Continuous asymmetrical flow field-flow fractionation for the purification of proteins and nanoparticles

Asymmetric flow field-flow fractionation as a multifunctional technique for the characterization of polymeric nanocarriers

“…To this purpose, it has lately been proposed the use of microstructured filtration membranes that present slanted grooves on their surface. The grooves not only increase sample retention and resolution [ 51 ] but also permit to carry out a two-dimensional size-based separation, as the solutes are subjected to size-related lateral displacement [ 52 ].…”

Label-Free Isolation of Exosomes Using Microfluidic Technologies

“…Field flow fractionation (FFF) is a flow-based sorting method applicable for separation of particles ranging from a few nanometers to about 100 μm in diameter. − This technique has been widely utilized to isolate and characterize biological and nonbiological particles. − To separate particles, a liquid suspension containing particles traveling (laminar flow with a parabolic profile) in a narrow channel (height of 50–500 μm) while being subjected to an externally applied field (liquid flows, centrifugal forces, gravity or electrical fields) perpendicular to the direction of suspension flow (Figure A). − The separation mechanism is based on the differences in density and hydrodynamic properties of particles that define particle mobility under the effect of forces perpendicular to each other; the forward force exerted by laminar channel flow and vertical forces exerted by the externally applied field and diffusion. External field forces drive the accumulation of particles at the bottom wall of the channel, whereas Brownian motion of the particles results in their diffusion toward the channel center. − Depending on their equilibrium position from the wall of the microchannel, particles travel at different speeds and thereby are separated as they move down the microchannel (Figure A). Particles at higher positions from the bottom wall (closer to the channel centerline) experience a faster flow rate, thereby they are eluted out of the channel earlier in comparison with the particles closer to the wall. − …”

“…External field forces drive the accumulation of particles at the bottom wall of the channel, whereas Brownian motion of the particles results in their diffusion toward the channel center. − Depending on their equilibrium position from the wall of the microchannel, particles travel at different speeds and thereby are separated as they move down the microchannel (Figure A). Particles at higher positions from the bottom wall (closer to the channel centerline) experience a faster flow rate, thereby they are eluted out of the channel earlier in comparison with the particles closer to the wall. − …”

Recent Advances in Separation-Based Techniques for Synthetic Polymer Characterization

“…Channel dimensions and separation performance of semipreparative AF4 were studied recently . Continuous AF4 fractionation for the purification of proteins and nanoparticles was achieved by a novel continuous two-dimensional AF4 (2D-AF4) system that can fractionate a feed solution of nanosized solutes according to their size in aqueous solvents . In the study, both protein and nanoparticle samples were used to demonstrate the new 2D-AF4 channel design.…”

“…54 Continuous AF4 fractionation for the purification of proteins and nanoparticles was achieved by a novel continuous two-dimensional AF4 (2D-AF4) system that can fractionate a feed solution of nanosized solutes according to their size in aqueous solvents. 55 In the study, both protein and nanoparticle samples were used to demonstrate the new 2D-AF4 channel design. This can be a much more effective tool than the traditional fraction collection approach for sample preparation for further analysis.…”