Figure 2.
Synthesis scheme of mPEG-PCC-g-FC-g-DC (A); chemical structure of mPEG-PCC-g-GEM-g-DC (B). Reagents: (i) KOH, DMF, benzyl bromide, 100 °C, 15 h; (ii) triphosgene, pyridine, CH2Cl2, −78 to 0 °C; (iii) DBU, CH2Cl2, methoxy-PEG5000-OH, RT, 3 h; (iv) 10% Pd/C, H2, ethyl acetate, RT, 40 psi, 3 h; (v) EDC, HOBT, DIPEA, DMF, dodecanol, fluorescein cadaverine (FC), RT, 48 h.