Studies that have analyzed fibroblast conditioned media and decellularized matrices with mass spectrometry have revealed that these feeder cells
secrete essential growth factors, ECM components, and cytokines into the culture media, which support hESC growth and proliferation, such as fibroblast growth factors (FGFs), transforming growth factor-[beta] (TGF[beta]), bone morphogenetic proteins (BMPs), Activin A, laminin-511, laminin-binding integrins, vitronectin, heparan sulphate proteoglycans, fibronectin, and collagen [22, 23].
These observations have implications for the regulation of both dermal and epithelial stem cells in the hair follicle, as well as confirming that hair follicle dermal cells have the potential to be a useful source of feeder cells
for the support and amplification of a range of stem cell types.
hiPS cells were maintained on mitomycin C- (MMC-) treated SNL feeder cells
(CiRA), MMC-treated mouse embryonic fibroblasts (MEFs), or SL10 feeder cells
(ReproCELL) in a primate ES cell medium (ReproCELL) supplemented with bFGF (4ng/ml).
Finally, they were seeded onto the feeder cells
in 96-well plates at a final concentration of 1.5 x [10.sup.4] cells per well.
The company adds a defined PICM-19H culture system (one free of feeder cells
and undefined cell culture medium constituents) may also be important for potential US Food and Drug Administration (FDA) approval of HepaLife's artificial liver device currently under development.
Video 1: p75+ FACS-sorted H9 cells showing motile p75+ cells tracking the adherent PA6 feeder cells
over a 12-hour time period between days 8 and 12 of differentiation.
In this study, we prepared differentiating cells derived from hES cell (d-hES) for use as a feeder cells
of embryo co-culture.
Concerns that stem cell transplants might pose a risk not only to recipient but also to close contacts and the general public prompted the Food and Drug Administration to establish Draconian safety and follow-up guidelines for any experiments in which patients are given stem cells that have been in contact with animal feeder cells
After 3-7 days, the compact ES-like colony was mechanically dissociated into several pieces and seeded on new feeder cells
. The cultures were monitored daily and the culture medium was changed every other day.
"Our recent experiments show that the feeder cells
are not the issue," Bongso said.
"In previous studies, midbrain DA neurons were induced from human iPSCs, but the method required co-culture with stromal mouse feeder cells
or Matrigel," Takahashi said.