Fig. 3

AE-MGNPs inhibited the tumor growth and remodeled the tumor microenvironment. Cell viability assays assessing the cytotoxicity of (a) AE-MNPs and (b) AE-GNPs in CAFs, CT26 and HUVEC after 72 h treatment at a concentration of melittin (4 µg/mL) and GSNO (29.99 µg/mL). Free melittin and GSNO were used as negative control. (c) The percentage of CRT-positive cells after 24 h of exposure. (d) Scheme of anti-cancer and TME remodeling evaluation in CT26 tumor-bearing mice. (e) Photographs and (f) tumor weight of excised tumors on day 15. (g) Melittin delivery reverses the activity of CAFs at the cellular level and inhibits the mRNA expression of α-SMA and FAP-α in CAFs. Untreated CAFs cells were used as controls. (h-i) Fluorescence microscopy images suggested the expression of α-SMA and FAP-α in CAFs after incubation using free melittin, MNPs or MGNPs. Untreated CAFs cells were served as negative controls. Scale bar, 50 μm. (j) Immunohistochemical staining of CAFs with α-SMA (upper) and collagen with Masson Trichrome (down) in tumor sections. Scale bar, 50 μm. *P < 0.05, **P < 0.01, ***P < 0.005, ****P < 0.001, ns No significance