular conformation) and fibrinogen (rod-shaped conformation) on poly-l-lactic acid (PLLA) scaffolds with different surface topographies, flat, fibrous and surfaces with aligned nanogrooves, were assessed by fluorescence spectroscopy monitoring, using tryptophan as structural probe. Hence, the maximum emission blue shift and the increase of fluorescence anisotropy observed after adsorption of globular and rod-like shaped proteins on surfaces with parallel nanogrooves were ascribed to more intense protein-surface interactions. Furthermore, the decrease of fluorescence anisotropy observed upon adsorption of proteins to scaffolds with fibrous morphology was more significant for rod-shaped proteins. This effect was associated to the ability of these proteins to adjust to curved surfaces. The additional unfolding of proteins induced upon adsorption on scaffolds with a fibrous morphology may be the reason for better cell attachment there, promoting an easier access of cell receptors to initially hidden protein regions (e.g. RGDS sequence), which are known to have a determinant role in cell attaching processes.
authors.affiliation: REQUIMTE/CQFB, Departamento de Química, FCT-UNL, Campus da Caparica, 2829-516 Caparica, Portugal. Electronic address: cmp@fct.unl.pt.
authors.forename: Carla A M
authors.initials: CA
authors.lastname: Portugal
authors.affiliation: MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Faculty of Science and Technology, Department of Tissue Regeneration, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Roman
authors.initials: R
authors.lastname: Truckenmüller
authors.affiliation: MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Faculty of Science and Technology, Department of Biomaterials Science & Technology, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Stamatialis
authors.affiliation: REQUIMTE/CQFB, Departamento de Química, FCT-UNL, Campus da Caparica, 2829-516 Caparica, Portugal.
authors.forename: João G
authors.initials: JG
authors.lastname: Crespo
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D019344:Lactic Acid / Q000737:chemistry; D011091:Polyesters; D011108:Polymers / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D011091:Polyesters; D011108:Polymers; D011506:Proteins; D019344:Lactic Acid; C033616:poly(lactide)
keywords: Fluorescence emission; Protein adhesion; Protein conformation; Surface topography; Tissue scaffold