Fig. 4
From: Nanoparticles mediated tumor microenvironment modulation: current advances and applications
Drug loaded NPs can target the hypoxic tumor vasculature, VEGF and immune cell populations: Lactate and adenosine as well as MDSCs and Tregs inhibit cytotoxic T lymphocytes and drive tumor growth. The conversion of M1 macrophages to M2 macrophages also contributes to tumor growth. Additionally, TGFβ-induced fibroblasts activate CAFs, which promote tumor progression. VEGF stimulates abnormal tumor vasculature and cancer development. Drug loaded NPs can target all of these pathways to suppress tumor growth. Furthermore, NPs loaded with oxygen can inhibit the hypoxic tumor vasculature by inducing oxygen, thus reversing hypoxia and limiting tumor growth