Starch-poly-є-caprolactone Microparticles Reduce the Needed Amount of BMP-2

  • E. R. Balmayor
  • G. A. Feichtinger
  • H. S. Azevedo
  • M. van Griensven
  • R. L. Reis
Symposium: Tribute to Dr. Marshall Urist: Musculoskeletal Growth Factors


BMP-2 is currently administered clinically using collagen matrices often requiring large amounts of BMP-2 due to burst release over a short period of time. We developed and tested a novel injectable drug delivery system consisting of starch-poly-є-caprolactone microparticles for inducing osteogenesis and requiring smaller amounts of BMP-2. We evaluated BMP-2 encapsulation efficiency and the in vitro release profile by enzyme-linked immunosorbent assay. BMP-2 was rapidly released during the first 12 hours, followed by sustained release for up to 10 days. We then evaluated the osteogenic potential of dexamethasone (standard osteogenic induction agent) and BMP-2 after incorporation and during release using an osteo/myoblast cell line (C2C12). Alkaline phosphatase activity was increased by released BMP-2. Mineralization occurred after stimulation with BMP-2-loaded microparticles. A luciferase assay for osteocalcin promoter activity showed high levels of activity upon treatment with BMP-2-loaded microparticles. In contrast, no osteogenesis occurred in C2C12 cells using dexamethasone-loaded microparticles. However, human adipose stem cells exposed to the microparticles produced high amounts of alkaline phosphatase. The data suggest starch-poly-є-caprolactone microparticles are suitable carriers for the incorporation and controlled release of glucocorticoids and growth factors. Specifically, they reduce the amount of BMP-2 needed and allow more sustained osteogenic effects.


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Copyright information

© The Association of Bone and Joint Surgeons® 2009

Authors and Affiliations

  • E. R. Balmayor
    • 1
    • 2
    • 3
  • G. A. Feichtinger
    • 3
  • H. S. Azevedo
    • 1
    • 2
  • M. van Griensven
    • 3
  • R. L. Reis
    • 1
    • 2
  1. 1.3B’s Research Group–Biomaterials, Biodegradables and Biomimetics, Department of Polymer EngineeringUniversity of Minho, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineCaldas das Taipas, GuimarãesPortugal
  2. 2.IBB–Institute for Biotechnology and BioengineeringPT Government Associated LaboratoryGuimarãesPortugal
  3. 3.Ludwig Boltzmann Institute for Experimental and Clinical TraumatologyAustrian Cluster for Tissue Regeneration, AUVA Research CentreViennaAustria

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