Figure 6.

Injectable ROS-responsive hydrogels for triggering drug release. (A) ROS-cleavable HA based hydrogels for O₂ generation: (i) the degradation behaviors of ROS responsive hydrogels with (R⁺/C⁺) or without CAT (R⁺/C⁻) and ROS-nonresponsive hydrogels with/without CAT (R⁻/C⁺ and R⁻/C⁻) in the presence/absence of H₂O₂, and (ii) O₂ generation of R⁺/C⁺ hydrogels in PBS and H₂O₂/PBS solutions. Reproduced with permission from Ref. [70] Copyright 2020 Wiley-VCH. (B) PTK crosslinked hydrogel for H₂O₂-mediated and dose dependent degradation: (i) the mechanical integrity loss of hydrogels in response to H₂O₂, and (ii) ROS cytotoxicity protection of PTK gel compared to 2D tissue culture (TC) and PEG-dt and peptide crosslinked gels, determined by total viable cell number 24 after exposure to H₂O₂. Reproduced with permission from Ref. [71] Copyright 2020 Elsevier Ltd. (C) Thermo- and ROS-responsive hydrogel composed of mPEG-PMet copolymer: (i) the H₂O₂-dependent degradation behavior of hydrogels, and (ii) rhodamine 6G released from hydrogels, which is triggered by H₂O₂ levels. Reproduced with permission from Ref. [72] Copyright 2016 Wiley-VCH. (D) Multifunctional hydrogel encapsulating NIM-loaded micelle and VAN-AgNCs (hydrogel@VAN-AgNC&MIC): (i) the pH and ROS-responsive behaviors of hydrogel for subsequent and sustained release of AgNCs, VAN and NIM, and (ii) antibacterial effect of hydrogels against both S. aureus and Pseudomonas aeruginosa (P. aeruginosa). Reproduced with permission from Ref. [73] Copyright 2021 American Chemical Society.