We performed a CG MD simulation of the self-assembly of the PEG-PLGA NP along with EEK using GROMACS 2020.3, with the MARTINI (martini22p) force field. The polarizable water model more accurately represents aqueous solution and the martini22p forcefield has been previously shown to accurately model PEG; 26 a non-standard MARTINI topology, which includes PEG, was used. The atomistic structure of the peptide, EEK, was converted into a CG representation using the CHARMM-GUI Martini Solution Maker. Previously reported experiments used a molar ratio of EEK to PEG-PLGA (PEG average M n = 5000, PLGA M n = 7000) of 1:14 (weight ratio is 1:100). As well as reproducing the experimental synthesis procedure within the simulation protocol, we have the same molecular weight polymer, polymer concentration and the PEG:PLGA ratio as were used in the experiments. 200 PEG-PLGA copolymers and 15 EEK peptides were randomly placed within a box of water with dimensions of 20×20×20 nm 3 (the system consists of 600 417 CG beads). This system is subsequently inserted into a larger box with of size 58 × 58 × 58 nm 3 so that the various components have space to assemble into the NP. Polarizable MARTINI water was added to the system and sodium (Na + ) and chlorine (Cl -) ions are added such that the salt concentration is 0.15 M. Periodic boundary conditions were used. The longrange electrostatic interactions were computed using the Reaction Field algorithm with the cut-off distance set to 11 Å. Lennard-Jones interactions also have a cut-off distance of 11 Å.