PIGF and neoplasm: Song et al. developed PEG and mannose-based nanoparticles modified with trimethyl chitosan and citraconic anhydride grafted polyallylamine hydrochloride (PEG = MT/PC NPs), delivering VEGF/placental growth factor (PIGF) siRNA to both cancer cells and M2-TAMs, which normalized tumor vascular, repolarized TAMs, and suppressed tumor progression simultaneously [52].