1. Nano Medical Engineering Laboratory, RIKEN (The Institute of Physical and Chemical Research), 2-1 Hirosawa, Wako, Saitama, 351-0198, Japan, Regenerative Medical Bioreactor Project, Kanagawa Academy of Science and Technology, KSP East 309, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan, and Dipartimento di Scienze e Tecnologie Chimiche e dei Biosistemi, Universita degli Studi di Siena, Via Aldo Moro 2, 1-53100 Siena, Italy