title: Layer-by-layer films as a biomimetic reservoir for rhBMP-2 delivery: controlled differentiation of myoblasts to osteoblasts.
abstract: Efficient delivery of growth or survival factors to cells is one of the most important long-term challenges of current cell-based tissue engineering strategies. The extracellular matrix acts as a reservoir for a number of growth factors through interactions with its components. In the matrix, growth factors are protected against circulating proteases and locally concentrated. Thus, the localized and long-lasting delivery of a matrix-bound recombinant human bone morphogenetic protein 2 (rhBMP-2) from a biomaterial surface would mimic in vivo conditions and increase BMP-2 efficiency by limiting its degradation. Herein, it is shown that crosslinked poly(L-lysine)/hyaluronan (HA) layer-by-layer films can serve as a reservoir for rhBMP-2 delivery to myoblasts and induce their differentiation into osteoblasts in a dose-dependent manner. The amount of rhBMP-2 loaded in the films is controlled by varying the deposition conditions and the film thickness. Its local concentration in the film is increased up to approximately 500-fold when compared to its initial solution concentration. Its adsorption on the films, as well as its diffusion within the films, is evidenced by microfluorimetry and confocal microscopy observations. A direct interaction of rhBMP-2 with HA is demonstrated by size-exclusion chromatography, which could be at the origin of the rhBMP-2 "trapping" in the film and of its low release from the films. The bioactivity of rhBMP-2-loaded films is due neither to film degradation nor to rhBMP-2 release. The rhBMP-2-containing films are extremely resistant and could sustain three successive culture sequences while remaining bioactive, thus confirming the important and protective effect of rhBMP-2 immobilization. These films may find applications in the local delivery of immobilized growth factors for tissue-engineered constructs and for metallic biomaterial surfaces, as they can be deposited on a wide range of substrates with different shapes, sizes, and composition.
authors.affiliation: UMR 5235 Dynamique des Interactions Membranaires Normales et Pathologiques CNRS, Université Montpellier II et I cc 107, Montpellier, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Crouzier
authors.forename: Kefeng
authors.initials: K
authors.lastname: Ren
authors.forename: Claire
authors.initials: C
authors.lastname: Nicolas
authors.forename: Christian
authors.initials: C
authors.lastname: Roy
authors.forename: Catherine
authors.initials: C
authors.lastname: Picart
mesh_terms: D000818:Animals; D040761:Biomimetic Materials / Q000737:chemistry*; D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins / Q000737:chemistry / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002460:Cell Line; D004058:Diffusion; D004337:Drug Carriers / Q000737:chemistry*; D008567:Membranes, Artificial; D051379:Mice; D032446:Myoblasts / Q000166:cytology* / Q000187:drug effects*; D010006:Osteoblasts / Q000166:cytology* / Q000187:drug effects*; D010012:Osteogenesis / Q000187:drug effects; D011994:Recombinant Proteins / Q000737:chemistry / Q000494:pharmacology*; D016212:Transforming Growth Factor beta / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D055396:Bone Morphogenetic Protein 2; D019485:Bone Morphogenetic Proteins; D004337:Drug Carriers; D008567:Membranes, Artificial; D011994:Recombinant Proteins; D016212:Transforming Growth Factor beta; C499469:recombinant human bone morphogenetic protein-2