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Dielectrophoretic behavior of PEGylated RNase A inside a microchannel with diamond‐shaped insulating posts
Author(s) -
MataGómez Marco A.,
GalloVillanueva Roberto C.,
GonzálezValdez José,
MartínezChapa Sergio O.,
RitoPalomares Marco
Publication year - 2016
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.201500311
Subject(s) - rnase p , pegylation , peg ratio , dielectrophoresis , electrokinetic phenomena , microchannel , chromatography , ribonuclease , materials science , electrophoresis , chemistry , nanotechnology , microfluidics , biochemistry , rna , finance , economics , gene
Ribonuclease A (RNase A) has proven potential as a therapeutic agent, especially in its PEGylated form. Grafting of PEG molecules to this protein yields mono‐PEGylated (mono‐PEG) and di‐PEGylated (di‐PEG) RNase A conjugates, and the unreacted protein. Mono‐PEG RNase A is of great interest. The use of electrokinetic forces in microdevices represents a novel alternative to chromatographic methods to separate this specie. This work describes the dielectrophoretic behavior of the main protein products of the RNase A PEGylation inside a microchannel with insulators under direct current electric fields. This approach represents the first step in route to design micro‐bioprocesses to separate PEGylated RNase A from unreacted native protein. The three proteins exhibited different dielectrophoretic behaviors. All of them experienced a marked streaming pattern at 3000 V consistent with positive dielectrophoresis. Native protein was not captured at any of the conditions tested, while mono‐PEG RNase A and di‐PEG RNase A were captured presumably due to positive dielectrophoresis at 4000 and 2500 V, respectively. Concentration of mono‐PEG RNase A with a maximal enrichment efficiency of ≈9.6 times the feed concentration was achieved in few seconds. These findings open the possibility of designing novel devices for rapid separation, concentration, and recovery of PEGylated RNase A in a one‐step operation.