FIGURE 2.

(a) Schematic representation of the synthesis of Fe₃O₄‐encapsulated PEI‐PEG NGs and (b) the mechanism for tumor theranostic. (c) Intracellular TGF‐β1 levels of PBS, free TGF‐β1, Fe₃O₄/PEI‐PEG NGs, TGF‐β1 NGs, scrambled (Scr) siRNA NGs, and Scr siRNA incubated cells, which were determined by the ELISA kit assay. (d) In vivo T₁‐weighted MRI and the corresponding signal‐to‐noise ratio (SNR) value of xenografted S180 tumors at different time points with the intravenous injection of Fe₃O₄ NPs and Fe₃O₄‐encapsulated PEI‐PEG NGs. Reprinted with permission from Peng et al. (2021). Copyright 2021. American Chemical Society