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Abstract The mechanism of separation methods, for example, liquid chromatography, is realized through rapid multiple adsorption‐desorption steps leading to the dynamic equilibrium state in a mixture of molecules with different partition coefficients. Sorting of colloidal particles, including protein complexes, cells, and viruses, is limited due to a high energy barrier, up to millions kT, required to detach particles from the interface, which is in dramatic contrast to a few kT for small molecules. Such a strong interaction renders particle adsorption quasi‐irreversible. The dynamic adsorption‐desorption equilibrium is approached very slowly, if ever attainable. This limitation is alleviated with a local oscillating repulsive mechanical force generated at the microstructured stimuli‐responsive polymer interface to switch between adsorption and mechanical‐force‐facilitated desorption of the particles. Such a dynamic regime enables the separation of colloidal mixtures based on the particle‐polymer interface affinity, and it could find use in research, diagnostics, and industrial‐scale label‐free sorting of highly asymmetric mixtures of colloids and cells.
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Biointerfaces from dynamic polymer interfaces to nanofiber 3D-scaffolds
The developed dynamic stimuli-responsive microstructured polymer brush interface, made of patterns of disjoining PNIPAM and adhesive RGD-PAA domains, is efficient for the separation and isolation of live or dead cells based on their affinity to the brush surface (Figure 1). The developed interface showed highly effective sorting of target cells from a complex mixture with non-target cells, even for highly asymmetric mixtures, because the quasi-irreversible and non-specific adsorption is compensated by oscillating repulsive mechanical forces generated by the stimuli-responsive interface. This oscillation between the adhesive and disjoining forces enables approaching the affinity-based equilibrium for cell adsorption at the interface.
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- Award ID(s):
- 2141138
- PAR ID:
- 10404213
- Date Published:
- Journal Name:
- Polymers in Medicine and Biology
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Abstract The mechanism of separation methods, for example, liquid chromatography, is realized through rapid multiple adsorption‐desorption steps leading to the dynamic equilibrium state in a mixture of molecules with different partition coefficients. Sorting of colloidal particles, including protein complexes, cells, and viruses, is limited due to a high energy barrier, up to millions kT, required to detach particles from the interface, which is in dramatic contrast to a few kT for small molecules. Such a strong interaction renders particle adsorption quasi‐irreversible. The dynamic adsorption‐desorption equilibrium is approached very slowly, if ever attainable. This limitation is alleviated with a local oscillating repulsive mechanical force generated at the microstructured stimuli‐responsive polymer interface to switch between adsorption and mechanical‐force‐facilitated desorption of the particles. Such a dynamic regime enables the separation of colloidal mixtures based on the particle‐polymer interface affinity, and it could find use in research, diagnostics, and industrial‐scale label‐free sorting of highly asymmetric mixtures of colloids and cells.more » « less
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