83cell feeder layers (Totonchi et al. 2010 ; Xu et al. 2001 ). iPSCs show excellent
growth in Matrigel. However, Matrigel is produced from Engelbreth–Holm–Swarm
mouse sarcoma cells, and thus it needs to be replaced with other matrices from
human or recombinant proteins. Other types of matrices have been developed to
culture iPSCs, such as CellStart (Ausubel et al. 2011 ; Bergstrom et al. 2011 ), recom-
binant proteins (Chen et al. 2011 ; Rodin et al. 2010 ), and synthetic polymers (Lu
et al. 2012 ; Mei et al. 2010 ). To remove the fetal bovine serum in culture medium,
knockout serum replacement (KSR) has been established as a defi nitive material for
maintaining human ESCs (Draper et al. 2004 ) and considered suitable to culture
iPSCs (Ludwig et al. 2006 ). However, both KSR and mTeSR1 also contain animal-
derived products. New media have been commercially developed as xeno-free
media for maintaining human pluripotent stem cells and iPSCs, such as TeSR2
(Meng et al. 2012 ), NutriStem (Sugii et al. 2010 ), Essential E8 (Chen et al. 2011 ),
and St emFit (Nakagawa et al. 2014 ) (Fig. 4.2 ).
Fig. 4.2 Protocols for production of clinical-grade iPSCs. Clinical-grade iPSC production method
requires virus-free systems, absence of animal-derived components, and less invasive techniques
4 New Trends in Clinical Applications of Induced Pluripotent Stem Cells