0599735 - ÚMCH 2025 RIV CH eng J - Journal Article
Poplewska, I. - Strachota, Beata - Strachota, Adam - Poplewski, G. - Antos, D.
Thermo- and pH-responsible gels for efficient protein adsorption and desorption.
Molecules. Roč. 29, č. 20 (2024), č. článku 4858. ISSN 1420-3049. E-ISSN 1420-3049
R&D Projects: GA MŠMT(CZ) LUAUS23004
Grant - others:AV ČR(CZ) ASRT-22-01
Program: Bilaterální spolupráce
Institutional support: RVO:61389013
Keywords : protein adsorption * protein release * hydrogels
OECD category: Polymer science
Impact factor: 4.2, year: 2023 ; AIS: 0.677, rok: 2023
Method of publishing: Open access
Result website:
https://www.mdpi.com/1420-3049/29/20/4858DOI: https://doi.org/10.3390/molecules29204858

Protein adsorption behavior was examined on poly(N-isopropylacrylamide-co-sodium methacrylate)-based hydrogels at different temperatures: 5, 20, and 37 °C, and pH: 4.5, 7, and 9.2. The hydrogels, whose covalent skeleton contains pendant anionic units due to the presence of the sodium methacrylate co-monomer, exhibited both thermo- and pH-sensitivity with different extents, which depended on the content of ionizable moieties and the cross-linker density. The hydrogel composition, temperature, and pH influenced the zeta potential of the hydrogels and their swelling properties. The proteins selected for the study, i.e., bovine serum albumin (BSA), ovalbumin (OVA), lysozyme (LYZ), and a monoclonal antibody (mAb2), differed in their aminoacidic composition and conformation, thus in isoelectric point, molecular weight, electrostatic charge, and hydrophobicity. Therefore, the response of their adsorption behavior to changes in the solution properties and the hydrogel composition was different. LYZ exhibited the strongest adsorption of all proteins with a maximum at pH 7 (189.5 mg g−1𝑔𝑒𝑙), adsorption of BSA and OVA reached maximum at pH 4.5 (24.4 and 23.5 mg g−1𝑔𝑒𝑙), whereas mAb2 was strongly adsorbed at 9.2 (21.7 mg g−1𝑔𝑒𝑙). This indicated the possibility of using the hydrogels for pH-mediated separation of proteins differing in charge under mild conditions in a water-rich environment of both the liquid solution and the adsorbed phase. The adsorption affinity of all proteins increased with temperature, which was attributed to the synergistic effects of attractive electrostatic and hydrophobic interactions. That effect was particularly marked for mAb2, for which the temperature change from 5 to 37 °C caused a twentyfold increase in adsorption. In all cases, the proteins could be released from the hydrogel surface by a reduction in temperature, an increase in pH, or a combination of both. This allows for the elimination of the use of salt solution as a desorbing agent, whose presence renders the recycling of buffering solutions difficult.
Permanent Link: https://hdl.handle.net/11104/0357833