Layer-by-layer films as a biomimetic reservoir for rhBMP-2 delivery: controlled differentiation of myoblasts to osteoblasts

Small. 2009 Mar;5(5):598-608. doi: 10.1002/smll.200800804.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomimetic Materials / chemistry*
  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins / chemistry
  • Bone Morphogenetic Proteins / pharmacology*
  • Cell Differentiation / drug effects
  • Cell Line
  • Diffusion
  • Drug Carriers / chemistry*
  • Membranes, Artificial
  • Mice
  • Myoblasts / cytology*
  • Myoblasts / drug effects*
  • Osteoblasts / cytology*
  • Osteoblasts / drug effects*
  • Osteogenesis / drug effects
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / pharmacology*
  • Transforming Growth Factor beta / chemistry
  • Transforming Growth Factor beta / pharmacology*

Substances

  • Bone Morphogenetic Protein 2
  • Bone Morphogenetic Proteins
  • Drug Carriers
  • Membranes, Artificial
  • Recombinant Proteins
  • Transforming Growth Factor beta
  • recombinant human bone morphogenetic protein-2