K. Wei, Y. Li, K. O. Kim, Y. Nakagawa, B. S. Kim*, K. Abe, G. Q. Chen, I. S. Kim*, “Fabrication of nano-hydroxyapatite on electrospun silk fibroin nanofiber and their effects in osteoblastic behavior”, J. Biomed. Mater. Res. Part A, 97A(3), 272-280 (2011).