To reduce bone fracture recovery time, bone morphogenetic proteins (BMPs) are important proteins to induce bone formation and regeneration. Many studies have reported BMPs increase bone-forming cell growth. They can be injected into implantation sites or coated onto traditional implantation materials, such as titanium. However, BMPs possess several hundred amino acids, which are difficult to synthesize or coat onto materials. The large molecular size and complex structures of BMPs limit their applications in industrial and clinical settings. Many researchers are trying to use short peptides to improve the growth of osteoblasts instead of the entire BMP molecule.

In this study, we chose several BMP-7 short peptide residues: SNVILKKYRN, KPSSAPTQLN and KAISVLYFDDS. We observed that short peptides could improve osteoblast proliferation, as well as the long term functions. We also found that the short peptide of BMP-7, KPSSAPTQLN promoted osteoblasts spreading and adhesion. As a result, the short peptides of BMP-7 have good bioactivity to enhance osteoblast growth, which are much easier to functionalize onto implant materials than the entire BMP molecule. For example, the peptides can be connected with helical rosette nanotubes (HRNs), which will generate nanotubes in body solutions and solidify into a viscous gel at body temperatures. These functionalized HRNs can be utilized as a novel drug delivery device. They can be injected into implantation sites and solidify in the body. Because of the natural orientation and good biocompatibility of nanotubes, they not only enhance the function of osteoblasts, but also release of BMP-7 peptides to increase the bone growth.