1. Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA.
2. Complex in Vitro Systems, Safety Assessment, Genentech Inc., South San Francisco, CA, USA.
3. Department of Chemical Engineering, Stanford University, Stanford, CA, USA.
4. Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA.
5. Department of Bioengineering, Stanford University, Stanford, CA, USA.