[1] Jilin Univ, Hosp 1, Dept Spine Surg, Changchun 130021, Jilin, Peoples R China
[2] Chinese Acad Sci, Changchun Inst Appl Chem, Key Lab Polymer Ecomat, Changchun 130022, Jilin, Peoples R China
[3] Nanjing Univ, Affiliated Drum Tower Hosp, Med Sch, Dept Spine Surg, Nanjing 210008, Jiangsu, Peoples R China
[4] Univ Penn, Dept Bioengn, Philadelphia, PA 19104 USA
[5] Hosp Univ Penn, Dept Neurosurg, 3400 Spruce St, Philadelphia, PA 19104 USA
[6] Jilin Biomed Polymers Engn Lab, 5625 Renmin St, Changchun 130022, Jilin, Peoples R China