Molecularly Imprinted Polymers with Shape-Memorable Imprint Cavities for Efficient Separation of Hemoglobin from Blood

Abstract

Efficient separation and purification of hemoglobin from blood and other complicated biological fluids still remains a big challenge. Molecularly imprinted polymers (MIPs) of hemoglobin are potential choices; however, they suffer from severe problems including difficult template removal and low imprinting efficiency like other protein-imprinted polymers. Herein, a novel MIP of bovine hemoglobin (BHb) was designed in which a peptide crosslinker (PC), instead of the commonly used crosslinkers, was used. The PC, a random copolymer of lysine and alanine, adopts an α-helical conformation at pH 10 but transits to a random coil conformation at pH 5. The introduction of alanine residues lowers the pH range at which the PC undergoes helix-coil transition. The imprint cavities in the polymers are shape-memorable due to the reversible and precise helix-coil transition of the peptide segments in the polymers. They can be enlarged by lowering pH from 10 to 5, thus allowing complete removal of the template protein under mild conditions. When the pH is adjusted back to 10, their original size and shape will be recovered. Therefore, the MIP binds the template protein BHb with high affinity. Compared with the MIP crosslinked with the commonly used crosslinker, the imprinting efficiency of the PC-crosslinked MIP is significantly improved. In addition, both the maximum adsorption capacity (641.9 mg/g) and imprinting factor (7.2) are much higher than the BHb MIPs reported previously. The new BHb MIP also exhibits high selectivity toward BHb and good reusability. Thanks to the high adsorption capacity and high selectivity of the MIP, when it was applied to extract BHb from bovine blood, BHb in the blood sample was extracted almost completely, and high purity product was obtained.

Disposable Saliva Sensors for Early Cancer Diagnosis Using Hyper-Cross-Linked Molecularly Imprinted Polymeric Electrocatalysts

“…The high specificity of sPMA2TA@g-C 3 N 4 -modified electrodes is because of their biomimetic nature, i.e., molecular imprinting of spermine leads to the formation of spermine-specific interaction sites, thereby inducing enzyme-like specificity. This phenomenon is well-known for enhancing the selective response of the bioinspired synthetic materials toward a variety of analytes. , …”

“…This phenomenon is well-known for enhancing the selective response of the bioinspired synthetic materials toward a variety of analytes. 33,34 Stability of sPMA2TA@g-C 3 N 4 Electrocatalysts. The operational performance of the sPMA2TA@g-C 3 N 4 electrocatalytic layer is assessed by repetitive electrochemical measurements over 2 weeks in a redox solution with 1000 nM spermine.…”

Molecularly Imprinted Polymer with High Capacity and Selectivity for Separation of Bovine Serum Albumin

“…Instead of the commonly used cross-linkers, such as BIS, this strategy uses peptide cross-linkers to synthesize the polymers. These peptide cross-linkers can be synthesized by solid phase peptide synthesis − or ring-opening polymerization of NCAs. − Unlike solid phase peptide synthesis, which is a stepwise procedure and therefore laborious and time-consuming, ring-opening polymerization of NCAs is one-step and allows for massive production. However, the two vinyl groups of the previously synthesized peptide cross-linkers are different and therefore may have different reactivities .…”

“…The peptide chains were introduced by using peptide cross-linkers (PCs). Previously we synthesized the PCs via solid phase peptide synthesis. − This stepwise and therefore laborious and time-consuming procedure was later replaced by one-step ring-opening polymerization of N-carboxyanhydrides (NCAs). − However, the two vinyl groups of the peptide cross-linkers are different, and these will have different reactivities. Here a PC with the same vinyl groups on both ends was synthesized.…”

Colorless, transparent, and shape memory polyurethane networks with high strength and recyclability

“…Compared with thermoplastic SMPs, thermoset SMPs have excellent mechanical properties, thermal stability, higher shape fixation and recovery ratios owing to the covalent network structures. Thus, they have a wide range of potential applications in many fields, including aerospace, 7,8 electronic devices, 9–12 intelligent structures, 13–16 smart textiles 17–19 and biomedical applications 20–22 …”