Installing logic-gate responses to a variety of biological substances in supramolecular hydrogel–enzyme hybrids

• Published in: Nature chemistry 2014-06, Vol.6 (6), p.511-518
• Main Authors: Ikeda, Masato, Tanida, Tatsuya, Yoshii, Tatsuyuki, Kurotani, Kazuya, Onogi, Shoji, Urayama, Kenji, Hamachi, Itaru
• Format: Article
• Language: English
• Subjects: 140/131; 140/58; 147/143; 147/3; 639/638/298/923/1027; 639/638/541/966; Analytical Chemistry; Biochemistry; Biological samples; Biomarkers; Boron Compounds - chemistry; Boron Compounds - metabolism; Catalysis; Chemistry; Chemistry/Food Science; Engineering schools; Enzymes; Glucose; Glucose Oxidase - metabolism; Humans; Hybrids; Hydrogels; Hydrogels - chemistry; Hydrogels - metabolism; Hydrogen Peroxide - pharmacology; Immunoglobulin G - metabolism; Inorganic Chemistry; Logic; Molecular Structure; Organic Chemistry; Oxidants - pharmacology; Peptide Fragments - chemistry; Peptide Fragments - metabolism; Peptides; Phase Transition; Phase transitions; Physical Chemistry; Water - chemistry
• ISSN: 1755-4330; 1755-4349
• DOI: 10.1038/nchem.1937

Soft materials that exhibit stimuli-responsive behaviour under aqueous conditions (such as supramolecular hydrogels composed of self-assembled nanofibres) have many potential biological applications. However, designing a macroscopic response to structurally complex biochemical stimuli in these materials still remains a challenge. Here we show that redox-responsive peptide-based hydrogels have the ability to encapsulate enzymes and still retain their activities. Moreover, cooperative coupling of enzymatic reactions with the gel response enables us to construct unique stimuli-responsive soft materials capable of sensing a variety of disease-related biomarkers. The programmable gel–sol response (even to biological samples) is visible to the naked eye. Furthermore, we built Boolean logic gates (OR and AND) into the hydrogel–enzyme hybrid materials, which were able to sense simultaneously plural specific biochemicals and execute a controlled drug release in accordance with the logic operation. The intelligent soft materials that we have developed may prove valuable in future medical diagnostics or treatments. Soft materials that can undergo a macroscopic change in response to external stimuli may prove useful for a range of biological applications. Now, it has been shown that hydrogels encapsulating active enzymes can undergo a gel–sol transition in the presence of a range of small-molecule triggers and can potentially be used as sensors or drug-delivery systems.