biostudies-literature00600Unknown14(2)Jiao CDeutsche ForschungsgemeinschaftStimuli-responsive hydrogels have a wide range of potential applications in microfluidics, which has drawn great attention. Double cross-linked hydrogels are very well suited for this application as they offer both stability and the required responsive behavior. Here, we report the integration of poly(<i>N</i>-isopropylacrylamide) (PNiPAAm) hydrogel with a permanent cross-linker (<i>N,N'</i>-methylenebisacrylamide, BIS) and a redox responsive reversible cross-linker (<i>N,N'</i>-bis(acryloyl)cystamine, BAC) into a microfluidic device through photopolymerization. Cleavage and re-formation of disulfide bonds introduced by BAC changed the cross-linking densities of the hydrogel dots, making them swell or shrink. Rheological measurements allowed for selecting hydrogels that withstand long-term shear forces present in microfluidic devices under continuous flow. Once implemented, the thiol-disulfide exchange allowed the hydrogel dots to successfully capture and release the protein bovine serum albumin (BSA). BSA was labeled with rhodamine B and functionalized with 2-(2-pyridyldithio)-ethylamine (PDA) to introduce disulfide bonds. The reversible capture and release of the protein reached an efficiency of 83.6% in release rate and could be repeated over 3 cycles within the microfluidic device. These results demonstrate that our redox-responsive hydrogel dots enable the dynamic capture and release of various different functionalized (macro)molecules (e.g., proteins and drugs) and have a great potential to be integrated into a lab-on-a-chip device for detection and/or delivery.Polymershttps://www.ebi.ac.uk/biostudies/studies/S-EPMC8780672biostudies-literatureReversible Protein Capture and Release by Redox-Responsive Hydrogel in Microfluidics.PMC8780672GRK 1865Geisler MGaitzsch JObst FAppelhans DVoit BChe YJiao CRichter A60falseReversible Protein Capture and Release by Redox-Responsive Hydrogel in Microfluidics.Stimuli-responsive hydrogels have a wide range of potential applications in microfluidics, which has drawn great attention. Double cross-linked hydrogels are very well suited for this application as they offer both stability and the required responsive behavior. Here, we report the integration of poly(<i>N</i>-isopropylacrylamide) (PNiPAAm) hydrogel with a permanent cross-linker (<i>N,N'</i>-methylenebisacrylamide, BIS) and a redox responsive reversible cross-linker (<i>N,N'</i>-bis(acryloyl)cystamine, BAC) into a microfluidic device through photopolymerization. Cleavage and re-formation of disulfide bonds introduced by BAC changed the cross-linking densities of the hydrogel dots, making them swell or shrink. Rheological measurements allowed for selecting hydrogels that withstand long-term shear forces present in microfluidic devices under continuous flow. Once implemented, the thiol-disulfide exchange allowed the hydrogel dots to successfully capture and release the protein bovine serum albumin (BSA). BSA was labeled with rhodamine B and functionalized with 2-(2-pyridyldithio)-ethylamine (PDA) to introduce disulfide bonds. The reversible capture and release of the protein reached an efficiency of 83.6% in release rate and could be repeated over 3 cycles within the microfluidic device. These results demonstrate that our redox-responsive hydrogel dots enable the dynamic capture and release of various different functionalized (macro)molecules (e.g., proteins and drugs) and have a great potential to be integrated into a lab-on-a-chip device for detection and/or delivery.2022-01-01T00:00:00Z2022 Jan2022-02-11T16:02:40.174Z2022-02-11T16:02:40.174ZS-EPMC87806723505467410.3390/polym14020267