Characterization of the PEO−PPO−PEO Triblock Copolymer and Its Application as a Separation Medium in Capillary Electrophoresis

Abstract

The Pluronic polyol F127, PEO99PPO69PEO99 (PEO and PPO being poly(ethylene oxide) and poly(propylene oxide), respectively) has the potential to be used as an effective separation medium in capillary electrophoresis (CE) for the separation of biomacromolecules such as DNA fragments and proteins. Static light scattering (SLS), dynamic light scattering (DLS), small-angle neutron scattering (SANS), and small-angle X-ray scattering (SAXS) were used to characterize the solution properties and the microstructures of F127 in the same electrophoresis buffer used in CE. In the dilute solution region, F127 in CE buffer forms micelles similar to that in water. At high solution concentrations, micelles tend to pack into some crystalline forms with relatively well-structured PPO centers. By using a combination of SANS and SAXS results, we are able to conclusively determine the gellike structure to have a facecentered cubic lattice. The effects of solvent, polymer concentration, temperature, and sample preparation procedure on the gel structure were studied. In the gellike region the aggregation number and also the micellar size are not sensitive to both the concentration change and the temperature change. The results of DNA electrophoretic migration in F127 gels also support these findings.

AND/R: Advanced neutron diffractometer/reflectometer for investigation of thin films and multilayers for the life sciences

“…A poly͑ethylene oxide͒/poly͑propylene oxide͒, PEO-PPO− PEO, triblock copolymer, the Pluronic polyol F127, forms crystalline structures in the gel phase at high concentrations. 19 F127 is discussed as a separation medium for biological macromolecules in capillary electrophoresis with applications in automated genome sequencing. A crystalline sample was studied that was prepared from an aqueous solution ͑21 wt% in D 2 O͒.…”

“…Scattering-length density profiles derived from simultaneous fits to both data sets in B. has been previously observed in small-angle x-ray scattering measurements. 19 The exposure time was 10 min. Diffraction for the ͑220͒ and ͑311͒ reflections were also observed.…”

Nucleation and growth of micellar polycrystals under time-dependent volume fraction conditions

“…Due to their amphiphilic character, thermoresponsive properties, and biocompatibility, the Pluronics copolymer are extensively used in industrial applications as antifoaming or thickener agents for instance, and have been recognized as having potentials in biomedical sciences [21,22]. Because these materials exhibit the viscoelastic properties of gels at room temperature and can flow at lower temperature, they have also been considered as potentially interesting hydrogels in electrophoresis experiments [23][24][25][26]. Pluronics samples are also at the heart of numerous more fundamental investigations.…”

Stabilizing Biomacromolecules in Nontoxic Nano-Structured Materials

“…31,34,36,37,40 The structure of the triblock is two blocks of PEO connected to a central block of PPO. All blocks of these copolymers are water soluble at low temperatures (!…”