Benjamin L Larson, Omar Z Fisher, Martin E Kolewe, Sara Yu, Farshid Guilak, Robert Langer, and Lisa E Freed
Langer Laboratory, Koch Institute
Scanning Electron Microscope

"These are three high magnification (SEM) images of biocompatible plastic filaments (PCL polymer) coated with a thin layer of bone inducing gel (melanic hydrogel). We had this great 3-dimensionally woven polymer fiber that was very biocompatible and strong enough to withstand a lot of compression and tension like bone. We also recently developed a hydrogel that produced some amazing pro-bone matrices but was very weak being a gel. We wanted to know if we could coat the polymer fiber mesh with this hydrogel and have it bind well in a thin enough layer.

After we took these images we were stunned at how the gel made a perfectly thin coating along the polymer fibers throughout the mesh.  With this knowledge we were then confident enough to culture the polymer/hydrogel combination with stem cells and observe beautiful bone formation on the meshes.  We were then able to place these in rats and observe no antigen-mediated immune response.  The next step for us will be to use the polymer/hydrogel composites to heal bone defects in rats and hopefully in the future, humans."