Work

A new method to immobilize urease in silk fibroin membrane by unidirectional nanopore dehydration

Year: 2024

Type: article

Abstract: The immobilization of free enzymes is crucial for enhancing their stability in different environments, enabling reusability, and expanding their applications. However, the development of a straightforward immobilization method that offers stability, high efficiency, biocompatibility, and modifiability remains a significant challenge. Silk fibroin (SF) is a good carrier for immobilized enzymes and drugs. Here, we employed urease as a model enzyme and utilized our developed technology called unidirectional nanopore dehydration (UND) to efficiently dehydrate a regenerated SF solution containing urease in a single step, resulting in the preparation of a highly functionalized SF membrane immobilizing urease (UI-SFM). The preparation process of UI-SFM is based on an all-water system, which is mild, green and able to efficiently and stably immobilize urease in the membranes, maintaining 92.7% and 82.8% relative enzyme activity after 30 days of storage in dry and hydrated states, respectively. Additionally, we performed additional post-treatments, including stretching and cross-linking with polyethylene glycol diglycidyl ether (PEGDE), to obtain two more robust immobilized urease membranes (UI-SFMs and UI-SFMc). The thermal and storage stability of these two membranes were significantly improved, and the recovery ratio of enzyme activity reached more than 90%. After 10 repetitions of the enzymatic reaction, the activity recovery of UI-SFMs and UI-SFMc remained at 92% and 88%, respectively. The results suggest that both UND-based and post-treatment-developed membranes exhibit excellent urease immobilization capabilities. Furthermore, the enzyme immobilization method offers a straightforward and versatile approach for efficient and stable enzyme immobilization, while its flexible modifiability caters to diverse application requirements.

Source: Biotechnology Progress

DOI: 10.1002/btpr.3502

Authors: Meng Zhang, Hai‐Yan Wang, Yu‐Qing Zhang

Institution: Soochow University

Language: English

Topic: Silk-based biomaterials and applications

Subfield: Biomaterials

Field: Materials Science

Domain: Physical Sciences

Open Access status: bronze

Funders: Jiangsu University, Priority Academic Program Development of Jiangsu Higher Education Institutions, Earmarked Fund for China Agriculture Research System

Awards: G1113057263, G2435441897, G7309016883