Fig. 2: Morphology and size distributions of nanoscavengers T^ECM-NS and PEG-T^ECM-NS.

In vitro evaluation of the ability of PEG-T^ECM-NS to bind collagen and scavenge ROS. a Schematic illustration of the preparation of NS, T^ECM-NS and PEG-T^ECM-NS. b TEM images of NS, T^ECM-NS, and PEG-T^ECM-NS (Scale bar: 100 nm). Independent experiments were repeated three times. c, d Size distributions and zeta potentials of NS and T^ECM-NS. Error bars represent mean ± s.d. derived from n = 5 independent replicates. Statistical significance was evaluated using Student’s unpaired t test. Asterisks indicate p values *P < 0.05, **P < 0.01, and ***P < 0.001 and n.s. represents no significant difference. e, f Size and zeta potential of T^ECM-NS after PEG caging at different T^ECM-NS: PEG mass ratios. Error bars represent mean ± s.d. derived from n = 5 independent replicates. g Drug release profiles of PEG-T^ECM-NS at pH 7.4 and pH 6.8 with or without 10 mM H₂O₂. h Monitoring the concentration of H₂O₂ in solution treated with or without PEG-T^ECM-NS. i PEG de-shielding rate from PEG-T^ECM-NS measured by ¹H NMR. j Binding of T^ECM-NS and PEG-T^ECM-NS at pH 7.4 and pH 6.8 to rat tail collagen type I measured by solid-phase fluorescence binding assay. Independent experiments were repeated three times. k ITC measurements recorded by titrating the free T^ECM, T^ECM-NS, PEG-T^ECM-NS, and PEG-TECM-NS pretreated with pH 6.8 buffer against collagen in a 20-injection experiment with a time interval of 10 min between successive injections. l CLSM images of the slices sectioned from the 4T1 tumour pieces (1 cm³) treated with T^ECM-NS and PEG-T^ECM-NS at pH 7.4 and pH 6.8 for about 4 h. Blue channel, nucleus; green channel, collagen and red channel, RB-labelled T^ECM-NS or PEG-T^ECM-NS.