The current standard therapies to treat bone defects, such as those caused by traumatic wounds, require the extraction of bones from other parts of the patient’s body or from donors and transplantation into the site of injury. This process, however, is painful and highly risky. Although approaches stimulating bone regeneration are attractive alternatives, they are limited by the lack of bioactive materials sustaining bone formation.

To overcome this issue, Paula Hammonda, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA, and colleagues developed a new polyelectrolyte multilayer thin film. This material is a porous nanostructure carrying BMP-2 (bone morphogenic protein-2) and PDGFBB (platelet-derived growth factor beta), two proteins that stimulate bone regeneration. When applied to orthopedic polymers, such as a biodegradable poly(lactic-co-glycolic acid) membrane, the new film released BMP-2 and PDGFBB in a controlled and prolonged manner, thereby promoting bone regeneration in animal models.

This new approach may be a clinically useful tool to cure bone defects.

• Adaptive growth factor delivery from a polyelectrolyte coating promotes synergistic bone tissue repair and reconstruction,
  Nisarg J. Shah, Md. Nasim Hydea, Mohiuddin A. Quadir, Noémie-Manuelle Dorval Courchesne, Howard J. Seeherman, Myron Nevins, Myron Spector, and Paula T. Hammond,
  Proc. Natl. Acad. Sci. U. S. A. 2014.
  DOI: 10.1073/pnas.1408035111