Sustained Levels of FGF2 Maintain Undifferentiated Stem Cell Cultures with Biweekly Feeding

Abstract

An essential aspect of stem cell culture is the successful maintenance of the undifferentiated state. Many types of stem cells are FGF2 dependent, and pluripotent stem cells are maintained by replacing FGF2-containing media daily, while tissue-specific stem cells are typically fed every 3rd day. Frequent feeding, however, results in significant variation in growth factor levels due to FGF2 instability, which limits effective maintenance due to spontaneous differentiation. We report that stabilization of FGF2 levels using controlled release PLGA microspheres improves expression of stem cell markers, increases stem cell numbers and decreases spontaneous differentiation. The controlled release FGF2 additive reduces the frequency of media changes needed to maintain stem cell cultures, so that human embryonic stem cells and induced pluripotent stem cells can be maintained successfully with biweekly feedings.

Multiple roles of Activin/Nodal, bone morphogenetic protein, fibroblast growth factor and Wnt/β-catenin signalling in the anterior neural patterning of adherent human embryonic stem cell cultures

“…We speculate that during the second week of differentiation a significant proportion of cells do not maintain their neural fate in spite of the presence of FGF2 or Noggin, without acquiring mesendodermal or extraembryonic fates. The reasons for the emergence of heterogeneous cell populations from initially homogeneous cultures could be explained by the presence of Notch-dependent lateral inhibition mechanisms [52], by fluctuations in exogenous growth factor signalling owing to their instability in the culture medium [53], and/or by unequal exposure to exogenous factors as colonies grow bigger during differentiation.…”

PLGA-Based Nanoparticles: a Safe and Suitable Delivery Platform for Osteoarticular Pathologies

“…Given the recent advances in synthesis and surface modification technologies, PLGA can be fine tuned to modify their size, loading (nucleic acid [5], drugs [6], or proteins [7] have been vectorized so far), degradation, and the shell of particles. Due to their biodegradability, PLGA particles are also used to ensure a controlled, sustained release of drugs [8].…”

Initiating Differentiation in Immortalized Multipotent Otic Progenitor Cells

“…In the current protocol, fresh media is constantly supplied to the cultures in order to maintain bFGF levels above 5 ng/ml without perturbing the otospheres. Stabilization of bFGF levels using controlled release from glycolic and lactic acid polyester microspheres could reduce the frequency of media changes needed to maintain steady levels of bFGF in media 31 . Addition of the steadily releasable bFGF will reduce the need to frequently add media to maintain bFGF levels in iMOP cultures.…”