Fig. 4

Au@Ag treatments decrease the number of proliferating cancer cells in fibroblast-rich tumour microdomains. High number of Ki67-positive cells can be identified in the alphaSMA-positive fibroblast-rich microdomains in saline-treated 4T1 tumours, while the number of proliferating tumour cells is markedly lower in the Au@Ag-treated tumours (a). In saline-treated tumours, a positive correlation can be identified between the numbers of Ki67- and alphaSMA-positive cells indicating that there is a noticeably higher proliferation activity in the fibroblast-rich regions of the cancerous tissue. On the other hand, loss of the positive correlation between Ki67- and alphaSMA-positive cells can be identified in Au@Ag-treated tumours, since the nanoparticle treatment decreased the number of Ki67-positive cells without influencing the number of infiltrated cancer-associated fibroblasts (b)