PMID- 16231604
OWN - NLM
STAT- MEDLINE
DCOM- 20051214
LR  - 20190922
IS  - 0920-5063 (Print)
IS  - 0920-5063 (Linking)
VI  - 16
IP  - 9
DP  - 2005
TI  - Structure and assembly of PEO-PPO-PEO co-polymers in mammalian cell-culture 
      media.
PG  - 1139-51
AB  - We investigate the structure of a poly(ethylene oxide)-poly(propylene oxide)-poly 
      (ethylene oxide) co-polymer, Pluronic F127, in mammalian cell-culture media. It 
      is well known that aqueous solutions of F127 gel at physiological temperatures 
      with this transition, which corresponds to the formation of a close-packed cubic 
      assembly of spherical micelles. Previous work has shown that in both mammalian 
      cell minimum essential medium (MEM) and MEM with added fetal bovine serum, the 
      gel phase boundary shifts to lower temperatures and concentrations as compared to 
      pure water. Using DLS, we have found that at 25 degrees C the critical micelle 
      concentration (CMC) decreases in the presence of MEM. Our SANS studies at 25 
      degrees C indicate that F127 in MEM-D2O also forms a close-packed cubic micellar 
      gel, suggesting that the mechanism of gelation is the same in both pure water and 
      MEM. Fits to the neutron spectra on 2 wt% F127 in D2O and MEM-D2O show a large 
      difference in the micelle aggregation number (Nagg) and a small difference in the 
      micelle size, with both Nagg and the micelle size larger in the presence of MEM. 
      In addition, our SANS spectra in MEM-D2O indicate repulsive interactions between 
      micelles at 2 wt% polymer, whereas no correlation peak is observed for this 
      concentration in water. Finally, moderately concentrated samples (5-18 wt% 
      polymer) in MEM exhibit slightly stronger ordering and sharper peaks, perhaps 
      indicating stronger intermicellar interactions in the presence of MEM. This 
      stronger repulsive interaction may be the cause of the shift in the liquid-gel 
      phase boundary that is observed.
FAU - Sharma, Praveen K
AU  - Sharma PK
AD  - Department of Chemical Engineering, 159 Goessmann Laboratory, University of 
      Massachusetts, Amherst, MA 01003, USA.
FAU - Matthew, Julie E
AU  - Matthew JE
FAU - Bhatia, Surita R
AU  - Bhatia SR
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PT  - Research Support, U.S. Gov't, Non-P.H.S.
PL  - England
TA  - J Biomater Sci Polym Ed
JT  - Journal of biomaterials science. Polymer edition
JID - 9007393
RN  - 0 (Culture Media)
RN  - 0 (Micelles)
RN  - 106392-12-5 (Poloxamer)
SB  - IM
MH  - Culture Media/*pharmacology
MH  - Micelles
MH  - Particle Size
MH  - Phase Transition/drug effects
MH  - Poloxamer/*chemistry
EDAT- 2005/10/20 09:00
MHDA- 2005/12/15 09:00
CRDT- 2005/10/20 09:00
PHST- 2005/10/20 09:00 [pubmed]
PHST- 2005/12/15 09:00 [medline]
PHST- 2005/10/20 09:00 [entrez]
AID - 10.1163/1568562054798545 [doi]
PST - ppublish
SO  - J Biomater Sci Polym Ed. 2005;16(9):1139-51. doi: 10.1163/1568562054798545.