1. a Cox Laboratory for Biomedical Engineering, Department of Chemical Engineering and Institute of Biosciences and Bioengineering, Rice University, P.O. Box 1892, Houston, TX 77251-1892, USA
2. b Department of Orthopaedic Surgery, Wilford Hall Medical Center, Lackland AFB, TX 78236, USA
3. c Department of Basic Sciences-Oral Biomaterials, University of Texas-Houston Health Science Center, Houston, TX 77030, USA
4. d Cox Laboratory for Biomedical Engineering, Department of Chemical Engineering and Institute of Biosciences and Bioengineering, Rice University, P.O. Box 1892, Houston, TX 77251-1892, USA