Tethering of Gly-Arg-Gly-Asp-Ser-Pro-Lys Peptides on Mg-Doped Hydroxyapatite

Stem cell homing, namely the recruitment of mesenchymal stem cells (MSCs) to injured tissues, is highly effective for bone regeneration in vivo. In order to explore whether the incorporation of mimetic peptide sequences on magnesium-doped (Mg-doped) hydroxyapatite (HA) may regulate the homing of MSCs, and thus induce cell migration to a specific site, we covalently functionalized MgHA disks with two chemotactic/haptotactic factors: either the fibronectin fragment III1-C human (FF III1-C), or the peptide sequence Gly-Arg-Gly-Asp-Ser-Pro-Lys, a fibronectin analog that is able to bind to integrin transmembrane receptors. Preliminary biological evaluation of MSC viability, analyzed by 3-(4,5-dimethyl­thiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, suggested that stem cells migrate to the MgHA disks in response to the grafted haptotaxis stimuli.