“…For example, in the >220 nm group, NPs modified with FA and cRGD peptide both showed almost the weakest fluorescence signals, which may be because NPs larger than 200 nm were easily cleared by the liver and spleen ( Sunoqrot et al, 2014 ; Blanco et al, 2015 ; Fan et al, 2020 ). In addition, immune cells such as macrophages phagocytose foreign particles in a size-dependent manner, with larger particles being more likely to be phagocytosed by macrophages than smaller particles ( Fang et al, 2006 ; Pacheco et al, 2013 ; Miyamoto et al, 2021 ). The active targeting and penetrating capabilities of FA-modified NPs to prostate tissues were superior to those of cRGD-modified NPs, and tail intravenous injection was beneficial for NPs to enter the blood circulation and achieve the purpose of targeting prostate tissues.…”