DNA-Responsive Hydrogels That Can Shrink or Swell

TLDR

Molecule‑responsive hydrogels are considered smart materials due to their unique properties, yet no DNA‑responsive hydrogels capable of swelling in response to specific DNAs have been reported, making dual shrinking and swelling materials highly desirable for biochemical and biomedical applications. The study aims to demonstrate a novel DNA‑responsive mechanism that enables hydrogels to either shrink or swell. The authors constructed hybrid hydrogels with rationally designed ssDNA cross‑linkers that respond to ssDNA samples by shrinking or swelling and can discriminate single‑base differences. The hybrid hydrogels shrink or swell in response to ssDNA, can detect single‑base mismatches, and show promise for DNA‑sensing devices and DNA‑triggered actuators.

Abstract

Molecule-responsive hydrogels are reputed to be smart materials because of their unique properties. We recently reported that hydrogels containing directly grafted single-stranded (ss) DNA or ssDNA-polyacrylamide conjugate in a semi-interpenetrating network (semi-IPN) manner that "only shrunk" by the addition of ssDNA samples. To date, however, no DNA-responsive hydrogels have been reported capable of "swelling" in response to specific DNAs. Smart materials capable of both shrinking and swelling in response to specific DNAs would be very useful in biochemical and biomedical applications. Here, we show a novel "shrinking or swelling" DNA-responsive mechanism. Novel hybrid hydrogels containing rationally designed ssDNA as the cross-linker were capable of shrinking or swelling in response to ssDNA samples and recognizing a single base difference in the samples. On the basis of the results presented in this paper, it is envisioned that these novel hybrid hydrogels could function and have potential in applications such as DNA-sensing devices and DNA-triggered actuators.