Mahmoodi, Mahboobeh, Kalantari, Mina, Mirhaj, Marjan (2020). Effect of Hydroxyapatite Nanoparticles on Differentiotion of Mesenchymal Stem ‍Cells  into Bone cells in Polycaprolacton/Keratin/Hydroxyapatite Scaffolds. *Advanced Processes in Materials Engineering*, 14(1), 55-71.