title: Secondary structure of rhBMP-2 in a protective biopolymeric carrier material.
abstract: Efficient delivery of growth factors is one of the great challenges of tissue engineering. Polyelectrolyte multilayer films (PEM) made of biopolymers have recently emerged as an interesting carrier for delivering recombinant human bone morphogenetic protein 2 (rhBMP-2 noted here BMP-2) to cells in a matrix-bound manner. We recently showed that PEM made of poly(l-lysine) and hyaluronan (PLL/HA) can retain high and tunable quantities of BMP-2 and can deliver it to cells to induce their differentiation in osteoblasts. Here, we investigate quantitatively by Fourier transform infrared spectroscopy (FTIR) the secondary structure of BMP-2 in solution as well as trapped in a biopolymeric thin film. We reveal that the major structural elements of BMP-2 in solution are intramolecular β-sheets and unordered structures as well as α-helices. Furthermore, we studied the secondary structure of rhBMP-2 trapped in hydrated films and in dry films since drying is an important step for future applications of these bioactive films onto orthopedic biomaterials. We demonstrate that the structural elements were preserved when BMP-2 was trapped in the biopolymeric film in hydrated conditions and, to a lesser extent, in dry state. Importantly, its bioactivity was maintained after drying of the film. Our results appear highly promising for future applications of these films as coatings of biomedical materials, to deliver bioactive proteins while preserving their bioactivity upon storage in dry state.
authors.affiliation: CNRS UMR 5628 (LMGP), Grenoble Institute of Technology and CNRS, 3 parvis Louis Néel, F-38016 Grenoble Cedex, France.
authors.forename: Flora
authors.initials: F
authors.lastname: Gilde
authors.forename: Ofélia
authors.initials: O
authors.lastname: Maniti
authors.forename: Raphael
authors.initials: R
authors.lastname: Guillot
authors.forename: Joao F
authors.initials: JF
authors.lastname: Mano
authors.forename: Delphine
authors.initials: D
authors.lastname: Logeart-Avramoglou
authors.forename: Frédéric
authors.initials: F
authors.lastname: Sailhan
authors.forename: Catherine
authors.initials: C
authors.lastname: Picart
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D001704:Biopolymers / Q000737:chemistry*; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry*; D001842:Bone and Bones; D002454:Cell Differentiation; D002478:Cells, Cultured; D004337:Drug Carriers; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects; D011107:Polylysine / Q000737:chemistry; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D023822:Tissue Engineering; D016212:Transforming Growth Factor beta / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D001704:Biopolymers; D055396:Bone Morphogenetic Protein 2; D004337:Drug Carriers; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2; D011107:Polylysine; D006820:Hyaluronic Acid