[1] Stanford Univ, Sch Med, Dept Orthoped Surg, 240 Pasteur Dr,BMI 258, Stanford, CA 94304 USA
[2] Stanford Univ, Dept Mat Sci & Engn, Stanford, CA 94304 USA
[3] Stanford Univ, Dept Bioengn, Stanford, CA 94304 USA
[4] Colorado State Univ, Dept Mech Engn, Ft Collins, CO 80523 USA
[5] Colorado State Univ, Sch Biomed Engn, Ft Collins, CO 80523 USA
[6] Colorado State Univ, Dept Clin Sci, Ft Collins, CO 80523 USA
[7] Colorado State Univ, Dept Microbiol Immunol & Pathol, Ft Collins, CO 80523 USA
[8] Stanford Univ, Dept Chem, Stanford, CA 94305 USA