Work

Temperature-Controlled Hybrid Hydrogels for Reversible and Selective Zinc(II) Removal from Minimal Culture Media

Year: 2025

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide Zinc ions (Zn 2+ ) play vital roles in living organisms, and Zn 2+ -deficient systems provide valuable platforms for studying zinc-dependent biological processes. Protein-functionalized materials offer advantages in constructing such systems by combining the physical removability of a solid-phase matrix with the high selectivity of zinc-binding proteins. Poly( N -isopropylacrylamide) (PNIPAM) hydrogel serves as a promising matrix by enabling temperature-controlled reversible adsorption. The zinc-binding domain of the Zap1 protein (Zap1zf12) is well suited as the protein component owing to its Zn 2+ specificity, dual binding sites, and PNIPAM-compatible structure. Here, we integrated Zap1zf12 into PNIPAM, generating a thermoresponsive hybrid hydrogel (PNIPAM- co -Zap1zf12) for selective Zn 2+ removal. PNIPAM- co -Zap1zf12 was constructed through rational cross-linking sites design in Zap1zf12, optimized protein modification, and refined hydrogel synthesis. This material exhibited reversible adsorption in response to biocompatible temperature shifts (37 °C capture, 25 °C release), allowing regeneration without competitive chelators. It achieved a Zn 2+ removal efficiency of 98.4 ± 7.3% (from 804.1 ± 41.9 nmol/L to 12.6 ± 5.8 nmol/L), and was successfully applied in various minimal culture media for selective Zn 2+ depletion. Therefore, PNIPAM- co -Zap1zf12 extends the applicability of the hybrid hydrogels by integrating dual-site zinc-binding proteins and enabling selective Zn 2+ adsorption. Moreover, it offers an effective approach for generating zinc-deficient conditions.

Source: ACS Omega

DOI: 10.1021/acsomega.5c08458