Chemical and photochemical DNA “gears” reversibly control stiffness, shape-memory, self-healing and controlled release properties of polyacrylamide hydrogels

Abstract

Stimuli-responsive polyacrylamide hydrogels crosslinked by glucosamine–boronate/G-quadruplexes or azobenzene-functionalized DNA reveal controlled stiffness using chemical or photochemical triggers.

New Developments in Medical Applications of Hybrid Hydrogels Containing Natural Polymers

“…The two-layer hybrid hydrogels that exhibits controlled stimuli-induced shape transitions are promising for the use in the biomedical field as intelligent actuators. Similar studies, of shape memory hydrogels that include DNA and polyacrylamide were found in the scientific literature [434,435]. In Figure 9 is illustrated a photoresponsive hybrid hydrogel that reveals light-induced switchable stiffness functions.…”

“…Schematic light-induced shape-memory transitions between the triangle-shaped, high-stiffness polyacrylamide-based hydrogel crosslinked by glucosamine-boronate ester bridges and trans-azobenzene stabilized duplex crosslinkers and the low-stiffness hydrogel crosslinked by the glucosamine-boronate esters only. Adapted from [435] Open Access, Copyright 2020, Royal Society of Chemistry].…”

Biocatalytic reversible control of the stiffness of DNA-modified responsive hydrogels: applications in shape-memory, self-healing and autonomous controlled release of insulin

“…39,40 Indeed, hydrogels cooperatively stabilized by duplex nucleic acid bridges and signal-triggered, recongurable cross-linkers were reported, demonstrating control over the stiffness of the hydrogels by means of pH, 39,41,42 K + -ions/ crown ethers 43,44 or light. [45][46][47] Also, aptamer-modied hydrogels were reported as functional matrices for the release of protein drugs. 48 Recently, light-induced control over the stiffness of hydrogels through incorporation of plasmonic Au nanoparticles/Au nanorods into duplex nucleic acid-bridged hydrogels was reported.…”

Near-infrared light-responsive hydrogels via peroxide-decorated MXene-initiated polymerization

“…"Smart" responsive hydrogels are now being widely studied in various elds such as so robotics, 1,2 sensors, 3,4 microdevices, 5 drug delivery, 6,7 cell/tissue engineering scaffolds, 8,9 and reaction vessels. 10,11 Exposure to different stimuli (for example light, temperature, pH, and electric eld) may cause these hydrogels to swell/shrink, bend/unbend, or swim/crawl, mimicking natural creatures with responsive behavior.…”