DNA-Based Hydrogels Loaded with Au Nanoparticles or Au Nanorods: Thermoresponsive Plasmonic Matrices for Shape-Memory, Self-Healing, Controlled Release, and Mechanical Applications

Abstract

Gold nanoparticles (AuNPs) or gold nanorods (AuNRs) are loaded in polyacrylamide hydrogels cooperatively cross-linked by bis-acrylamide and nucleic acid duplexes or boronate ester–glucosamine and nucleic acid duplexes. The thermoplasmonic properties of AuNPs and AuNRs are used to control the stiffness of the hydrogels. The irradiation of the AuNP-loaded (λ = 532 nm) or the AuNR-loaded (λ = 808 nm) hydrogels leads to thermoplasmonic heating of the hydrogels, the dehybridization of the DNA duplexes, and the formation of hydrogels with lower stiffness. By ON/OFF irradiation, the hydrogels are switched between low- and high-stiffness states. The reversible control over the stiffness properties of the hydrogels is used to develop shape-memory hydrogels and self-healing soft materials and to tailor thermoplasmonic switchable drug release. In addition, by designing bilayer composites of AuNP- and AuNR-loaded hydrogels, a reversible thermoplasmonic, light-induced bending is demonstrated, where the bending direction is controlled by the stress generated in the respective bilayer composite.

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

“…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. 49 These Au nanoparticlefunctionalized hydrogels enable thermoplasmonic heating, resulting in the thermal separation of the nucleic acid bridges and control over the stiffness of the hydrogel matrices. In addition, stimulus-responsive hydrogels were suggested to enable various applications, including the development of shape-memory, 39,41,50,51 self-healing matrices, 15,46,47 assembly of triggered and switchable drug release materials 52 and carriers, 53 the design of hydrogels exhibiting triggered mechanical bending properties, 54 the control over ion-transport through nanopores, 55 and the development of switchable electrocatalytic hydrogel materials.…”

Advances in Synthesis and Applications of Self-Healing Hydrogels

“…Many hydrogels have several properties, and thus have the potential to be used in many fields, such as controlled drug release, tissue engineering, actuators, and light-induced pumps (Wang et al, 2019a). Some hydrogels are still in a theoretical phase, and others have already been tested on animals, most of which have a more specific application, focusing on a certain treatment.…”

Stimuli‐Responsive Biomolecule‐Based Hydrogels and Their Applications

“…Indeed, Au NPs and Au NRs have been used to stimulate light-induced control over the stiffness of DNA-based hydrogels by means of the thermoplasmonic effect. [121] These systems were used as shape-memory,s elf-healing and signaltriggered drug-release matrices.F igure 29 outlines the synthesis and stiffness properties of two different thermoplasmonic hydrogels.I no ne system (Figure 29 A, Panel I), am ixture of acrylamide,b is(acrylamide), and 5'-acryditemodified self-complementary nucleic acids 17 were polymerized in the presence of Au NPs or Au NRs to yield the hydrogels Ia and Ib,r espectively,w hich are cooperatively crosslinked by bisacrylamide and the duplex nucleic acids 17/ 17.T he thermoplasmonic Au NPs induced separation of the nucleic acid crosslinkers (l = 532 nm, 1h), which led to the formation of ah ydrogel of lower stiffness.T he switchable "ON"/"OFF" irradiation of the hydrogel enabled its stiffness to be cycled between lower and higher stiffness values. strain:1 %, frequency:1Hz, 25 8 8C) of the higher stiffness hydrogel correspond to 55 Pa and 7Pa, whereas the G' and G'' values of the lower stiffness hydrogel were 22 Pa and 4.5 Pa, respectively.F igure 29 B, Panel II demonstrates the cyclic thermoplasmonic control of the stiffness upon "ON"/ "OFF" irradiation of the matrix.…”

“…Application of Ia or Ib for the assembleofA)light-induced shape-memory hydrogel structures and B) light-induced self-healing hydrogel structures. Adapted from Ref [121]…”