title: Surface investigation on biomimetic materials to control cell adhesion: the case of RGD conjugation on PCL.
abstract: The cell recognition of bioactive ligands immobilized on polymeric surfaces is strongly dependent on ligand presentation at the cell/material interface. While small peptide sequences such as Arg-Gly-Asp (RGD) are being widely used to obtain biomimetic interfaces, surface characteristics after immobilization as well as presentation of such ligands to cell receptors deserve more detailed investigation. Here, we immobilized an RGD-based sequence on poly(epsilon-caprolactone) (PCL), a largely widespread polymeric material used in biomedical applications, after polymer aminolysis. The surface characteristics along with the efficacy of the functionalization was monitored by surface analysis (FTIR-ATR, contact angle measurements, surface free energy determination) and spectrophotometric assays specially adapted for the analytical quantification of functional groups and/or peptides at the interface. Particular attention was paid to the evaluation of a number, morphology, and penetration depth of immobilized functional groups and/or peptides engrafted on polymeric substrates. In particular, a typical morphology in peptide distribution was evidenced on the surface raised from polymer crystallites, while a significant penetration depth of the engrafted molecules was revealed. NIH3T3 fibroblast adhesion studies verified the correct presentation of the ligand with enhanced cell attachment after peptide conjugation. Such work proposes a morphological and analytical approach in surface characterization to study the surface treatment and the distribution of ligands immobilized on polymeric substrates.
authors.affiliation: Interdisciplinary Research Centre on Biomaterials (CRIB) University Federico II, Piazzale Tecchio 80, 80125, Naples, Italy. causa@unina.it
authors.forename: Filippo
authors.initials: F
authors.lastname: Causa
authors.forename: Edmondo
authors.initials: E
authors.lastname: Battista
authors.forename: Raffaella
authors.initials: R
authors.lastname: Della Moglie
authors.forename: Daniela
authors.initials: D
authors.lastname: Guarnieri
authors.forename: Maria
authors.initials: M
authors.lastname: Iannone
authors.forename: Paolo A
authors.initials: PA
authors.lastname: Netti
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry*; D002448:Cell Adhesion; D002623:Chemistry Techniques, Analytical; D008024:Ligands; D051379:Mice; D041681:NIH 3T3 Cells; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism; D011091:Polyesters / Q000737:chemistry*; D011485:Protein Binding; D013057:Spectrum Analysis; D013499:Surface Properties
chemical_list: D008024:Ligands; D009842:Oligopeptides; D011091:Polyesters; C016240:polycaprolactone; C047981:arginyl-glycyl-aspartic acid