title: Bone morphogenetic protein-2 release from composite hydrogels of oligo(poly(ethylene glycol) fumarate) and gelatin.
abstract: OBJECTIVE
  Hydrogel composites of oligo(poly(ethylene glycol) fumarate) (OPF) and gelatin microparticles (GMs) were investigated as carriers of bone morphogenetic protein-2 (BMP-2) for bone tissue engineering applications.
  
  
  METHODS
  Hydrogel composites with different physical characteristics were prepared by changing the amount and type (acidic vs. basic) of gelatin incorporated in the OPF bulk phase. Composites with differing physical properties (degradation, swelling, and mechanical properties) and differing BMP-2 loading phase were investigated to determine the effect of these factors on BMP-2 release profiles over 28 days.
  
  
  RESULTS
  Overall, higher gelatin amount increased the degradation and swelling of composites, and acidic GMs further increased the degradation and swelling and reduced the compressive modulus of the composites. The most significant factor affecting the release of BMP-2 from composites was the loading phase of the growth factor: GM loading reduced the burst release, increased BMP-2 release during the later phases of the experiment, and increased the cumulative release in faster degrading samples.
  
  
  CONCLUSIONS
  The results indicate that the physical properties and the BMP-2 release kinetics of hydrogel composites can be controlled by adjusting multiple parameters at the time of the hydrogel composite fabrication.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Rice University, Houston, Texas, USA.
authors.forename: Lucas A
authors.initials: LA
authors.lastname: Kinard
authors.forename: Chia-Ye
authors.initials: CY
authors.lastname: Chu
authors.forename: Yasuhiko
authors.initials: Y
authors.lastname: Tabata
authors.forename: F Kurtis
authors.initials: FK
authors.lastname: Kasper
authors.forename: Antonios G
authors.initials: AG
authors.lastname: Mikos
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry; D055396:Bone Morphogenetic Protein 2 / Q000008:administration & dosage*; D003692:Delayed-Action Preparations / Q000737:chemistry*; D005780:Gelatin / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D008422:Materials Testing; D011091:Polyesters / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D023822:Tissue Engineering
chemical_list: D001672:Biocompatible Materials; D055396:Bone Morphogenetic Protein 2; D003692:Delayed-Action Preparations; D020100:Hydrogels; D011091:Polyesters; C469550:oligo(poly(ethylene glycol)fumarate); D011092:Polyethylene Glycols; D005780:Gelatin