Using the biopolymer heparin and a nanofiber scaffold, researchers at Northwestern University have developed a novel nanostructure that promotes blood vessel growth (Nano Lett., DOI: 10.1021/nl0613555). The system, developed by Samuel I. Stupp and his colleagues, could become an important tool in regenerative medicine, where new blood vessel formation is critical for growing new tissue. The nanofiber's basic building block is an amphiphile that has a hydrocarbon chain on one end and a peptide designed to bind heparin on the other. In the presence of heparin, these lengthy molecules assemble into cylindrical fibers with the hydrocarbon chains at the core and the peptide-heparin complex at the surface (shown). When combined with nanogram amounts of angiogenic growth factors known to interact with heparin, the nanostructures stimulate extensive new blood vessel formation in vivo. Stupp thinks the nanostructure's defined shape and surface account for its angiogenic properties. Preliminary experiments to treat skin wounds in rabbits and damaged heart tissue in mice have "shown promising results," he says.