The chemical synthesis procedure and 1H NMR spectrum of polymer conjugates. (A) Linoleyl chloride (LC) was first conjugated to the mPEG-NH2 and PEI through the reaction of an acid chloride with an amine. MTX was then conjugated to the H2N-PEI-LA through the acid and amine condensation reaction. (B) 1H NMR spectrum (500 MHz) of mPEG-2000 Da-NH2, LC, mPEG-LA, PEI-25 kDa, PEI-LA, MTX, MTX-PEI-LA. mPEG-2000 Da-NH2, LC, PEI-25 kDa, mPEG-LA, and PEI-LA were dissolved in deuterated chloroform (CDCl3). MTX was dissolved in deuterated dimethyl sulfoxide (DMSO-d6). MTX-PEI-LA was dissolved in deuterated water (D2O).