[1]State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China;
[2]Biomaterials & Tissue Engineering Division, Department of Endodontics, Periodontics and Prosthodontics, University of Maryland Dental School, Baltimore, USA;
[3]Biomaterials Group, Biosystems and Biomaterials Division, National Institute of Standards & Technology, Gaithersburg, USA;
[4]Center for Stem Cell Biology & Regenerative Medicine, University of Maryland School of Medicine, Baltimore, USA;
[5]Department of Mechanical Engineering, University of Maryland, Baltimore County, USA;