Fig. 4.

ROS scavenging gel (ROSS-A6) promoted HFSCs survival under oxidative stress. a. Structure of poly (NIPAAm₇₉-co-HEMA₁₅-co-AHPPE₆) (ROSS-A6 gel) and poly (NIPAAm-co-HEMA-co-APLA) (ROSIS gel, control gel). b. Tan δ of the hydrogel solution from 4 °C to 40 °C tested by HR-20 Rheometer. c. The storage modulus (G′) and the loss modulus (G″) of the hydrogel solution from 4 °C to 40 °C. d. Viscosity of the hydrogel tested at 4 °C with shear rate ramping from 1 to 50 s⁻¹. e, f, g. Encapsulation of MG53 in ROSS-A6 gel. The mixture solution was flowable (e) and injectable (f) at 4 °C, and it can quickly form solid gel at 37 °C (g). h. Schematic illustration of a 2D cell culture model with MG53/Gel/HFSCs with and without H₂O₂. i. HFSCs survival on gel at different time points examined by MTT assay. j. Live cell images illustrated that ROS responsive ROSS-A6 gel enhanced HFSCs survival rate under oxidative stress compared with non-ROS responsive ROSIS gel (*p < 0.05). HFSCs were pre-labeled with live cell tracker CMDil (red) and imaged by confocal microscopy with Z-stack mode at day 5. Scale bar = 50 μm. k.In vitro release kinetics of MG53 in ROSS-A6 gel for 21 days (n = 6).