Fig. 5

a High-resolution TEM of bcc-USINPs. b Cumulative Fe release from bcc-USINPs. c UV/visible absorption spectra of methylene blue solution in pH 5.5 buffer containing 1 mM H₂O₂ after adding bcc-Fe NPs, USIONPs, amor-USINPs, and bcc-USINPs to a concentration of 50 μg/mL [Fe]. d Bio-TEM image of a cross section of a HepG2 cell. Arrows indicate damaged mitochondria. e Fluorescence microscopy images of CRT expression on the MC38 tumor cell surface after treatment with PBS or bcc-USINPs. f, g HMGB1 secreted and ATP released from MC38 cells. h Average growth curves of MC38 tumor-bearing C57BL/6 mice after various treatments. i DC maturation in lymph nodes of MC38 tumor-bearing mice (gated on CD11c⁺ MHC II⁺ DC cells) after various treatments for assessment by flow cytometry. j FCM examination of the intratumor infiltration of CD8⁺ T cells (gated on CD3⁺ T cells). k Regulatory T (Treg) cell (gated on CD4⁺ T cells) frequencies in tumors after different treatments. Data are expressed as means ± SD (n = 3); **P < 0.01 and ***P < 0.001 [94].